Revert "Contact/event/task upload: use streams directly without extra byte[] array"

This reverts commit 3bde3758fc. Version bump to 1.0.9.1 Reason: A server MAY reject a request that contains a message body but not a Content-Length by responding with 411 (Length Required). (RFC 7230 3.3.3 Message Body Length)
2026-08-07 05:44:54 -04:00 · 2016-05-26 22:08:22 +02:00 · 2016-05-26 22:04:03 +02:00 · 2016-05-25 21:37:43 +02:00 · 2016-05-23 15:10:35 +02:00 · 2016-05-23 14:28:27 +02:00
256 changed files with 10448 additions and 14564 deletions
@@ -1,31 +0,0 @@
-image: registry.gitlab.com/bitfireat/davdroid:latest
-
-before_script:
-  - git submodule update --init --recursive
-  - export GRADLE_USER_HOME=`pwd`/.gradle; chmod +x gradlew
-
-cache:
-  paths:
-     - .gradle/
-     - apk/
-
-test:
-  script:
-    - (cd /sdk/emulator; ./emulator @test -no-audio -no-window & wait-for-emulator.sh)
-    - (mkdir -p apk && cd apk && wget -q https://f-droid.org/repo/org.dmfs.tasks_481.apk && adb install org.dmfs.tasks_481.apk)
-    - ./gradlew check mergeAndroidReports
-  artifacts:
-    paths:
-      - app/build/outputs/lint-results-debug.html
-      - app/build/reports
-      - build/reports
-
-pages:
-  script:
-    - ./gradlew app:dokka
-    - mkdir public && mv app/build/dokka public
-  artifacts:
-    paths:
-      - public
-  only:
-    - master-ose
@@ -1,12 +1,13 @@
 [submodule "dav4android"]
 	path = dav4android
-	url = ../dav4android.git
+	url = https://gitlab.com/bitfireAT/dav4android.git
 [submodule "ical4android"]
 	path = ical4android
-	url = ../ical4android.git
+	url = https://gitlab.com/bitfireAT/ical4android.git
 [submodule "vcard4android"]
 	path = vcard4android
-	url = ../vcard4android.git
-[submodule "cert4android"]
-	path = cert4android
-	url = ../cert4android.git
+	url = https://gitlab.com/bitfireAT/vcard4android.git
+[submodule "MemorizingTrustManager"]
+	path = MemorizingTrustManager
+	url = https://github.com/ge0rg/MemorizingTrustManager
+	ignore = dirty
@@ -1,40 +1,34 @@

-[![build status](https://gitlab.com/bitfireAT/davdroid/badges/master-ose/build.svg)](https://gitlab.com/bitfireAT/davdroid/commits/master-ose)
-
-
 DAVdroid
 ========

-Please see the [DAVdroid Web site](https://www.davdroid.com) for
+Please see the [DAVdroid Web site](https://davdroid.bitfire.at) for
 comprehensive information about DAVdroid.

 DAVdroid is licensed under the [GPLv3 License](LICENSE).

-News and updates: [@davdroidapp](https://twitter.com/davdroidapp) on Twitter
+News and updates: [@davdroidapp](https://twitter.com/davdroidapp)

-Help and discussion: [DAVdroid forums](https://www.davdroid.com/forums/)
-
-**If you want to support DAVdroid, please consider [donating to DAVdroid](https://www.davdroid.com/donate/)
-or [purchasing it](https://www.davdroid.com/download/).**
-
-Generated KDoc: https://bitfireAT.gitlab.io/davdroid/dokka/app/
+Help and discussion: [DAVdroid forums](https://davdroid.bitfire.at/forums)

 Parts of DAVdroid have been outsourced into these libraries:

-* [cert4android](https://gitlab.com/bitfireAT/cert4android) – custom certificate management
 * [dav4android](https://gitlab.com/bitfireAT/dav4android) – WebDAV/CalDav/CardDAV framework
 * [ical4android](https://gitlab.com/bitfireAT/ical4android) – iCalendar processing and Calendar Provider access
 * [vcard4android](https://gitlab.com/bitfireAT/vcard4android) – VCard processing and Contacts Provider access

+[![Flattr this!](https://api.flattr.com/button/flattr-badge-large.png)](https://flattr.com/submit/auto?user_id=bitfire&url=https://davdroid.bitfire.at&title=DAVdroid&category=software)
+

 USED THIRD-PARTY LIBRARIES
 ==========================

 Those libraries are used by DAVdroid (alphabetically):

-* [Ambilwarna](https://github.com/yukuku/ambilwarna) – [Apache License, Version 2.0](https://github.com/yukuku/ambilwarna/blob/master/LICENSE)
 * [dnsjava](http://www.xbill.org/dnsjava/) – [BSD License](http://www.xbill.org/dnsjava/dnsjava-current/LICENSE)
-* [ez-vcard](https://github.com/mangstadt/ez-vcard) – [New BSD License](http://opensource.org/licenses/BSD-3-Clause)
-* [iCal4j](https://github.com/ical4j/ical4j) – [New BSD License](http://sourceforge.net/p/ical4j/ical4j/ci/default/tree/LICENSE)
-* [okhttp](https://square.github.io/okhttp) – [Apache License, Version 2.0](https://square.github.io/okhttp/#license)
+* [ez-vcard](https://code.google.com/p/ez-vcard/) – [New BSD License](http://opensource.org/licenses/BSD-3-Clause)
+* [iCal4j](http://ical4j.sourceforge.net/) – [New BSD License](http://sourceforge.net/p/ical4j/ical4j/ci/default/tree/LICENSE)
+* [MemorizingTrustManager](https://github.com/ge0rg/MemorizingTrustManager) – [MIT License](https://raw.githubusercontent.com/ge0rg/MemorizingTrustManager/master/LICENSE.txt)
+* [okhttp](https://square.github.io/okhttp/) – [Apache License, Version 2.0](https://square.github.io/okhttp/#license)
 * [Project Lombok](http://projectlombok.org/) – [MIT License](http://opensource.org/licenses/mit-license.php)
+* [SLF4J](http://www.slf4j.org/) – [MIT License](http://www.slf4j.org/license.html)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) Ricki Hirner (bitfire web engineering).
+ * Copyright (c) 2013 – 2016 Ricki Hirner (bitfire web engineering).
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
@@ -7,37 +7,20 @@
 */

 apply plugin: 'com.android.application'
-apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-android-extensions'
-apply plugin: 'org.jetbrains.dokka-android'

 android {
-    compileSdkVersion 27
-    buildToolsVersion '27.0.1'
+    compileSdkVersion 23
+    buildToolsVersion "23.0.3"

    defaultConfig {
        applicationId "at.bitfire.davdroid"
+        minSdkVersion 14
+        targetSdkVersion 23
+
+        versionCode 101
+        versionName "1.0.9.1"

-        versionCode 205
        buildConfigField "long", "buildTime", System.currentTimeMillis() + "L"
-        buildConfigField "boolean", "customCerts", "true"
-
-        minSdkVersion 19        // Android 4.4
-        targetSdkVersion 27     // Android 8.1
-
-        // when using this, make sure that notification icons are real bitmaps
-        vectorDrawables.useSupportLibrary = true
-    }
-
-    flavorDimensions "type"
-
-    productFlavors {
-        standard {
-            versionName "1.10.1.1-ose"
-
-            buildConfigField "boolean", "customCerts", "true"
-            buildConfigField "boolean", "customCertsUI", "true"
-        }
    }

    buildTypes {
@@ -52,57 +35,46 @@ android {

    lintOptions {
        disable 'GoogleAppIndexingWarning'      // we don't need Google indexing, thanks
-        disable 'ImpliedQuantity', 'MissingQuantity'		// quantities from Transifex may vary
-        disable 'MissingTranslation', 'ExtraTranslation'	// translations from Transifex are not always up to date
-        disable "OnClick"     // doesn't recognize Kotlin onClick methods
+        disable 'GradleDependency'
+        disable 'GradleDynamicVersion'
+        disable 'IconColors'
+        disable 'IconLauncherShape'
+        disable 'IconMissingDensityFolder'
+        disable 'ImpliedQuantity'
+        disable 'MissingTranslation'
+        disable 'MissingQuantity'
        disable 'Recycle'           // doesn't understand Lombok's @Cleanup
        disable 'RtlEnabled'
        disable 'RtlHardcoded'
        disable 'Typos'
    }
    packagingOptions {
-        exclude 'META-INF/DEPENDENCIES'
-        exclude 'META-INF/LICENSE'
-    }
-
-    defaultConfig {
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        exclude 'LICENSE'
+        exclude 'META-INF/LICENSE.txt'
+        exclude 'META-INF/NOTICE.txt'
    }
 }

 dependencies {
-    compile project(':cert4android')
    compile project(':dav4android')
    compile project(':ical4android')
    compile project(':vcard4android')

-    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-
-    compile 'com.android.support:appcompat-v7:27.0.2'
-    compile 'com.android.support:cardview-v7:27.0.2'
-    compile 'com.android.support:design:27.0.2'
-    compile 'com.android.support:preference-v14:27.0.2'
+    compile 'com.android.support:appcompat-v7:23.+'
+    compile 'com.android.support:cardview-v7:23.+'
+    compile 'com.android.support:design:23.+'
+    compile 'com.android.support:preference-v7:23.+'

    compile 'com.github.yukuku:ambilwarna:2.0.1'
+    compile project(':MemorizingTrustManager')

-    compile 'com.squareup.okhttp3:logging-interceptor:3.9.1'
-    compile 'commons-io:commons-io:2.6'
-    compile 'dnsjava:dnsjava:2.1.8'
-    compile 'org.apache.commons:commons-lang3:3.6'
+    compile 'dnsjava:dnsjava:2.1.7'
+    compile 'org.apache.commons:commons-lang3:3.4'
    compile 'org.apache.commons:commons-collections4:4.1'
+    provided 'org.projectlombok:lombok:1.16.8'

    // for tests
-    //noinspection GradleDynamicVersion
-    androidTestCompile('com.android.support.test:runner:+') {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    }
-    //noinspection GradleDynamicVersion
-    androidTestCompile('com.android.support.test:rules:+') {
-        exclude group: 'com.android.support', module: 'support-annotations'
-    }
-    androidTestCompile 'junit:junit:4.12'
-    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.9.1'
-
    testCompile 'junit:junit:4.12'
-    testCompile 'com.squareup.okhttp3:mockwebserver:3.9.1'
+    testCompile 'com.squareup.okhttp3:mockwebserver:3.3.0'
+    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.3.0'
 }
@@ -1,43 +1,36 @@

 # ProGuard usage for DAVdroid:
-#       shrinking        yes (main reason for using ProGuard)
-#       optimization     yes
-#       obfuscation      no (DAVdroid is open-source)
-#       preverification  no
+# 	shrinking		yes - main reason for using ProGuard
+# 	optimization		no - too risky
+# 	obfuscation		no - DAVdroid is open-source
+# 	preverification		no (Android default)

 -dontobfuscate

-optimizations !code/simplification/arithmetic,!code/simplification/cast,!field/*,!class/merging/*
-optimizationpasses 5
-allowaccessmodification
-dontpreverify
-
-# Kotlin
-dontwarn kotlin.**
-
 # ez-vcard
-dontwarn ezvcard.io.json.**            # JSON serializer (for jCards) not used
-dontwarn freemarker.**                 # freemarker templating library (for creating hCards) not used
-dontwarn org.jsoup.**                  # jsoup library (for hCard parsing) not used
-keep class ezvcard.property.** { *; }  # keep all VCard properties (created at runtime)
+-dontwarn ezvcard.io.json.**			# JSON serializer (for jCards) not used
+-dontwarn freemarker.**				# freemarker templating library (for creating hCards) not used
+-dontwarn org.jsoup.**				# jsoup library (for hCard parsing) not used
+-dontwarn sun.misc.Perf
+-keep class ezvcard.property.** { *; }		# keep all VCard properties (created at runtime)

 # ical4j: ignore unused dynamic libraries
 -dontwarn aQute.**
-dontwarn groovy.**                       # Groovy-based ContentBuilder not used
-dontwarn javax.cache.**                  # no JCache support in Android
-dontwarn net.fortuna.ical4j.model.**
+-dontwarn groovy.**				# Groovy-based ContentBuilder not used
 -dontwarn org.codehaus.groovy.**
-dontwarn org.apache.log4j.**             # ignore warnings from log4j dependency
-keep class net.fortuna.ical4j.** { *; }  # keep all model classes (properties/factories, created at runtime)
-keep class org.threeten.bp.** { *; }     # keep ThreeTen (for time zone processing)
+-dontwarn org.apache.commons.logging.**		# Commons logging is not available
+-dontwarn net.fortuna.ical4j.model.**		# ignore warnings from Groovy dependency
+-keep class net.fortuna.ical4j.model.** { *; }	# keep all model classes (properties/factories, created at runtime)

 # okhttp
-dontwarn okio.**
-dontwarn javax.annotation.Nullable
-dontwarn javax.annotation.ParametersAreNonnullByDefault
+-dontwarn java.nio.file.**		# not available on Android
+-dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
+
+# MemorizingTrustManager
+-dontwarn de.duenndns.ssl.MemorizingTrustManager

 # dnsjava
-dontwarn sun.net.spi.nameservice.**   # not available on Android
+-dontwarn sun.net.spi.nameservice.**		# not available on Android

 # DAVdroid + libs
-keep class at.bitfire.** { *; }       # all DAVdroid code is required
+-keep class at.bitfire.** { *; }	# all DAVdroid code is required
@@ -1,128 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.support.test.InstrumentationRegistry.getInstrumentation
-import at.bitfire.cert4android.CustomCertManager
-import okhttp3.OkHttpClient
-import okhttp3.Request
-import okhttp3.mockwebserver.MockWebServer
-import org.apache.commons.io.IOUtils
-import org.apache.commons.lang3.ArrayUtils.contains
-import org.junit.After
-import org.junit.Assert.*
-import org.junit.Before
-import org.junit.Test
-import java.net.Socket
-import java.security.KeyFactory
-import java.security.KeyStore
-import java.security.Principal
-import java.security.cert.CertificateFactory
-import java.security.cert.X509Certificate
-import java.security.spec.PKCS8EncodedKeySpec
-import javax.net.ssl.SSLSocket
-import javax.net.ssl.TrustManagerFactory
-import javax.net.ssl.X509ExtendedKeyManager
-import javax.net.ssl.X509TrustManager
-
-class CustomTlsSocketFactoryTest {
-
-    lateinit var certMgr: CustomCertManager
-    lateinit var factory: CustomTlsSocketFactory
-    val server = MockWebServer()
-
-    @Before
-    fun startServer() {
-        certMgr = CustomCertManager(getInstrumentation().context, false, true)
-        factory = CustomTlsSocketFactory(null, certMgr)
-        server.start()
-    }
-
-    @After
-    fun stopServer() {
-        server.shutdown()
-        certMgr.close()
-    }
-
-
-    @Test
-    fun testSendClientCertificate() {
-        var public: X509Certificate? = null
-        javaClass.classLoader.getResourceAsStream("sample.crt").use {
-            public = CertificateFactory.getInstance("X509").generateCertificate(it) as? X509Certificate
-        }
-        assertNotNull(public)
-
-        val keyFactory = KeyFactory.getInstance("RSA")
-        val private = keyFactory.generatePrivate(PKCS8EncodedKeySpec(readResource("sample.key")))
-        assertNotNull(private)
-
-        val keyStore = KeyStore.getInstance("AndroidKeyStore")
-        keyStore.load(null)
-        val alias = "sample"
-        keyStore.setKeyEntry(alias, private, null, arrayOf(public))
-        assertTrue(keyStore.containsAlias(alias))
-
-        val trustManagerFactory = TrustManagerFactory.getInstance("X509")
-        trustManagerFactory.init(null as KeyStore?)
-        val trustManager = trustManagerFactory.trustManagers.first() as X509TrustManager
-
-        val factory = CustomTlsSocketFactory(object: X509ExtendedKeyManager() {
-            override fun getServerAliases(p0: String?, p1: Array<out Principal>?): Array<String>? = null
-            override fun chooseServerAlias(p0: String?, p1: Array<out Principal>?, p2: Socket?) = null
-
-            override fun getClientAliases(p0: String?, p1: Array<out Principal>?) =
-                    arrayOf(alias)
-
-            override fun chooseClientAlias(p0: Array<out String>?, p1: Array<out Principal>?, p2: Socket?) =
-                    alias
-
-            override fun getCertificateChain(forAlias: String?) =
-                    arrayOf(public).takeIf { forAlias == alias }
-
-            override fun getPrivateKey(forAlias: String?) =
-                    private.takeIf { forAlias == alias }
-        }, trustManager)
-
-        /* known client cert test URLs (thanks!):
-        *  - https://prod.idrix.eu/secure/
-        *  - https://server.cryptomix.com/secure/
-        */
-        val client = OkHttpClient.Builder()
-                .sslSocketFactory(factory, trustManager)
-                .build()
-        client.newCall(Request.Builder()
-                .get()
-                .url("https://prod.idrix.eu/secure/")
-                .build()).execute().use { response ->
-            assertTrue(response.isSuccessful)
-            assertTrue(response.body()!!.string().contains("CN=User Cert,O=Internet Widgits Pty Ltd,ST=Some-State,C=CA"))
-        }
-    }
-
-    @Test
-    fun testUpgradeTLS() {
-        val s = factory.createSocket(server.hostName, server.port)
-        assertTrue(s is SSLSocket)
-        val ssl = s as SSLSocket
-
-        assertFalse(contains(ssl.enabledProtocols, "SSLv3"))
-        assertTrue(contains(ssl.enabledProtocols, "TLSv1"))
-        assertTrue(contains(ssl.enabledProtocols, "TLSv1.1"))
-        assertTrue(contains(ssl.enabledProtocols, "TLSv1.2"))
-    }
-
-
-    private fun readResource(name: String): ByteArray {
-        this.javaClass.classLoader.getResourceAsStream(name).use {
-            return IOUtils.toByteArray(it)
-        }
-    }
-
-}
@@ -0,0 +1,53 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.os.Build;
+import android.test.InstrumentationTestCase;
+
+import java.io.IOException;
+import java.net.Socket;
+
+import javax.net.ssl.SSLSocket;
+
+import de.duenndns.ssl.MemorizingTrustManager;
+import okhttp3.mockwebserver.MockWebServer;
+
+public class SSLSocketFactoryCompatTest extends InstrumentationTestCase {
+
+    SSLSocketFactoryCompat factory;
+    MockWebServer server = new MockWebServer();
+
+    @Override
+    protected void setUp() throws Exception {
+        factory = new SSLSocketFactoryCompat(new MemorizingTrustManager(getInstrumentation().getTargetContext().getApplicationContext()));
+        server.start();
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        server.shutdown();
+    }
+
+
+    public void testUpgradeTLS() throws IOException {
+        Socket s = factory.createSocket(server.getHostName(), server.getPort());
+        assertTrue(s instanceof SSLSocket);
+
+        SSLSocket ssl = (SSLSocket)s;
+        assertFalse(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "SSLv3"));
+        assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1"));
+
+        if (Build.VERSION.SDK_INT >= 16) {
+            assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1.1"));
+            assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1.2"));
+        }
+    }
+
+}
@@ -1,5 +1,5 @@
 /*
- * Copyright © Ricki Hirner (bitfire web engineering).
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
@@ -10,9 +10,7 @@ package at.bitfire.davdroid.model;

 import android.content.ContentValues;

-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import junit.framework.TestCase;

 import java.io.IOException;

@@ -25,28 +23,10 @@ import at.bitfire.davdroid.model.ServiceDB.Collections;
 import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;

-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+public class CollectionInfoTest extends TestCase {

-public class CollectionInfoTest {
-
-    HttpClient httpClient;
    MockWebServer server = new MockWebServer();

-    @Before
-    public void setUp() {
-        httpClient = new HttpClient.Builder().build();
-    }
-
-    @After
-    public void shutDown() {
-        httpClient.close();
-    }
-
-
-    @Test
    public void testFromDavResource() throws IOException, HttpException, DavException {
        // r/w address book
        server.enqueue(new MockResponse()
@@ -62,13 +42,13 @@ public class CollectionInfoTest {
                        "</response>" +
                        "</multistatus>"));

-        DavResource dav = new DavResource(httpClient.getOkHttpClient(), server.url("/"));
+        DavResource dav = new DavResource(HttpClient.create(), server.url("/"));
        dav.propfind(0, ResourceType.NAME);
-        CollectionInfo info = new CollectionInfo(dav);
-        assertEquals(CollectionInfo.Type.ADDRESS_BOOK, info.getType());
-        assertFalse(info.getReadOnly());
-        assertEquals("My Contacts", info.getDisplayName());
-        assertEquals("My Contacts Description", info.getDescription());
+        CollectionInfo info = CollectionInfo.fromDavResource(dav);
+        assertEquals(CollectionInfo.Type.ADDRESS_BOOK, info.type);
+        assertFalse(info.readOnly);
+        assertEquals("My Contacts", info.displayName);
+        assertEquals("My Contacts Description", info.description);

        // read-only calendar, no display name
        server.enqueue(new MockResponse()
@@ -86,25 +66,23 @@ public class CollectionInfoTest {
                        "</response>" +
                        "</multistatus>"));

-        dav = new DavResource(httpClient.getOkHttpClient(), server.url("/"));
+        dav = new DavResource(HttpClient.create(), server.url("/"));
        dav.propfind(0, ResourceType.NAME);
-        info = new CollectionInfo(dav);
-        assertEquals(CollectionInfo.Type.CALENDAR, info.getType());
-        assertTrue(info.getReadOnly());
-        assertNull(info.getDisplayName());
-        assertEquals("My Calendar", info.getDescription());
-        assertEquals(0xFFFF0000, (int)info.getColor());
-        assertEquals("tzdata", info.getTimeZone());
-        assertTrue(info.getSupportsVEVENT());
-        assertTrue(info.getSupportsVTODO());
+        info = CollectionInfo.fromDavResource(dav);
+        assertEquals(CollectionInfo.Type.CALENDAR, info.type);
+        assertTrue(info.readOnly);
+        assertNull(info.displayName);
+        assertEquals("My Calendar", info.description);
+        assertEquals(0xFFFF0000, (int)info.color);
+        assertEquals("tzdata", info.timeZone);
+        assertTrue(info.supportsVEVENT);
+        assertTrue(info.supportsVTODO);
    }

-    @Test
    public void testFromDB() {
        ContentValues values = new ContentValues();
        values.put(Collections.ID, 1);
        values.put(Collections.SERVICE_ID, 1);
-        values.put(Collections.TYPE, CollectionInfo.Type.CALENDAR.name());
        values.put(Collections.URL, "http://example.com");
        values.put(Collections.READ_ONLY, 1);
        values.put(Collections.DISPLAY_NAME, "display name");
@@ -115,19 +93,18 @@ public class CollectionInfoTest {
        values.put(Collections.SUPPORTS_VTODO, 1);
        values.put(Collections.SYNC, 1);

-        CollectionInfo info = new CollectionInfo(values);
-        assertEquals(CollectionInfo.Type.CALENDAR, info.getType());
-        assertEquals(1, (long)info.getId());
-        assertEquals(1, (long)info.getServiceID());
-        assertEquals("http://example.com", info.getUrl());
-        assertTrue(info.getReadOnly());
-        assertEquals("display name", info.getDisplayName());
-        assertEquals("description", info.getDescription());
-        assertEquals(0xFFFF0000, (int)info.getColor());
-        assertEquals("tzdata", info.getTimeZone());
-        assertTrue(info.getSupportsVEVENT());
-        assertTrue(info.getSupportsVTODO());
-        assertTrue(info.getSelected());
+        CollectionInfo info = CollectionInfo.fromDB(values);
+        assertEquals(1, info.id);
+        assertEquals(1, (long)info.serviceID);
+        assertEquals("http://example.com", info.url);
+        assertTrue(info.readOnly);
+        assertEquals("display name", info.displayName);
+        assertEquals("description", info.description);
+        assertEquals(0xFFFF0000, (int)info.color);
+        assertEquals("tzdata", info.timeZone);
+        assertTrue(info.supportsVEVENT);
+        assertTrue(info.supportsVTODO);
+        assertTrue(info.selected);
    }

 }
@@ -1,39 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import at.bitfire.davdroid.App
-import junit.framework.Assert.assertEquals
-import junit.framework.Assert.assertFalse
-import org.junit.Test
-
-class DefaultsProviderTest {
-
-    private val provider: Provider = DefaultsProvider()
-
-    @Test
-    fun testHas() {
-        assertEquals(Pair(false, true), provider.has("notExisting"))
-        assertEquals(Pair(true, true), provider.has(App.OVERRIDE_PROXY))
-    }
-
-    @Test
-    fun testGet() {
-        assertEquals(Pair("localhost", true), provider.getString(App.OVERRIDE_PROXY_HOST))
-        assertEquals(Pair(8118, true), provider.getInt(App.OVERRIDE_PROXY_PORT))
-    }
-
-    @Test
-    fun testPutRemove() {
-        assertEquals(Pair(false, true), provider.isWritable(App.OVERRIDE_PROXY))
-        assertFalse(provider.putBoolean(App.OVERRIDE_PROXY, true))
-        assertFalse(provider.remove(App.OVERRIDE_PROXY))
-    }
-
-}
@@ -1,44 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import android.content.ServiceConnection
-import android.support.test.InstrumentationRegistry
-import android.support.test.InstrumentationRegistry.getTargetContext
-import at.bitfire.davdroid.App
-import junit.framework.Assert.*
-import org.junit.After
-import org.junit.Before
-import org.junit.Test
-
-class SettingsTest {
-
-    lateinit var settings: Settings.Stub
-
-    @Before
-    fun init() {
-        InstrumentationRegistry.getContext().isRestricted
-        settings = Settings.getInstance(getTargetContext())!!
-    }
-
-    @After
-    fun shutdown() {
-        settings.close()
-    }
-
-
-    @Test
-    fun testHas() {
-        assertFalse(settings.has("notExisting"))
-
-        // provided by DefaultsProvider
-        assertTrue(settings.has(App.OVERRIDE_PROXY))
-    }
-
-}
@@ -1,5 +1,5 @@
 /*
- * Copyright © Ricki Hirner (bitfire web engineering).
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
@@ -8,9 +8,7 @@

 package at.bitfire.davdroid.ui.setup;

-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import android.test.InstrumentationTestCase;

 import java.io.IOException;
 import java.net.URI;
@@ -20,28 +18,24 @@ import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
 import at.bitfire.dav4android.property.AddressbookHomeSet;
 import at.bitfire.dav4android.property.ResourceType;
+import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.HttpClient;
-import at.bitfire.davdroid.log.Logger;
-import at.bitfire.davdroid.model.Credentials;
+import at.bitfire.davdroid.ui.setup.DavResourceFinder;
 import at.bitfire.davdroid.ui.setup.DavResourceFinder.Configuration.ServiceInfo;
+import at.bitfire.davdroid.ui.setup.LoginCredentials;
+import okhttp3.OkHttpClient;
 import okhttp3.mockwebserver.Dispatcher;
 import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
 import okhttp3.mockwebserver.RecordedRequest;

-import static android.support.test.InstrumentationRegistry.getTargetContext;
-import static junit.framework.TestCase.assertFalse;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-
-public class DavResourceFinderTest {
+public class DavResourceFinderTest extends InstrumentationTestCase {

    MockWebServer server = new MockWebServer();

    DavResourceFinder finder;
-    HttpClient client;
-    LoginInfo loginInfo;
+    OkHttpClient client;
+    LoginCredentials credentials;

    private static final String
            PATH_NO_DAV = "/nodav",
@@ -54,51 +48,49 @@ public class DavResourceFinderTest {
            SUBPATH_ADDRESSBOOK_HOMESET = "/addressbooks",
            SUBPATH_ADDRESSBOOK = "/addressbooks/private-contacts";

-    @Before
-    public void initServerAndClient() throws Exception {
+    @Override
+    protected void setUp() throws Exception {
        server.setDispatcher(new TestDispatcher());
        server.start();

-        loginInfo = new LoginInfo(URI.create("/"), new Credentials("mock", "12345"));
-        finder = new DavResourceFinder(getTargetContext(), loginInfo);
+        credentials = new LoginCredentials(URI.create("/"), "mock", "12345", true);
+        finder = new DavResourceFinder(getInstrumentation().getContext(), credentials);

-        client = new HttpClient.Builder()
-                .addAuthentication(null, loginInfo.credentials)
-                .build();
+        client = HttpClient.create();
+        client = HttpClient.addAuthentication(client, credentials.userName, credentials.password, credentials.authPreemptive);
    }

-    @After
-    public void stopServer() throws Exception {
+    @Override
+    protected void tearDown() throws Exception {
        server.shutdown();
    }

-    @Test
+
    public void testRememberIfAddressBookOrHomeset() throws IOException, HttpException, DavException {
        ServiceInfo info;

        // before dav.propfind(), no info is available
-        DavResource dav = new DavResource(client.getOkHttpClient(), server.url(PATH_CARDDAV + SUBPATH_PRINCIPAL));
+        DavResource dav = new DavResource(client, server.url(PATH_CARDDAV + SUBPATH_PRINCIPAL));
        finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(0, info.getCollections().size());
-        assertEquals(0, info.getHomeSets().size());
+        assertEquals(0, info.collections.size());
+        assertEquals(0, info.homeSets.size());

        // recognize home set
        dav.propfind(0, AddressbookHomeSet.NAME);
        finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(0, info.getCollections().size());
-        assertEquals(1, info.getHomeSets().size());
-        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK_HOMESET + "/").uri(), info.getHomeSets().iterator().next());
+        assertEquals(0, info.collections.size());
+        assertEquals(1, info.homeSets.size());
+        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK_HOMESET + "/").uri(), info.homeSets.iterator().next());

        // recognize address book
-        dav = new DavResource(client.getOkHttpClient(), server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK));
+        dav = new DavResource(client, server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK));
        dav.propfind(0, ResourceType.NAME);
        finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(1, info.getCollections().size());
-        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK + "/").uri(), info.getCollections().keySet().iterator().next());
-        assertEquals(0, info.getHomeSets().size());
+        assertEquals(1, info.collections.size());
+        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK + "/").uri(), info.collections.keySet().iterator().next());
+        assertEquals(0, info.homeSets.size());
    }

-    @Test
    public void testProvidesService() throws IOException {
        assertFalse(finder.providesService(server.url(PATH_NO_DAV), DavResourceFinder.Service.CALDAV));
        assertFalse(finder.providesService(server.url(PATH_NO_DAV), DavResourceFinder.Service.CARDDAV));
@@ -113,7 +105,6 @@ public class DavResourceFinderTest {
        assertTrue(finder.providesService(server.url(PATH_CALDAV_AND_CARDDAV), DavResourceFinder.Service.CARDDAV));
    }

-    @Test
    public void testGetCurrentUserPrincipal() throws IOException, HttpException, DavException {
        assertNull(finder.getCurrentUserPrincipal(server.url(PATH_NO_DAV), DavResourceFinder.Service.CALDAV));
        assertNull(finder.getCurrentUserPrincipal(server.url(PATH_NO_DAV), DavResourceFinder.Service.CARDDAV));
@@ -138,11 +129,8 @@ public class DavResourceFinderTest {

        @Override
        public MockResponse dispatch(RecordedRequest rq) throws InterruptedException {
-            if (!checkAuth(rq)) {
-                MockResponse authenticate = new MockResponse().setResponseCode(401);
-                authenticate.setHeader("WWW-Authenticate", "Basic realm=\"test\"");
-                return authenticate;
-            }
+            if (!checkAuth(rq))
+                return new MockResponse().setResponseCode(401);

            String path = rq.getPath();

@@ -179,7 +167,7 @@ public class DavResourceFinderTest {
                                "</resourcetype>";
                        break;
                }
-                Logger.log.info("Sending props: " + props);
+                App.log.info("Sending props: " + props);
                return new MockResponse()
                        .setResponseCode(207)
                        .setBody("<multistatus xmlns='DAV:' xmlns:CARD='urn:ietf:params:xml:ns:carddav'>" +
@@ -1,24 +0,0 @@
-----BEGIN CERTIFICATE-----
-MIIEEzCCAfsCAQEwDQYJKoZIhvcNAQEFBQAwRjELMAkGA1UEBhMCQ0ExEzARBgNV
-BAgMClNvbWUtU3RhdGUxEDAOBgNVBAoMB0NBIENlcnQxEDAOBgNVBAMMB0NBIENl
-cnQwHhcNMTgwMTEzMjAyOTI5WhcNMTkwMTEzMjAyOTI5WjBZMQswCQYDVQQGEwJD
-QTETMBEGA1UECAwKU29tZS1TdGF0ZTEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0
-cyBQdHkgTHRkMRIwEAYDVQQDDAlVc2VyIENlcnQwggEiMA0GCSqGSIb3DQEBAQUA
-A4IBDwAwggEKAoIBAQDqOyHAeG4psE/f6i/eTfwbhn6j7WaFXxZiSOWwpQZmzRrx
-MrfkABJCk0X7KNgCaJcmBkG9G1Ri4HfKrxvJFswMXknlq+0ulGBk7oDnZM+pihuX
-3D9VCWMMkCqYhLCGADj2zB2mkX4LpcMRi6XoOetKURE/vcIy7rSLAtJM6ZRdftfh
-2ZxnautS1Tyujh9Au3NI/+Of80tT/nA+oBJQeT1fB/ga1OQlZP5kjSaA7IPiIbTz
-QBO+r898MvqK/lwsvOYnWAp7TY03z+vPfCs0zjijZEl9Wrl0hW6o5db5kU1v5bcr
-p87hxFJsGD2HIr2y6kvYfL2hn+h9iANyYdRnUgapAgMBAAEwDQYJKoZIhvcNAQEF
-BQADggIBAHANsiJITedXPyp89lVMEmGY3zKtOqgQ3tqjvjlNt2sdPnj7wmZbmrNd
-sa90S/UwOn8PzEFOVxYy1BPlljlEjtjmc4OHMcm4P4Zv36uawHilmK8V+zT59gCK
-ftB5FP2TLFUFi2X9o8J06d0xJRE77uewN155NV4RmPuP4b/tMmeixoQppHqLqEr5
-lgEUnt3Mh1ctmeFQFJR6lJ01hlB0gdpVHIhzrVLTO3uo8ePLJTmxP6tyKl/HXj9F
-mpVsKb1kriKwbkGczfw99OUZeUVbTwQOR07r0SrG71B7IuDvxIORnhQc1OUjt7ob
-wjdaZauAHxpGBRu+hw9Yqaxchk9Gldy1nEjGyyVCD0FU5taXbl8PhBWEDc4U9tI+
-xVNmPpsSuCsbz3Mjd1YIVRGL99vLrKsQcj+TNM+jJKKRKes3ihl+l/0FwG6UuO7L
-EvjlUg5hOtYi1D7xuYyMjroGBGh7swYMt6w4eCDbcjzcCkaCi0H2pScM/rLBpDjS
-LIoGCvZ1LBdi933/iOj1/8dxGZwY6fEgcyiD2n0xAgYIniLWjEZXOMdIK5FNTNga
-Tswanvp+6Noa4oIu/hl/LXvPMsouaWfSEbRe0Dshi3GpLj3YtEHoN9DHB8bn7jy5
-34By81GT41m5kq3hWP//x9kSHYSADpbovCbKbElU1qSt6vTVR4nq
-----END CERTIFICATE-----
@@ -15,29 +15,35 @@
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.GET_ACCOUNTS"/>
+    <uses-permission android:name="android.permission.MANAGE_ACCOUNTS"/>
    <uses-permission android:name="android.permission.READ_SYNC_SETTINGS"/>
-    <uses-permission android:name="android.permission.READ_SYNC_STATS"/>
    <uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS"/>
-    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
-
-    <!-- account management permissions not required for own accounts since API level 22 -->
-    <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" android:maxSdkVersion="22"/>
-    <uses-permission android:name="android.permission.GET_ACCOUNTS" android:maxSdkVersion="22"/>
-    <uses-permission android:name="android.permission.MANAGE_ACCOUNTS" android:maxSdkVersion="22"/>

+    <!-- legacy permissions -->
+    <uses-permission
+        android:name="android.permission.AUTHENTICATE_ACCOUNTS"
+        android:maxSdkVersion="22"
+        tools:ignore="UnusedAttribute"/>
    <!--
         for writing external log files; permission only required for SDK <= 18 because since then,
         writing to app-private directory doesn't require extra permissions
    -->
-    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="18"/>
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="18"/>
+    <uses-permission
+        android:name="android.permission.READ_EXTERNAL_STORAGE"
+        android:maxSdkVersion="18"
+        tools:ignore="UnusedAttribute"/>
+    <uses-permission
+        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+        android:maxSdkVersion="18"
+        tools:ignore="UnusedAttribute"/>

    <!-- other permissions -->
-    <!-- android.permission-group.CONTACTS -->
    <uses-permission android:name="android.permission.READ_CONTACTS"/>
+    <!-- android.permission-group.CONTACTS -->
    <uses-permission android:name="android.permission.WRITE_CONTACTS"/>
-    <!-- android.permission-group.CALENDAR -->
    <uses-permission android:name="android.permission.READ_CALENDAR"/>
+    <!-- android.permission-group.CALENDAR -->
    <uses-permission android:name="android.permission.WRITE_CALENDAR"/>

    <!-- ical4android declares task access permissions -->
@@ -46,15 +52,95 @@
        android:name=".App"
        android:allowBackup="true"
        android:fullBackupContent="false"
-        android:networkSecurityConfig="@xml/network_security_config"
-        android:icon="@mipmap/ic_launcher"
+        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme"
        tools:ignore="UnusedAttribute">

-        <service android:name=".DavService"/>
-        <service android:name=".settings.Settings"/>
+        <receiver
+            android:name=".App$ReinitLoggingReceiver"
+            android:exported="false"
+            android:process=":sync">
+            <intent-filter>
+                <action android:name="at.bitfire.davdroid.REINIT_LOGGER"/>
+            </intent-filter>
+        </receiver>
+        <receiver
+            android:name=".AccountSettings$AppUpdatedReceiver"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.PACKAGE_REPLACED" />
+                <data android:scheme="package" android:path="at.bitfire.davdroid" />
+            </intent-filter>
+        </receiver>

+        <service
+            android:name=".syncadapter.AccountAuthenticatorService"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="android.accounts.AccountAuthenticator"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.accounts.AccountAuthenticator"
+                android:resource="@xml/account_authenticator"/>
+        </service>
+        <service
+            android:name=".syncadapter.ContactsSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_contacts"/>
+            <meta-data
+                android:name="android.provider.CONTACTS_STRUCTURE"
+                android:resource="@xml/contacts"/>
+        </service>
+        <service
+            android:name=".syncadapter.CalendarsSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_calendars"/>
+        </service>
+        <service
+            android:name=".syncadapter.TasksSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_tasks"/>
+        </service>
+
+        <service
+            android:name=".DavService"
+            android:enabled="true">
+        </service>
+        <receiver
+            android:name=".AccountsChangedReceiver"
+            android:enabled="true"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.accounts.LOGIN_ACCOUNTS_CHANGED"/>
+            </intent-filter>
+        </receiver>
+        
        <activity
            android:name=".ui.AccountsActivity"
            android:label="@string/app_name"
@@ -101,106 +187,14 @@

        <activity
            android:name=".ui.DebugInfoActivity"
-            android:parentActivityName=".ui.AppSettingsActivity"
            android:exported="true"
            android:label="@string/debug_info_title">
        </activity>
-        <provider
-            android:name="android.support.v4.content.FileProvider"
-            android:authorities="@string/authority_log_provider"
-            android:grantUriPermissions="true"
-            android:exported="false">
-            <meta-data
-                android:name="android.support.FILE_PROVIDER_PATHS"
-                android:resource="@xml/log_paths" />
-        </provider>

-        <!-- account type "DAVdroid" -->
-        <service
-            android:name=".syncadapter.AccountAuthenticatorService"
-            android:exported="false">
-            <intent-filter>
-                <action android:name="android.accounts.AccountAuthenticator"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.accounts.AccountAuthenticator"
-                android:resource="@xml/account_authenticator"/>
-        </service>
-        <service
-            android:name=".syncadapter.CalendarsSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_calendars"/>
-        </service>
-        <service
-            android:name=".syncadapter.TasksSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_tasks"/>
-        </service>
-
-        <!-- account type "DAVdroid Address book" -->
-        <service
-            android:name=".syncadapter.NullAuthenticatorService"
-            android:exported="false">
-            <intent-filter>
-                <action android:name="android.accounts.AccountAuthenticator"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.accounts.AccountAuthenticator"
-                android:resource="@xml/account_authenticator_address_book"/>
-        </service>
-        <provider
-            android:authorities="@string/address_books_authority"
-            android:exported="false"
-            android:label="@string/address_books_authority_title"
-            android:name=".syncadapter.AddressBookProvider"
-            android:multiprocess="false"/>
-        <service
-            android:name=".syncadapter.AddressBooksSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_address_books"/>
-        </service>
-        <service
-            android:name=".syncadapter.ContactsSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_contacts"/>
-            <meta-data
-                android:name="android.provider.CONTACTS_STRUCTURE"
-                android:resource="@xml/contacts"/>
-        </service>
+        <!-- MemorizingTrustManager -->
+        <activity
+            android:name="de.duenndns.ssl.MemorizingActivity"
+            android:theme="@android:style/Theme.Holo.Light.Dialog.NoActionBar"/>

    </application>

@@ -1,28 +0,0 @@
-package at.bitfire.davdroid.settings;
-
-import at.bitfire.davdroid.settings.ISettingsObserver;
-
-interface ISettings {
-
-    void forceReload();
-
-    boolean has(String key);
-
-    boolean getBoolean(String key, boolean defaultValue);
-    int getInt(String key, int defaultValue);
-    long getLong(String key, long defaultValue);
-    String getString(String key, String defaultValue);
-
-    boolean isWritable(String key);
-
-    boolean putBoolean(String key, boolean value);
-    boolean putInt(String key, int value);
-    boolean putLong(String key, long value);
-    boolean putString(String key, String value);
-
-    boolean remove(String key);
-
-    void registerObserver(ISettingsObserver observer);
-    void unregisterObserver(ISettingsObserver observer);
-
-}
@@ -1,7 +0,0 @@
-package at.bitfire.davdroid.settings;
-
-interface ISettingsObserver {
-
-    void onSettingsChanged();
-
-}
@@ -0,0 +1,405 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.annotation.SuppressLint;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.content.BroadcastReceiver;
+import android.content.ContentProviderClient;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.Intent;
+import android.content.PeriodicSync;
+import android.database.sqlite.SQLiteDatabase;
+import android.graphics.drawable.BitmapDrawable;
+import android.os.Bundle;
+import android.provider.CalendarContract;
+import android.provider.ContactsContract;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v7.app.NotificationCompat;
+import android.text.TextUtils;
+
+import java.lang.reflect.Method;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import at.bitfire.davdroid.model.ServiceDB.HomeSets;
+import at.bitfire.davdroid.model.ServiceDB.Services;
+import at.bitfire.davdroid.resource.LocalAddressBook;
+import at.bitfire.davdroid.resource.LocalCalendar;
+import at.bitfire.davdroid.resource.LocalTaskList;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.TaskProvider;
+import at.bitfire.vcard4android.ContactsStorageException;
+import lombok.Cleanup;
+import okhttp3.HttpUrl;
+
+public class AccountSettings {
+    private final static int CURRENT_VERSION = 3;
+    private final static String
+            KEY_SETTINGS_VERSION = "version",
+
+            KEY_USERNAME = "user_name",
+            KEY_AUTH_PREEMPTIVE = "auth_preemptive",
+
+            KEY_WIFI_ONLY = "wifi_only",            // sync on WiFi only (default: false)
+            KEY_WIFI_ONLY_SSID = "wifi_only_ssid";  // restrict sync to specific WiFi SSID
+
+    /** Time range limitation to the past [in days]
+        value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
+              < 0 (-1)          no limit
+              >= 0              entries more than n days in the past won't be synchronized
+     */
+    private final static String KEY_TIME_RANGE_PAST_DAYS = "time_range_past_days";
+    private final static int DEFAULT_TIME_RANGE_PAST_DAYS = 90;
+
+    /* Whether DAVdroid sets the local calendar color to the value from service DB at every sync
+       value = null (not existing)     true (default)
+               "0"                     false */
+    private final static String KEY_MANAGE_CALENDAR_COLORS = "manage_calendar_colors";
+
+    public final static long SYNC_INTERVAL_MANUALLY = -1;
+
+    final Context context;
+    final AccountManager accountManager;
+    final Account account;
+
+
+    public AccountSettings(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
+        this.context = context;
+        this.account = account;
+
+        accountManager = AccountManager.get(context);
+
+        synchronized(AccountSettings.class) {
+            String versionStr = accountManager.getUserData(account, KEY_SETTINGS_VERSION);
+            if (versionStr == null)
+                throw new InvalidAccountException(account);
+
+            int version = 0;
+            try {
+                version = Integer.parseInt(versionStr);
+            } catch (NumberFormatException ignored) {
+            }
+            App.log.info("Account " + account.name + " has version " + version + ", current version: " + CURRENT_VERSION);
+
+            if (version < CURRENT_VERSION) {
+                Notification notify = new NotificationCompat.Builder(context)
+                        .setSmallIcon(R.drawable.ic_new_releases_light)
+                        .setLargeIcon(((BitmapDrawable)context.getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                        .setContentTitle(context.getString(R.string.settings_version_update))
+                        .setContentText(context.getString(R.string.settings_version_update_settings_updated))
+                        .setSubText(context.getString(R.string.settings_version_update_install_hint))
+                        .setStyle(new NotificationCompat.BigTextStyle()
+                                .bigText(context.getString(R.string.settings_version_update_settings_updated)))
+                        .setCategory(NotificationCompat.CATEGORY_SYSTEM)
+                        .setPriority(NotificationCompat.PRIORITY_HIGH)
+                        .setLocalOnly(true)
+                        .build();
+                NotificationManager nm = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
+                nm.notify(Constants.NOTIFICATION_ACCOUNT_SETTINGS_UPDATED, notify);
+
+                update(version);
+            }
+        }
+    }
+
+    public static Bundle initialUserData(String userName, boolean preemptive) {
+        Bundle bundle = new Bundle();
+        bundle.putString(KEY_SETTINGS_VERSION, String.valueOf(CURRENT_VERSION));
+        bundle.putString(KEY_USERNAME, userName);
+        bundle.putString(KEY_AUTH_PREEMPTIVE, Boolean.toString(preemptive));
+        return bundle;
+    }
+
+
+    // authentication settings
+
+    public String username() { return accountManager.getUserData(account, KEY_USERNAME); }
+    public void username(@NonNull String userName) { accountManager.setUserData(account, KEY_USERNAME, userName); }
+
+    public String password() { return accountManager.getPassword(account); }
+    public void password(@NonNull String password) { accountManager.setPassword(account, password); }
+
+    public boolean preemptiveAuth() { return Boolean.parseBoolean(accountManager.getUserData(account, KEY_AUTH_PREEMPTIVE)); }
+    public void preemptiveAuth(boolean preemptive) { accountManager.setUserData(account, KEY_AUTH_PREEMPTIVE, Boolean.toString(preemptive)); }
+
+
+    // sync. settings
+
+    public Long getSyncInterval(@NonNull String authority) {
+        if (ContentResolver.getIsSyncable(account, authority) <= 0)
+            return null;
+
+        if (ContentResolver.getSyncAutomatically(account, authority)) {
+            List<PeriodicSync> syncs = ContentResolver.getPeriodicSyncs(account, authority);
+            if (syncs.isEmpty())
+                return SYNC_INTERVAL_MANUALLY;
+            else
+                return syncs.get(0).period;
+        } else
+            return SYNC_INTERVAL_MANUALLY;
+    }
+
+    public void setSyncInterval(@NonNull String authority, long seconds) {
+        if (seconds == SYNC_INTERVAL_MANUALLY) {
+            ContentResolver.setSyncAutomatically(account, authority, false);
+        } else {
+            ContentResolver.setSyncAutomatically(account, authority, true);
+            ContentResolver.addPeriodicSync(account, authority, new Bundle(), seconds);
+        }
+    }
+
+    public boolean getSyncWifiOnly() {
+        return accountManager.getUserData(account, KEY_WIFI_ONLY) != null;
+    }
+
+    public void setSyncWiFiOnly(boolean wiFiOnly) {
+        accountManager.setUserData(account, KEY_WIFI_ONLY, wiFiOnly ? "1" : null);
+    }
+
+    @Nullable
+    public String getSyncWifiOnlySSID() {
+        return accountManager.getUserData(account, KEY_WIFI_ONLY_SSID);
+    }
+
+    public void setSyncWifiOnlySSID(String ssid) {
+        accountManager.setUserData(account, KEY_WIFI_ONLY_SSID, ssid);
+    }
+
+
+    // CalDAV settings
+
+    public Integer getTimeRangePastDays() {
+        String strDays = accountManager.getUserData(account, KEY_TIME_RANGE_PAST_DAYS);
+        if (strDays != null) {
+            int days = Integer.valueOf(strDays);
+            return days < 0 ? null : days;
+        } else
+            return DEFAULT_TIME_RANGE_PAST_DAYS;
+    }
+
+    public void setTimeRangePastDays(Integer days) {
+        accountManager.setUserData(account, KEY_TIME_RANGE_PAST_DAYS, String.valueOf(days == null ? -1 : days));
+    }
+
+    public boolean getManageCalendarColors() {
+        return accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS) == null;
+    }
+
+    public void setManageCalendarColors(boolean manage) {
+        accountManager.setUserData(account, KEY_MANAGE_CALENDAR_COLORS, manage ? null : "0");
+    }
+
+
+    // update from previous account settings
+
+    private void update(int fromVersion) {
+        for (int toVersion = fromVersion + 1; toVersion <= CURRENT_VERSION; toVersion++) {
+            App.log.info("Updating account " + account.name + " from version " + fromVersion + " to " + toVersion);
+            try {
+                Method updateProc = getClass().getDeclaredMethod("update_" + fromVersion + "_" + toVersion);
+                updateProc.invoke(this);
+            } catch (Exception e) {
+                App.log.log(Level.SEVERE, "Couldn't update account settings", e);
+            }
+            fromVersion = toVersion;
+        }
+    }
+
+    @SuppressWarnings({ "Recycle", "unused" })
+    private void update_1_2() throws ContactsStorageException {
+        /* - KEY_ADDRESSBOOK_URL ("addressbook_url"),
+           - KEY_ADDRESSBOOK_CTAG ("addressbook_ctag"),
+           - KEY_ADDRESSBOOK_VCARD_VERSION ("addressbook_vcard_version") are not used anymore (now stored in ContactsContract.SyncState)
+           - KEY_LAST_ANDROID_VERSION ("last_android_version") has been added
+        */
+
+        // move previous address book info to ContactsContract.SyncState
+        @Cleanup("release") ContentProviderClient provider = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
+        if (provider == null)
+            throw new ContactsStorageException("Couldn't access Contacts provider");
+
+        LocalAddressBook addr = new LocalAddressBook(account, provider);
+
+        // until now, ContactsContract.Settings.UNGROUPED_VISIBLE was not set explicitly
+        ContentValues values = new ContentValues();
+        values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1);
+        addr.updateSettings(values);
+
+        String url = accountManager.getUserData(account, "addressbook_url");
+        if (!TextUtils.isEmpty(url))
+            addr.setURL(url);
+        accountManager.setUserData(account, "addressbook_url", null);
+
+        String cTag = accountManager.getUserData(account, "addressbook_ctag");
+        if (!TextUtils.isEmpty(cTag))
+            addr.setCTag(cTag);
+        accountManager.setUserData(account, "addressbook_ctag", null);
+
+        accountManager.setUserData(account, KEY_SETTINGS_VERSION, "2");
+    }
+
+    @SuppressWarnings({ "Recycle", "unused" })
+    private void update_2_3() {
+        // Don't show a warning for Android updates anymore
+        accountManager.setUserData(account, "last_android_version", null);
+
+        Long serviceCardDAV = null, serviceCalDAV = null;
+
+        ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(context);
+        try {
+            SQLiteDatabase db = dbHelper.getWritableDatabase();
+            // we have to create the WebDAV Service database only from the old address book, calendar and task list URLs
+
+            // CardDAV: migrate address books
+            ContentProviderClient client = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
+            if (client != null)
+                try {
+                    LocalAddressBook addrBook = new LocalAddressBook(account, client);
+                    String url = addrBook.getURL();
+                    if (url != null) {
+                        App.log.fine("Migrating address book " + url);
+
+                        // insert CardDAV service
+                        ContentValues values = new ContentValues();
+                        values.put(Services.ACCOUNT_NAME, account.name);
+                        values.put(Services.SERVICE, Services.SERVICE_CARDDAV);
+                        serviceCardDAV = db.insert(Services._TABLE, null, values);
+
+                        // insert address book
+                        values.clear();
+                        values.put(Collections.SERVICE_ID, serviceCardDAV);
+                        values.put(Collections.URL, url);
+                        values.put(Collections.SYNC, 1);
+                        db.insert(Collections._TABLE, null, values);
+
+                        // insert home set
+                        HttpUrl homeSet = HttpUrl.parse(url).resolve("../");
+                        values.clear();
+                        values.put(HomeSets.SERVICE_ID, serviceCardDAV);
+                        values.put(HomeSets.URL, homeSet.toString());
+                        db.insert(HomeSets._TABLE, null, values);
+                    }
+
+                } catch (ContactsStorageException e) {
+                    App.log.log(Level.SEVERE, "Couldn't migrate address book", e);
+                } finally {
+                    client.release();
+                }
+
+            // CalDAV: migrate calendars + task lists
+            Set<String> collections = new HashSet<>();
+            Set<HttpUrl> homeSets = new HashSet<>();
+
+            client = context.getContentResolver().acquireContentProviderClient(CalendarContract.AUTHORITY);
+            if (client != null)
+                try {
+                    LocalCalendar calendars[] = (LocalCalendar[])LocalCalendar.find(account, client, LocalCalendar.Factory.INSTANCE, null, null);
+                    for (LocalCalendar calendar : calendars) {
+                        String url = calendar.getName();
+                        App.log.fine("Migrating calendar " + url);
+                        collections.add(url);
+                        homeSets.add(HttpUrl.parse(url).resolve("../"));
+                    }
+                } catch (CalendarStorageException e) {
+                    App.log.log(Level.SEVERE, "Couldn't migrate calendars", e);
+                } finally {
+                    client.release();
+                }
+
+            TaskProvider provider = LocalTaskList.acquireTaskProvider(context.getContentResolver());
+            if (provider != null)
+                try {
+                    LocalTaskList[] taskLists = (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
+                    for (LocalTaskList taskList : taskLists) {
+                        String url = taskList.getSyncId();
+                        App.log.fine("Migrating task list " + url);
+                        collections.add(url);
+                        homeSets.add(HttpUrl.parse(url).resolve("../"));
+                    }
+                } catch (CalendarStorageException e) {
+                    App.log.log(Level.SEVERE, "Couldn't migrate task lists", e);
+                } finally {
+                    provider.close();
+                }
+
+            if (!collections.isEmpty()) {
+                // insert CalDAV service
+                ContentValues values = new ContentValues();
+                values.put(Services.ACCOUNT_NAME, account.name);
+                values.put(Services.SERVICE, Services.SERVICE_CALDAV);
+                serviceCalDAV = db.insert(Services._TABLE, null, values);
+
+                // insert collections
+                for (String url : collections) {
+                    values.clear();
+                    values.put(Collections.SERVICE_ID, serviceCalDAV);
+                    values.put(Collections.URL, url);
+                    values.put(Collections.SYNC, 1);
+                    db.insert(Collections._TABLE, null, values);
+                }
+
+                // insert home sets
+                for (HttpUrl homeSet : homeSets) {
+                    values.clear();
+                    values.put(HomeSets.SERVICE_ID, serviceCalDAV);
+                    values.put(HomeSets.URL, homeSet.toString());
+                    db.insert(HomeSets._TABLE, null, values);
+                }
+            }
+        } finally {
+            dbHelper.close();
+        }
+
+        // initiate service detection (refresh) to get display names, colors etc.
+        Intent refresh = new Intent(context, DavService.class);
+        refresh.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
+        if (serviceCardDAV != null) {
+            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, serviceCardDAV);
+            context.startService(refresh);
+        }
+        if (serviceCalDAV != null) {
+            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, serviceCalDAV);
+            context.startService(refresh);
+        }
+
+        accountManager.setUserData(account, KEY_SETTINGS_VERSION, "3");
+    }
+
+
+    public static class AppUpdatedReceiver extends BroadcastReceiver {
+
+        @Override
+        @SuppressLint("UnsafeProtectedBroadcastReceiver")
+        public void onReceive(Context context, Intent intent) {
+            App.log.info("DAVdroid was updated, checking for AccountSettings version");
+
+            // peek into AccountSettings to initiate a possible migration
+            AccountManager accountManager = AccountManager.get(context);
+            for (Account account : accountManager.getAccountsByType(Constants.ACCOUNT_TYPE))
+                try {
+                    App.log.info("Checking account " + account.name);
+                    new AccountSettings(context, account);
+                } catch (InvalidAccountException e) {
+                    App.log.log(Level.SEVERE, "Couldn't check for updated account settings", e);
+                }
+        }
+
+    }
+
+}
@@ -1,527 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid
-
-import android.accounts.Account
-import android.accounts.AccountManager
-import android.content.*
-import android.os.Build
-import android.os.Bundle
-import android.os.Parcel
-import android.os.RemoteException
-import android.provider.CalendarContract
-import android.provider.ContactsContract
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.Credentials
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.*
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.resource.LocalCalendar
-import at.bitfire.davdroid.resource.LocalTaskList
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.ical4android.AndroidCalendar
-import at.bitfire.ical4android.AndroidTaskList
-import at.bitfire.ical4android.CalendarStorageException
-import at.bitfire.ical4android.TaskProvider
-import at.bitfire.vcard4android.ContactsStorageException
-import at.bitfire.vcard4android.GroupMethod
-import okhttp3.HttpUrl
-import org.apache.commons.lang3.StringUtils
-import org.dmfs.tasks.contract.TaskContract
-import java.util.*
-import java.util.logging.Level
-
-class AccountSettings @Throws(InvalidAccountException::class) constructor(
-        val context: Context,
-        val settings: ISettings,
-        val account: Account
-) {
-
-    companion object {
-
-        val CURRENT_VERSION = 8
-        val KEY_SETTINGS_VERSION = "version"
-
-        val KEY_USERNAME = "user_name"
-        val KEY_CERTIFICATE_ALIAS = "certificate_alias"
-
-        val KEY_WIFI_ONLY = "wifi_only"               // sync on WiFi only (default: false)
-        val KEY_WIFI_ONLY_SSIDS = "wifi_only_ssids"   // restrict sync to specific WiFi SSIDs
-
-        /** Time range limitation to the past [in days]
-        value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
-        < 0 (-1)          no limit
-        >= 0              entries more than n days in the past won't be synchronized
-         */
-        val KEY_TIME_RANGE_PAST_DAYS = "time_range_past_days"
-        val DEFAULT_TIME_RANGE_PAST_DAYS = 90
-
-        /* Whether DAVdroid sets the local calendar color to the value from service DB at every sync
-           value = null (not existing)     true (default)
-                   "0"                     false */
-        val KEY_MANAGE_CALENDAR_COLORS = "manage_calendar_colors"
-
-        /* Whether DAVdroid populates and uses CalendarContract.Colors
-           value = null (not existing)     false (default)
-                   "1"                     true */
-        val KEY_EVENT_COLORS = "event_colors"
-
-        /** Contact group method:
-        value = null (not existing)     groups as separate VCards (default)
-        "CATEGORIES"            groups are per-contact CATEGORIES
-         */
-        val KEY_CONTACT_GROUP_METHOD = "contact_group_method"
-
-        @JvmField
-        val SYNC_INTERVAL_MANUALLY = -1L
-
-        fun initialUserData(credentials: Credentials): Bundle {
-            val bundle = Bundle(2)
-            bundle.putString(KEY_SETTINGS_VERSION, CURRENT_VERSION.toString())
-
-            when (credentials.type) {
-                Credentials.Type.UsernamePassword ->
-                    bundle.putString(KEY_USERNAME, credentials.userName)
-                Credentials.Type.ClientCertificate ->
-                    bundle.putString(KEY_CERTIFICATE_ALIAS, credentials.certificateAlias)
-            }
-
-            return bundle
-        }
-
-    }
-
-
-    val accountManager: AccountManager = AccountManager.get(context)
-
-    init {
-        synchronized(AccountSettings::class.java) {
-            val versionStr = accountManager.getUserData(account, KEY_SETTINGS_VERSION) ?: throw InvalidAccountException(account)
-            var version = 0
-            try {
-                version = Integer.parseInt(versionStr)
-            } catch (e: NumberFormatException) {
-            }
-            Logger.log.fine("Account ${account.name} has version $version, current version: $CURRENT_VERSION")
-
-            if (version < CURRENT_VERSION)
-                update(version)
-        }
-    }
-
-
-    // authentication settings
-
-    fun credentials() = Credentials(
-            accountManager.getUserData(account, KEY_USERNAME),
-            accountManager.getPassword(account),
-            accountManager.getUserData(account, KEY_CERTIFICATE_ALIAS)
-    )
-
-    fun credentials(credentials: Credentials) {
-        accountManager.setUserData(account, KEY_USERNAME, credentials.userName)
-        accountManager.setPassword(account, credentials.password)
-        accountManager.setUserData(account, KEY_CERTIFICATE_ALIAS, credentials.certificateAlias)
-    }
-
-
-    // sync. settings
-
-    fun getSyncInterval(authority: String): Long? {
-        if (ContentResolver.getIsSyncable(account, authority) <= 0)
-            return null
-
-        return if (ContentResolver.getSyncAutomatically(account, authority))
-            ContentResolver.getPeriodicSyncs(account, authority).firstOrNull()?.period ?: SYNC_INTERVAL_MANUALLY
-        else
-            SYNC_INTERVAL_MANUALLY
-    }
-
-    fun setSyncInterval(authority: String, seconds: Long) {
-        if (seconds == SYNC_INTERVAL_MANUALLY) {
-            ContentResolver.setSyncAutomatically(account, authority, false)
-        } else {
-            ContentResolver.setSyncAutomatically(account, authority, true)
-            ContentResolver.addPeriodicSync(account, authority, Bundle(), seconds)
-        }
-    }
-
-    fun getSyncWifiOnly() = if (settings.has(KEY_WIFI_ONLY))
-            settings.getBoolean(KEY_WIFI_ONLY, false)
-                else
-            accountManager.getUserData(account, KEY_WIFI_ONLY) != null
-    fun setSyncWiFiOnly(wiFiOnly: Boolean) =
-            accountManager.setUserData(account, KEY_WIFI_ONLY, if (wiFiOnly) "1" else null)
-
-    fun getSyncWifiOnlySSIDs(): List<String>? = (if (settings.has(KEY_WIFI_ONLY_SSIDS))
-                settings.getString(KEY_WIFI_ONLY_SSIDS, null)
-            else
-                accountManager.getUserData(account, KEY_WIFI_ONLY_SSIDS))?.split(',')
-    fun setSyncWifiOnlySSIDs(ssids: List<String>?) =
-            accountManager.setUserData(account, KEY_WIFI_ONLY_SSIDS, StringUtils.trimToNull(ssids?.joinToString(",")))
-
-
-    // CalDAV settings
-
-    fun getTimeRangePastDays(): Int? {
-        val strDays = accountManager.getUserData(account, KEY_TIME_RANGE_PAST_DAYS)
-        if (strDays != null) {
-            val days = Integer.valueOf(strDays)
-            return if (days < 0) null else days
-        } else
-            return DEFAULT_TIME_RANGE_PAST_DAYS
-    }
-
-    fun setTimeRangePastDays(days: Int?) =
-            accountManager.setUserData(account, KEY_TIME_RANGE_PAST_DAYS, (days ?: -1).toString())
-
-    fun getManageCalendarColors() = if (settings.has(KEY_MANAGE_CALENDAR_COLORS))
-        settings.getBoolean(KEY_MANAGE_CALENDAR_COLORS, false)
-    else
-        accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS) == null
-    fun setManageCalendarColors(manage: Boolean) =
-            accountManager.setUserData(account, KEY_MANAGE_CALENDAR_COLORS, if (manage) null else "0")
-
-    fun getEventColors() = if (settings.has(KEY_EVENT_COLORS))
-            settings.getBoolean(KEY_EVENT_COLORS, false)
-                else
-            accountManager.getUserData(account, KEY_EVENT_COLORS) != null
-    fun setEventColors(useColors: Boolean) =
-            accountManager.setUserData(account, KEY_EVENT_COLORS, if (useColors) "1" else null)
-
-    // CardDAV settings
-
-    fun getGroupMethod(): GroupMethod {
-        val name = settings.getString(KEY_CONTACT_GROUP_METHOD, null) ?:
-                accountManager.getUserData(account, KEY_CONTACT_GROUP_METHOD)
-        if (name != null)
-            try {
-                return GroupMethod.valueOf(name)
-            }
-            catch (e: IllegalArgumentException) {
-            }
-        return GroupMethod.GROUP_VCARDS
-    }
-
-    fun setGroupMethod(method: GroupMethod) {
-        accountManager.setUserData(account, KEY_CONTACT_GROUP_METHOD, method.name)
-    }
-
-
-    // update from previous account settings
-
-    private fun update(baseVersion: Int) {
-        for (toVersion in baseVersion+1 .. CURRENT_VERSION) {
-            val fromVersion = toVersion-1
-            Logger.log.info("Updating account ${account.name} from version $fromVersion to $toVersion")
-            try {
-                val updateProc = this::class.java.getDeclaredMethod("update_${fromVersion}_$toVersion")
-                updateProc.invoke(this)
-
-                Logger.log.info("Account version update successful")
-                accountManager.setUserData(account, KEY_SETTINGS_VERSION, toVersion.toString())
-            } catch (e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't update account settings", e)
-            }
-        }
-    }
-
-    @Suppress("unused")
-    private fun update_7_8() {
-        TaskProvider.acquire(context, TaskProvider.ProviderName.OpenTasks)?.let { provider ->
-            // ETag is now in sync_version instead of sync1
-            // UID  is now in _uid         instead of sync2
-            val cursor = provider.client.query(TaskProvider.syncAdapterUri(provider.tasksUri(), account),
-                    arrayOf(TaskContract.Tasks._ID, TaskContract.Tasks.SYNC1, TaskContract.Tasks.SYNC2),
-                    "${TaskContract.Tasks.ACCOUNT_TYPE}=? AND ${TaskContract.Tasks.ACCOUNT_NAME}=?",
-                    arrayOf(account.type, account.name), null)
-            while (cursor.moveToNext()) {
-                val id = cursor.getLong(0)
-                val eTag = cursor.getString(1)
-                val uid = cursor.getString(2)
-                val values = ContentValues(4)
-                values.put(TaskContract.Tasks._UID, uid)
-                values.put(TaskContract.Tasks.SYNC_VERSION, eTag)
-                values.putNull(TaskContract.Tasks.SYNC1)
-                values.putNull(TaskContract.Tasks.SYNC2)
-                Logger.log.log(Level.FINER, "Updating task $id", values)
-                provider.client.update(
-                        TaskProvider.syncAdapterUri(ContentUris.withAppendedId(provider.tasksUri(), id), account),
-                        values, null, null)
-            }
-        }
-    }
-
-    @Suppress("unused")
-    private fun update_6_7() {
-        // add calendar colors
-        context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
-            try {
-                AndroidCalendar.insertColors(provider, account)
-            } finally {
-                if (Build.VERSION.SDK_INT >= 24)
-                    provider.close()
-                else
-                    provider.release()
-            }
-        }
-
-        // update allowed WiFi settings key
-        val onlySSID = accountManager.getUserData(account, "wifi_only_ssid")
-        accountManager.setUserData(account, KEY_WIFI_ONLY_SSIDS, onlySSID)
-        accountManager.setUserData(account, "wifi_only_ssid", null)
-    }
-
-    @Suppress("unused")
-    private fun update_5_6() {
-        context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)?.let { provider ->
-            val parcel = Parcel.obtain()
-            try {
-                // don't run syncs during the migration
-                ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0)
-                ContentResolver.setIsSyncable(account, context.getString(R.string.address_books_authority), 0)
-                ContentResolver.cancelSync(account, null)
-
-                // get previous address book settings (including URL)
-                val raw = ContactsContract.SyncState.get(provider, account)
-                if (raw == null)
-                    Logger.log.info("No contacts sync state, ignoring account")
-                else {
-                    parcel.unmarshall(raw, 0, raw.size)
-                    parcel.setDataPosition(0)
-                    val params = parcel.readBundle()
-                    val url = params.getString("url")
-                    if (url == null)
-                        Logger.log.info("No address book URL, ignoring account")
-                    else {
-                        // create new address book
-                        val info = CollectionInfo(url)
-                        info.type = CollectionInfo.Type.ADDRESS_BOOK
-                        info.displayName = account.name
-                        Logger.log.log(Level.INFO, "Creating new address book account", url)
-                        val addressBookAccount = Account(LocalAddressBook.accountName(account, info), context.getString(R.string.account_type_address_book))
-                        if (!accountManager.addAccountExplicitly(addressBookAccount, null, LocalAddressBook.initialUserData(account, info.url)))
-                            throw ContactsStorageException("Couldn't create address book account")
-
-                        // move contacts to new address book
-                        Logger.log.info("Moving contacts from $account to $addressBookAccount")
-                        val newAccount = ContentValues(2)
-                        newAccount.put(ContactsContract.RawContacts.ACCOUNT_NAME, addressBookAccount.name)
-                        newAccount.put(ContactsContract.RawContacts.ACCOUNT_TYPE, addressBookAccount.type)
-                        val affected = provider.update(ContactsContract.RawContacts.CONTENT_URI.buildUpon()
-                                .appendQueryParameter(ContactsContract.RawContacts.ACCOUNT_NAME, account.name)
-                                .appendQueryParameter(ContactsContract.RawContacts.ACCOUNT_TYPE, account.type)
-                                .appendQueryParameter(ContactsContract.CALLER_IS_SYNCADAPTER, "true").build(),
-                                newAccount,
-                                "${ContactsContract.RawContacts.ACCOUNT_NAME}=? AND ${ContactsContract.RawContacts.ACCOUNT_TYPE}=?",
-                                arrayOf(account.name, account.type))
-                        Logger.log.info("$affected contacts moved to new address book")
-                    }
-
-                    ContactsContract.SyncState.set(provider, account, null)
-                }
-            } catch(e: RemoteException) {
-                throw ContactsStorageException("Couldn't migrate contacts to new address book", e)
-            } finally {
-                parcel.recycle()
-                if (Build.VERSION.SDK_INT >= 24)
-                    provider.close()
-                else
-                    provider.release()
-            }
-        }
-
-        // update version number so that further syncs don't repeat the migration
-        accountManager.setUserData(account, KEY_SETTINGS_VERSION, "6")
-
-        // request sync of new address book account
-        ContentResolver.setIsSyncable(account, context.getString(R.string.address_books_authority), 1)
-        setSyncInterval(context.getString(R.string.address_books_authority), Constants.DEFAULT_SYNC_INTERVAL)
-    }
-
-    /* Android 7.1.1 OpenTasks fix */
-    @Suppress("unused")
-    private fun update_4_5() {
-        // call PackageChangedReceiver which then enables/disables OpenTasks sync when it's (not) available
-        PackageChangedReceiver.updateTaskSync(context)
-    }
-
-    @Suppress("unused")
-    private fun update_3_4() {
-        setGroupMethod(GroupMethod.CATEGORIES)
-    }
-
-    @Suppress("unused")
-    private fun update_2_3() {
-        // Don't show a warning for Android updates anymore
-        accountManager.setUserData(account, "last_android_version", null)
-
-        var serviceCardDAV: Long? = null
-        var serviceCalDAV: Long? = null
-
-        ServiceDB.OpenHelper(context).use { dbHelper ->
-            val db = dbHelper.writableDatabase
-            // we have to create the WebDAV Service database only from the old address book, calendar and task list URLs
-
-            // CardDAV: migrate address books
-            context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)?.let { client ->
-                try {
-                    val addrBook = LocalAddressBook(context, account, client)
-                    val url = addrBook.getURL()
-                    Logger.log.fine("Migrating address book $url")
-
-                    // insert CardDAV service
-                    val values = ContentValues(3)
-                    values.put(Services.ACCOUNT_NAME, account.name)
-                    values.put(Services.SERVICE, Services.SERVICE_CARDDAV)
-                    serviceCardDAV = db.insert(Services._TABLE, null, values)
-
-                    // insert address book
-                    values.clear()
-                    values.put(Collections.SERVICE_ID, serviceCardDAV)
-                    values.put(Collections.URL, url)
-                    values.put(Collections.SYNC, 1)
-                    db.insert(Collections._TABLE, null, values)
-
-                    // insert home set
-                    HttpUrl.parse(url)?.let {
-                        val homeSet = it.resolve("../")
-                        values.clear()
-                        values.put(HomeSets.SERVICE_ID, serviceCardDAV)
-                        values.put(HomeSets.URL, homeSet.toString())
-                        db.insert(HomeSets._TABLE, null, values)
-                    }
-                } catch (e: ContactsStorageException) {
-                    Logger.log.log(Level.SEVERE, "Couldn't migrate address book", e)
-                } finally {
-                    if (Build.VERSION.SDK_INT >= 24)
-                        client.close()
-                    else
-                        @Suppress("deprecation")
-                        client.release()
-                }
-            }
-
-            // CalDAV: migrate calendars + task lists
-            val collections = HashSet<String>()
-            val homeSets = HashSet<HttpUrl>()
-
-            context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { client ->
-                try {
-                    val calendars = AndroidCalendar.find(account, client, LocalCalendar.Factory, null, null)
-                    for (calendar in calendars)
-                        calendar.name?.let { url ->
-                            Logger.log.fine("Migrating calendar $url")
-                            collections.add(url)
-                            HttpUrl.parse(url)?.resolve("../")?.let { homeSets.add(it) }
-                        }
-                } catch (e: CalendarStorageException) {
-                    Logger.log.log(Level.SEVERE, "Couldn't migrate calendars", e)
-                } finally {
-                    if (Build.VERSION.SDK_INT >= 24)
-                        client.close()
-                    else
-                        @Suppress("deprecation")
-                        client.release()
-                }
-            }
-
-            AndroidTaskList.acquireTaskProvider(context)?.use { provider ->
-                try {
-                    val taskLists = AndroidTaskList.find(account, provider, LocalTaskList.Factory, null, null)
-                    for (taskList in taskLists)
-                        taskList.syncId?.let { url ->
-                            Logger.log.fine("Migrating task list $url")
-                            collections.add(url)
-                            HttpUrl.parse(url)?.resolve("../")?.let { homeSets.add(it) }
-                        }
-                } catch (e: CalendarStorageException) {
-                    Logger.log.log(Level.SEVERE, "Couldn't migrate task lists", e)
-                }
-            }
-
-            if (!collections.isEmpty()) {
-                // insert CalDAV service
-                val values = ContentValues(3)
-                values.put(Services.ACCOUNT_NAME, account.name)
-                values.put(Services.SERVICE, Services.SERVICE_CALDAV)
-                serviceCalDAV = db.insert(Services._TABLE, null, values)
-
-                // insert collections
-                for (url in collections) {
-                    values.clear()
-                    values.put(Collections.SERVICE_ID, serviceCalDAV)
-                    values.put(Collections.URL, url)
-                    values.put(Collections.SYNC, 1)
-                    db.insert(Collections._TABLE, null, values)
-                }
-
-                // insert home sets
-                for (homeSet in homeSets) {
-                    values.clear()
-                    values.put(HomeSets.SERVICE_ID, serviceCalDAV)
-                    values.put(HomeSets.URL, homeSet.toString())
-                    db.insert(HomeSets._TABLE, null, values)
-                }
-            }
-        }
-
-        // initiate service detection (refresh) to get display names, colors etc.
-        val refresh = Intent(context, DavService::class.java)
-        refresh.action = DavService.ACTION_REFRESH_COLLECTIONS
-        serviceCardDAV?.let {
-            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, it)
-            context.startService(refresh)
-        }
-        serviceCalDAV?.let {
-            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, it)
-            context.startService(refresh)
-        }
-    }
-
-    @Suppress("unused")
-    private fun update_1_2() {
-        /* - KEY_ADDRESSBOOK_URL ("addressbook_url"),
-           - KEY_ADDRESSBOOK_CTAG ("addressbook_ctag"),
-           - KEY_ADDRESSBOOK_VCARD_VERSION ("addressbook_vcard_version") are not used anymore (now stored in ContactsContract.SyncState)
-           - KEY_LAST_ANDROID_VERSION ("last_android_version") has been added
-        */
-
-        // move previous address book info to ContactsContract.SyncState
-        val provider = context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY) ?:
-            throw ContactsStorageException("Couldn't access Contacts provider")
-
-        try {
-            val addr = LocalAddressBook(context, account, provider)
-
-            // until now, ContactsContract.Settings.UNGROUPED_VISIBLE was not set explicitly
-            val values = ContentValues()
-            values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1)
-            addr.updateSettings(values)
-
-            val url = accountManager.getUserData(account, "addressbook_url")
-            if (!url.isNullOrEmpty())
-                addr.setURL(url)
-            accountManager.setUserData(account, "addressbook_url", null)
-
-            val cTag = accountManager.getUserData (account, "addressbook_ctag")
-            if (!cTag.isNullOrEmpty())
-                addr.setCTag(cTag)
-            accountManager.setUserData(account, "addressbook_ctag", null)
-        } finally {
-            if (Build.VERSION.SDK_INT >= 24)
-                provider.close()
-            else
-                @Suppress("deprecation")
-                provider.release()
-        }
-    }
-
-}
@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.accounts.OnAccountsUpdateListener;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class AccountsChangedReceiver extends BroadcastReceiver {
+
+    protected static final List<OnAccountsUpdateListener> listeners = new LinkedList<>();
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        Intent serviceIntent = new Intent(context, DavService.class);
+        serviceIntent.setAction(DavService.ACTION_ACCOUNTS_UPDATED);
+        context.startService(serviceIntent);
+
+        for (OnAccountsUpdateListener listener : listeners)
+            listener.onAccountsUpdated(null);
+    }
+
+    public static void registerListener(OnAccountsUpdateListener listener, boolean callImmediately) {
+        listeners.add(listener);
+        if (callImmediately)
+            listener.onAccountsUpdated(null);
+    }
+
+    public static void unregisterListener(OnAccountsUpdateListener listener) {
+        listeners.remove(listener);
+    }
+
+}
@@ -0,0 +1,143 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.app.Application;
+import android.app.NotificationManager;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.drawable.BitmapDrawable;
+import android.support.v7.app.NotificationCompat;
+import android.util.Log;
+
+import org.apache.commons.lang3.time.DateFormatUtils;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.logging.FileHandler;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.net.ssl.HostnameVerifier;
+
+import at.bitfire.davdroid.log.LogcatHandler;
+import at.bitfire.davdroid.log.PlainTextFormatter;
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.Settings;
+import de.duenndns.ssl.MemorizingTrustManager;
+import lombok.Cleanup;
+import lombok.Getter;
+import okhttp3.internal.tls.OkHostnameVerifier;
+
+public class App extends Application {
+    public static final String LOG_TO_EXTERNAL_STORAGE = "logToExternalStorage";
+
+    @Getter
+    private static MemorizingTrustManager memorizingTrustManager;
+
+    @Getter
+    private static SSLSocketFactoryCompat sslSocketFactoryCompat;
+
+    @Getter
+    private static HostnameVerifier hostnameVerifier;
+
+    public final static Logger log = Logger.getLogger("davdroid");
+    static {
+        at.bitfire.dav4android.Constants.log = Logger.getLogger("davdroid.dav4android");
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+
+        // initialize MemorizingTrustManager
+        memorizingTrustManager = new MemorizingTrustManager(this);
+        sslSocketFactoryCompat = new SSLSocketFactoryCompat(memorizingTrustManager);
+        hostnameVerifier = memorizingTrustManager.wrapHostnameVerifier(OkHostnameVerifier.INSTANCE);
+
+        // initializer logger
+        reinitLogger();
+    }
+
+    public void reinitLogger() {
+        // don't use Android default logging, we have our own handlers
+        log.setUseParentHandlers(false);
+
+        @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(this);
+        Settings settings = new Settings(dbHelper.getReadableDatabase());
+
+        boolean logToFile = settings.getBoolean(LOG_TO_EXTERNAL_STORAGE, false),
+                logVerbose = logToFile || Log.isLoggable(log.getName(), Log.DEBUG);
+
+        // set logging level according to preferences
+        log.setLevel(logVerbose ? Level.ALL : Level.INFO);
+
+        // remove all handlers
+        for (Handler handler : log.getHandlers())
+            log.removeHandler(handler);
+
+        // add logcat handler
+        log.addHandler(LogcatHandler.INSTANCE);
+
+        NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+        // log to external file according to preferences
+        if (logToFile) {
+            NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
+            builder .setSmallIcon(R.drawable.ic_sd_storage_light)
+                    .setLargeIcon(((BitmapDrawable)getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .setContentTitle(getString(R.string.logging_davdroid_file_logging))
+                    .setLocalOnly(true);
+
+            File dir = getExternalFilesDir(null);
+            if (dir != null)
+                try {
+                    String fileName = new File(dir, "davdroid-" + android.os.Process.myPid() + "-" +
+                            DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMdd-HHmmss") + ".txt").toString();
+                    log.info("Logging to " + fileName);
+
+                    FileHandler fileHandler = new FileHandler(fileName);
+                    fileHandler.setFormatter(PlainTextFormatter.DEFAULT);
+                    log.addHandler(fileHandler);
+                    builder .setContentText(dir.getPath())
+                            .setSubText(getString(R.string.logging_to_external_storage_warning))
+                            .setCategory(NotificationCompat.CATEGORY_STATUS)
+                            .setPriority(NotificationCompat.PRIORITY_HIGH)
+                            .setStyle(new NotificationCompat.BigTextStyle()
+                                    .bigText(getString(R.string.logging_to_external_storage, dir.getPath())))
+                            .setOngoing(true);
+
+                } catch (IOException e) {
+                    log.log(Level.SEVERE, "Couldn't create external log file", e);
+
+                    builder .setContentText(getString(R.string.logging_couldnt_create_file, e.getLocalizedMessage()))
+                            .setCategory(NotificationCompat.CATEGORY_ERROR);
+                }
+            else
+                builder.setContentText(getString(R.string.logging_no_external_storage));
+
+            nm.notify(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING, builder.build());
+        } else
+            nm.cancel(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING);
+    }
+
+
+    public static class ReinitLoggingReceiver extends BroadcastReceiver {
+
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            log.info("Received broadcast: re-initializing logger");
+
+            App app = (App)context.getApplicationContext();
+            app.reinitLogger();
+        }
+
+    }
+}
@@ -1,56 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.app.Application
-import android.content.Context
-import android.graphics.Bitmap
-import android.graphics.drawable.BitmapDrawable
-import android.os.Build
-import android.support.v7.app.AppCompatDelegate
-import at.bitfire.davdroid.log.Logger
-
-class App: Application() {
-
-    companion object {
-
-        @JvmField val DISTRUST_SYSTEM_CERTIFICATES = "distrust_system_certs"
-        @JvmField val OVERRIDE_PROXY = "override_proxy"
-        @JvmField val OVERRIDE_PROXY_HOST = "override_proxy_host"
-        @JvmField val OVERRIDE_PROXY_PORT = "override_proxy_port"
-
-        @JvmField val OVERRIDE_PROXY_HOST_DEFAULT = "localhost"
-        @JvmField val OVERRIDE_PROXY_PORT_DEFAULT = 8118
-
-
-        @JvmStatic
-        fun getLauncherBitmap(context: Context): Bitmap? {
-            val drawableLogo = if (android.os.Build.VERSION.SDK_INT >= 21)
-                    context.getDrawable(R.mipmap.ic_launcher)
-                else
-                    @Suppress("deprecation")
-                    context.resources.getDrawable(R.mipmap.ic_launcher)
-            return if (drawableLogo is BitmapDrawable)
-                drawableLogo.bitmap
-            else
-                null
-        }
-
-    }
-
-
-    override fun onCreate() {
-        super.onCreate()
-        Logger.initialize(this)
-
-        if (Build.VERSION.SDK_INT <= 21)
-            AppCompatDelegate.setCompatVectorFromResourcesEnabled(true)
-    }
-
-}
@@ -0,0 +1,33 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid;
+
+import java.lang.reflect.Array;
+
+public class ArrayUtils {
+
+	@SuppressWarnings("unchecked")
+	public static <T> T[][] partition(T[] bigArray, int max) {
+		int nItems = bigArray.length;
+		int nPartArrays = (nItems + max-1)/max;
+		
+		T[][] partArrays = (T[][])Array.newInstance(bigArray.getClass().getComponentType(), nPartArrays, 0); 
+		
+		// nItems is now the number of remaining items
+		for (int i = 0; nItems > 0; i++) {
+			int n = (nItems < max) ? nItems : max;
+			partArrays[i] = (T[])Array.newInstance(bigArray.getClass().getComponentType(), n); 
+			System.arraycopy(bigArray, i*max, partArrays[i], 0, n);
+			
+			nItems -= n;
+		}
+		
+		return partArrays;
+	}
+	
+}
@@ -0,0 +1,29 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid;
+
+import android.net.Uri;
+
+public class Constants {
+
+	public static final String
+		ACCOUNT_TYPE = "bitfire.at.davdroid";
+
+    // notification IDs
+    public final static int
+            NOTIFICATION_ACCOUNT_SETTINGS_UPDATED = 0,
+            NOTIFICATION_EXTERNAL_FILE_LOGGING = 1,
+            NOTIFICATION_REFRESH_COLLECTIONS = 2,
+            NOTIFICATION_CONTACTS_SYNC = 10,
+            NOTIFICATION_CALENDAR_SYNC = 11,
+            NOTIFICATION_TASK_SYNC = 12,
+            NOTIFICATION_PERMISSIONS = 20;
+
+    public static final Uri webUri = Uri.parse("https://davdroid.bitfire.at/?pk_campaign=davdroid-app");
+
+}
@@ -1,23 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid
-
-object Constants {
-
-    // notification IDs
-    @JvmField val NOTIFICATION_EXTERNAL_FILE_LOGGING = 1
-    @JvmField val NOTIFICATION_REFRESH_COLLECTIONS = 2
-    @JvmField val NOTIFICATION_CONTACTS_SYNC = 10
-    @JvmField val NOTIFICATION_CALENDAR_SYNC = 11
-    @JvmField val NOTIFICATION_TASK_SYNC = 12
-    @JvmField val NOTIFICATION_PERMISSIONS = 20
-
-    @JvmField
-    val DEFAULT_SYNC_INTERVAL = 4 * 3600L    // 4 hours
-
-}
@@ -1,165 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.os.Build
-import at.bitfire.davdroid.log.Logger
-import java.io.IOException
-import java.net.InetAddress
-import java.net.Socket
-import java.security.GeneralSecurityException
-import java.util.*
-import javax.net.ssl.*
-
-/**
- * Custom TLS socket factory with support for
- *   - enabling/disabling algorithms depending on the Android version,
- *   - client certificate authentication
- */
-class CustomTlsSocketFactory(
-        keyManager: KeyManager?,
-        trustManager: X509TrustManager
-): SSLSocketFactory() {
-
-    private var delegate: SSLSocketFactory
-
-    companion object {
-        // Android 5.0+ (API level 21) provides reasonable default settings
-        // but it still allows SSLv3
-        // https://developer.android.com/reference/javax/net/ssl/SSLSocket.html
-        var protocols: Array<String>? = null
-        var cipherSuites: Array<String>? = null
-        init {
-            if (Build.VERSION.SDK_INT >= 23) {
-                // Since Android 6.0 (API level 23),
-                // - TLSv1.1 and TLSv1.2 is enabled by default
-                // - SSLv3 is disabled by default
-                // - all modern ciphers are activated by default
-                protocols = null
-                cipherSuites = null
-                Logger.log.fine("Using device default TLS protocols/ciphers")
-            } else {
-                (SSLSocketFactory.getDefault().createSocket() as? SSLSocket)?.use { socket ->
-                    try {
-                        /* set reasonable protocol versions */
-                        // - enable all supported protocols (enables TLSv1.1 and TLSv1.2 on Android <5.0)
-                        // - remove all SSL versions (especially SSLv3) because they're insecure now
-                        val _protocols = LinkedList<String>()
-                        for (protocol in socket.supportedProtocols.filterNot { it.contains("SSL", true) })
-                            _protocols += protocol
-                        Logger.log.info("Enabling (only) these TLS protocols: ${_protocols.joinToString(", ")}")
-                        protocols = _protocols.toTypedArray()
-
-                        /* set up reasonable cipher suites */
-                        val knownCiphers = arrayOf(
-                                // TLS 1.2
-                                "TLS_RSA_WITH_AES_256_GCM_SHA384",
-                                "TLS_RSA_WITH_AES_128_GCM_SHA256",
-                                "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
-                                "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
-                                "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
-                                "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
-                                "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
-                                // maximum interoperability
-                                "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
-                                "SSL_RSA_WITH_3DES_EDE_CBC_SHA",
-                                "TLS_RSA_WITH_AES_128_CBC_SHA",
-                                // additionally
-                                "TLS_RSA_WITH_AES_256_CBC_SHA",
-                                "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA",
-                                "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
-                                "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
-                                "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA"
-                        )
-                        val availableCiphers = socket.supportedCipherSuites
-                        Logger.log.info("Available cipher suites: ${availableCiphers.joinToString(", ")}")
-
-                        /* For maximum security, preferredCiphers should *replace* enabled ciphers (thus
-                         * disabling ciphers which are enabled by default, but have become unsecure), but for
-                         * the security level of DAVdroid and maximum compatibility, disabling of insecure
-                         * ciphers should be a server-side task */
-
-                        // for the final set of enabled ciphers, take the ciphers enabled by default, ...
-                        val _cipherSuites = LinkedList<String>()
-                        _cipherSuites.addAll(socket.enabledCipherSuites)
-                        Logger.log.fine("Cipher suites enabled by default: ${_cipherSuites.joinToString(", ")}")
-                        // ... add explicitly allowed ciphers ...
-                        _cipherSuites.addAll(knownCiphers)
-                        // ... and keep only those which are actually available
-                        _cipherSuites.retainAll(availableCiphers)
-
-                        Logger.log.info("Enabling (only) these TLS ciphers: " + _cipherSuites.joinToString(", "))
-                        cipherSuites = _cipherSuites.toTypedArray()
-                    } catch (e: IOException) {
-                        Logger.log.severe("Couldn't determine default TLS settings")
-                    }
-                }
-            }
-        }
-    }
-
-
-    init {
-        try {
-            val sslContext = SSLContext.getInstance("TLS")
-            sslContext.init(
-                    if (keyManager != null) arrayOf(keyManager) else null,
-                    arrayOf(trustManager),
-                    null)
-            delegate = sslContext.socketFactory
-        } catch (e: GeneralSecurityException) {
-            throw IllegalStateException()      // system has no TLS
-        }
-    }
-
-    override fun getDefaultCipherSuites(): Array<String>? = cipherSuites ?: delegate.defaultCipherSuites
-    override fun getSupportedCipherSuites(): Array<String>? = cipherSuites ?: delegate.supportedCipherSuites
-
-    override fun createSocket(s: Socket, host: String, port: Int, autoClose: Boolean): Socket {
-        val ssl = delegate.createSocket(s, host, port, autoClose)
-        if (ssl is SSLSocket)
-            upgradeTLS(ssl)
-        return ssl
-    }
-
-    override fun createSocket(host: String, port: Int): Socket {
-        val ssl = delegate.createSocket(host, port)
-        if (ssl is SSLSocket)
-            upgradeTLS(ssl)
-        return ssl
-    }
-
-    override fun createSocket(host: String, port: Int, localHost: InetAddress, localPort: Int): Socket {
-        val ssl = delegate.createSocket(host, port, localHost, localPort)
-        if (ssl is SSLSocket)
-            upgradeTLS(ssl)
-        return ssl
-    }
-
-    override fun createSocket(host: InetAddress, port: Int): Socket {
-        val ssl = delegate.createSocket(host, port)
-        if (ssl is SSLSocket)
-            upgradeTLS(ssl)
-        return ssl
-    }
-
-    override fun createSocket(address: InetAddress, port: Int, localAddress: InetAddress, localPort: Int): Socket {
-        val ssl = delegate.createSocket(address, port, localAddress, localPort)
-        if (ssl is SSLSocket)
-            upgradeTLS(ssl)
-        return ssl
-    }
-
-
-    private fun upgradeTLS(ssl: SSLSocket) {
-        protocols?.let { ssl.enabledProtocols = it }
-        cipherSuites?.let { ssl.enabledCipherSuites = it }
-    }
-
-}
@@ -0,0 +1,427 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.graphics.drawable.BitmapDrawable;
+import android.os.Binder;
+import android.os.IBinder;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v7.app.NotificationCompat;
+import android.text.TextUtils;
+
+import org.apache.commons.collections4.iterators.IteratorChain;
+import org.apache.commons.collections4.iterators.SingletonIterator;
+
+import java.io.IOException;
+import java.lang.ref.WeakReference;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Level;
+
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.UrlUtils;
+import at.bitfire.dav4android.exception.DavException;
+import at.bitfire.dav4android.exception.HttpException;
+import at.bitfire.dav4android.property.AddressbookHomeSet;
+import at.bitfire.dav4android.property.CalendarHomeSet;
+import at.bitfire.dav4android.property.CalendarProxyReadFor;
+import at.bitfire.dav4android.property.CalendarProxyWriteFor;
+import at.bitfire.dav4android.property.GroupMembership;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import at.bitfire.davdroid.model.ServiceDB.HomeSets;
+import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
+import at.bitfire.davdroid.model.ServiceDB.Services;
+import at.bitfire.davdroid.ui.DebugInfoActivity;
+import lombok.Cleanup;
+import okhttp3.HttpUrl;
+import okhttp3.OkHttpClient;
+
+public class DavService extends Service {
+
+    public static final String
+            ACTION_ACCOUNTS_UPDATED = "accountsUpdated",
+            ACTION_REFRESH_COLLECTIONS = "refreshCollections",
+            EXTRA_DAV_SERVICE_ID = "davServiceID";
+
+    private final IBinder binder = new InfoBinder();
+
+    private final Set<Long> runningRefresh = new HashSet<>();
+    private final List<WeakReference<RefreshingStatusListener>> refreshingStatusListeners = new LinkedList<>();
+
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        if (intent != null) {
+            String action = intent.getAction();
+            long id = intent.getLongExtra(EXTRA_DAV_SERVICE_ID, -1);
+
+            switch (action) {
+                case ACTION_ACCOUNTS_UPDATED:
+                    cleanupAccounts();
+                    break;
+                case ACTION_REFRESH_COLLECTIONS:
+                    if (runningRefresh.add(id)) {
+                        new Thread(new RefreshCollections(id)).start();
+                        for (WeakReference<RefreshingStatusListener> ref : refreshingStatusListeners) {
+                            RefreshingStatusListener listener = ref.get();
+                            if (listener != null)
+                                listener.onDavRefreshStatusChanged(id, true);
+                        }
+                    }
+                    break;
+            }
+        }
+
+        return START_NOT_STICKY;
+    }
+
+
+    /* BOUND SERVICE PART
+       for communicating with the activities
+    */
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return binder;
+    }
+
+    public interface RefreshingStatusListener {
+        void onDavRefreshStatusChanged(long id, boolean refreshing);
+    }
+
+    public class InfoBinder extends Binder {
+        public boolean isRefreshing(long id) {
+            return runningRefresh.contains(id);
+        }
+
+        public void addRefreshingStatusListener(@NonNull RefreshingStatusListener listener, boolean callImmediate) {
+            refreshingStatusListeners.add(new WeakReference<>(listener));
+            if (callImmediate)
+                for (long id : runningRefresh)
+                    listener.onDavRefreshStatusChanged(id, true);
+        }
+
+        public void removeRefreshingStatusListener(@NonNull RefreshingStatusListener listener) {
+            for (Iterator<WeakReference<RefreshingStatusListener>> iterator = refreshingStatusListeners.iterator(); iterator.hasNext(); ) {
+                RefreshingStatusListener item = iterator.next().get();
+                if (listener.equals(item))
+                    iterator.remove();
+            }
+        }
+    }
+
+
+    /* ACTION RUNNABLES
+       which actually do the work
+     */
+
+    void cleanupAccounts() {
+        App.log.info("Cleaning up orphaned accounts");
+
+        final OpenHelper dbHelper = new OpenHelper(this);
+        try {
+            SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+            List<String> sqlAccountNames = new LinkedList<>();
+            AccountManager am = AccountManager.get(this);
+            for (Account account : am.getAccountsByType(Constants.ACCOUNT_TYPE))
+                sqlAccountNames.add(DatabaseUtils.sqlEscapeString(account.name));
+
+            if (sqlAccountNames.isEmpty())
+                db.delete(Services._TABLE, null, null);
+            else
+                db.delete(Services._TABLE, Services.ACCOUNT_NAME + " NOT IN (" + TextUtils.join(",", sqlAccountNames) + ")", null);
+        } finally {
+            dbHelper.close();
+        }
+    }
+
+    private class RefreshCollections implements Runnable {
+        final long service;
+        final OpenHelper dbHelper;
+        SQLiteDatabase db;
+
+        RefreshCollections(long davServiceId) {
+            this.service = davServiceId;
+            dbHelper = new OpenHelper(DavService.this);
+        }
+
+        @Override
+        public void run() {
+            Account account = null;
+
+            try {
+                db = dbHelper.getWritableDatabase();
+
+                String serviceType = serviceType();
+                App.log.info("Refreshing " + serviceType + " collections of service #" + service);
+
+                // get account
+                account = account();
+
+                // create authenticating OkHttpClient (credentials taken from account settings)
+                OkHttpClient httpClient = HttpClient.create(DavService.this, account);
+
+                // refresh home sets: principal
+                Set<HttpUrl> homeSets = readHomeSets();
+                HttpUrl principal = readPrincipal();
+                if (principal != null) {
+                    App.log.fine("Querying principal for home sets");
+                    DavResource dav = new DavResource(httpClient, principal);
+                    queryHomeSets(serviceType, dav, homeSets);
+
+                    // refresh home sets: calendar-proxy-read/write-for
+                    CalendarProxyReadFor proxyRead = (CalendarProxyReadFor)dav.properties.get(CalendarProxyReadFor.NAME);
+                    if (proxyRead != null)
+                        for (String href : proxyRead.principals) {
+                            App.log.fine("Principal is a read-only proxy for " + href + ", checking for home sets");
+                            queryHomeSets(serviceType, new DavResource(httpClient, dav.location.resolve(href)), homeSets);
+                        }
+                    CalendarProxyWriteFor proxyWrite = (CalendarProxyWriteFor)dav.properties.get(CalendarProxyWriteFor.NAME);
+                    if (proxyWrite != null)
+                        for (String href : proxyWrite.principals) {
+                            App.log.fine("Principal is a read-write proxy for " + href + ", checking for home sets");
+                            queryHomeSets(serviceType, new DavResource(httpClient, dav.location.resolve(href)), homeSets);
+                        }
+
+                    // refresh home sets: direct group memberships
+                    GroupMembership groupMembership = (GroupMembership)dav.properties.get(GroupMembership.NAME);
+                    if (groupMembership != null)
+                        for (String href : groupMembership.hrefs) {
+                            App.log.fine("Principal is member of group " + href + ", checking for home sets");
+                            DavResource group = new DavResource(httpClient, dav.location.resolve(href));
+                            try {
+                                queryHomeSets(serviceType, group, homeSets);
+                            } catch(HttpException|DavException e) {
+                                App.log.log(Level.WARNING, "Couldn't query member group ", e);
+                            }
+                        }
+                }
+
+                // now refresh collections (taken from home sets)
+                Map<HttpUrl, CollectionInfo> collections = readCollections();
+
+                // (remember selections before)
+                Set<HttpUrl> selectedCollections = new HashSet<>();
+                for (CollectionInfo info : collections.values())
+                    if (info.selected)
+                        selectedCollections.add(HttpUrl.parse(info.url));
+
+                for (Iterator<HttpUrl> itHomeSets = homeSets.iterator(); itHomeSets.hasNext(); ) {
+                    HttpUrl homeSet = itHomeSets.next();
+                    App.log.fine("Listing home set " + homeSet);
+
+                    DavResource dav = new DavResource(httpClient, homeSet);
+                    try {
+                        dav.propfind(1, CollectionInfo.DAV_PROPERTIES);
+                        IteratorChain<DavResource> itCollections = new IteratorChain<>(dav.members.iterator(), new SingletonIterator(dav));
+                        while (itCollections.hasNext()) {
+                            DavResource member = itCollections.next();
+                            CollectionInfo info = CollectionInfo.fromDavResource(member);
+                            info.confirmed = true;
+                            App.log.log(Level.FINE, "Found collection", info);
+
+                            if ((serviceType.equals(Services.SERVICE_CARDDAV) && info.type == CollectionInfo.Type.ADDRESS_BOOK) ||
+                                (serviceType.equals(Services.SERVICE_CALDAV) && info.type == CollectionInfo.Type.CALENDAR))
+                                collections.put(member.location, info);
+                        }
+                    } catch(HttpException e) {
+                        if (e.status == 403 || e.status == 404 || e.status == 410)
+                            // delete home set only if it was not accessible (40x)
+                            itHomeSets.remove();
+                    }
+                }
+
+                // check/refresh unconfirmed collections
+                for (Iterator<Map.Entry<HttpUrl, CollectionInfo>> iterator = collections.entrySet().iterator(); iterator.hasNext(); ) {
+                    Map.Entry<HttpUrl, CollectionInfo> entry = iterator.next();
+                    HttpUrl url = entry.getKey();
+                    CollectionInfo info = entry.getValue();
+
+                    if (!info.confirmed)
+                        try {
+                            DavResource dav = new DavResource(httpClient, url);
+                            dav.propfind(0, CollectionInfo.DAV_PROPERTIES);
+                            info = CollectionInfo.fromDavResource(dav);
+                            info.confirmed = true;
+
+                            // remove unusable collections
+                            if ((serviceType.equals(Services.SERVICE_CARDDAV) && info.type != CollectionInfo.Type.ADDRESS_BOOK) ||
+                                (serviceType.equals(Services.SERVICE_CALDAV) && info.type != CollectionInfo.Type.CALENDAR))
+                                iterator.remove();
+                        } catch(HttpException e) {
+                            if (e.status == 403 || e.status == 404 || e.status == 410)
+                                // delete collection only if it was not accessible (40x)
+                                iterator.remove();
+                            else
+                                throw e;
+                        }
+                }
+
+                // restore selections
+                for (HttpUrl url : selectedCollections) {
+                    CollectionInfo info = collections.get(url);
+                    if (info != null)
+                        info.selected = true;
+                }
+
+                try {
+                    db.beginTransactionNonExclusive();
+                    saveHomeSets(homeSets);
+                    saveCollections(collections.values());
+                    db.setTransactionSuccessful();
+                } finally {
+                    db.endTransaction();
+                }
+
+            } catch(InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Invalid account", e);
+            } catch(IOException|HttpException|DavException e) {
+                App.log.log(Level.SEVERE, "Couldn't refresh collection list", e);
+
+                Intent debugIntent = new Intent(DavService.this, DebugInfoActivity.class);
+                debugIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e);
+                if (account != null)
+                    debugIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account);
+
+                NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+                Notification notify = new NotificationCompat.Builder(DavService.this)
+                        .setSmallIcon(R.drawable.ic_error_light)
+                        .setLargeIcon(((BitmapDrawable)getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                        .setContentTitle(getString(R.string.dav_service_refresh_failed))
+                        .setContentText(getString(R.string.dav_service_refresh_couldnt_refresh))
+                        .setContentIntent(PendingIntent.getActivity(DavService.this, 0, debugIntent, PendingIntent.FLAG_UPDATE_CURRENT))
+                        .build();
+                nm.notify(Constants.NOTIFICATION_REFRESH_COLLECTIONS, notify);
+            } finally {
+                dbHelper.close();
+
+                runningRefresh.remove(service);
+                for (WeakReference<RefreshingStatusListener> ref : refreshingStatusListeners) {
+                    RefreshingStatusListener listener = ref.get();
+                    if (listener != null)
+                        listener.onDavRefreshStatusChanged(service, false);
+                }
+            }
+        }
+
+        /**
+         * Checks if the given URL defines home sets and adds them to the home set list.
+         * @param serviceType       CalDAV/CardDAV (calendar home set / addressbook home set)
+         * @param dav               DavResource to check
+         * @param homeSets          set where found home set URLs will be put into
+         */
+        private void queryHomeSets(String serviceType, DavResource dav, Set<HttpUrl> homeSets) throws IOException, HttpException, DavException {
+            if (Services.SERVICE_CARDDAV.equals(serviceType)) {
+                dav.propfind(0, AddressbookHomeSet.NAME, GroupMembership.NAME);
+                AddressbookHomeSet addressbookHomeSet = (AddressbookHomeSet)dav.properties.get(AddressbookHomeSet.NAME);
+                if (addressbookHomeSet != null)
+                    for (String href : addressbookHomeSet.hrefs)
+                        homeSets.add(UrlUtils.withTrailingSlash(dav.location.resolve(href)));
+            } else if (Services.SERVICE_CALDAV.equals(serviceType)) {
+                dav.propfind(0, CalendarHomeSet.NAME, CalendarProxyReadFor.NAME, CalendarProxyWriteFor.NAME, GroupMembership.NAME);
+                CalendarHomeSet calendarHomeSet = (CalendarHomeSet)dav.properties.get(CalendarHomeSet.NAME);
+                if (calendarHomeSet != null)
+                    for (String href : calendarHomeSet.hrefs)
+                        homeSets.add(UrlUtils.withTrailingSlash(dav.location.resolve(href)));
+            }
+        }
+
+
+        @NonNull
+        private Account account() {
+            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.ACCOUNT_NAME }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
+            if (cursor.moveToNext()) {
+                return new Account(cursor.getString(0), Constants.ACCOUNT_TYPE);
+            } else
+                throw new IllegalArgumentException("Service not found");
+        }
+
+        @NonNull
+        private String serviceType() {
+            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.SERVICE }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
+            if (cursor.moveToNext())
+                return cursor.getString(0);
+            else
+                throw new IllegalArgumentException("Service not found");
+        }
+
+        @Nullable
+        private HttpUrl readPrincipal() {
+            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.PRINCIPAL }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
+            if (cursor.moveToNext()) {
+                String principal = cursor.getString(0);
+                if (principal != null)
+                    return HttpUrl.parse(cursor.getString(0));
+            }
+            return null;
+        }
+
+        @NonNull
+        private Set<HttpUrl> readHomeSets() {
+            Set<HttpUrl> homeSets = new LinkedHashSet<>();
+            @Cleanup Cursor cursor = db.query(HomeSets._TABLE, new String[] { HomeSets.URL }, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
+            while (cursor.moveToNext())
+                homeSets.add(HttpUrl.parse(cursor.getString(0)));
+            return homeSets;
+        }
+
+        private void saveHomeSets(Set<HttpUrl> homeSets) {
+            db.delete(HomeSets._TABLE, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) });
+            for (HttpUrl homeSet : homeSets) {
+                ContentValues values = new ContentValues(1);
+                values.put(HomeSets.SERVICE_ID, service);
+                values.put(HomeSets.URL, homeSet.toString());
+                db.insertOrThrow(HomeSets._TABLE, null, values);
+            }
+        }
+
+        @NonNull
+        private Map<HttpUrl, CollectionInfo> readCollections() {
+            Map<HttpUrl, CollectionInfo> collections = new LinkedHashMap<>();
+            @Cleanup Cursor cursor = db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?", new String[]{String.valueOf(service)}, null, null, null);
+            while (cursor.moveToNext()) {
+                ContentValues values = new ContentValues();
+                DatabaseUtils.cursorRowToContentValues(cursor, values);
+                collections.put(HttpUrl.parse(values.getAsString(Collections.URL)), CollectionInfo.fromDB(values));
+            }
+            return collections;
+        }
+
+        private void saveCollections(Iterable<CollectionInfo> collections) {
+            db.delete(Collections._TABLE, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) });
+            for (CollectionInfo collection : collections) {
+                ContentValues values = collection.toDB();
+                App.log.log(Level.FINE, "Saving collection", values);
+                values.put(Collections.SERVICE_ID, service);
+                db.insertWithOnConflict(Collections._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
+            }
+        }
+    }
+
+}
@@ -1,344 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.accounts.Account
-import android.app.PendingIntent
-import android.app.Service
-import android.content.ContentValues
-import android.content.Intent
-import android.database.DatabaseUtils
-import android.database.sqlite.SQLiteDatabase
-import android.os.Binder
-import android.support.v4.app.NotificationCompat
-import at.bitfire.dav4android.DavResource
-import at.bitfire.dav4android.UrlUtils
-import at.bitfire.dav4android.exception.DavException
-import at.bitfire.dav4android.exception.HttpException
-import at.bitfire.dav4android.property.*
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.ServiceDB.*
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.settings.Settings
-import at.bitfire.davdroid.ui.DebugInfoActivity
-import at.bitfire.davdroid.ui.NotificationUtils
-import okhttp3.HttpUrl
-import org.apache.commons.collections4.iterators.IteratorChain
-import org.apache.commons.collections4.iterators.SingletonIterator
-import java.io.IOException
-import java.lang.ref.WeakReference
-import java.util.*
-import java.util.logging.Level
-import kotlin.concurrent.thread
-
-class DavService: Service() {
-
-    companion object {
-        @JvmField val ACTION_REFRESH_COLLECTIONS = "refreshCollections"
-        @JvmField val EXTRA_DAV_SERVICE_ID = "davServiceID"
-    }
-
-    private val runningRefresh = HashSet<Long>()
-    private val refreshingStatusListeners = LinkedList<WeakReference<RefreshingStatusListener>>()
-
-
-    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        intent?.let {
-            val id = intent.getLongExtra(EXTRA_DAV_SERVICE_ID, -1)
-
-            when (intent.action) {
-                ACTION_REFRESH_COLLECTIONS ->
-                    if (runningRefresh.add(id)) {
-                        thread { refreshCollections(id) }
-                        refreshingStatusListeners.forEach { it.get()?.onDavRefreshStatusChanged(id, true) }
-                    }
-            }
-        }
-
-        return START_NOT_STICKY
-    }
-
-
-    /* BOUND SERVICE PART
-       for communicating with the activities
-    */
-
-    interface RefreshingStatusListener {
-        fun onDavRefreshStatusChanged(id: Long, refreshing: Boolean)
-    }
-
-    private val binder = InfoBinder()
-
-    inner class InfoBinder: Binder() {
-        fun isRefreshing(id: Long) = runningRefresh.contains(id)
-
-        fun addRefreshingStatusListener(listener: RefreshingStatusListener, callImmediate: Boolean) {
-            refreshingStatusListeners += WeakReference<RefreshingStatusListener>(listener)
-            if (callImmediate)
-                runningRefresh.forEach { id -> listener.onDavRefreshStatusChanged(id, true) }
-        }
-
-        fun removeRefreshingStatusListener(listener: RefreshingStatusListener) {
-            val iter = refreshingStatusListeners.iterator()
-            while (iter.hasNext()) {
-                val item = iter.next().get()
-                if (listener == item)
-                    iter.remove()
-            }
-        }
-    }
-
-    override fun onBind(intent: Intent?) = binder
-
-
-
-    /* ACTION RUNNABLES
-       which actually do the work
-     */
-
-    private fun refreshCollections(service: Long) {
-        OpenHelper(this@DavService).use { dbHelper ->
-            val db = dbHelper.writableDatabase
-
-            val serviceType by lazy {
-                db.query(Services._TABLE, arrayOf(Services.SERVICE), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                    if (cursor.moveToNext())
-                        return@lazy cursor.getString(0)
-                } ?: throw IllegalArgumentException("Service not found")
-            }
-
-            val account by lazy {
-                db.query(Services._TABLE, arrayOf(Services.ACCOUNT_NAME), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                    if (cursor.moveToNext())
-                        return@lazy Account(cursor.getString(0), getString(R.string.account_type))
-                }
-                throw IllegalArgumentException("Account not found")
-            }
-
-            val homeSets by lazy {
-                val homeSets = mutableSetOf<HttpUrl>()
-                db.query(HomeSets._TABLE, arrayOf(HomeSets.URL), "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                    while (cursor.moveToNext())
-                        HttpUrl.parse(cursor.getString(0))?.let { homeSets += it }
-                }
-                homeSets
-            }
-
-            val collections by lazy {
-                val collections = mutableMapOf<HttpUrl, CollectionInfo>()
-                db.query(Collections._TABLE, null, "${Collections.SERVICE_ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                    while (cursor.moveToNext()) {
-                        val values = ContentValues()
-                        DatabaseUtils.cursorRowToContentValues(cursor, values)
-                        values.getAsString(Collections.URL)?.let { url ->
-                            HttpUrl.parse(url)?.let { collections.put(it, CollectionInfo(values)) }
-                        }
-                    }
-                }
-                collections
-            }
-
-            fun readPrincipal(): HttpUrl? {
-                db.query(Services._TABLE, arrayOf(Services.PRINCIPAL), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                    if (cursor.moveToNext())
-                        cursor.getString(0)?.let { return HttpUrl.parse(it) }
-                }
-                return null
-            }
-
-            /**
-             * Checks if the given URL defines home sets and adds them to the home set list.
-             * @param dav               DavResource to check
-             */
-            @Throws(IOException::class, HttpException::class, DavException::class)
-            fun queryHomeSets(dav: DavResource) {
-                when (serviceType) {
-                    Services.SERVICE_CARDDAV -> {
-                        dav.propfind(0, AddressbookHomeSet.NAME, GroupMembership.NAME)
-                        for ((resource, addressbookHomeSet) in dav.findProperties(AddressbookHomeSet::class.java))
-                            for (href in addressbookHomeSet.hrefs)
-                                resource.location.resolve(href)?.let { homeSets += UrlUtils.withTrailingSlash(it) }
-                    }
-                    Services.SERVICE_CALDAV -> {
-                        dav.propfind(0, CalendarHomeSet.NAME, CalendarProxyReadFor.NAME, CalendarProxyWriteFor.NAME, GroupMembership.NAME)
-                        for ((resource, calendarHomeSet) in dav.findProperties(CalendarHomeSet::class.java))
-                            for (href in calendarHomeSet.hrefs)
-                                resource.location.resolve(href)?.let { homeSets.add(UrlUtils.withTrailingSlash(it)) }
-                    }
-                }
-            }
-
-            fun saveHomeSets() {
-                db.delete(HomeSets._TABLE, "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()))
-                for (homeSet in homeSets) {
-                    val values = ContentValues(2)
-                    values.put(HomeSets.SERVICE_ID, service)
-                    values.put(HomeSets.URL, homeSet.toString())
-                    db.insertOrThrow(HomeSets._TABLE, null, values)
-                }
-            }
-
-            fun saveCollections() {
-                db.delete(Collections._TABLE, "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()))
-                for ((_,collection) in collections) {
-                    val values = collection.toDB()
-                    Logger.log.log(Level.FINE, "Saving collection", values)
-                    values.put(Collections.SERVICE_ID, service)
-                    db.insertWithOnConflict(Collections._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE)
-                }
-            }
-
-
-            try {
-                Logger.log.info("Refreshing $serviceType collections of service #$service")
-
-                Settings.getInstance(this)?.use { settings ->
-                    // create authenticating OkHttpClient (credentials taken from account settings)
-                    HttpClient.Builder(this, settings, AccountSettings(this, settings, account))
-                            .setForeground(true)
-                            .build().use { client ->
-                        val httpClient = client.okHttpClient
-
-                        // refresh home set list (from principal)
-                        readPrincipal()?.let { principalUrl ->
-                            Logger.log.fine("Querying principal $principalUrl for home sets")
-                            val principal = DavResource(httpClient, principalUrl)
-                            queryHomeSets(principal)
-
-                            // refresh home sets: calendar-proxy-read/write-for
-                            for ((resource, proxyRead) in principal.findProperties(CalendarProxyReadFor::class.java))
-                                for (href in proxyRead.hrefs) {
-                                    Logger.log.fine("Principal is a read-only proxy for $href, checking for home sets")
-                                    resource.location.resolve(href)?.let { queryHomeSets(DavResource(httpClient, it)) }
-                                }
-                            for ((resource, proxyWrite) in principal.findProperties(CalendarProxyWriteFor::class.java))
-                                for (href in proxyWrite.hrefs) {
-                                    Logger.log.fine("Principal is a read/write proxy for $href, checking for home sets")
-                                    resource.location.resolve(href)?.let { queryHomeSets(DavResource(httpClient, it)) }
-                                }
-
-                            // refresh home sets: direct group memberships
-                            principal.properties[GroupMembership::class.java]?.let { groupMembership ->
-                                for (href in groupMembership.hrefs) {
-                                    Logger.log.fine("Principal is member of group $href, checking for home sets")
-                                    principal.location.resolve(href)?.let { url ->
-                                        try {
-                                            queryHomeSets(DavResource(httpClient, url))
-                                        } catch(e: HttpException) {
-                                            Logger.log.log(Level.WARNING, "Couldn't query member group", e)
-                                        } catch(e: DavException) {
-                                            Logger.log.log(Level.WARNING, "Couldn't query member group", e)
-                                        }
-                                    }
-                                }
-                            }
-                        }
-
-                        // remember selected collections
-                        val selectedCollections = HashSet<HttpUrl>()
-                        collections.values
-                                .filter { it.selected }
-                                .forEach { (url,_) -> HttpUrl.parse(url)?.let { selectedCollections.add(it) } }
-
-                        // now refresh collections (taken from home sets)
-                        val itHomeSets = homeSets.iterator()
-                        while (itHomeSets.hasNext()) {
-                            val homeSetUrl = itHomeSets.next()
-                            Logger.log.fine("Listing home set $homeSetUrl")
-
-                            val homeSet = DavResource(httpClient, homeSetUrl)
-                            try {
-                                homeSet.propfind(1, *CollectionInfo.DAV_PROPERTIES)
-                                val itCollections = IteratorChain<DavResource>(homeSet.members.iterator(), homeSet.related.iterator(), SingletonIterator(homeSet))
-                                while (itCollections.hasNext()) {
-                                    val member = itCollections.next()
-                                    val info = CollectionInfo(member)
-                                    info.confirmed = true
-                                    Logger.log.log(Level.FINE, "Found collection", info)
-
-                                    if ((serviceType == Services.SERVICE_CARDDAV && info.type == CollectionInfo.Type.ADDRESS_BOOK) ||
-                                            (serviceType == Services.SERVICE_CALDAV && arrayOf(CollectionInfo.Type.CALENDAR, CollectionInfo.Type.WEBCAL).contains(info.type)))
-                                        collections[member.location] = info
-                                }
-                            } catch(e: HttpException) {
-                                if (e.status in arrayOf(403, 404, 410))
-                                // delete home set only if it was not accessible (40x)
-                                    itHomeSets.remove()
-                            }
-                        }
-
-                        // check/refresh unconfirmed collections
-                        val itCollections = collections.entries.iterator()
-                        while (itCollections.hasNext()) {
-                            val (url, info) = itCollections.next()
-                            if (!info.confirmed)
-                                try {
-                                    val collection = DavResource(httpClient, url)
-                                    collection.propfind(0, *CollectionInfo.DAV_PROPERTIES)
-                                    val info = CollectionInfo(collection)
-                                    info.confirmed = true
-
-                                    // remove unusable collections
-                                    if ((serviceType == Services.SERVICE_CARDDAV && info.type != CollectionInfo.Type.ADDRESS_BOOK) ||
-                                            (serviceType == Services.SERVICE_CALDAV && !arrayOf(CollectionInfo.Type.CALENDAR, CollectionInfo.Type.WEBCAL).contains(info.type)) ||
-                                            (info.type == CollectionInfo.Type.WEBCAL && info.source == null))
-                                        itCollections.remove()
-                                } catch(e: HttpException) {
-                                    if (e.status in arrayOf(403, 404, 410))
-                                    // delete collection only if it was not accessible (40x)
-                                        itCollections.remove()
-                                    else
-                                        throw e
-                                }
-                        }
-
-                        // restore selections
-                        for (url in selectedCollections)
-                            collections[url]?.let { it.selected = true }
-                    }
-
-                }
-
-                db.beginTransactionNonExclusive()
-                try {
-                    saveHomeSets()
-                    saveCollections()
-                    db.setTransactionSuccessful()
-                } finally {
-                    db.endTransaction()
-                }
-
-            } catch(e: InvalidAccountException) {
-                Logger.log.log(Level.SEVERE, "Invalid account", e)
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't refresh collection list", e)
-
-                val debugIntent = Intent(this@DavService, DebugInfoActivity::class.java)
-                debugIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e)
-                debugIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account)
-
-                val nm = NotificationUtils.createChannels(this)
-                val notify = NotificationCompat.Builder(this, NotificationUtils.CHANNEL_SYNC_PROBLEMS)
-                        .setSmallIcon(R.drawable.ic_sync_error_notification)
-                        .setLargeIcon(App.getLauncherBitmap(this))
-                        .setContentTitle(getString(R.string.dav_service_refresh_failed))
-                        .setContentText(getString(R.string.dav_service_refresh_couldnt_refresh))
-                        .setContentIntent(PendingIntent.getActivity(this, 0, debugIntent, PendingIntent.FLAG_UPDATE_CURRENT))
-                        .build()
-                nm.notify(Constants.NOTIFICATION_REFRESH_COLLECTIONS, notify)
-            } finally {
-                runningRefresh.remove(service)
-                refreshingStatusListeners.forEach { it.get()?.onDavRefreshStatusChanged(service, false) }
-            }
-        }
-
-    }
-
-}
@@ -0,0 +1,41 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.support.annotation.NonNull;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+import okhttp3.HttpUrl;
+
+public class DavUtils {
+
+    public static String ARGBtoCalDAVColor(int colorWithAlpha) {
+        byte alpha = (byte)(colorWithAlpha >> 24);
+        int color = colorWithAlpha & 0xFFFFFF;
+        return String.format("#%06X%02X", color, alpha);
+    }
+
+    public static String lastSegmentOfUrl(@NonNull String url) {
+        // the list returned by HttpUrl.pathSegments() is unmodifiable, so we have to create a copy
+        List<String> segments = new LinkedList<>(HttpUrl.parse(url).pathSegments());
+        Collections.reverse(segments);
+
+        for (String segment : segments)
+            if (!StringUtils.isEmpty(segment))
+                return segment;
+
+        return "/";
+    }
+
+}
@@ -1,86 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.annotation.TargetApi
-import android.content.Context
-import android.net.ConnectivityManager
-import android.os.Build
-import at.bitfire.davdroid.log.Logger
-import okhttp3.HttpUrl
-import org.xbill.DNS.*
-import java.util.*
-
-/**
- * Some WebDAV and related network utility methods
- */
-object DavUtils {
-
-    @JvmStatic
-    fun ARGBtoCalDAVColor(colorWithAlpha: Int): String {
-        val alpha = (colorWithAlpha shr 24) and 0xFF
-        val color = colorWithAlpha and 0xFFFFFF
-        return String.format("#%06X%02X", color, alpha)
-    }
-
-    @JvmStatic
-    fun lastSegmentOfUrl(url: String): String {
-        val httpUrl = HttpUrl.parse(url) ?: throw IllegalArgumentException("url not parsable")
-
-        // the list returned by HttpUrl.pathSegments() is unmodifiable, so we have to create a copy
-        val segments = LinkedList<String>(httpUrl.pathSegments())
-        Collections.reverse(segments)
-
-        return segments.firstOrNull { it.isNotEmpty() } ?: "/"
-    }
-
-    fun prepareLookup(context: Context, lookup: Lookup) {
-        @TargetApi(Build.VERSION_CODES.O)
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            /* Since Android 8, the system properties net.dns1, net.dns2, ... are not available anymore.
-               The current version of dnsjava relies on these properties to find the default name servers,
-               so we have to add the servers explicitly (fortunately, there's an Android API to
-               get the active DNS servers). */
-            val connectivity = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
-            val activeLink = connectivity.getLinkProperties(connectivity.activeNetwork)
-            val simpleResolvers = activeLink.dnsServers.map {
-                Logger.log.fine("Using DNS server ${it.hostAddress}")
-                val resolver = SimpleResolver()
-                resolver.setAddress(it)
-                resolver
-            }
-            val resolver = ExtendedResolver(simpleResolvers.toTypedArray())
-            lookup.setResolver(resolver)
-        }
-    }
-
-    fun selectSRVRecord(records: Array<Record>?): SRVRecord? {
-        val srvRecords = records?.filterIsInstance(SRVRecord::class.java)
-        srvRecords?.let {
-            if (it.size > 1)
-                Logger.log.warning("Multiple SRV records not supported yet; using first one")
-            return it.firstOrNull()
-        }
-        return null
-    }
-
-    fun pathsFromTXTRecords(records: Array<Record>?): List<String> {
-        val paths = LinkedList<String>()
-        records?.filterIsInstance(TXTRecord::class.java)?.forEach { txt ->
-            @Suppress("UNCHECKED_CAST")
-            for (segment in txt.strings as List<String>)
-                if (segment.startsWith("path=")) {
-                    paths.add(segment.substring(5))
-                    break
-                }
-        }
-        return paths
-    }
-
-}
@@ -0,0 +1,157 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.accounts.Account;
+import android.content.Context;
+import android.os.Build;
+import android.support.annotation.NonNull;
+
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import at.bitfire.dav4android.BasicDigestAuthenticator;
+import lombok.RequiredArgsConstructor;
+import okhttp3.Credentials;
+import okhttp3.Interceptor;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+import okhttp3.logging.HttpLoggingInterceptor;
+
+public class HttpClient {
+    private static final OkHttpClient client = new OkHttpClient();
+    private static final UserAgentInterceptor userAgentInterceptor = new UserAgentInterceptor();
+
+    private static final String userAgent;
+    static {
+        String date = new SimpleDateFormat("yyyy/MM/dd", Locale.US).format(new Date(BuildConfig.buildTime));
+        userAgent = "DAVdroid/" + BuildConfig.VERSION_NAME + " (" + date + "; dav4android; okhttp3) Android/" + Build.VERSION.RELEASE;
+    }
+
+    private HttpClient() {
+    }
+
+    public static OkHttpClient create(@NonNull Context context, @NonNull Account account, @NonNull final Logger logger) throws InvalidAccountException {
+        OkHttpClient.Builder builder = defaultBuilder(logger);
+
+        // use account settings for authentication and logging
+        AccountSettings settings = new AccountSettings(context, account);
+
+        if (settings.preemptiveAuth())
+            builder.addNetworkInterceptor(new PreemptiveAuthenticationInterceptor(settings.username(), settings.password()));
+        else
+            builder.authenticator(new BasicDigestAuthenticator(null, settings.username(), settings.password()));
+
+        return builder.build();
+    }
+
+    public static OkHttpClient create(@NonNull Logger logger) {
+        return defaultBuilder(logger).build();
+    }
+
+    public static OkHttpClient create(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
+        return create(context, account, App.log);
+    }
+
+    public static OkHttpClient create() {
+        return create(App.log);
+    }
+
+    private static OkHttpClient.Builder defaultBuilder(@NonNull final Logger logger) {
+        OkHttpClient.Builder builder = client.newBuilder();
+
+        // use MemorizingTrustManager to manage self-signed certificates
+        if (App.getSslSocketFactoryCompat() != null)
+            builder.sslSocketFactory(App.getSslSocketFactoryCompat(), App.getMemorizingTrustManager());
+        if (App.getHostnameVerifier() != null)
+            builder.hostnameVerifier(App.getHostnameVerifier());
+
+        // set timeouts
+        builder.connectTimeout(30, TimeUnit.SECONDS);
+        builder.writeTimeout(30, TimeUnit.SECONDS);
+        builder.readTimeout(120, TimeUnit.SECONDS);
+
+        // don't allow redirects, because it would break PROPFIND handling
+        builder.followRedirects(false);
+
+        // add User-Agent to every request
+        builder.addNetworkInterceptor(userAgentInterceptor);
+
+        // add cookie store for non-persistent cookies (some services like Horde use cookies for session tracking)
+        builder.cookieJar(MemoryCookieStore.INSTANCE);
+
+        // add network logging, if requested
+        if (logger.isLoggable(Level.FINEST)) {
+            HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
+                @Override
+                public void log(String message) {
+                    logger.finest(message);
+                }
+            });
+            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
+            builder.addInterceptor(loggingInterceptor);
+        }
+
+        return builder;
+    }
+
+    private static OkHttpClient.Builder addAuthentication(@NonNull OkHttpClient.Builder builder, @NonNull String username, @NonNull String password, boolean preemptive) {
+        if (preemptive)
+            builder.addNetworkInterceptor(new PreemptiveAuthenticationInterceptor(username, password));
+        else
+            builder.authenticator(new BasicDigestAuthenticator(null, username, password));
+        return builder;
+    }
+
+    public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String username, @NonNull String password, boolean preemptive) {
+        OkHttpClient.Builder builder = client.newBuilder();
+        addAuthentication(builder, username, password, preemptive);
+        return builder.build();
+    }
+
+    public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String host, @NonNull String username, @NonNull String password) {
+        return client.newBuilder()
+                .authenticator(new BasicDigestAuthenticator(host, username, password))
+                .build();
+    }
+
+
+    static class UserAgentInterceptor implements Interceptor {
+        @Override
+        public Response intercept(Chain chain) throws IOException {
+            Locale locale = Locale.getDefault();
+            Request request = chain.request().newBuilder()
+                    .header("User-Agent", userAgent)
+                    .header("Accept-Language", locale.getLanguage() + "-" + locale.getCountry() + ", " + locale.getLanguage() + ";q=0.7, *;q=0.5")
+                    .build();
+            return chain.proceed(request);
+        }
+    }
+
+    @RequiredArgsConstructor
+    static class PreemptiveAuthenticationInterceptor implements Interceptor {
+        final String username, password;
+
+        @Override
+        public Response intercept(Chain chain) throws IOException {
+            App.log.fine("Adding basic authorization header for user " + username);
+            Request request = chain.request().newBuilder()
+                    .header("Authorization", Credentials.basic(username, password))
+                    .build();
+            return chain.proceed(request);
+        }
+    }
+
+}
@@ -1,235 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.content.Context
-import android.os.Build
-import android.security.KeyChain
-import at.bitfire.cert4android.CustomCertManager
-import at.bitfire.dav4android.BasicDigestAuthHandler
-import at.bitfire.dav4android.UrlUtils
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.Credentials
-import at.bitfire.davdroid.settings.ISettings
-import okhttp3.Cache
-import okhttp3.Interceptor
-import okhttp3.OkHttpClient
-import okhttp3.Response
-import okhttp3.internal.tls.OkHostnameVerifier
-import okhttp3.logging.HttpLoggingInterceptor
-import java.io.Closeable
-import java.io.File
-import java.net.InetSocketAddress
-import java.net.Proxy
-import java.net.Socket
-import java.security.KeyStore
-import java.security.Principal
-import java.text.DateFormat
-import java.util.*
-import java.util.concurrent.TimeUnit
-import java.util.logging.Level
-import javax.net.ssl.KeyManager
-import javax.net.ssl.TrustManagerFactory
-import javax.net.ssl.X509ExtendedKeyManager
-import javax.net.ssl.X509TrustManager
-
-class HttpClient private constructor(
-        val okHttpClient: OkHttpClient,
-        private val certManager: CustomCertManager?
-): Closeable {
-
-    companion object {
-        /** [OkHttpClient] singleton to build all clients from */
-        val sharedClient = OkHttpClient.Builder()
-                // set timeouts
-                .connectTimeout(30, TimeUnit.SECONDS)
-                .writeTimeout(30, TimeUnit.SECONDS)
-                .readTimeout(120, TimeUnit.SECONDS)
-
-                // don't allow redirects by default, because it would break PROPFIND handling
-                .followRedirects(false)
-
-                // add User-Agent to every request
-                .addNetworkInterceptor(UserAgentInterceptor)
-
-                .build()!!
-    }
-
-    override fun close() {
-        certManager?.close()
-    }
-
-    class Builder @JvmOverloads constructor(
-            val context: Context? = null,
-            val settings: ISettings? = null,
-            accountSettings: AccountSettings? = null,
-            val logger: java.util.logging.Logger = Logger.log
-    ) {
-        private var certManager: CustomCertManager? = null
-        private var certificateAlias: String? = null
-
-        private val orig = sharedClient.newBuilder()
-
-        init {
-            // add cookie store for non-persistent cookies (some services like Horde use cookies for session tracking)
-            orig.cookieJar(MemoryCookieStore())
-
-            // add network logging, if requested
-            if (logger.isLoggable(Level.FINEST)) {
-                val loggingInterceptor = HttpLoggingInterceptor(HttpLoggingInterceptor.Logger {
-                    message -> logger.finest(message)
-                })
-                loggingInterceptor.level = HttpLoggingInterceptor.Level.BODY
-                orig.addInterceptor(loggingInterceptor)
-            }
-
-            settings?.let {
-                // custom proxy support
-                try {
-                    if (settings.getBoolean(App.OVERRIDE_PROXY, false)) {
-                        val address = InetSocketAddress(
-                                settings.getString(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT),
-                                settings.getInt(App.OVERRIDE_PROXY_PORT, App.OVERRIDE_PROXY_PORT_DEFAULT)
-                        )
-
-                        val proxy = Proxy(Proxy.Type.HTTP, address)
-                        orig.proxy(proxy)
-                        Logger.log.log(Level.INFO, "Using proxy", proxy)
-                    }
-                } catch(e: Exception) {
-                    Logger.log.log(Level.SEVERE, "Can't set proxy, ignoring", e)
-                }
-
-                context?.let {
-                    if (BuildConfig.customCerts)
-                        customCertManager(CustomCertManager(context, BuildConfig.customCertsUI, !settings.getBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, false)))
-
-                    // use account settings for authentication
-                    accountSettings?.let {
-                        addAuthentication(null, it.credentials())
-                    }
-                }
-            }
-        }
-
-        constructor(context: Context, host: String?, credentials: Credentials): this(context) {
-            addAuthentication(host, credentials)
-        }
-
-        fun withDiskCache(): Builder {
-            val context = context ?: throw IllegalArgumentException("Context is required to find the cache directory")
-            for (dir in arrayOf(context.externalCacheDir, context.cacheDir)) {
-                if (dir.exists() && dir.canWrite()) {
-                    val cacheDir = File(dir, "HttpClient")
-                    cacheDir.mkdir()
-                    Logger.log.fine("Using disk cache: $cacheDir")
-                    orig.cache(Cache(cacheDir, 10*1024*1024))
-                    break
-                }
-            }
-            return this
-        }
-
-        fun followRedirects(follow: Boolean): Builder {
-            orig.followRedirects(follow)
-            return this
-        }
-
-        fun customCertManager(manager: CustomCertManager) {
-            certManager = manager
-        }
-        fun setForeground(foreground: Boolean): Builder {
-            certManager?.appInForeground = foreground
-            return this
-        }
-
-        fun addAuthentication(host: String?, credentials: Credentials): Builder {
-            when (credentials.type) {
-                Credentials.Type.UsernamePassword -> {
-                    val authHandler = BasicDigestAuthHandler(UrlUtils.hostToDomain(host), credentials.userName!!, credentials.password!!)
-                    orig    .addNetworkInterceptor(authHandler)
-                            .authenticator(authHandler)
-                }
-                Credentials.Type.ClientCertificate -> {
-                    certificateAlias = credentials.certificateAlias
-                }
-            }
-            return this
-        }
-
-        fun build(): HttpClient {
-            val trustManager = certManager ?: {
-                val factory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm())
-                factory.init(null as KeyStore?)
-                factory.trustManagers.first() as X509TrustManager
-            }()
-
-            val hostnameVerifier = certManager?.hostnameVerifier(OkHostnameVerifier.INSTANCE)
-                    ?: OkHostnameVerifier.INSTANCE
-
-            var keyManager: KeyManager? = null
-            try {
-                certificateAlias?.let { alias ->
-                    // get client certificate and private key
-                    val certs = KeyChain.getCertificateChain(context, alias) ?: return@let
-                    val key = KeyChain.getPrivateKey(context, alias) ?: return@let
-                    logger.fine("Using client certificate $alias for authentication (chain length: ${certs.size})")
-
-                    // create Android KeyStore (performs key operations without revealing secret data to DAVdroid)
-                    val keyStore = KeyStore.getInstance("AndroidKeyStore")
-                    keyStore.load(null)
-
-                    // create KeyManager
-                    keyManager = object: X509ExtendedKeyManager() {
-                        override fun getServerAliases(p0: String?, p1: Array<out Principal>?): Array<String>? = null
-                        override fun chooseServerAlias(p0: String?, p1: Array<out Principal>?, p2: Socket?) = null
-
-                        override fun getClientAliases(p0: String?, p1: Array<out Principal>?) =
-                                arrayOf(alias)
-
-                        override fun chooseClientAlias(p0: Array<out String>?, p1: Array<out Principal>?, p2: Socket?) =
-                                alias
-
-                        override fun getCertificateChain(forAlias: String?) =
-                                certs.takeIf { forAlias == alias }
-
-                        override fun getPrivateKey(forAlias: String?) =
-                                key.takeIf { forAlias == alias }
-                    }
-                }
-            } catch (e: Exception) {
-                logger.log(Level.SEVERE, "Couldn't set up client certificate authentication", e)
-            }
-
-            orig.sslSocketFactory(CustomTlsSocketFactory(keyManager, trustManager), trustManager)
-            orig.hostnameVerifier(hostnameVerifier)
-
-            return HttpClient(orig.build(), certManager)
-        }
-
-    }
-
-
-    private object UserAgentInterceptor: Interceptor {
-
-        private val userAgentDate = DateFormat.getDateInstance(DateFormat.SHORT, Locale.US).format(Date(BuildConfig.buildTime))
-        private val userAgent = "DAVdroid/${BuildConfig.VERSION_NAME} ($userAgentDate; dav4android; okhttp3) Android/${Build.VERSION.RELEASE}"
-
-        override fun intercept(chain: Interceptor.Chain): Response {
-            val locale = Locale.getDefault()
-            val request = chain.request().newBuilder()
-                    .header("User-Agent", userAgent)
-                    .header("Accept-Language", "${locale.language}-${locale.country}, ${locale.language};q=0.7, *;q=0.5")
-                    .build()
-            return chain.proceed(request)
-        }
-
-    }
-
-}
@@ -0,0 +1,19 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.accounts.Account;
+
+public class InvalidAccountException extends Exception {
+
+    public InvalidAccountException(Account account) {
+        super("Invalid account: " + account);
+    }
+
+}
@@ -1,13 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.accounts.Account
-
-class InvalidAccountException(account: Account): Exception("Invalid account: $account")
@@ -0,0 +1,46 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import okhttp3.Cookie;
+import okhttp3.CookieJar;
+import okhttp3.HttpUrl;
+
+/**
+ * Primitive cookie store that stores cookies in a (volatile) hash map.
+ * Will be sufficient for session cookies.
+ */
+public class MemoryCookieStore implements CookieJar {
+
+    public static final MemoryCookieStore INSTANCE = new MemoryCookieStore();
+
+    protected final Map<HttpUrl, List<Cookie>> store = new ConcurrentHashMap<>();
+
+
+    @Override
+    public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
+        store.put(url, cookies);
+    }
+
+    @Override
+    public List<Cookie> loadForRequest(HttpUrl url) {
+        List<Cookie> cookies = store.get(url);
+
+        if (cookies == null)
+            cookies = Collections.emptyList();
+
+        return cookies;
+    }
+
+}
@@ -1,63 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import okhttp3.Cookie
-import okhttp3.CookieJar
-import okhttp3.HttpUrl
-import org.apache.commons.collections4.keyvalue.MultiKey
-import org.apache.commons.collections4.map.HashedMap
-import org.apache.commons.collections4.map.MultiKeyMap
-import java.util.*
-
-/**
- * Primitive cookie store that stores cookies in a (volatile) hash map.
- * Will be sufficient for session cookies.
- */
-class MemoryCookieStore: CookieJar {
-
-    /**
-     * Stored cookies. The multi-key consists of three parts: name, domain, and path.
-     * This ensures that cookies can be overwritten. [RFC 6265 5.3 Storage Model]
-     * Not thread-safe!
-     */
-    val storage = MultiKeyMap.multiKeyMap(HashedMap<MultiKey<out String>, Cookie>())!!
-
-    override fun saveFromResponse(url: HttpUrl, cookies: List<Cookie>) {
-        synchronized(storage) {
-            for (cookie in cookies)
-                storage.put(cookie.name(), cookie.domain(), cookie.path(), cookie)
-        }
-    }
-
-    override fun loadForRequest(url: HttpUrl): List<Cookie> {
-        val cookies = LinkedList<Cookie>()
-
-        synchronized(storage) {
-            val iter = storage.mapIterator()
-            while (iter.hasNext()) {
-                iter.next()
-                val cookie = iter.value
-
-                // remove expired cookies
-                if (cookie.expiresAt() <= System.currentTimeMillis()) {
-                    iter.remove()
-                    continue
-                }
-
-                // add applicable cookies
-                if (cookie.matches(url))
-                    cookies += cookie
-            }
-        }
-
-        return cookies
-    }
-
-}
@@ -1,65 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid
-
-import android.accounts.Account
-import android.annotation.SuppressLint
-import android.content.BroadcastReceiver
-import android.content.ContentResolver
-import android.content.Context
-import android.content.Intent
-import android.os.Bundle
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.Services
-import at.bitfire.davdroid.resource.LocalTaskList
-import at.bitfire.ical4android.TaskProvider
-
-class PackageChangedReceiver: BroadcastReceiver() {
-
-    @SuppressLint("MissingPermission")
-    override fun onReceive(context: Context, intent: Intent) {
-        if (intent.action == Intent.ACTION_PACKAGE_ADDED || intent.action == Intent.ACTION_PACKAGE_FULLY_REMOVED)
-            updateTaskSync(context)
-    }
-
-
-    companion object {
-
-        @JvmStatic
-        fun updateTaskSync(context: Context) {
-            val tasksInstalled = LocalTaskList.tasksProviderAvailable(context)
-            Logger.log.info("Package (un)installed; OpenTasks provider now available = $tasksInstalled")
-
-            // check all accounts and (de)activate OpenTasks if a CalDAV service is defined
-            ServiceDB.OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.readableDatabase
-
-                db.query(Services._TABLE, arrayOf(Services.ACCOUNT_NAME),
-                        "${Services.SERVICE}=?", arrayOf(Services.SERVICE_CALDAV), null, null, null)?.use { cursor ->
-                    while (cursor.moveToNext()) {
-                        val account = Account(cursor.getString(0), context.getString(R.string.account_type))
-
-                        if (tasksInstalled) {
-                            if (ContentResolver.getIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority) <= 0) {
-                                ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1)
-                                ContentResolver.setSyncAutomatically(account, TaskProvider.ProviderName.OpenTasks.authority, true)
-                                ContentResolver.addPeriodicSync(account, TaskProvider.ProviderName.OpenTasks.authority, Bundle(), Constants.DEFAULT_SYNC_INTERVAL)
-                            }
-                        } else
-                            ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0)
-
-                    }
-                }
-            }
-        }
-
-    }
-
-}
@@ -0,0 +1,172 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.os.Build;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.security.GeneralSecurityException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Locale;
+
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocket;
+import javax.net.ssl.SSLSocketFactory;
+import javax.net.ssl.X509TrustManager;
+
+import de.duenndns.ssl.MemorizingTrustManager;
+import lombok.Cleanup;
+
+public class SSLSocketFactoryCompat extends SSLSocketFactory {
+
+    private SSLSocketFactory delegate;
+
+    // Android 5.0+ (API level21) provides reasonable default settings
+    // but it still allows SSLv3
+    // https://developer.android.com/reference/javax/net/ssl/SSLSocket.html
+    static String protocols[] = null, cipherSuites[] = null;
+    static {
+        try {
+            @Cleanup SSLSocket socket = (SSLSocket)SSLSocketFactory.getDefault().createSocket();
+            if (socket != null) {
+                /* set reasonable protocol versions */
+                // - enable all supported protocols (enables TLSv1.1 and TLSv1.2 on Android <5.0)
+                // - remove all SSL versions (especially SSLv3) because they're insecure now
+                List<String> protocols = new LinkedList<>();
+                for (String protocol : socket.getSupportedProtocols())
+                    if (!protocol.toUpperCase(Locale.US).contains("SSL"))
+                        protocols.add(protocol);
+                App.log.info("Setting allowed TLS protocols: " + TextUtils.join(", ", protocols));
+                SSLSocketFactoryCompat.protocols = protocols.toArray(new String[protocols.size()]);
+
+                /* set up reasonable cipher suites */
+                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+                    // choose known secure cipher suites
+                    List<String> allowedCiphers = Arrays.asList(
+                            // TLS 1.2
+                            "TLS_RSA_WITH_AES_256_GCM_SHA384",
+                            "TLS_RSA_WITH_AES_128_GCM_SHA256",
+                            "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
+                            "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+                            "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+                            "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
+                            "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+                            // maximum interoperability
+                            "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
+                            "TLS_RSA_WITH_AES_128_CBC_SHA",
+                            // additionally
+                            "TLS_RSA_WITH_AES_256_CBC_SHA",
+                            "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA",
+                            "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+                            "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
+                            "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA");
+                    List<String> availableCiphers = Arrays.asList(socket.getSupportedCipherSuites());
+                    App.log.info("Available cipher suites: " + TextUtils.join(", ", availableCiphers));
+                    App.log.info("Cipher suites enabled by default: " + TextUtils.join(", ", socket.getEnabledCipherSuites()));
+
+                    // take all allowed ciphers that are available and put them into preferredCiphers
+                    HashSet<String> preferredCiphers = new HashSet<>(allowedCiphers);
+                    preferredCiphers.retainAll(availableCiphers);
+
+                    /* For maximum security, preferredCiphers should *replace* enabled ciphers (thus disabling
+                     * ciphers which are enabled by default, but have become unsecure), but I guess for
+                     * the security level of DAVdroid and maximum compatibility, disabling of insecure
+                     * ciphers should be a server-side task */
+
+                    // add preferred ciphers to enabled ciphers
+                    HashSet<String> enabledCiphers = preferredCiphers;
+                    enabledCiphers.addAll(new HashSet<>(Arrays.asList(socket.getEnabledCipherSuites())));
+
+                    App.log.info("Enabling (only) those TLS ciphers: " + TextUtils.join(", ", enabledCiphers));
+                    SSLSocketFactoryCompat.cipherSuites = enabledCiphers.toArray(new String[enabledCiphers.size()]);
+                }
+            }
+        } catch (IOException e) {
+            App.log.severe("Couldn't determine default TLS settings");
+        }
+    }
+
+    public SSLSocketFactoryCompat(@NonNull MemorizingTrustManager mtm) {
+        try {
+            SSLContext sslContext = SSLContext.getInstance("TLS");
+            sslContext.init(null, new X509TrustManager[] { mtm }, null);
+            delegate = sslContext.getSocketFactory();
+        } catch (GeneralSecurityException e) {
+            throw new AssertionError(); // The system has no TLS. Just give up.
+        }
+    }
+
+    private void upgradeTLS(SSLSocket ssl) {
+        if (protocols != null)
+            ssl.setEnabledProtocols(protocols);
+
+        if (cipherSuites != null)
+            ssl.setEnabledCipherSuites(cipherSuites);
+    }
+
+
+    @Override
+    public String[] getDefaultCipherSuites() {
+        return cipherSuites;
+    }
+
+    @Override
+    public String[] getSupportedCipherSuites() {
+        return cipherSuites;
+    }
+
+    @Override
+    public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
+        Socket ssl = delegate.createSocket(s, host, port, autoClose);
+        if (ssl instanceof SSLSocket)
+            upgradeTLS((SSLSocket)ssl);
+        return ssl;
+    }
+
+    @Override
+    public Socket createSocket(String host, int port) throws IOException {
+        Socket ssl = delegate.createSocket(host, port);
+        if (ssl instanceof SSLSocket)
+            upgradeTLS((SSLSocket)ssl);
+        return ssl;
+    }
+
+    @Override
+    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException {
+        Socket ssl = delegate.createSocket(host, port, localHost, localPort);
+        if (ssl instanceof SSLSocket)
+            upgradeTLS((SSLSocket)ssl);
+        return ssl;
+    }
+
+    @Override
+    public Socket createSocket(InetAddress host, int port) throws IOException {
+        Socket ssl = delegate.createSocket(host, port);
+        if (ssl instanceof SSLSocket)
+            upgradeTLS((SSLSocket)ssl);
+        return ssl;
+    }
+
+    @Override
+    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
+        Socket ssl = delegate.createSocket(address, port, localAddress, localPort);
+        if (ssl instanceof SSLSocket)
+            upgradeTLS((SSLSocket)ssl);
+        return ssl;
+    }
+
+}
@@ -0,0 +1,59 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log;
+
+import android.util.Log;
+
+import org.apache.commons.lang3.math.NumberUtils;
+
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.LogRecord;
+
+public class LogcatHandler extends Handler {
+    private static final int MAX_LINE_LENGTH = 3000;
+    public static final LogcatHandler INSTANCE = new LogcatHandler();
+
+    private LogcatHandler() {
+        super();
+        setFormatter(PlainTextFormatter.LOGCAT);
+        setLevel(Level.ALL);
+    }
+
+    @Override
+    public void publish(LogRecord r) {
+        String text = getFormatter().format(r);
+        int level = r.getLevel().intValue();
+
+        int end = text.length();
+        for (int pos = 0; pos < end; pos += MAX_LINE_LENGTH) {
+            String line = text.substring(pos, NumberUtils.min(pos + MAX_LINE_LENGTH, end));
+
+            if (level >= Level.SEVERE.intValue())
+                Log.e(r.getLoggerName(), line);
+            else if (level >= Level.WARNING.intValue())
+                Log.w(r.getLoggerName(), line);
+            else if (level >= Level.CONFIG.intValue())
+                Log.i(r.getLoggerName(), line);
+            else if (level >= Level.FINER.intValue())
+                Log.d(r.getLoggerName(), line);
+            else
+                Log.v(r.getLoggerName(), line);
+        }
+    }
+
+    @Override
+    public void flush() {
+    }
+
+    @Override
+    public void close() {
+    }
+
+}
@@ -1,50 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log
-
-import android.util.Log
-
-import org.apache.commons.lang3.math.NumberUtils
-
-import java.util.logging.Handler
-import java.util.logging.Level
-import java.util.logging.LogRecord
-
-object LogcatHandler: Handler() {
-
-    private val MAX_LINE_LENGTH = 3000
-
-    init {
-        formatter = PlainTextFormatter.LOGCAT
-        level = Level.ALL
-    }
-
-    override fun publish(r: LogRecord) {
-        val text = formatter.format(r)
-        val level = r.level.intValue()
-
-        val end = text.length
-        var pos = 0
-        while (pos < end) {
-            val line = text.substring(pos, NumberUtils.min(pos + MAX_LINE_LENGTH, end))
-            when {
-                level >= Level.SEVERE.intValue()  -> Log.e(r.loggerName, line)
-                level >= Level.WARNING.intValue() -> Log.w(r.loggerName, line)
-                level >= Level.CONFIG.intValue()  -> Log.i(r.loggerName, line)
-                level >= Level.FINER.intValue()   -> Log.d(r.loggerName, line)
-                else                              -> Log.v(r.loggerName, line)
-            }
-            pos += MAX_LINE_LENGTH
-        }
-    }
-
-    override fun flush() {}
-    override fun close() {}
-
-}
@@ -1,109 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log
-
-import android.app.PendingIntent
-import android.content.Context
-import android.content.Intent
-import android.content.SharedPreferences
-import android.os.Process
-import android.preference.PreferenceManager
-import android.support.v4.app.NotificationCompat
-import android.util.Log
-import at.bitfire.davdroid.App
-import at.bitfire.davdroid.Constants
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.ui.AppSettingsActivity
-import at.bitfire.davdroid.ui.NotificationUtils
-import org.apache.commons.lang3.time.DateFormatUtils
-import java.io.File
-import java.io.IOException
-import java.util.logging.FileHandler
-import java.util.logging.Level
-
-object Logger {
-
-    val LOG_TO_EXTERNAL_STORAGE = "log_to_external_storage"
-
-    @JvmField
-    val log = java.util.logging.Logger.getLogger("davdroid")!!
-
-
-    lateinit private var preferences: SharedPreferences
-
-    fun initialize(context: Context) {
-        preferences = PreferenceManager.getDefaultSharedPreferences(context)
-        preferences.registerOnSharedPreferenceChangeListener { _, s ->
-            if (s == LOG_TO_EXTERNAL_STORAGE)
-                reinitialize(context.applicationContext)
-        }
-
-        reinitialize(context.applicationContext)
-    }
-
-    private fun reinitialize(context: Context) {
-        val logToFile = preferences.getBoolean(LOG_TO_EXTERNAL_STORAGE, false)
-        val logVerbose = logToFile || Log.isLoggable(log.name, Log.DEBUG)
-
-        log.info("Verbose logging: $logVerbose; to file: $logToFile")
-
-        // set logging level according to preferences
-        val rootLogger = java.util.logging.Logger.getLogger("")
-        rootLogger.level = if (logVerbose) Level.ALL else Level.INFO
-
-        // remove all handlers and add our own logcat handler
-        rootLogger.useParentHandlers = false
-        rootLogger.handlers.forEach { rootLogger.removeHandler(it) }
-        rootLogger.addHandler(LogcatHandler)
-
-        val nm = NotificationUtils.createChannels(context)
-        // log to external file according to preferences
-        if (logToFile) {
-            val builder = NotificationCompat.Builder(context, NotificationUtils.CHANNEL_DEBUG)
-            builder .setSmallIcon(R.drawable.ic_sd_storage_notification)
-                    .setLargeIcon(App.getLauncherBitmap(context))
-                    .setContentTitle(context.getString(R.string.logging_davdroid_file_logging))
-                    .setLocalOnly(true)
-
-            val dir = context.getExternalFilesDir(null)
-            if (dir != null)
-                try {
-                    val fileName = File(dir, "davdroid-${Process.myPid()}-${DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMdd-HHmmss")}.txt").toString()
-                    log.info("Logging to $fileName")
-
-                    val fileHandler = FileHandler(fileName)
-                    fileHandler.formatter = PlainTextFormatter.DEFAULT
-                    rootLogger.addHandler(fileHandler)
-
-                    val prefIntent = Intent(context, AppSettingsActivity::class.java)
-                    prefIntent.putExtra(AppSettingsActivity.EXTRA_SCROLL_TO, LOG_TO_EXTERNAL_STORAGE)
-
-                    builder .setContentText(dir.path)
-                            .setCategory(NotificationCompat.CATEGORY_STATUS)
-                            .setPriority(NotificationCompat.PRIORITY_HIGH)
-                            .setContentIntent(PendingIntent.getActivity(context, 0, prefIntent, PendingIntent.FLAG_UPDATE_CURRENT))
-                            .setStyle(NotificationCompat.BigTextStyle()
-                                    .bigText(context.getString(R.string.logging_to_external_storage, dir.path)))
-                            .setOngoing(true)
-
-                } catch(e: IOException) {
-                    log.log(Level.SEVERE, "Couldn't create external log file", e)
-
-                    builder .setContentText(context.getString(R.string.logging_couldnt_create_file, e.localizedMessage))
-                            .setCategory(NotificationCompat.CATEGORY_ERROR)
-                }
-            else
-                builder.setContentText(context.getString(R.string.logging_no_external_storage))
-
-            nm.notify(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING, builder.build())
-        } else
-            nm.cancel(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING)
-    }
-
-}
@@ -0,0 +1,63 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log;
+
+import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.exception.ExceptionUtils;
+import org.apache.commons.lang3.time.DateFormatUtils;
+
+import java.util.logging.Formatter;
+import java.util.logging.LogRecord;
+
+public class PlainTextFormatter extends Formatter {
+    public final static PlainTextFormatter
+            LOGCAT = new PlainTextFormatter(true),
+            DEFAULT = new PlainTextFormatter(false);
+
+    private final boolean logcat;
+
+    private PlainTextFormatter(boolean onLogcat) {
+        this.logcat = onLogcat;
+    }
+
+    @Override
+    @SuppressWarnings("ThrowableResultOfMethodCallIgnored")
+    public String format(LogRecord r) {
+        StringBuilder builder = new StringBuilder();
+
+        if (!logcat)
+            builder .append(DateFormatUtils.format(r.getMillis(), "yyyy-MM-dd HH:mm:ss"))
+                    .append(" ").append(r.getThreadID()).append(" ");
+
+        builder.append(String.format("[%s] %s", shortClassName(r.getSourceClassName()), r.getMessage()));
+
+        if (r.getThrown() != null)
+            builder .append("\nEXCEPTION ")
+                    .append(ExceptionUtils.getStackTrace(r.getThrown()));
+
+        if (r.getParameters() != null) {
+            int idx = 1;
+            for (Object param : r.getParameters())
+                builder.append("\n\tPARAMETER #").append(idx++).append(" = ").append(param);
+        }
+
+        if (!logcat)
+            builder.append("\n");
+
+        return builder.toString();
+    }
+
+    private String shortClassName(String className) {
+        String s = StringUtils.replace(className, "at.bitfire.davdroid.", "");
+        return StringUtils.replace(s, "at.bitfire.", "");
+    }
+
+}
@@ -1,61 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log
-
-import org.apache.commons.lang3.StringUtils
-import org.apache.commons.lang3.exception.ExceptionUtils
-import org.apache.commons.lang3.time.DateFormatUtils
-import java.util.logging.Formatter
-import java.util.logging.LogRecord
-
-class PlainTextFormatter private constructor(
-        private val logcat: Boolean
-): Formatter() {
-
-    companion object {
-        @JvmField val LOGCAT = PlainTextFormatter(true)
-        @JvmField val DEFAULT = PlainTextFormatter(false)
-
-        val MAX_MESSAGE_LENGTH = 20000
-    }
-
-    override fun format(r: LogRecord): String {
-        val builder = StringBuilder()
-
-        if (!logcat)
-            builder .append(DateFormatUtils.format(r.millis, "yyyy-MM-dd HH:mm:ss"))
-                    .append(" ").append(r.threadID).append(" ")
-
-        val className = shortClassName(r.sourceClassName)
-        if (className != r.loggerName)
-            builder.append("[").append(className).append("] ")
-
-        builder.append(StringUtils.abbreviate(r.message, MAX_MESSAGE_LENGTH))
-
-        r.thrown?.let {
-            builder .append("\nEXCEPTION ")
-                    .append(ExceptionUtils.getStackTrace(it))
-        }
-
-        r.parameters?.let {
-            for ((idx, param) in it.withIndex())
-                builder.append("\n\tPARAMETER #").append(idx).append(" = ").append(param)
-        }
-
-        if (!logcat)
-            builder.append("\n")
-
-        return builder.toString()
-    }
-
-    private fun shortClassName(className: String) = className
-            .replace(Regex("^at\\.bitfire\\.(dav|cert4an|dav4an|ical4an|vcard4an)droid\\."), "")
-            .replace(Regex("\\$.*$"), "")
-
-}
@@ -0,0 +1,40 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log;
+
+import java.util.logging.Handler;
+import java.util.logging.LogRecord;
+
+public class StringHandler extends Handler {
+
+    StringBuilder builder = new StringBuilder();
+
+    public StringHandler() {
+        super();
+        setFormatter(PlainTextFormatter.DEFAULT);
+    }
+
+    @Override
+    public void publish(LogRecord record) {
+        builder.append(getFormatter().format(record));
+    }
+
+    @Override
+    public void flush() {
+    }
+
+    @Override
+    public void close() {
+    }
+
+    @Override
+    public String toString() {
+        return builder.toString();
+    }
+}
@@ -1,31 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log
-
-import java.util.logging.Handler
-import java.util.logging.LogRecord
-
-class StringHandler: Handler() {
-
-    val builder = StringBuilder()
-
-    init {
-        formatter = PlainTextFormatter.DEFAULT
-    }
-
-    override fun publish(record: LogRecord) {
-        builder.append(formatter.format(record))
-    }
-
-    override fun flush() {}
-    override fun close() {}
-
-    override fun toString() = builder.toString()
-
-}
@@ -0,0 +1,163 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model;
+
+import android.content.ContentValues;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.Serializable;
+
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.Property;
+import at.bitfire.dav4android.property.AddressbookDescription;
+import at.bitfire.dav4android.property.CalendarColor;
+import at.bitfire.dav4android.property.CalendarDescription;
+import at.bitfire.dav4android.property.CalendarTimezone;
+import at.bitfire.dav4android.property.CurrentUserPrivilegeSet;
+import at.bitfire.dav4android.property.DisplayName;
+import at.bitfire.dav4android.property.ResourceType;
+import at.bitfire.dav4android.property.SupportedAddressData;
+import at.bitfire.dav4android.property.SupportedCalendarComponentSet;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import lombok.ToString;
+
+@ToString
+public class CollectionInfo implements Serializable {
+    public long id;
+    public Long serviceID;
+
+    public enum Type {
+        ADDRESS_BOOK,
+        CALENDAR
+    }
+    public Type type;
+
+    public String url;
+
+    public boolean readOnly;
+    public String displayName, description;
+    public Integer color;
+
+    public String timeZone;
+    public Boolean supportsVEVENT;
+    public Boolean supportsVTODO;
+
+    public boolean selected;
+
+    // non-persistent properties
+    public boolean confirmed;
+
+
+    public static final Property.Name[] DAV_PROPERTIES = {
+            ResourceType.NAME,
+            CurrentUserPrivilegeSet.NAME,
+            DisplayName.NAME,
+            AddressbookDescription.NAME, SupportedAddressData.NAME,
+            CalendarDescription.NAME, CalendarColor.NAME, SupportedCalendarComponentSet.NAME
+    };
+
+    public static CollectionInfo fromDavResource(DavResource dav) {
+        CollectionInfo info = new CollectionInfo();
+        info.url = dav.location.toString();
+
+        ResourceType type = (ResourceType)dav.properties.get(ResourceType.NAME);
+        if (type != null) {
+            if (type.types.contains(ResourceType.ADDRESSBOOK))
+                info.type = Type.ADDRESS_BOOK;
+            else if (type.types.contains(ResourceType.CALENDAR))
+                info.type = Type.CALENDAR;
+        }
+
+        info.readOnly = false;
+        CurrentUserPrivilegeSet privilegeSet = (CurrentUserPrivilegeSet)dav.properties.get(CurrentUserPrivilegeSet.NAME);
+        if (privilegeSet != null)
+            info.readOnly = !privilegeSet.mayWriteContent;
+
+        DisplayName displayName = (DisplayName)dav.properties.get(DisplayName.NAME);
+        if (displayName != null && !StringUtils.isEmpty(displayName.displayName))
+            info.displayName = displayName.displayName;
+
+        if (info.type == Type.ADDRESS_BOOK) {
+            AddressbookDescription addressbookDescription = (AddressbookDescription)dav.properties.get(AddressbookDescription.NAME);
+            if (addressbookDescription != null)
+                info.description = addressbookDescription.description;
+
+        } else if (info.type == Type.CALENDAR) {
+            CalendarDescription calendarDescription = (CalendarDescription)dav.properties.get(CalendarDescription.NAME);
+            if (calendarDescription != null)
+                info.description = calendarDescription.description;
+
+            CalendarColor calendarColor = (CalendarColor)dav.properties.get(CalendarColor.NAME);
+            if (calendarColor != null)
+                info.color = calendarColor.color;
+
+            CalendarTimezone timeZone = (CalendarTimezone)dav.properties.get(CalendarTimezone.NAME);
+            if (timeZone != null)
+                info.timeZone = timeZone.vTimeZone;
+
+            info.supportsVEVENT = info.supportsVTODO = true;
+            SupportedCalendarComponentSet supportedCalendarComponentSet = (SupportedCalendarComponentSet)dav.properties.get(SupportedCalendarComponentSet.NAME);
+            if (supportedCalendarComponentSet != null) {
+                info.supportsVEVENT = supportedCalendarComponentSet.supportsEvents;
+                info.supportsVTODO = supportedCalendarComponentSet.supportsTasks;
+            }
+        }
+
+        return info;
+    }
+
+
+    public static CollectionInfo fromDB(ContentValues values) {
+        CollectionInfo info = new CollectionInfo();
+        info.id = values.getAsLong(Collections.ID);
+        info.serviceID = values.getAsLong(Collections.SERVICE_ID);
+
+        info.url = values.getAsString(Collections.URL);
+        info.readOnly = values.getAsInteger(Collections.READ_ONLY) != 0;
+        info.displayName = values.getAsString(Collections.DISPLAY_NAME);
+        info.description = values.getAsString(Collections.DESCRIPTION);
+
+        info.color = values.getAsInteger(Collections.COLOR);
+
+        info.timeZone = values.getAsString(Collections.TIME_ZONE);
+        info.supportsVEVENT = getAsBooleanOrNull(values, Collections.SUPPORTS_VEVENT);
+        info.supportsVTODO = getAsBooleanOrNull(values, Collections.SUPPORTS_VTODO);
+
+        info.selected = values.getAsInteger(Collections.SYNC) != 0;
+        return info;
+    }
+
+    public ContentValues toDB() {
+        ContentValues values = new ContentValues();
+        // Collections.SERVICE_ID is never changed
+
+        values.put(Collections.URL, url);
+        values.put(Collections.READ_ONLY, readOnly ? 1 : 0);
+        values.put(Collections.DISPLAY_NAME, displayName);
+        values.put(Collections.DESCRIPTION, description);
+        values.put(Collections.COLOR, color);
+
+        values.put(Collections.TIME_ZONE, timeZone);
+        if (supportsVEVENT != null)
+            values.put(Collections.SUPPORTS_VEVENT, supportsVEVENT ? 1 : 0);
+        if (supportsVTODO != null)
+            values.put(Collections.SUPPORTS_VTODO, supportsVTODO ? 1 : 0);
+
+        values.put(Collections.SYNC, selected ? 1 : 0);
+        return values;
+    }
+
+
+    private static Boolean getAsBooleanOrNull(ContentValues values, String field) {
+        Integer i = values.getAsInteger(field);
+        return (i == null) ? null : (i != 0);
+    }
+
+}
@@ -1,163 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model
-
-import android.content.ContentValues
-import at.bitfire.dav4android.DavResource
-import at.bitfire.dav4android.property.*
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import java.io.Serializable
-
-data class CollectionInfo @JvmOverloads constructor(
-        val url: String,
-
-        var id: Long? = null,
-        var serviceID: Long? = null,
-
-        var type: Type? = null,
-
-        var readOnly: Boolean = false,
-        var forceReadOnly: Boolean = false,
-        var displayName: String? = null,
-        var description: String? = null,
-        var color: Int? = null,
-
-        var timeZone: String? = null,
-        var supportsVEVENT: Boolean = false,
-        var supportsVTODO: Boolean = false,
-        var selected: Boolean = false,
-
-        // subscriptions
-        var source: String? = null,
-
-        // non-persistent properties
-        var confirmed: Boolean = false
-): Serializable {
-
-    enum class Type {
-        ADDRESS_BOOK,
-        CALENDAR,
-        WEBCAL          // iCalendar subscription
-    }
-
-    companion object {
-
-        @JvmField
-        val DAV_PROPERTIES = arrayOf(
-            ResourceType.NAME,
-            CurrentUserPrivilegeSet.NAME,
-            DisplayName.NAME,
-            AddressbookDescription.NAME, SupportedAddressData.NAME,
-            CalendarDescription.NAME, CalendarColor.NAME, SupportedCalendarComponentSet.NAME,
-            Source.NAME
-        )
-
-    }
-
-
-    constructor(dav: DavResource): this(dav.location.toString()) {
-        dav.properties[ResourceType::class.java]?.let { type ->
-            when {
-                type.types.contains(ResourceType.ADDRESSBOOK) -> this.type = Type.ADDRESS_BOOK
-                type.types.contains(ResourceType.CALENDAR)    -> this.type = Type.CALENDAR
-                type.types.contains(ResourceType.SUBSCRIBED)  -> this.type = Type.WEBCAL
-            }
-        }
-
-        dav.properties[CurrentUserPrivilegeSet::class.java]?.let { privilegeSet ->
-            readOnly = !privilegeSet.mayWriteContent
-        }
-
-        dav.properties[DisplayName::class.java]?.let {
-            if (!it.displayName.isNullOrEmpty())
-                displayName = it.displayName
-        }
-
-        when (type) {
-            Type.ADDRESS_BOOK -> {
-                dav.properties[AddressbookDescription::class.java]?.let { description = it.description }
-            }
-            Type.CALENDAR, Type.WEBCAL -> {
-                dav.properties[CalendarDescription::class.java]?.let { description = it.description }
-                dav.properties[CalendarColor::class.java]?.let { color = it.color }
-                dav.properties[CalendarTimezone::class.java]?.let { timeZone = it.vTimeZone }
-
-                if (type == Type.CALENDAR) {
-                    supportsVEVENT = true
-                    supportsVTODO = true
-                    dav.properties[SupportedCalendarComponentSet::class.java]?.let {
-                        supportsVEVENT = it.supportsEvents
-                        supportsVTODO = it.supportsTasks
-                    }
-                } else { // Type.WEBCAL
-                    dav.properties[Source::class.java]?.let { source = it.hrefs.firstOrNull() }
-                    supportsVEVENT = true
-                }
-            }
-        }
-    }
-
-
-    constructor(values: ContentValues): this(values.getAsString(Collections.URL)) {
-        id = values.getAsLong(Collections.ID)
-        serviceID = values.getAsLong(Collections.SERVICE_ID)
-        type = try {
-            Type.valueOf(values.getAsString(Collections.TYPE))
-        } catch (e: Exception) {
-            null
-        }
-
-        readOnly = values.getAsInteger(Collections.READ_ONLY) != 0
-        forceReadOnly = values.getAsInteger(Collections.FORCE_READ_ONLY) != 0
-        displayName = values.getAsString(Collections.DISPLAY_NAME)
-        description = values.getAsString(Collections.DESCRIPTION)
-
-        color = values.getAsInteger(Collections.COLOR)
-
-        timeZone = values.getAsString(Collections.TIME_ZONE)
-        supportsVEVENT = getAsBooleanOrNull(values, Collections.SUPPORTS_VEVENT) ?: false
-        supportsVTODO = getAsBooleanOrNull(values, Collections.SUPPORTS_VTODO) ?: false
-
-        source = values.getAsString(Collections.SOURCE)
-
-        selected = values.getAsInteger(Collections.SYNC) != 0
-    }
-
-    fun toDB(): ContentValues {
-        val values = ContentValues()
-        // Collections.SERVICE_ID is never changed
-        type?.let { values.put(Collections.TYPE, it.name) }
-
-        values.put(Collections.URL, url)
-        values.put(Collections.READ_ONLY, if (readOnly) 1 else 0)
-        values.put(Collections.FORCE_READ_ONLY, if (forceReadOnly) 1 else 0)
-        values.put(Collections.DISPLAY_NAME, displayName)
-        values.put(Collections.DESCRIPTION, description)
-        values.put(Collections.COLOR, color)
-
-        values.put(Collections.TIME_ZONE, timeZone)
-        values.put(Collections.SUPPORTS_VEVENT, if (supportsVEVENT) 1 else 0)
-        values.put(Collections.SUPPORTS_VTODO, if (supportsVTODO) 1 else 0)
-
-        values.put(Collections.SOURCE, source)
-
-        values.put(Collections.SYNC, if (selected) 1 else 0)
-        return values
-    }
-
-
-    private fun getAsBooleanOrNull(values: ContentValues, field: String): Boolean? {
-        val i = values.getAsInteger(field)
-        return if (i == null)
-            null
-        else
-            (i != 0)
-    }
-
-}
@@ -1,41 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model
-
-import java.io.Serializable
-
-class Credentials @JvmOverloads constructor(
-        @JvmField val userName: String? = null,
-        @JvmField val password: String? = null,
-        @JvmField val certificateAlias: String? = null
-): Serializable {
-
-    enum class Type {
-        UsernamePassword,
-        ClientCertificate
-    }
-
-    val type: Type
-
-    init {
-        type = when {
-            !certificateAlias.isNullOrEmpty() ->
-                Type.ClientCertificate
-            !userName.isNullOrEmpty() && !password.isNullOrEmpty() ->
-                Type.UsernamePassword
-            else ->
-                throw IllegalArgumentException("Either username/password or certificate alias must be set")
-        }
-    }
-
-    override fun toString(): String {
-        return "Credentials(type=$type, userName=$userName, certificateAlias=$certificateAlias)"
-    }
-
-}
@@ -0,0 +1,186 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteException;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Build;
+
+import at.bitfire.davdroid.App;
+import lombok.Cleanup;
+
+public class ServiceDB {
+
+    public static class Settings {
+        public static final String
+                _TABLE = "settings",
+                NAME = "setting",
+                VALUE = "value";
+    }
+
+    public static class Services {
+        public static final String
+                _TABLE = "services",
+                ID = "_id",
+                ACCOUNT_NAME = "accountName",
+                SERVICE = "service",
+                PRINCIPAL = "principal";
+
+        // allowed values for SERVICE column
+        public static final String
+                SERVICE_CALDAV = "caldav",
+                SERVICE_CARDDAV = "carddav";
+    }
+
+    public static class HomeSets {
+        public static final String
+                _TABLE = "homesets",
+                ID = "_id",
+                SERVICE_ID = "serviceID",
+                URL = "url";
+    }
+
+    public static class Collections {
+        public static final String
+                _TABLE = "collections",
+                ID = "_id",
+                SERVICE_ID = "serviceID",
+                URL = "url",
+                READ_ONLY = "readOnly",
+                DISPLAY_NAME = "displayName",
+                DESCRIPTION = "description",
+                COLOR = "color",
+                TIME_ZONE = "timezone",
+                SUPPORTS_VEVENT = "supportsVEVENT",
+                SUPPORTS_VTODO = "supportsVTODO",
+                SYNC = "sync";
+    }
+
+
+    public static class OpenHelper extends SQLiteOpenHelper {
+        private static final String DATABASE_NAME = "services.db";
+        private static final int DATABASE_VERSION = 1;
+
+        public OpenHelper(Context context) {
+            super(context, DATABASE_NAME, null, DATABASE_VERSION);
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
+                setWriteAheadLoggingEnabled(true);
+        }
+
+        @Override
+        public void onOpen(SQLiteDatabase db) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
+                db.setForeignKeyConstraintsEnabled(true);
+            else {
+                if (!db.enableWriteAheadLogging())
+                    App.log.warning("Couldn't enable write-ahead logging");
+
+                db.execSQL("PRAGMA foreign_keys=ON;");
+            }
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            App.log.info("Creating database " + db.getPath());
+
+            db.execSQL("CREATE TABLE " + Settings._TABLE + "(" +
+                    Settings.NAME + " TEXT NOT NULL," +
+                    Settings.VALUE + " TEXT NOT NULL" +
+            ")");
+            db.execSQL("CREATE UNIQUE INDEX settings_name ON " + Settings._TABLE + " (" + Settings.NAME + ")");
+
+            db.execSQL("CREATE TABLE " + Services._TABLE + "(" +
+                    Services.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    Services.ACCOUNT_NAME + " TEXT NOT NULL," +
+                    Services.SERVICE + " TEXT NOT NULL," +
+                    Services.PRINCIPAL + " TEXT NULL" +
+            ")");
+            db.execSQL("CREATE UNIQUE INDEX services_account ON " + Services._TABLE + " (" + Services.ACCOUNT_NAME + "," + Services.SERVICE + ")");
+
+            db.execSQL("CREATE TABLE " + HomeSets._TABLE + "(" +
+                    HomeSets.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    HomeSets.SERVICE_ID + " INTEGER NOT NULL REFERENCES " + Services._TABLE +" ON DELETE CASCADE," +
+                    HomeSets.URL + " TEXT NOT NULL" +
+             ")");
+            db.execSQL("CREATE UNIQUE INDEX homesets_service_url ON " + HomeSets._TABLE + "(" + HomeSets.SERVICE_ID + "," + HomeSets.URL + ")");
+
+            db.execSQL("CREATE TABLE " + Collections._TABLE + "(" +
+                    Collections.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    Collections.SERVICE_ID + " INTEGER NOT NULL REFERENCES " + Services._TABLE +" ON DELETE CASCADE," +
+                    Collections.URL + " TEXT NOT NULL," +
+                    Collections.READ_ONLY + " INTEGER DEFAULT 0 NOT NULL," +
+                    Collections.DISPLAY_NAME + " TEXT NULL," +
+                    Collections.DESCRIPTION + " TEXT NULL," +
+                    Collections.COLOR + " INTEGER NULL," +
+                    Collections.TIME_ZONE + " TEXT NULL," +
+                    Collections.SUPPORTS_VEVENT + " INTEGER NULL," +
+                    Collections.SUPPORTS_VTODO + " INTEGER NULL," +
+                    Collections.SYNC + " INTEGER DEFAULT 0 NOT NULL" +
+            ")");
+            db.execSQL("CREATE UNIQUE INDEX collections_service_url ON " + Collections._TABLE + "(" + Collections.SERVICE_ID + "," + Collections.URL + ")");
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        }
+
+
+        public void dump(StringBuilder sb) {
+            SQLiteDatabase db = getReadableDatabase();
+            db.beginTransactionNonExclusive();
+
+            // iterate through all tables
+            @Cleanup Cursor cursorTables = db.query("sqlite_master", new String[] { "name" }, "type='table'", null, null, null, null);
+            while (cursorTables.moveToNext()) {
+                String table = cursorTables.getString(0);
+                sb.append(table).append("\n");
+                @Cleanup Cursor cursor = db.query(table, null, null, null, null, null, null);
+
+                // print columns
+                int cols = cursor.getColumnCount();
+                sb.append("\t| ");
+                for (int i = 0; i < cols; i++) {
+                    sb.append(" ");
+                    sb.append(cursor.getColumnName(i));
+                    sb.append(" |");
+                }
+                sb.append("\n");
+
+                // print rows
+                while (cursor.moveToNext()) {
+                    sb.append("\t| ");
+                    for (int i = 0; i < cols; i++) {
+                        sb.append(" ");
+                        try {
+                            String value = cursor.getString(i);
+                            if (value != null)
+                                sb.append(value
+                                        .replace("\r", "<CR>")
+                                        .replace("\n", "<LF>"));
+                            else
+                                sb.append("<null>");
+
+                        } catch (SQLiteException e) {
+                            sb.append("<unprintable>");
+                        }
+                        sb.append(" |");
+                    }
+                    sb.append("\n");
+                }
+                sb.append("----------\n");
+            }
+            db.endTransaction();
+        }
+    }
+
+}
@@ -1,231 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model
-
-import android.content.ContentValues
-import android.content.Context
-import android.database.sqlite.SQLiteDatabase
-import android.database.sqlite.SQLiteException
-import android.database.sqlite.SQLiteOpenHelper
-import android.preference.PreferenceManager
-import at.bitfire.davdroid.App
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.ui.StartupDialogFragment
-import java.io.Closeable
-import java.util.logging.Level
-
-class ServiceDB {
-
-    /*object Settings {
-        @JvmField val _TABLE = "settings"
-        @JvmField val NAME = "setting"
-        @JvmField val VALUE = "value"
-    }*/
-
-    object Services {
-        @JvmField val _TABLE = "services"
-        @JvmField val ID = "_id"
-        @JvmField val ACCOUNT_NAME = "accountName"
-        @JvmField val SERVICE = "service"
-        @JvmField val PRINCIPAL = "principal"
-
-        // allowed values for SERVICE column
-        @JvmField val SERVICE_CALDAV = "caldav"
-        @JvmField val SERVICE_CARDDAV = "carddav"
-    }
-
-    object HomeSets {
-        @JvmField val _TABLE = "homesets"
-        @JvmField val ID = "_id"
-        @JvmField val SERVICE_ID = "serviceID"
-        @JvmField val URL = "url"
-    }
-
-    object Collections {
-        @JvmField val _TABLE = "collections"
-        @JvmField val ID = "_id"
-        @JvmField val TYPE = "type"
-        @JvmField val SERVICE_ID = "serviceID"
-        @JvmField val URL = "url"
-        @JvmField val READ_ONLY = "readOnly"
-        @JvmField val FORCE_READ_ONLY = "forceReadOnly"
-        @JvmField val DISPLAY_NAME = "displayName"
-        @JvmField val DESCRIPTION = "description"
-        @JvmField val COLOR = "color"
-        @JvmField val TIME_ZONE = "timezone"
-        @JvmField val SUPPORTS_VEVENT = "supportsVEVENT"
-        @JvmField val SUPPORTS_VTODO = "supportsVTODO"
-        @JvmField val SOURCE = "source"
-        @JvmField val SYNC = "sync"
-    }
-
-    companion object {
-
-        @JvmStatic
-        fun onRenameAccount(db: SQLiteDatabase, oldName: String, newName: String) {
-            val values = ContentValues(1)
-            values.put(Services.ACCOUNT_NAME, newName)
-            db.updateWithOnConflict(Services._TABLE, values, Services.ACCOUNT_NAME + "=?", arrayOf(oldName), SQLiteDatabase.CONFLICT_REPLACE)
-        }
-
-    }
-
-
-    class OpenHelper(
-            val context: Context
-    ): SQLiteOpenHelper(context, DATABASE_NAME, null, DATABASE_VERSION), Closeable {
-
-        companion object {
-            val DATABASE_NAME = "services.db"
-            val DATABASE_VERSION = 4
-        }
-
-        override fun onConfigure(db: SQLiteDatabase) {
-            setWriteAheadLoggingEnabled(true)
-            db.setForeignKeyConstraintsEnabled(true)
-        }
-
-        override fun onCreate(db: SQLiteDatabase) {
-            Logger.log.info("Creating database " + db.path)
-
-            db.execSQL("CREATE TABLE ${Services._TABLE}(" +
-                    "${Services.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    "${Services.ACCOUNT_NAME} TEXT NOT NULL," +
-                    "${Services.SERVICE} TEXT NOT NULL," +
-                    "${Services.PRINCIPAL} TEXT NULL)")
-            db.execSQL("CREATE UNIQUE INDEX services_account ON ${Services._TABLE} (${Services.ACCOUNT_NAME},${Services.SERVICE})")
-
-            db.execSQL("CREATE TABLE ${HomeSets._TABLE}(" +
-                    "${HomeSets.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    "${HomeSets.SERVICE_ID} INTEGER NOT NULL REFERENCES ${Services._TABLE} ON DELETE CASCADE," +
-                    "${HomeSets.URL} TEXT NOT NULL)")
-            db.execSQL("CREATE UNIQUE INDEX homesets_service_url ON ${HomeSets._TABLE}(${HomeSets.SERVICE_ID},${HomeSets.URL})")
-
-            db.execSQL("CREATE TABLE ${Collections._TABLE}(" +
-                    "${Collections.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    "${Collections.SERVICE_ID} INTEGER NOT NULL REFERENCES ${Services._TABLE} ON DELETE CASCADE," +
-                    "${Collections.TYPE} TEXT NOT NULL," +
-                    "${Collections.URL} TEXT NOT NULL," +
-                    "${Collections.READ_ONLY} INTEGER DEFAULT 0 NOT NULL," +
-                    "${Collections.FORCE_READ_ONLY} INTEGER DEFAULT 0 NOT NULL," +
-                    "${Collections.DISPLAY_NAME} TEXT NULL," +
-                    "${Collections.DESCRIPTION} TEXT NULL," +
-                    "${Collections.COLOR} INTEGER NULL," +
-                    "${Collections.TIME_ZONE} TEXT NULL," +
-                    "${Collections.SUPPORTS_VEVENT} INTEGER NULL," +
-                    "${Collections.SUPPORTS_VTODO} INTEGER NULL," +
-                    "${Collections.SOURCE} TEXT NULL," +
-                    "${Collections.SYNC} INTEGER DEFAULT 0 NOT NULL)")
-            db.execSQL("CREATE UNIQUE INDEX collections_service_url ON ${Collections._TABLE}(${Collections.SERVICE_ID},${Collections.URL})")
-        }
-
-        override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
-            for (upgradeFrom in oldVersion until newVersion) {
-                val upgradeTo = upgradeFrom + 1
-                Logger.log.info("Upgrading database from version $upgradeFrom to $upgradeTo")
-                try {
-                    val upgradeProc = this::class.java.getDeclaredMethod("upgrade_${upgradeFrom}_$upgradeTo", SQLiteDatabase::class.java)
-                    upgradeProc.invoke(this, db)
-                } catch(e: Exception) {
-                    Logger.log.log(Level.SEVERE, "Couldn't upgrade database", e)
-                }
-            }
-        }
-
-        @Suppress("unused")
-        private fun upgrade_3_4(db: SQLiteDatabase) {
-            db.execSQL("ALTER TABLE ${Collections._TABLE} ADD COLUMN ${Collections.FORCE_READ_ONLY} INTEGER DEFAULT 0 NOT NULL")
-        }
-
-        @Suppress("unused")
-        private fun upgrade_2_3(db: SQLiteDatabase) {
-            val edit = PreferenceManager.getDefaultSharedPreferences(context).edit()
-            try {
-                db.query("settings", arrayOf("setting", "value"), null, null, null, null, null).use { cursor ->
-                    while (cursor.moveToNext()) {
-                        when (cursor.getString(0)) {
-                            "distrustSystemCerts" -> edit.putBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, cursor.getInt(1) != 0)
-                            "overrideProxy" -> edit.putBoolean(App.OVERRIDE_PROXY, cursor.getInt(1) != 0)
-                            "overrideProxyHost" -> edit.putString(App.OVERRIDE_PROXY_HOST, cursor.getString(1))
-                            "overrideProxyPort" -> edit.putInt(App.OVERRIDE_PROXY_PORT, cursor.getInt(1))
-
-                            StartupDialogFragment.HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED ->
-                                edit.putBoolean(StartupDialogFragment.HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED, cursor.getInt(1) != 0)
-                            StartupDialogFragment.HINT_OPENTASKS_NOT_INSTALLED ->
-                                edit.putBoolean(StartupDialogFragment.HINT_OPENTASKS_NOT_INSTALLED, cursor.getInt(1) != 0)
-                        }
-                    }
-                }
-                db.execSQL("DROP TABLE settings")
-            } finally {
-                edit.apply()
-            }
-        }
-
-        @Suppress("unused")
-        private fun upgrade_1_2(db: SQLiteDatabase) {
-            db.execSQL("ALTER TABLE ${Collections._TABLE} ADD COLUMN ${Collections.TYPE} TEXT NOT NULL DEFAULT ''")
-            db.execSQL("ALTER TABLE ${Collections._TABLE} ADD COLUMN ${Collections.SOURCE} TEXT NULL")
-            db.execSQL("UPDATE ${Collections._TABLE} SET ${Collections.TYPE}=(" +
-                    "SELECT CASE ${Services.SERVICE} WHEN ? THEN ? ELSE ? END " +
-                    "FROM ${Services._TABLE} WHERE ${Services.ID}=${Collections._TABLE}.${Collections.SERVICE_ID}" +
-                    ")",
-                    arrayOf(Services.SERVICE_CALDAV, CollectionInfo.Type.CALENDAR, CollectionInfo.Type.ADDRESS_BOOK))
-        }
-
-
-        fun dump(sb: StringBuilder) {
-            val db = readableDatabase
-            db.beginTransactionNonExclusive()
-
-            // iterate through all tables
-            db.query("sqlite_master", arrayOf("name"), "type='table'", null, null, null, null).use { cursorTables ->
-                while (cursorTables.moveToNext()) {
-                    val table = cursorTables.getString(0)
-                    sb.append(table).append("\n")
-                    db.query(table, null, null, null, null, null, null).use { cursor ->
-                        // print columns
-                        val cols = cursor.columnCount
-                        sb.append("\t| ")
-                        for (i in 0 until cols)
-                            sb  .append(" ")
-                                .append(cursor.getColumnName(i))
-                                .append(" |")
-                        sb.append("\n")
-
-                        // print rows
-                        while (cursor.moveToNext()) {
-                            sb.append("\t| ")
-                            for (i in 0 until cols) {
-                                sb.append(" ")
-                                try {
-                                    val value = cursor.getString(i)
-                                    if (value != null)
-                                        sb.append(value
-                                                .replace("\r", "<CR>")
-                                                .replace("\n", "<LF>"))
-                                    else
-                                        sb.append("<null>")
-
-                                } catch (e: SQLiteException) {
-                                    sb.append("<unprintable>")
-                                }
-                                sb.append(" |")
-                            }
-                            sb.append("\n")
-                        }
-                        sb.append("----------\n")
-                    }
-                }
-                db.endTransaction()
-            }
-        }
-    }
-
-}
@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+
+import lombok.Cleanup;
+
+public class Settings {
+
+    final SQLiteDatabase db;
+
+    public Settings(SQLiteDatabase db) {
+        this.db = db;
+    }
+
+    public boolean getBoolean(String name, boolean defaultValue) {
+        @Cleanup Cursor cursor = db.query(ServiceDB.Settings._TABLE, new String[] { ServiceDB.Settings.VALUE },
+                ServiceDB.Settings.NAME + "=?", new String[] { name }, null, null, null);
+        if (cursor.moveToNext())
+            return cursor.getInt(0) != 0;
+        else
+            return defaultValue;
+    }
+
+    public void putBoolean(String name, boolean value) {
+        ContentValues values = new ContentValues(2);
+        values.put(ServiceDB.Settings.NAME, name);
+        values.put(ServiceDB.Settings.VALUE, value ? 1 : 0);
+        db.insertWithOnConflict(ServiceDB.Settings._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
+    }
+
+    public void remove(String name) {
+        db.delete(ServiceDB.Settings._TABLE, ServiceDB.Settings.NAME + "=?", new String[] { name });
+    }
+
+}
@@ -1,28 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model
-
-import android.provider.ContactsContract.RawContacts
-
-object UnknownProperties {
-
-    @JvmField
-    val CONTENT_ITEM_TYPE = "x.davdroid/unknown-properties"
-
-
-    @JvmField
-    val MIMETYPE = RawContacts.Data.MIMETYPE
-
-    @JvmField
-    val RAW_CONTACT_ID = RawContacts.Data.RAW_CONTACT_ID
-
-    @JvmField
-    val UNKNOWN_PROPERTIES = RawContacts.Data.DATA1
-
-}
@@ -0,0 +1,215 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.resource;
+
+import android.accounts.Account;
+import android.content.ContentProviderClient;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.RemoteException;
+import android.provider.ContactsContract;
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
+import android.provider.ContactsContract.Data;
+import android.provider.ContactsContract.Groups;
+import android.provider.ContactsContract.RawContacts;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.vcard4android.AndroidAddressBook;
+import at.bitfire.vcard4android.AndroidContact;
+import at.bitfire.vcard4android.AndroidGroupFactory;
+import at.bitfire.vcard4android.ContactsStorageException;
+import lombok.Cleanup;
+
+
+public class LocalAddressBook extends AndroidAddressBook implements LocalCollection {
+
+    protected static final String
+            SYNC_STATE_CTAG = "ctag",
+            SYNC_STATE_URL = "url";
+
+    private final Bundle syncState = new Bundle();
+
+
+    public LocalAddressBook(Account account, ContentProviderClient provider) {
+        super(account, provider, AndroidGroupFactory.INSTANCE, LocalContact.Factory.INSTANCE);
+    }
+
+
+    /**
+     * Returns an array of local contacts, excluding those which have been modified locally (and not uploaded yet).
+     */
+    @Override
+    public LocalContact[] getAll() throws ContactsStorageException {
+        return (LocalContact[])queryContacts(null, null);
+    }
+
+    /**
+     * Returns an array of local contacts which have been deleted locally. (DELETED != 0).
+     */
+    @Override
+    public LocalContact[] getDeleted() throws ContactsStorageException {
+        return (LocalContact[])queryContacts(RawContacts.DELETED + "!=0", null);
+    }
+
+    /**
+     * Returns an array of local contacts which have been changed locally (DIRTY != 0).
+     */
+    @Override
+    public LocalContact[] getDirty() throws ContactsStorageException {
+        return (LocalContact[])queryContacts(RawContacts.DIRTY + "!=0", null);
+    }
+
+    /**
+     * Returns an array of local contacts which don't have a file name yet.
+     */
+    @Override
+    public LocalContact[] getWithoutFileName() throws ContactsStorageException {
+        return (LocalContact[])queryContacts(AndroidContact.COLUMN_FILENAME + " IS NULL", null);
+    }
+
+    public void deleteAll()  throws ContactsStorageException {
+        try {
+            provider.delete(syncAdapterURI(RawContacts.CONTENT_URI), null, null);
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't delete all local contacts", e);
+        }
+    }
+
+
+    // GROUPS
+
+    /**
+     * Finds the first group with the given title.
+     * @param displayName   title of the group to look for
+     * @return              group with given title, or null if none
+     */
+    @SuppressWarnings("Recycle")
+    public LocalGroup findGroupByTitle(String displayName) throws ContactsStorageException {
+        try {
+            @Cleanup Cursor cursor = provider.query(syncAdapterURI(Groups.CONTENT_URI),
+                    new String[] { Groups._ID },
+                    ContactsContract.Groups.TITLE + "=?", new String[] { displayName }, null);
+            if (cursor != null && cursor.moveToNext())
+                return new LocalGroup(this, cursor.getLong(0));
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't find local contact group", e);
+        }
+        return null;
+    }
+
+    @SuppressWarnings("Recycle")
+    public LocalGroup[] getDeletedGroups() throws ContactsStorageException {
+        List<LocalGroup> groups = new LinkedList<>();
+        try {
+            @Cleanup Cursor cursor = provider.query(syncAdapterURI(Groups.CONTENT_URI),
+                    new String[] { Groups._ID },
+                    Groups.DELETED + "!=0", null, null);
+            while (cursor != null && cursor.moveToNext())
+                groups.add(new LocalGroup(this, cursor.getLong(0)));
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't query deleted groups", e);
+        }
+        return groups.toArray(new LocalGroup[groups.size()]);
+    }
+
+    @SuppressWarnings("Recycle")
+    public LocalGroup[] getDirtyGroups() throws ContactsStorageException {
+        List<LocalGroup> groups = new LinkedList<>();
+        try {
+            @Cleanup Cursor cursor = provider.query(syncAdapterURI(Groups.CONTENT_URI),
+                    new String[] { Groups._ID },
+                    Groups.DIRTY + "!=0", null, null);
+            while (cursor != null && cursor.moveToNext())
+                groups.add(new LocalGroup(this, cursor.getLong(0)));
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't query dirty groups", e);
+        }
+        return groups.toArray(new LocalGroup[groups.size()]);
+    }
+
+    @SuppressWarnings("Recycle")
+    public void markMembersDirty(long groupId) throws ContactsStorageException {
+        ContentValues dirty = new ContentValues(1);
+        dirty.put(RawContacts.DIRTY, 1);
+        try {
+            // query all GroupMemberships of this groupId, mark every corresponding raw contact as DIRTY
+            @Cleanup Cursor cursor = provider.query(syncAdapterURI(Data.CONTENT_URI),
+                    new String[] { GroupMembership.RAW_CONTACT_ID },
+                    Data.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?",
+                    new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(groupId) }, null);
+            while (cursor != null && cursor.moveToNext()) {
+                long id = cursor.getLong(0);
+                App.log.fine("Marking raw contact #" + id + " as dirty");
+                provider.update(syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, id)), dirty, null, null);
+            }
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't query dirty groups", e);
+        }
+    }
+
+
+    // SYNC STATE
+
+    @SuppressWarnings("Recycle")
+    protected void readSyncState() throws ContactsStorageException {
+        @Cleanup("recycle") Parcel parcel = Parcel.obtain();
+        byte[] raw = getSyncState();
+        syncState.clear();
+        if (raw != null) {
+            parcel.unmarshall(raw, 0, raw.length);
+            parcel.setDataPosition(0);
+            syncState.putAll(parcel.readBundle());
+        }
+    }
+
+    @SuppressWarnings("Recycle")
+    protected void writeSyncState() throws ContactsStorageException {
+        @Cleanup("recycle") Parcel parcel = Parcel.obtain();
+        parcel.writeBundle(syncState);
+        setSyncState(parcel.marshall());
+    }
+
+    public String getURL() throws ContactsStorageException {
+        synchronized (syncState) {
+            readSyncState();
+            return syncState.getString(SYNC_STATE_URL);
+        }
+    }
+
+    public void setURL(String url) throws ContactsStorageException {
+        synchronized (syncState) {
+            readSyncState();
+            syncState.putString(SYNC_STATE_URL, url);
+            writeSyncState();
+        }
+    }
+
+    @Override
+    public String getCTag() throws ContactsStorageException {
+        synchronized (syncState) {
+            readSyncState();
+            return syncState.getString(SYNC_STATE_CTAG);
+        }
+    }
+
+    @Override
+    public void setCTag(String cTag) throws ContactsStorageException {
+        synchronized (syncState) {
+            readSyncState();
+            syncState.putString(SYNC_STATE_CTAG, cTag);
+            writeSyncState();
+        }
+    }
+
+}
@@ -1,366 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.resource
-
-import android.accounts.Account
-import android.accounts.AccountManager
-import android.annotation.TargetApi
-import android.content.*
-import android.os.Build
-import android.os.Bundle
-import android.os.RemoteException
-import android.provider.ContactsContract
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership
-import android.provider.ContactsContract.Groups
-import android.provider.ContactsContract.RawContacts
-import android.util.Base64
-import at.bitfire.davdroid.DavUtils
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.vcard4android.*
-import java.io.ByteArrayOutputStream
-import java.io.FileNotFoundException
-import java.util.*
-import java.util.logging.Level
-
-/**
- * A local address book. Requires an own Android account, because Android manages contacts per
- * account and there is no such thing as "address books". So, DAVdroid creates a "DAVdroid
- * address book" account for every CardDAV address book. These accounts are bound to a
- * DAVdroid main account.
- */
-class LocalAddressBook(
-        private val context: Context,
-        account: Account,
-        provider: ContentProviderClient?
-): AndroidAddressBook<LocalContact, LocalGroup>(account, provider, LocalContact.Factory, LocalGroup.Factory), LocalCollection<LocalResource> {
-
-    companion object {
-
-        val USER_DATA_MAIN_ACCOUNT_TYPE = "real_account_type"
-        val USER_DATA_MAIN_ACCOUNT_NAME = "real_account_name"
-        val USER_DATA_URL = "url"
-        val USER_DATA_READ_ONLY = "read_only"
-        val USER_DATA_CTAG = "ctag"
-
-        @JvmStatic
-        @Throws(ContactsStorageException::class)
-        fun create(context: Context, provider: ContentProviderClient, mainAccount: Account, info: CollectionInfo): LocalAddressBook {
-            val accountManager = AccountManager.get(context)
-
-            val account = Account(accountName(mainAccount, info), context.getString(R.string.account_type_address_book))
-            if (!accountManager.addAccountExplicitly(account, null, initialUserData(mainAccount, info.url)))
-                throw ContactsStorageException("Couldn't create address book account")
-
-            val addressBook = LocalAddressBook(context, account, provider)
-            ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true)
-
-            // set up Contacts Provider Settings
-            val values = ContentValues(2)
-            values.put(ContactsContract.Settings.SHOULD_SYNC, 1)
-            values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1)
-            addressBook.updateSettings(values)
-
-            return addressBook
-        }
-
-        @JvmStatic
-        @Throws(ContactsStorageException::class)
-        fun find(context: Context, provider: ContentProviderClient, mainAccount: Account?): List<LocalAddressBook> {
-            val accountManager = AccountManager.get(context)
-
-            val result = LinkedList<LocalAddressBook>()
-            accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))
-                    .map { LocalAddressBook(context, it, provider) }
-                    .filter { mainAccount == null || it.getMainAccount() == mainAccount }
-                    .forEach { result += it }
-
-            return result
-        }
-
-        @JvmStatic
-        fun accountName(mainAccount: Account, info: CollectionInfo): String {
-            val baos = ByteArrayOutputStream()
-            baos.write(info.url.hashCode())
-            val hash = Base64.encodeToString(baos.toByteArray(), Base64.NO_WRAP or Base64.NO_PADDING)
-
-            val sb = StringBuilder(if (info.displayName.isNullOrEmpty()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
-            sb      .append(" (")
-                    .append(mainAccount.name)
-                    .append(" ")
-                    .append(hash)
-                    .append(")")
-            return sb.toString()
-        }
-
-        @JvmStatic
-        fun initialUserData(mainAccount: Account, url: String): Bundle {
-            val bundle = Bundle(3)
-            bundle.putString(USER_DATA_MAIN_ACCOUNT_NAME, mainAccount.name)
-            bundle.putString(USER_DATA_MAIN_ACCOUNT_TYPE, mainAccount.type)
-            bundle.putString(USER_DATA_URL, url)
-            return bundle
-        }
-
-    }
-
-    /**
-     * Whether contact groups (LocalGroup resources) are included in query results for
-     * {@link #getAll()}, {@link #getDeleted()}, {@link #getDirty()} and
-     * {@link #getWithoutFileName()}.
-     */
-    var includeGroups = true
-
-
-    /* operations on the collection (address book) itself */
-
-    @Throws(ContactsStorageException::class)
-    fun update(info: CollectionInfo) {
-        val newAccountName = accountName(getMainAccount(), info)
-
-        @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-        if (account.name != newAccountName && Build.VERSION.SDK_INT >= 21) {
-            val accountManager = AccountManager.get(context)
-            val future = accountManager.renameAccount(account, newAccountName, {
-                try {
-                    // update raw contacts to new account name
-                    provider?.let { provider ->
-                        val values = ContentValues(1)
-                        values.put(RawContacts.ACCOUNT_NAME, newAccountName)
-                        provider.update(syncAdapterURI(RawContacts.CONTENT_URI), values, "${RawContacts.ACCOUNT_NAME}=?", arrayOf(account.name))
-                    }
-                } catch(e: RemoteException) {
-                    Logger.log.log(Level.WARNING, "Couldn't re-assign contacts to new account name", e)
-                }
-            }, null)
-            account = future.result
-        }
-
-        Constants.log.info("Address book read-only? = ${info.readOnly}")
-        setReadOnly(info.readOnly || info.forceReadOnly)
-
-        // make sure it will still be synchronized when contacts are updated
-        ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true)
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun delete() {
-        val accountManager = AccountManager.get(context)
-        try {
-            if (Build.VERSION.SDK_INT >= 22)
-                accountManager.removeAccount(account, null, null, null)
-            else
-                @Suppress("deprecation")
-                accountManager.removeAccount(account, null, null)
-        } catch(e: Exception) {
-            throw ContactsStorageException("Couldn't remove address book", e)
-        }
-    }
-
-
-    /* operations on members (contacts/groups) */
-
-    @Throws(ContactsStorageException::class, FileNotFoundException::class)
-    fun findContactByUID(uid: String): LocalContact {
-        val contacts = queryContacts("${AndroidContact.COLUMN_UID}=?", arrayOf(uid))
-        if (contacts.isEmpty())
-            throw FileNotFoundException()
-        return contacts.first()
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun getAll(): List<LocalResource> {
-        val all = LinkedList<LocalResource>()
-        all.addAll(queryContacts(null, null))
-        if (includeGroups)
-            all.addAll(queryGroups(null, null))
-        return all
-    }
-
-    /**
-     * Returns an array of local contacts/groups which have been deleted locally. (DELETED != 0).
-     */
-    @Throws(ContactsStorageException::class)
-    override fun getDeleted(): List<LocalResource> {
-        val deleted = LinkedList<LocalResource>()
-        deleted.addAll(getDeletedContacts())
-        if (includeGroups)
-            deleted.addAll(getDeletedGroups())
-        return deleted
-    }
-
-    /**
-     * Queries all contacts with DIRTY flag and checks whether their data checksum has changed, i.e.
-     * if they're "really dirty" (= data has changed, not only metadata, which is not hashed).
-     * The DIRTY flag is removed from contacts which are not "really dirty", i.e. from contacts
-     * whose contact data checksum has not changed.
-     * @return number of "really dirty" contacts
-     */
-    @Throws(ContactsStorageException::class)
-    fun verifyDirty(): Int {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
-            throw IllegalStateException("verifyDirty() should not be called on Android != 7")
-
-        var reallyDirty = 0
-        for (contact in getDirtyContacts())
-            try {
-                val lastHash = contact.getLastHashCode()
-                val currentHash = contact.dataHashCode()
-                if (lastHash == currentHash) {
-                    // hash is code still the same, contact is not "really dirty" (only metadata been have changed)
-                    Logger.log.log(Level.FINE, "Contact data hash has not changed, resetting dirty flag", contact)
-                    contact.resetDirty()
-                } else {
-                    Logger.log.log(Level.FINE, "Contact data has changed from hash $lastHash to $currentHash", contact)
-                    reallyDirty++
-                }
-            } catch(e: FileNotFoundException) {
-                throw ContactsStorageException("Couldn't calculate hash code", e)
-            }
-
-        if (includeGroups)
-            reallyDirty += getDirtyGroups().size
-
-        return reallyDirty
-    }
-
-    /**
-     * Returns an array of local contacts/groups which have been changed locally (DIRTY != 0).
-     */
-    @Throws(ContactsStorageException::class)
-    override fun getDirty(): List<LocalResource> {
-        val dirty = LinkedList<LocalResource>()
-        dirty.addAll(getDirtyContacts())
-        if (includeGroups)
-            dirty.addAll(getDirtyGroups())
-        return dirty
-    }
-
-    /**
-     * Returns an array of local contacts which don't have a file name yet.
-     */
-    @Throws(ContactsStorageException::class)
-    override fun getWithoutFileName(): List<LocalResource> {
-        val nameless = LinkedList<LocalResource>()
-        nameless.addAll(queryContacts("${AndroidContact.COLUMN_FILENAME} IS NULL", null))
-        if (includeGroups)
-            nameless.addAll(queryGroups("${AndroidGroup.COLUMN_FILENAME} IS NULL", null))
-        return nameless
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun getDeletedContacts() = queryContacts("${RawContacts.DELETED} != 0", null)
-
-    @Throws(ContactsStorageException::class)
-    fun getDirtyContacts() = queryContacts("${RawContacts.DIRTY} != 0", null)
-
-    @Throws(ContactsStorageException::class)
-    fun getDeletedGroups() = queryGroups("${Groups.DELETED} != 0", null)
-
-    @Throws(ContactsStorageException::class)
-    fun getDirtyGroups() = queryGroups("${Groups.DIRTY} != 0", null)
-
-    @Throws(ContactsStorageException::class)
-    fun getByGroupMembership(groupID: Long): List<LocalContact> {
-        try {
-            val ids = HashSet<Long>()
-
-            provider!!.query(syncAdapterURI(ContactsContract.Data.CONTENT_URI),
-                    arrayOf(RawContacts.Data.RAW_CONTACT_ID),
-                    "(${GroupMembership.MIMETYPE}=? AND ${GroupMembership.GROUP_ROW_ID}=?) OR (${CachedGroupMembership.MIMETYPE}=? AND ${CachedGroupMembership.GROUP_ID}=?)",
-                    arrayOf(GroupMembership.CONTENT_ITEM_TYPE, groupID.toString(), CachedGroupMembership.CONTENT_ITEM_TYPE, groupID.toString()),
-                    null)?.use { cursor ->
-                while (cursor.moveToNext())
-                    ids += cursor.getLong(0)
-            }
-
-            return ids.map { id -> LocalContact(this, id, null, null) }
-        } catch (e: RemoteException) {
-            throw ContactsStorageException("Couldn't query contacts", e)
-        }
-    }
-
-
-    /* special group operations */
-
-    /**
-     * Finds the first group with the given title. If there is no group with this
-     * title, a new group is created.
-     * @param title     title of the group to look for
-     * @return          id of the group with given title
-     * @throws ContactsStorageException on contact provider errors
-     */
-    @Throws(ContactsStorageException::class)
-    fun findOrCreateGroup(title: String): Long {
-        try {
-            provider!!.query(syncAdapterURI(Groups.CONTENT_URI), arrayOf(Groups._ID),
-                    "${Groups.TITLE}=?", arrayOf(title), null)?.use { cursor ->
-                if (cursor.moveToNext())
-                    return cursor.getLong(0)
-            }
-
-            val values = ContentValues(1)
-            values.put(Groups.TITLE, title)
-            val uri = provider.insert(syncAdapterURI(Groups.CONTENT_URI), values)
-            return ContentUris.parseId(uri)
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't find local contact group", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun removeEmptyGroups() {
-        // find groups without members
-        /** should be done using {@link Groups.SUMMARY_COUNT}, but it's not implemented in Android yet */
-        queryGroups(null, null).filter { it.getMembers().isEmpty() }.forEach { group ->
-            Logger.log.log(Level.FINE, "Deleting group", group)
-            group.delete()
-        }
-    }
-
-
-    // SETTINGS
-
-    @Throws(ContactsStorageException::class)
-    fun getMainAccount(): Account {
-        val accountManager = AccountManager.get(context)
-        val name = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_NAME)
-        val type = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE)
-        if (name != null && type != null)
-            return Account(name, type)
-        else
-            throw ContactsStorageException("Address book doesn't exist anymore")
-    }
-
-    fun setMainAccount(mainAccount: Account) {
-        val accountManager = AccountManager.get(context)
-        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_NAME, mainAccount.name)
-        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE, mainAccount.type)
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun getURL() =
-            AccountManager.get(context).getUserData(account, USER_DATA_URL) ?: throw ContactsStorageException("Address book has no URL")
-
-    fun setURL(url: String) =
-            AccountManager.get(context).setUserData(account, USER_DATA_URL, url)
-
-    fun getReadOnly() =
-            AccountManager.get(context).getUserData(account, USER_DATA_READ_ONLY) != null
-
-    fun setReadOnly(readOnly: Boolean) =
-            AccountManager.get(context).setUserData(account, USER_DATA_READ_ONLY, if (readOnly) "1" else null)
-
-    override fun getCTag(): String? =
-            AccountManager.get(context).getUserData(account, USER_DATA_CTAG)
-
-    override fun setCTag(cTag: String?) =
-            AccountManager.get(context).setUserData(account, USER_DATA_CTAG, cTag)
-
-}
@@ -0,0 +1,267 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.accounts.Account;
+import android.annotation.TargetApi;
+import android.content.ContentProviderClient;
+import android.content.ContentProviderOperation;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Build;
+import android.os.RemoteException;
+import android.provider.CalendarContract;
+import android.provider.CalendarContract.Calendars;
+import android.provider.CalendarContract.Events;
+import android.provider.CalendarContract.Reminders;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
+
+import net.fortuna.ical4j.model.component.VTimeZone;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.FileNotFoundException;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.DavUtils;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.ical4android.AndroidCalendar;
+import at.bitfire.ical4android.AndroidCalendarFactory;
+import at.bitfire.ical4android.BatchOperation;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.DateUtils;
+import at.bitfire.vcard4android.ContactsStorageException;
+import lombok.Cleanup;
+import okhttp3.HttpUrl;
+
+public class LocalCalendar extends AndroidCalendar implements LocalCollection {
+
+    public static final int defaultColor = 0xFF8bc34a;     // light green 500
+
+    public static final String COLUMN_CTAG = Calendars.CAL_SYNC1;
+
+    protected static final int
+            DIRTY_INCREASE_SEQUENCE = 1,
+            DIRTY_DONT_INCREASE_SEQUENCE = 2;
+
+    static String[] BASE_INFO_COLUMNS = new String[] {
+            Events._ID,
+            Events._SYNC_ID,
+            LocalEvent.COLUMN_ETAG
+    };
+
+    @Override
+    protected String[] eventBaseInfoColumns() {
+        return BASE_INFO_COLUMNS;
+    }
+
+
+    protected LocalCalendar(Account account, ContentProviderClient provider, long id) {
+        super(account, provider, LocalEvent.Factory.INSTANCE, id);
+    }
+
+    public static Uri create(@NonNull Account account, @NonNull ContentProviderClient provider, @NonNull CollectionInfo info) throws CalendarStorageException {
+        ContentValues values = valuesFromCollectionInfo(info, true);
+
+        // ACCOUNT_NAME and ACCOUNT_TYPE are required (see docs)! If it's missing, other apps will crash.
+        values.put(Calendars.ACCOUNT_NAME, account.name);
+        values.put(Calendars.ACCOUNT_TYPE, account.type);
+        values.put(Calendars.OWNER_ACCOUNT, account.name);
+
+        // flag as visible & synchronizable at creation, might be changed by user at any time
+        values.put(Calendars.VISIBLE, 1);
+        values.put(Calendars.SYNC_EVENTS, 1);
+
+        return create(account, provider, values);
+    }
+
+    public void update(CollectionInfo info, boolean updateColor) throws CalendarStorageException {
+        update(valuesFromCollectionInfo(info, updateColor));
+    }
+
+    @TargetApi(15)
+    private static ContentValues valuesFromCollectionInfo(CollectionInfo info, boolean withColor) {
+        ContentValues values = new ContentValues();
+        values.put(Calendars.NAME, info.url);
+        values.put(Calendars.CALENDAR_DISPLAY_NAME, !TextUtils.isEmpty(info.displayName) ? info.displayName : DavUtils.lastSegmentOfUrl(info.url));
+
+        if (withColor)
+            values.put(Calendars.CALENDAR_COLOR, info.color != null ? info.color : defaultColor);
+
+        if (info.readOnly)
+            values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_READ);
+        else {
+            values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER);
+            values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1);
+            values.put(Calendars.CAN_ORGANIZER_RESPOND, 1);
+        }
+
+        if (!TextUtils.isEmpty(info.timeZone)) {
+            VTimeZone timeZone = DateUtils.parseVTimeZone(info.timeZone);
+            if (timeZone != null && timeZone.getTimeZoneId() != null)
+                values.put(Calendars.CALENDAR_TIME_ZONE, DateUtils.findAndroidTimezoneID(timeZone.getTimeZoneId().getValue()));
+        }
+        values.put(Calendars.ALLOWED_REMINDERS, Reminders.METHOD_ALERT);
+        if (Build.VERSION.SDK_INT >= 15) {
+            values.put(Calendars.ALLOWED_AVAILABILITY, StringUtils.join(new int[] { Reminders.AVAILABILITY_TENTATIVE, Reminders.AVAILABILITY_FREE, Reminders.AVAILABILITY_BUSY }, ","));
+            values.put(Calendars.ALLOWED_ATTENDEE_TYPES, StringUtils.join(new int[] { CalendarContract.Attendees.TYPE_OPTIONAL, CalendarContract.Attendees.TYPE_REQUIRED, CalendarContract.Attendees.TYPE_RESOURCE }, ", "));
+        }
+        return values;
+    }
+
+
+    @Override
+    public LocalResource[] getAll() throws CalendarStorageException, ContactsStorageException {
+        return (LocalEvent[])queryEvents(Events.ORIGINAL_ID + " IS NULL", null);
+    }
+
+    @Override
+    public LocalEvent[] getDeleted() throws CalendarStorageException {
+        return (LocalEvent[])queryEvents(Events.DELETED + "!=0 AND " + Events.ORIGINAL_ID + " IS NULL", null);
+    }
+
+    @Override
+    public LocalEvent[] getWithoutFileName() throws CalendarStorageException {
+        return (LocalEvent[])queryEvents(Events._SYNC_ID + " IS NULL AND " + Events.ORIGINAL_ID + " IS NULL", null);
+    }
+
+    @Override
+    public LocalResource[] getDirty() throws CalendarStorageException, FileNotFoundException {
+        List<LocalResource> dirty = new LinkedList<>();
+
+        // get dirty events which are not required to have an increased SEQUENCE value
+        Collections.addAll(dirty, (LocalEvent[])queryEvents(Events.DIRTY + "=" + DIRTY_DONT_INCREASE_SEQUENCE + " AND " + Events.ORIGINAL_ID + " IS NULL", null));
+
+        // get dirty events which are required to have an increased SEQUENCE value
+        for (LocalEvent event : (LocalEvent[])queryEvents(Events.DIRTY + "=" + DIRTY_INCREASE_SEQUENCE + " AND " + Events.ORIGINAL_ID + " IS NULL", null)) {
+            if (event.getEvent().sequence == null)      // sequence has not been assigned yet (i.e. this event was just locally created)
+                event.getEvent().sequence = 0;
+            else
+                event.getEvent().sequence++;
+            dirty.add(event);
+        }
+
+        return dirty.toArray(new LocalResource[dirty.size()]);
+    }
+
+
+    @Override
+    @SuppressWarnings("Recycle")
+    public String getCTag() throws CalendarStorageException {
+        try {
+            @Cleanup Cursor cursor = provider.query(calendarSyncURI(), new String[] { COLUMN_CTAG }, null, null, null);
+            if (cursor != null && cursor.moveToNext())
+                return cursor.getString(0);
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't read local (last known) CTag", e);
+        }
+        return null;
+    }
+
+    @Override
+    public void setCTag(String cTag) throws CalendarStorageException, ContactsStorageException {
+        try {
+            ContentValues values = new ContentValues(1);
+            values.put(COLUMN_CTAG, cTag);
+            provider.update(calendarSyncURI(), values, null, null);
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
+        }
+    }
+
+    @SuppressWarnings("Recycle")
+    public void processDirtyExceptions() throws CalendarStorageException {
+        // process deleted exceptions
+        App.log.info("Processing deleted exceptions");
+        try {
+            @Cleanup Cursor cursor = provider.query(
+                    syncAdapterURI(Events.CONTENT_URI),
+                    new String[] { Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE },
+                    Events.DELETED + "!=0 AND " + Events.ORIGINAL_ID + " IS NOT NULL", null, null);
+            while (cursor != null && cursor.moveToNext()) {
+                App.log.fine("Found deleted exception, removing; then re-schuling original event");
+                long    id = cursor.getLong(0),             // can't be null (by definition)
+                        originalID = cursor.getLong(1);     // can't be null (by query)
+
+                // get original event's SEQUENCE
+                @Cleanup Cursor cursor2 = provider.query(
+                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)),
+                        new String[] { LocalEvent.COLUMN_SEQUENCE },
+                        null, null, null);
+                int originalSequence = (cursor2 == null || cursor2.isNull(0)) ? 0 : cursor2.getInt(0);
+
+                BatchOperation batch = new BatchOperation(provider);
+                // re-schedule original event and set it to DIRTY
+                batch.enqueue(ContentProviderOperation.newUpdate(
+                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
+                        .withValue(LocalEvent.COLUMN_SEQUENCE, originalSequence + 1)
+                        .withValue(Events.DIRTY, DIRTY_INCREASE_SEQUENCE)
+                        .build());
+                // remove exception
+                batch.enqueue(ContentProviderOperation.newDelete(
+                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id))).build());
+                batch.commit();
+            }
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't process locally modified exception", e);
+        }
+
+        // process dirty exceptions
+        App.log.info("Processing dirty exceptions");
+        try {
+            @Cleanup Cursor cursor = provider.query(
+                    syncAdapterURI(Events.CONTENT_URI),
+                    new String[] { Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE },
+                    Events.DIRTY + "!=0 AND " + Events.ORIGINAL_ID + " IS NOT NULL", null, null);
+            while (cursor != null && cursor.moveToNext()) {
+                App.log.fine("Found dirty exception, increasing SEQUENCE to re-schedule");
+                long    id = cursor.getLong(0),             // can't be null (by definition)
+                        originalID = cursor.getLong(1);     // can't be null (by query)
+                int sequence = cursor.isNull(2) ? 0 : cursor.getInt(2);
+
+                BatchOperation batch = new BatchOperation(provider);
+                // original event to DIRTY
+                batch.enqueue(ContentProviderOperation.newUpdate(
+                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
+                        .withValue(Events.DIRTY, DIRTY_DONT_INCREASE_SEQUENCE)
+                        .build());
+                // increase SEQUENCE and set DIRTY to 0
+                batch.enqueue(ContentProviderOperation.newUpdate(
+                                syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
+                                .withValue(LocalEvent.COLUMN_SEQUENCE, sequence + 1)
+                                .withValue(Events.DIRTY, 0)
+                                .build());
+                batch.commit();
+            }
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't process locally modified exception", e);
+        }
+    }
+
+
+    public static class Factory implements AndroidCalendarFactory {
+        public static final Factory INSTANCE = new Factory();
+
+        @Override
+        public AndroidCalendar newInstance(Account account, ContentProviderClient provider, long id) {
+            return new LocalCalendar(account, provider, id);
+        }
+
+        @Override
+        public AndroidCalendar[] newArray(int size) {
+            return new LocalCalendar[size];
+        }
+    }
+}
@@ -1,236 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.accounts.Account
-import android.content.ContentProviderClient
-import android.content.ContentProviderOperation
-import android.content.ContentUris
-import android.content.ContentValues
-import android.net.Uri
-import android.os.RemoteException
-import android.provider.CalendarContract
-import android.provider.CalendarContract.*
-import at.bitfire.davdroid.DavUtils
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.ical4android.*
-import java.io.FileNotFoundException
-import java.util.*
-import java.util.logging.Level
-
-class LocalCalendar private constructor(
-        account: Account,
-        provider: ContentProviderClient,
-        id: Long
-): AndroidCalendar<LocalEvent>(account, provider, LocalEvent.Factory, id), LocalCollection<LocalEvent> {
-
-    companion object {
-
-        val defaultColor = 0xFF8bc34a.toInt()     // light green 500
-
-        val COLUMN_CTAG = Calendars.CAL_SYNC1
-
-        val BASE_INFO_COLUMNS = arrayOf(
-            Events._ID,
-            Events._SYNC_ID,
-            LocalEvent.COLUMN_ETAG
-        )
-
-
-        @Throws(CalendarStorageException::class)
-        fun create(account: Account, provider: ContentProviderClient, info: CollectionInfo): Uri {
-            val values = valuesFromCollectionInfo(info, true)
-
-            // ACCOUNT_NAME and ACCOUNT_TYPE are required (see docs)! If it's missing, other apps will crash.
-            values.put(Calendars.ACCOUNT_NAME, account.name)
-            values.put(Calendars.ACCOUNT_TYPE, account.type)
-            values.put(Calendars.OWNER_ACCOUNT, account.name)
-
-            // flag as visible & synchronizable at creation, might be changed by user at any time
-            values.put(Calendars.VISIBLE, 1)
-            values.put(Calendars.SYNC_EVENTS, 1)
-            return create(account, provider, values)
-        }
-
-        private fun valuesFromCollectionInfo(info: CollectionInfo, withColor: Boolean): ContentValues {
-            val values = ContentValues()
-            values.put(Calendars.NAME, info.url)
-            values.put(Calendars.CALENDAR_DISPLAY_NAME, if (info.displayName.isNullOrBlank()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
-
-            if (withColor)
-                values.put(Calendars.CALENDAR_COLOR, info.color ?: defaultColor)
-
-            if (info.readOnly || info.forceReadOnly)
-                values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_READ)
-            else {
-                values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER)
-                values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1)
-                values.put(Calendars.CAN_ORGANIZER_RESPOND, 1)
-            }
-
-            info.timeZone?.let { tzData ->
-                try {
-                    val timeZone = DateUtils.parseVTimeZone(tzData)
-                    timeZone.timeZoneId?.let { tzId ->
-                        values.put(Calendars.CALENDAR_TIME_ZONE, DateUtils.findAndroidTimezoneID(tzId.value))
-                    }
-                } catch(e: IllegalArgumentException) {
-                    Logger.log.log(Level.WARNING, "Couldn't parse calendar default time zone", e)
-                }
-            }
-            values.put(Calendars.ALLOWED_REMINDERS, "${Reminders.METHOD_ALERT},${Reminders.METHOD_EMAIL}")
-            values.put(Calendars.ALLOWED_AVAILABILITY, "${Reminders.AVAILABILITY_TENTATIVE},${Reminders.AVAILABILITY_FREE},${Reminders.AVAILABILITY_BUSY}")
-            values.put(Calendars.ALLOWED_ATTENDEE_TYPES, "${CalendarContract.Attendees.TYPE_OPTIONAL},${CalendarContract.Attendees.TYPE_REQUIRED},${CalendarContract.Attendees.TYPE_RESOURCE}")
-            return values
-        }
-
-    }
-
-
-    override fun eventBaseInfoColumns() = BASE_INFO_COLUMNS
-
-
-    @Throws(CalendarStorageException::class)
-    fun update(info: CollectionInfo, updateColor: Boolean) =
-            update(valuesFromCollectionInfo(info, updateColor))
-
-    @Throws(CalendarStorageException::class)
-    override fun getAll(): List<LocalEvent> =
-            queryEvents("${Events.ORIGINAL_ID} IS NULL", null)
-
-    @Throws(CalendarStorageException::class)
-    override fun getDeleted() =
-            queryEvents("${Events.DELETED}!=0 AND ${Events.ORIGINAL_ID} IS NULL", null)
-
-    @Throws(CalendarStorageException::class)
-    override fun getWithoutFileName() =
-            queryEvents("${Events._SYNC_ID} IS NULL AND ${Events.ORIGINAL_ID} IS NULL", null)
-
-    @Throws(FileNotFoundException::class, CalendarStorageException::class)
-    override fun getDirty(): List<LocalEvent> {
-        val dirty = LinkedList<LocalEvent>()
-
-        // get dirty events which are required to have an increased SEQUENCE value
-        for (localEvent in queryEvents("${Events.DIRTY}!=0 AND ${Events.ORIGINAL_ID} IS NULL", null)) {
-            val event = localEvent.event!!
-            val sequence = event.sequence
-            if (event.sequence == null)      // sequence has not been assigned yet (i.e. this event was just locally created)
-                event.sequence = 0
-            else if (localEvent.weAreOrganizer)
-                event.sequence = sequence!! + 1
-            dirty += localEvent
-        }
-
-        return dirty
-    }
-
-    @Throws(CalendarStorageException::class)
-    override fun getCTag(): String? =
-        try {
-            provider.query(calendarSyncURI(), arrayOf(COLUMN_CTAG), null, null, null)?.use { cursor ->
-                if (cursor.moveToNext())
-                    return cursor.getString(0)
-            }
-            null
-        } catch (e: RemoteException) {
-            throw CalendarStorageException("Couldn't read local (last known) CTag", e)
-        }
-
-    @Throws(CalendarStorageException::class)
-    override fun setCTag(cTag: String?) {
-        try {
-            val values = ContentValues(1)
-            values.put(COLUMN_CTAG, cTag)
-            provider.update(calendarSyncURI(), values, null, null)
-        } catch (e: RemoteException) {
-            throw CalendarStorageException("Couldn't write local (last known) CTag", e)
-        }
-    }
-
-    @Throws(CalendarStorageException::class)
-    fun processDirtyExceptions() {
-        try {
-            // process deleted exceptions
-            Logger.log.info("Processing deleted exceptions")
-            provider.query(
-                    syncAdapterURI(Events.CONTENT_URI),
-                    arrayOf(Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE),
-                    "${Events.DELETED}!=0 AND ${Events.ORIGINAL_ID} IS NOT NULL", null, null)?.use { cursor ->
-                while (cursor.moveToNext()) {
-                    Logger.log.fine("Found deleted exception, removing; then re-scheduling original event")
-                    val id = cursor.getLong(0)             // can't be null (by definition)
-                    val originalID = cursor.getLong(1)     // can't be null (by query)
-
-                    val batch = BatchOperation(provider)
-
-                    // get original event's SEQUENCE
-                    provider.query(
-                            syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)),
-                            arrayOf(LocalEvent.COLUMN_SEQUENCE),
-                            null, null, null)?.use { cursor2 ->
-                        val originalSequence = if (cursor2.isNull(0)) 0 else cursor2.getInt(0)
-
-                        // re-schedule original event and set it to DIRTY
-                        batch.enqueue(BatchOperation.Operation(
-                                ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                                        .withValue(LocalEvent.COLUMN_SEQUENCE, originalSequence + 1)
-                                        .withValue(Events.DIRTY, 1)
-                        ))
-                    }
-
-                    // remove exception
-                    batch.enqueue(BatchOperation.Operation(
-                            ContentProviderOperation.newDelete(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
-                    ))
-                    batch.commit()
-                }
-            }
-
-            // process dirty exceptions
-            Logger.log.info("Processing dirty exceptions")
-            provider.query(
-                    syncAdapterURI(Events.CONTENT_URI),
-                    arrayOf(Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE),
-                    "${Events.DIRTY}!=0 AND ${Events.ORIGINAL_ID} IS NOT NULL", null, null)?.use { cursor ->
-                while (cursor.moveToNext()) {
-                    Logger.log.fine("Found dirty exception, increasing SEQUENCE to re-schedule")
-                    val id = cursor.getLong(0)             // can't be null (by definition)
-                    val originalID = cursor.getLong(1)     // can't be null (by query)
-                    val sequence = if (cursor.isNull(2)) 0 else cursor.getInt(2)
-
-                    val batch = BatchOperation(provider)
-                    // original event to DIRTY
-                    batch.enqueue(BatchOperation.Operation (
-                            ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                                    .withValue(Events.DIRTY, 1)
-                    ))
-                    // increase SEQUENCE and set DIRTY to 0
-                    batch.enqueue(BatchOperation.Operation (
-                            ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
-                                    .withValue(LocalEvent.COLUMN_SEQUENCE, sequence + 1)
-                                    .withValue(Events.DIRTY, 0)
-                    ))
-                    batch.commit()
-                }
-            }
-        } catch (e: RemoteException) {
-            throw CalendarStorageException("Couldn't process locally modified exception", e)
-        }
-    }
-
-
-    object Factory: AndroidCalendarFactory<LocalCalendar> {
-
-        override fun newInstance(account: Account, provider: ContentProviderClient, id: Long) =
-            LocalCalendar(account, provider, id)
-
-    }
-
-}
@@ -0,0 +1,26 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import java.io.FileNotFoundException;
+
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.vcard4android.ContactsStorageException;
+
+public interface LocalCollection {
+
+    LocalResource[] getDeleted() throws CalendarStorageException, ContactsStorageException;
+    LocalResource[] getWithoutFileName()  throws CalendarStorageException, ContactsStorageException;
+    LocalResource[] getDirty() throws CalendarStorageException, ContactsStorageException, FileNotFoundException;
+
+    LocalResource[] getAll() throws CalendarStorageException, ContactsStorageException;
+
+    String getCTag() throws CalendarStorageException, ContactsStorageException;
+    void setCTag(String cTag) throws CalendarStorageException, ContactsStorageException;
+}
@@ -1,35 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import at.bitfire.ical4android.CalendarStorageException
-import at.bitfire.vcard4android.ContactsStorageException
-import java.io.FileNotFoundException
-
-interface LocalCollection<out T: LocalResource> {
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun getDeleted(): List<T>
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun getWithoutFileName(): List<T>
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class, FileNotFoundException::class)
-    fun getDirty(): List<T>
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun getAll(): List<T>
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun getCTag(): String?
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun setCTag(cTag: String?)
-
-}
@@ -0,0 +1,143 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.content.ContentProviderOperation;
+import android.content.ContentValues;
+import android.os.RemoteException;
+import android.provider.ContactsContract;
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
+
+import java.io.FileNotFoundException;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.vcard4android.AndroidAddressBook;
+import at.bitfire.vcard4android.AndroidContact;
+import at.bitfire.vcard4android.AndroidContactFactory;
+import at.bitfire.vcard4android.BatchOperation;
+import at.bitfire.vcard4android.Contact;
+import at.bitfire.vcard4android.ContactsStorageException;
+import ezvcard.Ezvcard;
+
+public class LocalContact extends AndroidContact implements LocalResource {
+    static {
+        Contact.productID = "+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " vcard4android ez-vcard/" + Ezvcard.VERSION;
+    }
+
+    protected LocalContact(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
+        super(addressBook, id, fileName, eTag);
+    }
+
+    public LocalContact(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
+        super(addressBook, contact, fileName, eTag);
+    }
+
+    public void clearDirty(String eTag) throws ContactsStorageException {
+        try {
+            ContentValues values = new ContentValues(1);
+            values.put(ContactsContract.RawContacts.DIRTY, 0);
+            values.put(COLUMN_ETAG, eTag);
+            addressBook.provider.update(rawContactSyncURI(), values, null, null);
+
+            this.eTag = eTag;
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't clear dirty flag", e);
+        }
+    }
+
+    public void updateFileNameAndUID(String uid) throws ContactsStorageException {
+        try {
+            String newFileName = uid + ".vcf";
+
+            ContentValues values = new ContentValues(2);
+            values.put(COLUMN_FILENAME, newFileName);
+            values.put(COLUMN_UID, uid);
+            addressBook.provider.update(rawContactSyncURI(), values, null, null);
+
+            fileName = newFileName;
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't update UID", e);
+        }
+    }
+
+
+    // group support
+
+    @Override
+    protected void populateGroupMembership(ContentValues row) {
+        if (row.containsKey(GroupMembership.GROUP_ROW_ID)) {
+            long groupId = row.getAsLong(GroupMembership.GROUP_ROW_ID);
+
+            // fetch group
+            LocalGroup group = new LocalGroup(addressBook, groupId);
+            try {
+                Contact groupInfo = group.getContact();
+
+                // add to CATEGORIES
+                contact.categories.add(groupInfo.displayName);
+            } catch (FileNotFoundException|ContactsStorageException e) {
+                App.log.log(Level.WARNING, "Couldn't find assigned group #" + groupId + ", ignoring membership", e);
+            }
+        }
+    }
+
+    @Override
+    protected void insertGroupMemberships(BatchOperation batch) throws ContactsStorageException {
+        for (String category : contact.categories) {
+            // Is there already a category with this display name?
+            LocalGroup group = ((LocalAddressBook)addressBook).findGroupByTitle(category);
+
+            if (group == null) {
+                // no, we have to create the group before inserting the membership
+
+                Contact groupInfo = new Contact();
+                groupInfo.displayName = category;
+                group = new LocalGroup(addressBook, groupInfo);
+                group.create();
+            }
+
+            Long groupId = group.getId();
+            if (groupId != null) {
+                ContentProviderOperation.Builder builder = ContentProviderOperation.newInsert(dataSyncURI());
+                if (id == null)
+                    builder.withValueBackReference(GroupMembership.RAW_CONTACT_ID, 0);
+                else
+                    builder.withValue(GroupMembership.RAW_CONTACT_ID, id);
+                builder .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
+                        .withValue(GroupMembership.GROUP_ROW_ID, groupId);
+                batch.enqueue(builder.build());
+            }
+        }
+    }
+
+
+    // factory
+
+    static class Factory extends AndroidContactFactory {
+        static final Factory INSTANCE = new Factory();
+
+        @Override
+        public LocalContact newInstance(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
+            return new LocalContact(addressBook, id, fileName, eTag);
+        }
+
+        @Override
+        public LocalContact newInstance(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
+            return new LocalContact(addressBook, contact, fileName, eTag);
+        }
+
+        public LocalContact[] newArray(int size) {
+            return new LocalContact[size];
+        }
+
+    }
+
+}
@@ -1,284 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.content.ContentProviderOperation
-import android.content.ContentValues
-import android.os.Build
-import android.os.RemoteException
-import android.provider.ContactsContract
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership
-import android.provider.ContactsContract.RawContacts.Data
-import at.bitfire.davdroid.BuildConfig
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.UnknownProperties
-import at.bitfire.vcard4android.*
-import ezvcard.Ezvcard
-import java.io.FileNotFoundException
-import java.util.*
-
-class LocalContact: AndroidContact, LocalResource {
-
-    companion object {
-
-        init {
-            Contact.productID = "+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ez-vcard/" + Ezvcard.VERSION
-        }
-
-        val COLUMN_HASHCODE = ContactsContract.RawContacts.SYNC3
-
-    }
-
-    private val cachedGroupMemberships = HashSet<Long>()
-    private val groupMemberships = HashSet<Long>()
-
-
-    constructor(addressBook: AndroidAddressBook<LocalContact,*>, id: Long, fileName: String?, eTag: String?):
-            super(addressBook, id, fileName, eTag)
-
-    constructor(addressBook: AndroidAddressBook<LocalContact,*>, contact: Contact, fileName: String?, eTag: String?):
-            super(addressBook, contact, fileName, eTag)
-
-
-    @Throws(ContactsStorageException::class)
-    fun resetDeleted() {
-        val values = ContentValues(1)
-        values.put(ContactsContract.RawContacts.DELETED, 0)
-        try {
-            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't clear deleted flag", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun resetDirty() {
-        val values = ContentValues(1)
-        values.put(ContactsContract.RawContacts.DIRTY, 0)
-        try {
-            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't clear dirty flag", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun clearDirty(eTag: String?) {
-        try {
-            val values = ContentValues(3)
-            values.put(COLUMN_ETAG, eTag)
-            values.put(ContactsContract.RawContacts.DIRTY, 0)
-
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
-                // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                val hashCode = dataHashCode()
-                values.put(COLUMN_HASHCODE, hashCode)
-                Logger.log.finer("Clearing dirty flag with eTag = $eTag, contact hash = $hashCode")
-            }
-
-            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
-
-            this.eTag = eTag
-        } catch(e: Exception) {
-            throw ContactsStorageException("Couldn't clear dirty flag", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun prepareForUpload() {
-        try {
-            val uid = UUID.randomUUID().toString()
-            val newFileName = uid + ".vcf"
-
-            val values = ContentValues(2)
-            values.put(COLUMN_FILENAME, newFileName)
-            values.put(COLUMN_UID, uid)
-            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
-
-            fileName = newFileName
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't update UID", e)
-        }
-    }
-
-
-    @Throws(ContactsStorageException::class)
-    override fun populateData(mimeType: String, row: ContentValues) {
-        when (mimeType) {
-            CachedGroupMembership.CONTENT_ITEM_TYPE ->
-                cachedGroupMemberships.add(row.getAsLong(CachedGroupMembership.GROUP_ID))
-            GroupMembership.CONTENT_ITEM_TYPE ->
-                groupMemberships.add(row.getAsLong(GroupMembership.GROUP_ROW_ID))
-            UnknownProperties.CONTENT_ITEM_TYPE ->
-                try {
-                    contact!!.unknownProperties = row.getAsString(UnknownProperties.UNKNOWN_PROPERTIES)
-                } catch(e: FileNotFoundException) {
-                    throw ContactsStorageException("Couldn't fetch data rows", e)
-                }
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun insertDataRows(batch: BatchOperation) {
-        super.insertDataRows(batch)
-
-        try {
-            contact!!.unknownProperties?.let { unknownProperties ->
-                val op: BatchOperation.Operation
-                val builder = ContentProviderOperation.newInsert(dataSyncURI())
-                if (id == null)
-                    op = BatchOperation.Operation(builder, UnknownProperties.RAW_CONTACT_ID, 0)
-                else {
-                    op = BatchOperation.Operation(builder)
-                    builder.withValue(UnknownProperties.RAW_CONTACT_ID, id)
-                }
-                builder .withValue(UnknownProperties.MIMETYPE, UnknownProperties.CONTENT_ITEM_TYPE)
-                        .withValue(UnknownProperties.UNKNOWN_PROPERTIES, unknownProperties)
-                batch.enqueue(op)
-            }
-        } catch(e: FileNotFoundException) {
-            throw ContactsStorageException("Couldn't insert data rows", e)
-        }
-
-    }
-
-
-    /**
-     * Calculates a hash code from the contact's data (VCard) and group memberships.
-     * Attention: re-reads {@link #contact} from the database, discarding all changes in memory
-     * @return hash code of contact data (including group memberships)
-     */
-    @Throws(FileNotFoundException::class, ContactsStorageException::class)
-    internal fun dataHashCode(): Int {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
-            throw IllegalStateException("dataHashCode() should not be called on Android != 7")
-
-        // reset contact so that getContact() reads from database
-        contact = null
-
-        // groupMemberships is filled by getContact()
-        val dataHash = contact!!.hashCode()
-        val groupHash = groupMemberships.hashCode()
-        Logger.log.finest("Calculated data hash = $dataHash, group memberships hash = $groupHash")
-        return dataHash xor groupHash
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun updateHashCode(batch: BatchOperation?) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
-            throw IllegalStateException("updateHashCode() should not be called on Android != 7")
-
-        val values = ContentValues(1)
-        try {
-            val hashCode = dataHashCode()
-            Logger.log.fine("Storing contact hash = $hashCode")
-            values.put(COLUMN_HASHCODE, hashCode)
-
-            if (batch == null)
-                addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
-            else {
-                val builder = ContentProviderOperation
-                        .newUpdate(rawContactSyncURI())
-                        .withValues(values)
-                batch.enqueue(BatchOperation.Operation(builder))
-            }
-        } catch(e: Exception) {
-            throw ContactsStorageException("Couldn't store contact checksum", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    fun getLastHashCode(): Int {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
-            throw IllegalStateException("getLastHashCode() should not be called on Android != 7")
-
-        try {
-            addressBook.provider!!.query(rawContactSyncURI(), arrayOf(COLUMN_HASHCODE), null, null, null)?.use { c ->
-                if (c.moveToNext() && !c.isNull(0))
-                    return c.getInt(0)
-            }
-            return 0
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Could't read last hash code", e)
-        }
-    }
-
-
-    fun addToGroup(batch: BatchOperation, groupID: Long) {
-        batch.enqueue(BatchOperation.Operation(
-                ContentProviderOperation.newInsert(dataSyncURI())
-                        .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
-                        .withValue(GroupMembership.RAW_CONTACT_ID, id)
-                        .withValue(GroupMembership.GROUP_ROW_ID, groupID)
-        ))
-        groupMemberships.add(groupID)
-
-        batch.enqueue(BatchOperation.Operation(
-                ContentProviderOperation.newInsert(dataSyncURI())
-                        .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                        .withValue(CachedGroupMembership.RAW_CONTACT_ID, id)
-                        .withValue(CachedGroupMembership.GROUP_ID, groupID)
-                        .withYieldAllowed(true)
-        ))
-        cachedGroupMemberships.add(groupID)
-    }
-
-    fun removeGroupMemberships(batch: BatchOperation) {
-        batch.enqueue(BatchOperation.Operation(
-                ContentProviderOperation.newDelete(dataSyncURI())
-                        .withSelection(
-                                Data.RAW_CONTACT_ID + "=? AND " + Data.MIMETYPE + " IN (?,?)",
-                                arrayOf(id.toString(), GroupMembership.CONTENT_ITEM_TYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                        )
-                        .withYieldAllowed(true)
-        ))
-        groupMemberships.clear()
-        cachedGroupMemberships.clear()
-    }
-
-    /**
-     * Returns the IDs of all groups the contact was member of (cached memberships).
-     * Cached memberships are kept in sync with memberships by DAVdroid and are used to determine
-     * whether a membership has been deleted/added when a raw contact is dirty.
-     * @return set of {@link GroupMembership#GROUP_ROW_ID} (may be empty)
-     * @throws ContactsStorageException   on contact provider errors
-     * @throws FileNotFoundException      if the current contact can't be found
-     */
-    @Throws(FileNotFoundException::class, ContactsStorageException::class)
-    fun getCachedGroupMemberships(): Set<Long> {
-        contact
-        return cachedGroupMemberships
-    }
-
-    /**
-     * Returns the IDs of all groups the contact is member of.
-     * @return set of {@link GroupMembership#GROUP_ROW_ID}s (may be empty)
-     * @throws ContactsStorageException   on contact provider errors
-     * @throws FileNotFoundException      if the current contact can't be found
-     */
-    @Throws(FileNotFoundException::class, ContactsStorageException::class)
-    fun getGroupMemberships(): Set<Long> {
-        contact
-        return groupMemberships
-    }
-
-
-    // factory
-
-    object Factory: AndroidContactFactory<LocalContact> {
-
-        override fun newInstance(addressBook: AndroidAddressBook<LocalContact, *>, id: Long, fileName: String?, eTag: String?) =
-                LocalContact(addressBook, id, fileName, eTag)
-
-        override fun newInstance(addressBook: AndroidAddressBook<LocalContact, *>, contact: Contact, fileName: String?, eTag: String?) =
-                LocalContact(addressBook, contact, fileName, eTag)
-
-    }
-
-}
@@ -0,0 +1,146 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.annotation.TargetApi;
+import android.content.ContentProviderOperation;
+import android.content.ContentValues;
+import android.os.Build;
+import android.os.RemoteException;
+import android.provider.CalendarContract;
+import android.provider.CalendarContract.Events;
+import android.support.annotation.NonNull;
+
+import net.fortuna.ical4j.model.property.ProdId;
+
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.ical4android.AndroidCalendar;
+import at.bitfire.ical4android.AndroidEvent;
+import at.bitfire.ical4android.AndroidEventFactory;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.Event;
+import lombok.Getter;
+import lombok.Setter;
+
+@TargetApi(17)
+public class LocalEvent extends AndroidEvent implements LocalResource {
+    static {
+        Event.prodId = new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4android ical4j/2.x");
+    }
+
+    static final String COLUMN_ETAG = CalendarContract.Events.SYNC_DATA1,
+                        COLUMN_UID = Build.VERSION.SDK_INT >= 17 ? Events.UID_2445 : Events.SYNC_DATA2,
+                        COLUMN_SEQUENCE = CalendarContract.Events.SYNC_DATA3;
+
+    @Getter protected String fileName;
+    @Getter @Setter protected String eTag;
+
+    public LocalEvent(@NonNull AndroidCalendar calendar, Event event, String fileName, String eTag) {
+        super(calendar, event);
+        this.fileName = fileName;
+        this.eTag = eTag;
+    }
+
+    protected LocalEvent(@NonNull AndroidCalendar calendar, long id, ContentValues baseInfo) {
+        super(calendar, id, baseInfo);
+        if (baseInfo != null) {
+            fileName = baseInfo.getAsString(Events._SYNC_ID);
+            eTag = baseInfo.getAsString(COLUMN_ETAG);
+        }
+    }
+
+
+    /* process LocalEvent-specific fields */
+
+    @Override
+    protected void populateEvent(ContentValues values) {
+        super.populateEvent(values);
+        fileName = values.getAsString(Events._SYNC_ID);
+        eTag = values.getAsString(COLUMN_ETAG);
+        event.uid = values.getAsString(COLUMN_UID);
+
+        event.sequence = values.getAsInteger(COLUMN_SEQUENCE);
+    }
+
+    @Override
+    protected void buildEvent(Event recurrence, ContentProviderOperation.Builder builder) {
+        super.buildEvent(recurrence, builder);
+
+        boolean buildException = recurrence != null;
+        Event eventToBuild = buildException ? recurrence : event;
+
+        builder .withValue(COLUMN_UID, event.uid)
+                .withValue(COLUMN_SEQUENCE, eventToBuild.sequence)
+                .withValue(CalendarContract.Events.DIRTY, 0)
+                .withValue(CalendarContract.Events.DELETED, 0);
+
+        if (buildException)
+            builder.withValue(Events.ORIGINAL_SYNC_ID, fileName);
+        else
+            builder .withValue(Events._SYNC_ID, fileName)
+                    .withValue(COLUMN_ETAG, eTag);
+    }
+
+
+    /* custom queries */
+
+    public void updateFileNameAndUID(String uid) throws CalendarStorageException {
+        try {
+            String newFileName = uid + ".ics";
+
+            ContentValues values = new ContentValues(2);
+            values.put(Events._SYNC_ID, newFileName);
+            values.put(COLUMN_UID, uid);
+            calendar.provider.update(eventSyncURI(), values, null, null);
+
+            fileName = newFileName;
+            if (event != null)
+                event.uid = uid;
+
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't update UID", e);
+        }
+    }
+
+    @Override
+    public void clearDirty(String eTag) throws CalendarStorageException {
+        try {
+            ContentValues values = new ContentValues(2);
+            values.put(CalendarContract.Events.DIRTY, 0);
+            values.put(COLUMN_ETAG, eTag);
+            if (event != null)
+                values.put(COLUMN_SEQUENCE, event.sequence);
+            calendar.provider.update(eventSyncURI(), values, null, null);
+
+            this.eTag = eTag;
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't update UID", e);
+        }
+    }
+
+
+    static class Factory implements AndroidEventFactory {
+        static final Factory INSTANCE = new Factory();
+
+        @Override
+        public AndroidEvent newInstance(AndroidCalendar calendar, long id, ContentValues baseInfo) {
+            return new LocalEvent(calendar, id, baseInfo);
+        }
+
+        @Override
+        public AndroidEvent newInstance(AndroidCalendar calendar, Event event) {
+            return new LocalEvent(calendar, event, null, null);
+        }
+
+        @Override
+        public AndroidEvent[] newArray(int size) {
+            return new LocalEvent[size];
+        }
+    }
+}
@@ -1,141 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.content.ContentProviderOperation
-import android.content.ContentValues
-import android.provider.CalendarContract
-import android.provider.CalendarContract.Events
-import at.bitfire.davdroid.BuildConfig
-import at.bitfire.ical4android.*
-import net.fortuna.ical4j.model.property.ProdId
-import java.io.FileNotFoundException
-import java.util.*
-
-class LocalEvent: AndroidEvent, LocalResource {
-
-    companion object {
-        init {
-            iCalendar.prodId = ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4j/2.x")
-        }
-
-        val COLUMN_ETAG = CalendarContract.Events.SYNC_DATA1
-        val COLUMN_SEQUENCE = CalendarContract.Events.SYNC_DATA3
-    }
-
-    override var fileName: String? = null
-    override var eTag: String? = null
-
-    var weAreOrganizer = true
-
-
-    constructor(calendar: AndroidCalendar<*>, event: Event, fileName: String?, eTag: String?): super(calendar, event) {
-        this.fileName = fileName
-        this.eTag = eTag
-    }
-
-    private constructor(calendar: AndroidCalendar<*>, id: Long, baseInfo: ContentValues?): super(calendar, id, baseInfo) {
-        baseInfo?.let {
-            fileName = it.getAsString(Events._SYNC_ID)
-            eTag = it.getAsString(COLUMN_ETAG)
-        }
-    }
-
-
-    /* process LocalEvent-specific fields */
-
-    @Throws(FileNotFoundException::class, CalendarStorageException::class)
-    override fun populateEvent(row: ContentValues) {
-        super.populateEvent(row)
-        val event = requireNotNull(event)
-
-        fileName = row.getAsString(Events._SYNC_ID)
-        eTag = row.getAsString(COLUMN_ETAG)
-        event.uid = row.getAsString(Events.UID_2445)
-
-        event.sequence = row.getAsInteger(COLUMN_SEQUENCE)
-        val isOrganizer = row.getAsInteger(Events.IS_ORGANIZER)
-        weAreOrganizer = isOrganizer != null && isOrganizer != 0
-    }
-
-    @Throws(FileNotFoundException::class, CalendarStorageException::class)
-    override fun buildEvent(recurrence: Event?, builder: ContentProviderOperation.Builder) {
-        super.buildEvent(recurrence, builder)
-        val event = requireNotNull(event)
-
-        val buildException = recurrence != null
-        val eventToBuild = recurrence ?: event
-
-        builder .withValue(Events.UID_2445, event.uid)
-                .withValue(COLUMN_SEQUENCE, eventToBuild.sequence)
-                .withValue(CalendarContract.Events.DIRTY, 0)
-                .withValue(CalendarContract.Events.DELETED, 0)
-
-        if (buildException)
-            builder .withValue(Events.ORIGINAL_SYNC_ID, fileName)
-        else
-            builder .withValue(Events._SYNC_ID, fileName)
-                    .withValue(COLUMN_ETAG, eTag)
-    }
-
-
-    /* custom queries */
-
-    @Throws(CalendarStorageException::class)
-    override fun prepareForUpload() {
-        try {
-            var uid: String? = null
-            calendar.provider.query(eventSyncURI(), arrayOf(Events.UID_2445), null, null, null)?.use { cursor ->
-                if (cursor.moveToNext())
-                    uid = cursor.getString(0)
-            }
-            if (uid == null)
-                uid = UUID.randomUUID().toString()
-
-            val newFileName = "$uid.ics"
-
-            val values = ContentValues(2)
-            values.put(Events._SYNC_ID, newFileName)
-            values.put(Events.UID_2445, uid)
-            calendar.provider.update(eventSyncURI(), values, null, null)
-
-            fileName = newFileName
-            event!!.uid = uid
-
-        } catch(e: Exception) {
-            throw CalendarStorageException("Couldn't update UID", e)
-        }
-    }
-
-    @Throws(CalendarStorageException::class)
-    override fun clearDirty(eTag: String?) {
-        try {
-            val values = ContentValues(2)
-            values.put(CalendarContract.Events.DIRTY, 0)
-            values.put(COLUMN_ETAG, eTag)
-            values.put(COLUMN_SEQUENCE, event!!.sequence)
-            calendar.provider.update(eventSyncURI(), values, null, null)
-
-            this.eTag = eTag
-        } catch (e: Exception) {
-            throw CalendarStorageException("Couldn't update UID", e)
-        }
-    }
-
-
-    object Factory: AndroidEventFactory<LocalEvent> {
-
-        override fun newInstance(calendar: AndroidCalendar<*>, id: Long, baseInfo: ContentValues?) =
-                LocalEvent(calendar, id, baseInfo)
-
-        override fun newInstance(calendar: AndroidCalendar<*>, event: Event) =
-                LocalEvent(calendar, event, null, null)
-
-    }
-}
@@ -0,0 +1,35 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.content.ContentValues;
+import android.provider.ContactsContract;
+
+import at.bitfire.vcard4android.AndroidAddressBook;
+import at.bitfire.vcard4android.AndroidGroup;
+import at.bitfire.vcard4android.Contact;
+import at.bitfire.vcard4android.ContactsStorageException;
+
+public class LocalGroup extends AndroidGroup {
+
+    public LocalGroup(AndroidAddressBook addressBook, long id) {
+        super(addressBook, id);
+    }
+
+    public LocalGroup(AndroidAddressBook addressBook, Contact contact) {
+        super(addressBook, contact);
+    }
+
+    public void clearDirty() throws ContactsStorageException {
+        ContentValues values = new ContentValues(1);
+        values.put(ContactsContract.Groups.DIRTY, 0);
+        update(values);
+    }
+
+}
@@ -1,255 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.content.ContentProviderOperation
-import android.content.ContentUris
-import android.content.ContentValues
-import android.os.Build
-import android.os.Parcel
-import android.os.RemoteException
-import android.provider.ContactsContract
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership
-import android.provider.ContactsContract.Groups
-import android.provider.ContactsContract.RawContacts
-import android.provider.ContactsContract.RawContacts.Data
-import at.bitfire.dav4android.Constants
-import at.bitfire.vcard4android.*
-import java.io.FileNotFoundException
-import java.util.*
-import java.util.logging.Level
-
-class LocalGroup: AndroidGroup, LocalResource {
-
-    companion object {
-
-        /** marshaled list of member UIDs, as sent by server */
-        val COLUMN_PENDING_MEMBERS = Groups.SYNC3
-
-        /**
-         * Processes all groups with non-null {@link #COLUMN_PENDING_MEMBERS}: the pending memberships
-         * are (if possible) applied, keeping cached memberships in sync.
-         * @param addressBook    address book to take groups from
-         * @throws ContactsStorageException on contact provider errors
-         */
-        @JvmStatic
-        @Throws(ContactsStorageException::class)
-        fun applyPendingMemberships(addressBook: LocalAddressBook) {
-            try {
-                addressBook.provider!!.query(
-                        addressBook.syncAdapterURI(Groups.CONTENT_URI),
-                        arrayOf(Groups._ID, COLUMN_PENDING_MEMBERS),
-                        "$COLUMN_PENDING_MEMBERS IS NOT NULL", null,
-                        null
-                )?.use { cursor ->
-                    val batch = BatchOperation(addressBook.provider)
-                    while (cursor.moveToNext()) {
-                        val id = cursor.getLong(0)
-                        Constants.log.fine("Assigning members to group $id")
-
-                        // required for workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                        val changeContactIDs = HashSet<Long>()
-
-                        // delete all memberships and cached memberships for this group
-                        for (contact in addressBook.getByGroupMembership(id)) {
-                            contact.removeGroupMemberships(batch)
-                            changeContactIDs.add(contact.id!!)
-                        }
-
-                        // extract list of member UIDs
-                        val members = LinkedList<String>()
-                        val raw = cursor.getBlob(1)
-                        val parcel = Parcel.obtain()
-                        try {
-                            parcel.unmarshall(raw, 0, raw.size)
-                            parcel.setDataPosition(0)
-                            parcel.readStringList(members)
-                        } finally {
-                            parcel.recycle()
-                        }
-
-                        // insert memberships
-                        for (uid in members) {
-                            Constants.log.fine("Assigning member: $uid")
-                            try {
-                                val member = addressBook.findContactByUID(uid)
-                                member.addToGroup(batch, id)
-                                changeContactIDs.add(member.id!!)
-                            } catch(e: FileNotFoundException) {
-                                Constants.log.log(Level.WARNING, "Group member not found: $uid", e)
-                            }
-                        }
-
-                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
-                            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                            changeContactIDs
-                                    .map { LocalContact(addressBook, it, null, null) }
-                                    .forEach { it.updateHashCode(batch) }
-
-                        // remove pending memberships
-                        batch.enqueue(BatchOperation.Operation(
-                                ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))
-                                        .withValue(COLUMN_PENDING_MEMBERS, null)
-                                        .withYieldAllowed(true)
-                                ))
-
-                        batch.commit()
-                    }
-                }
-            } catch(e: RemoteException) {
-                throw ContactsStorageException("Couldn't get pending memberships", e)
-            }
-        }
-
-    }
-
-
-    constructor(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, id: Long, fileName: String?, eTag: String?):
-        super(addressBook, id, fileName, eTag)
-
-    constructor(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, contact: Contact, fileName: String?, eTag: String?):
-        super(addressBook, contact, fileName, eTag)
-
-
-    @Throws(ContactsStorageException::class)
-    fun resetDeleted() {
-        val uri = ContentUris.withAppendedId(addressBook.syncAdapterURI(ContactsContract.Groups.CONTENT_URI), requireNotNull(id))
-
-        val values = ContentValues(1)
-        values.put(ContactsContract.Groups.DELETED, 0)
-        try {
-            addressBook.provider!!.update(uri, values, null, null)
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't clear deleted flag", e)
-        }
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun clearDirty(eTag: String?) {
-        val id = requireNotNull(id)
-
-        val values = ContentValues(2)
-        values.put(Groups.DIRTY, 0)
-        values.put(COLUMN_ETAG, eTag)
-        this.eTag = eTag
-        update(values)
-
-        // update cached group memberships
-        val batch = BatchOperation(addressBook.provider!!)
-
-        // delete cached group memberships
-        batch.enqueue(BatchOperation.Operation(
-                ContentProviderOperation.newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                        .withSelection(
-                                CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?",
-                                arrayOf(CachedGroupMembership.CONTENT_ITEM_TYPE, id.toString())
-                        )
-        ))
-
-        // insert updated cached group memberships
-        for (member in getMembers())
-            batch.enqueue(BatchOperation.Operation(
-                    ContentProviderOperation.newInsert(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                            .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                            .withValue(CachedGroupMembership.RAW_CONTACT_ID, member)
-                            .withValue(CachedGroupMembership.GROUP_ID, id)
-                            .withYieldAllowed(true)
-            ))
-
-        batch.commit()
-    }
-
-    @Throws(ContactsStorageException::class)
-    override fun prepareForUpload() {
-        val uid = UUID.randomUUID().toString()
-        val newFileName = "$uid.vcf"
-
-        val values = ContentValues(2)
-        values.put(COLUMN_FILENAME, newFileName)
-        values.put(COLUMN_UID, uid)
-        update(values)
-
-        fileName = newFileName
-    }
-
-    @Throws(FileNotFoundException::class, ContactsStorageException::class)
-    override fun contentValues(): ContentValues  {
-        val values = super.contentValues()
-
-        val members = Parcel.obtain()
-        try {
-            members.writeStringList(contact!!.members)
-            values.put(COLUMN_PENDING_MEMBERS, members.marshall())
-        } finally {
-            members.recycle()
-        }
-        return values
-    }
-
-
-    /**
-     * Marks all members of the current group as dirty.
-     */
-    @Throws(ContactsStorageException::class)
-    fun markMembersDirty() {
-        val batch = BatchOperation(addressBook.provider!!)
-
-        for (member in getMembers())
-            batch.enqueue(BatchOperation.Operation(
-                    ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, member)))
-                            .withValue(RawContacts.DIRTY, 1)
-                            .withYieldAllowed(true)
-            ))
-
-        batch.commit()
-    }
-
-
-    // helpers
-
-    /**
-     * Lists all members of this group.
-     * @return list of all members' raw contact IDs
-     * @throws ContactsStorageException on contact provider errorst
-     */
-    @Throws(ContactsStorageException::class)
-    internal fun getMembers(): List<Long> {
-        val id = requireNotNull(id)
-        val members = LinkedList<Long>()
-        try {
-            addressBook.provider!!.query(
-                    addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI),
-                    arrayOf(Data.RAW_CONTACT_ID),
-                    "${GroupMembership.MIMETYPE}=? AND ${GroupMembership.GROUP_ROW_ID}=?",
-                    arrayOf(GroupMembership.CONTENT_ITEM_TYPE, id.toString()),
-                    null
-            )?.use { cursor ->
-                while (cursor.moveToNext())
-                    members.add(cursor.getLong(0))
-            }
-        } catch(e: RemoteException) {
-            throw ContactsStorageException("Couldn't list group members", e)
-        }
-        return members
-    }
-
-
-    // factory
-
-    object Factory: AndroidGroupFactory<LocalGroup> {
-
-        override fun newInstance(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, id: Long, fileName: String?, eTag: String?) =
-                LocalGroup(addressBook, id, fileName, eTag)
-
-        override fun newInstance(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, contact: Contact, fileName: String?, eTag: String?) =
-                LocalGroup(addressBook, contact, fileName, eTag)
-
-    }
-
-}
@@ -0,0 +1,26 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.vcard4android.ContactsStorageException;
+
+public interface LocalResource {
+
+    Long getId();
+
+    String getFileName();
+    String getETag();
+
+    int delete() throws CalendarStorageException, ContactsStorageException;
+
+    void updateFileNameAndUID(String uuid) throws CalendarStorageException, ContactsStorageException;
+    void clearDirty(String eTag) throws CalendarStorageException, ContactsStorageException;
+
+}
@@ -1,30 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import at.bitfire.ical4android.CalendarStorageException
-import at.bitfire.vcard4android.ContactsStorageException
-
-interface LocalResource {
-
-    val id: Long?
-
-    var fileName: String?
-    var eTag: String?
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun delete(): Int
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun prepareForUpload()
-
-    @Throws(CalendarStorageException::class, ContactsStorageException::class)
-    fun clearDirty(eTag: String?)
-
-}
@@ -0,0 +1,138 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.content.ContentProviderOperation;
+import android.content.ContentValues;
+import android.os.RemoteException;
+import android.provider.CalendarContract.Events;
+import android.support.annotation.NonNull;
+
+import net.fortuna.ical4j.model.property.ProdId;
+
+import org.dmfs.provider.tasks.TaskContract.Tasks;
+
+import java.io.FileNotFoundException;
+import java.text.ParseException;
+
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.ical4android.AndroidTask;
+import at.bitfire.ical4android.AndroidTaskFactory;
+import at.bitfire.ical4android.AndroidTaskList;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.Task;
+import lombok.Getter;
+import lombok.Setter;
+
+public class LocalTask extends AndroidTask implements LocalResource {
+    static {
+        Task.prodId = new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4android ical4j/2.x");
+    }
+
+    static final String COLUMN_ETAG = Tasks.SYNC1,
+                        COLUMN_UID = Tasks.SYNC2,
+                        COLUMN_SEQUENCE = Tasks.SYNC3;
+
+    @Getter protected String fileName;
+    @Getter @Setter protected String eTag;
+
+    public LocalTask(@NonNull AndroidTaskList taskList, Task task, String fileName, String eTag) {
+        super(taskList, task);
+        this.fileName = fileName;
+        this.eTag = eTag;
+    }
+
+    protected LocalTask(@NonNull AndroidTaskList taskList, long id, ContentValues baseInfo) {
+        super(taskList, id);
+        if (baseInfo != null) {
+            fileName = baseInfo.getAsString(Events._SYNC_ID);
+            eTag = baseInfo.getAsString(COLUMN_ETAG);
+        }
+    }
+
+
+    /* process LocalTask-specific fields */
+
+    @Override
+    protected void populateTask(ContentValues values) throws FileNotFoundException, RemoteException, ParseException {
+        super.populateTask(values);
+
+        fileName = values.getAsString(Events._SYNC_ID);
+        eTag = values.getAsString(COLUMN_ETAG);
+        task.uid = values.getAsString(COLUMN_UID);
+
+        task.sequence = values.getAsInteger(COLUMN_SEQUENCE);
+    }
+
+    @Override
+    protected void buildTask(ContentProviderOperation.Builder builder, boolean update) {
+        super.buildTask(builder, update);
+        builder .withValue(Tasks._SYNC_ID, fileName)
+                .withValue(COLUMN_UID, task.uid)
+                .withValue(COLUMN_SEQUENCE, task.sequence)
+                .withValue(COLUMN_ETAG, eTag);
+    }
+
+
+    /* custom queries */
+
+    public void updateFileNameAndUID(String uid) throws CalendarStorageException {
+        try {
+            String newFileName = uid + ".ics";
+
+            ContentValues values = new ContentValues(2);
+            values.put(Tasks._SYNC_ID, newFileName);
+            values.put(COLUMN_UID, uid);
+            taskList.provider.client.update(taskSyncURI(), values, null, null);
+
+            fileName = newFileName;
+            if (task != null)
+                task.uid = uid;
+
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't update UID", e);
+        }
+    }
+
+    @Override
+    public void clearDirty(String eTag) throws CalendarStorageException {
+        try {
+            ContentValues values = new ContentValues(2);
+            values.put(Tasks._DIRTY, 0);
+            values.put(COLUMN_ETAG, eTag);
+            if (task != null)
+                values.put(COLUMN_SEQUENCE, task.sequence);
+            taskList.provider.client.update(taskSyncURI(), values, null, null);
+
+            this.eTag = eTag;
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't update _DIRTY/ETag/SEQUENCE", e);
+        }
+    }
+
+
+    static class Factory implements AndroidTaskFactory {
+        static final Factory INSTANCE = new Factory();
+
+        @Override
+        public LocalTask newInstance(AndroidTaskList taskList, long id, ContentValues baseInfo) {
+            return new LocalTask(taskList, id, baseInfo);
+        }
+
+        @Override
+        public LocalTask newInstance(AndroidTaskList taskList, Task task) {
+            return new LocalTask(taskList, task, null, null);
+        }
+
+        @Override
+        public LocalTask[] newArray(int size) {
+            return new LocalTask[size];
+        }
+    }
+}
@@ -1,114 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.content.ContentProviderOperation
-import android.content.ContentValues
-import android.provider.CalendarContract.Events
-import at.bitfire.ical4android.*
-import org.dmfs.tasks.contract.TaskContract.Tasks
-import java.io.FileNotFoundException
-import java.text.ParseException
-import java.util.*
-
-class LocalTask: AndroidTask, LocalResource {
-
-    companion object {
-        val COLUMN_ETAG = Tasks.SYNC_VERSION
-        val COLUMN_SEQUENCE = Tasks.SYNC3
-    }
-
-    override var fileName: String? = null
-    override var eTag: String? = null
-
-    constructor(taskList: AndroidTaskList<*>, task: Task, fileName: String?, eTag: String?): super(taskList, task) {
-        this.fileName = fileName
-        this.eTag = eTag
-    }
-
-    private constructor(taskList: AndroidTaskList<*>, id: Long, baseInfo: ContentValues?): super(taskList, id) {
-        baseInfo?.let {
-            fileName = it.getAsString(Events._SYNC_ID)
-            eTag = it.getAsString(COLUMN_ETAG)
-        }
-    }
-
-
-    /* process LocalTask-specific fields */
-
-    @Throws(ParseException::class)
-    override fun populateTask(values: ContentValues) {
-        super.populateTask(values)
-
-        fileName = values.getAsString(Events._SYNC_ID)
-        eTag = values.getAsString(COLUMN_ETAG)
-
-        val task = requireNotNull(task)
-        task.sequence = values.getAsInteger(COLUMN_SEQUENCE)
-    }
-
-    @Throws(FileNotFoundException::class, CalendarStorageException::class)
-    override fun buildTask(builder: ContentProviderOperation.Builder, update: Boolean) {
-        super.buildTask(builder, update)
-        val task = requireNotNull(task)
-
-        builder .withValue(Tasks._SYNC_ID, fileName)
-                .withValue(COLUMN_SEQUENCE, task.sequence)
-                .withValue(COLUMN_ETAG, eTag)
-    }
-
-
-    /* custom queries */
-
-    @Throws(CalendarStorageException::class)
-    override fun prepareForUpload() {
-        try {
-            val uid = UUID.randomUUID().toString()
-            val newFileName = uid + ".ics"
-
-            val values = ContentValues(2)
-            values.put(Tasks._SYNC_ID, newFileName)
-            values.put(Tasks._UID, uid)
-            taskList.provider.client.update(taskSyncURI(), values, null, null)
-
-            fileName = newFileName
-
-            task!!.uid = uid
-        } catch (e: Exception) {
-            throw CalendarStorageException("Couldn't update UID", e)
-        }
-    }
-
-    @Throws(CalendarStorageException::class)
-    override fun clearDirty(eTag: String?) {
-        try {
-            val values = ContentValues(2)
-            values.put(Tasks._DIRTY, 0)
-            values.put(COLUMN_ETAG, eTag)
-
-            values.put(COLUMN_SEQUENCE, task!!.sequence)
-            taskList.provider.client.update(taskSyncURI(), values, null, null)
-
-            this.eTag = eTag
-        } catch (e: Exception) {
-            throw CalendarStorageException("Couldn't update _DIRTY/ETag/SEQUENCE", e)
-        }
-    }
-
-
-    object Factory: AndroidTaskFactory<LocalTask> {
-
-        override fun newInstance(calendar: AndroidTaskList<*>, id: Long, baseInfo: ContentValues?) =
-                LocalTask(calendar, id, baseInfo)
-
-        override fun newInstance(calendar: AndroidTaskList<*>, task: Task) =
-                LocalTask(calendar, task, null, null)
-
-    }
-}
@@ -0,0 +1,167 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource;
+
+import android.accounts.Account;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Build;
+import android.os.RemoteException;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
+
+import org.dmfs.provider.tasks.TaskContract.TaskLists;
+import org.dmfs.provider.tasks.TaskContract.Tasks;
+
+import java.io.FileNotFoundException;
+
+import at.bitfire.davdroid.DavUtils;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.ical4android.AndroidTaskList;
+import at.bitfire.ical4android.AndroidTaskListFactory;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.TaskProvider;
+import lombok.Cleanup;
+
+public class LocalTaskList extends AndroidTaskList implements LocalCollection {
+
+    public static final int defaultColor = 0xFFC3EA6E;     // "DAVdroid green"
+
+    public static final String COLUMN_CTAG = TaskLists.SYNC_VERSION;
+
+    static String[] BASE_INFO_COLUMNS = new String[] {
+            Tasks._ID,
+            Tasks._SYNC_ID,
+            LocalTask.COLUMN_ETAG
+    };
+
+    // can be cached, because after installing OpenTasks, you have to re-install DAVdroid anyway
+    private static Boolean tasksProviderAvailable;
+
+
+    @Override
+    protected String[] taskBaseInfoColumns() {
+        return BASE_INFO_COLUMNS;
+    }
+
+
+    protected LocalTaskList(Account account, TaskProvider provider, long id) {
+        super(account, provider, LocalTask.Factory.INSTANCE, id);
+    }
+
+    public static Uri create(Account account, TaskProvider provider, CollectionInfo info) throws CalendarStorageException {
+        ContentValues values = valuesFromCollectionInfo(info, true);
+        values.put(TaskLists.OWNER, account.name);
+        values.put(TaskLists.SYNC_ENABLED, 1);
+        values.put(TaskLists.VISIBLE, 1);
+        return create(account, provider, values);
+    }
+
+    public void update(CollectionInfo info, boolean updateColor) throws CalendarStorageException {
+        update(valuesFromCollectionInfo(info, updateColor));
+    }
+
+    private static ContentValues valuesFromCollectionInfo(CollectionInfo info, boolean withColor) {
+        ContentValues values = new ContentValues();
+        values.put(TaskLists._SYNC_ID, info.url);
+        values.put(TaskLists.LIST_NAME, !TextUtils.isEmpty(info.displayName) ? info.displayName : DavUtils.lastSegmentOfUrl(info.url));
+
+        if (withColor)
+            values.put(TaskLists.LIST_COLOR, info.color != null ? info.color : defaultColor);
+
+        return values;
+    }
+
+
+    @Override
+    public LocalTask[] getAll() throws CalendarStorageException {
+        return (LocalTask[])queryTasks(null, null);
+    }
+
+    @Override
+    public LocalTask[] getDeleted() throws CalendarStorageException {
+        return (LocalTask[])queryTasks(Tasks._DELETED + "!=0", null);
+    }
+
+    @Override
+    public LocalTask[] getWithoutFileName() throws CalendarStorageException {
+        return (LocalTask[])queryTasks(Tasks._SYNC_ID + " IS NULL", null);
+    }
+
+    @Override
+    public LocalResource[] getDirty() throws CalendarStorageException, FileNotFoundException {
+        LocalTask[] tasks = (LocalTask[])queryTasks(Tasks._DIRTY + "!=0", null);
+        if (tasks != null)
+        for (LocalTask task : tasks) {
+            if (task.getTask().sequence == null)    // sequence has not been assigned yet (i.e. this task was just locally created)
+                task.getTask().sequence = 0;
+            else
+                task.getTask().sequence++;
+        }
+        return tasks;
+    }
+
+
+    @Override
+    @SuppressWarnings("Recycle")
+    public String getCTag() throws CalendarStorageException {
+        try {
+            @Cleanup Cursor cursor = provider.client.query(taskListSyncUri(), new String[] { COLUMN_CTAG }, null, null, null);
+            if (cursor != null && cursor.moveToNext())
+                return cursor.getString(0);
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't read local (last known) CTag", e);
+        }
+        return null;
+    }
+
+    @Override
+    public void setCTag(String cTag) throws CalendarStorageException {
+        try {
+            ContentValues values = new ContentValues(1);
+            values.put(COLUMN_CTAG, cTag);
+            provider.client.update(taskListSyncUri(), values, null, null);
+        } catch (RemoteException e) {
+            throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
+        }
+    }
+
+
+    // helpers
+
+    public static boolean tasksProviderAvailable(@NonNull Context context) {
+        if (tasksProviderAvailable != null)
+            return tasksProviderAvailable;
+        else {
+            if (Build.VERSION.SDK_INT >= 23)
+                return context.getPackageManager().resolveContentProvider(TaskProvider.ProviderName.OpenTasks.authority, 0) != null;
+            else {
+                @Cleanup TaskProvider provider = TaskProvider.acquire(context.getContentResolver(), TaskProvider.ProviderName.OpenTasks);
+                return tasksProviderAvailable = (provider != null);
+            }
+        }
+    }
+
+
+    public static class Factory implements AndroidTaskListFactory {
+        public static final Factory INSTANCE = new Factory();
+
+        @Override
+        public AndroidTaskList newInstance(Account account, TaskProvider provider, long id) {
+            return new LocalTaskList(account, provider, id);
+        }
+
+        @Override
+        public AndroidTaskList[] newArray(int size) {
+            return new LocalTaskList[size];
+        }
+    }
+}
@@ -1,164 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource
-
-import android.accounts.Account
-import android.content.ContentProviderClient
-import android.content.ContentResolver
-import android.content.ContentValues
-import android.content.Context
-import android.net.Uri
-import android.os.Build
-import at.bitfire.davdroid.DavUtils
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.ical4android.AndroidTaskList
-import at.bitfire.ical4android.AndroidTaskListFactory
-import at.bitfire.ical4android.CalendarStorageException
-import at.bitfire.ical4android.TaskProvider
-import org.dmfs.tasks.contract.TaskContract.TaskLists
-import org.dmfs.tasks.contract.TaskContract.Tasks
-import java.io.FileNotFoundException
-
-class LocalTaskList private constructor(
-        account: Account,
-        provider: TaskProvider,
-        id: Long
-): AndroidTaskList<LocalTask>(account, provider, LocalTask.Factory, id), LocalCollection<LocalTask> {
-
-    companion object {
-
-        val defaultColor = 0xFFC3EA6E.toInt()     // "DAVdroid green"
-
-        val COLUMN_CTAG = TaskLists.SYNC_VERSION
-
-        val BASE_INFO_COLUMNS = arrayOf(
-            Tasks._ID,
-            Tasks._SYNC_ID,
-            LocalTask.COLUMN_ETAG
-        )
-
-        @JvmStatic
-        fun tasksProviderAvailable(context: Context): Boolean {
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
-                return context.packageManager.resolveContentProvider(TaskProvider.ProviderName.OpenTasks.authority, 0) != null
-            else {
-                val provider = TaskProvider.acquire(context, TaskProvider.ProviderName.OpenTasks)
-                provider?.use { return true }
-                return false
-            }
-        }
-
-        @JvmStatic
-        @Throws(CalendarStorageException::class)
-        fun create(account: Account, provider: TaskProvider, info: CollectionInfo): Uri {
-            val values = valuesFromCollectionInfo(info, true)
-            values.put(TaskLists.OWNER, account.name)
-            values.put(TaskLists.SYNC_ENABLED, 1)
-            values.put(TaskLists.VISIBLE, 1)
-            return create(account, provider, values)
-        }
-
-        @JvmStatic
-        @Throws(Exception::class)
-        fun onRenameAccount(resolver: ContentResolver, oldName: String, newName: String) {
-            var client: ContentProviderClient? = null
-            try {
-                client = resolver.acquireContentProviderClient(TaskProvider.ProviderName.OpenTasks.authority)
-                client?.use {
-                    val values = ContentValues(1)
-                    values.put(Tasks.ACCOUNT_NAME, newName)
-                    it.update(Tasks.getContentUri(TaskProvider.ProviderName.OpenTasks.authority), values, "${Tasks.ACCOUNT_NAME}=?", arrayOf(oldName))
-                }
-            } finally {
-                if (Build.VERSION.SDK_INT >= 24)
-                    client?.close()
-                else
-                    client?.release()
-            }
-        }
-
-        private fun valuesFromCollectionInfo(info: CollectionInfo, withColor: Boolean): ContentValues {
-            val values = ContentValues(3)
-            values.put(TaskLists._SYNC_ID, info.url)
-            values.put(TaskLists.LIST_NAME, if (info.displayName.isNullOrBlank()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
-
-            if (withColor)
-                values.put(TaskLists.LIST_COLOR, info.color ?: defaultColor)
-
-            return values
-        }
-
-    }
-
-
-    override fun taskBaseInfoColumns() = BASE_INFO_COLUMNS
-
-
-    @Throws(CalendarStorageException::class)
-    fun update(info: CollectionInfo, updateColor: Boolean) {
-        update(valuesFromCollectionInfo(info, updateColor))
-    }
-
-
-    @Throws(CalendarStorageException::class)
-    override fun getAll() = queryTasks(null, null)
-
-    @Throws(CalendarStorageException::class)
-    override fun getDeleted() = queryTasks("${Tasks._DELETED}!=0", null)
-
-    @Throws(CalendarStorageException::class)
-    override fun getWithoutFileName() = queryTasks("${Tasks._SYNC_ID} IS NULL", null)
-
-    @Throws(FileNotFoundException::class, CalendarStorageException::class)
-    override fun getDirty(): List<LocalTask> {
-        val tasks = queryTasks("${Tasks._DIRTY}!=0", null)
-        for (localTask in tasks) {
-            val task = requireNotNull(localTask.task)
-            val sequence = task.sequence
-            if (sequence == null)    // sequence has not been assigned yet (i.e. this task was just locally created)
-                task.sequence = 0
-            else
-                task.sequence = sequence + 1
-        }
-        return tasks
-    }
-
-
-    @Throws(CalendarStorageException::class)
-    override fun getCTag(): String? =
-        try {
-            provider.client.query(taskListSyncUri(), arrayOf(COLUMN_CTAG), null, null, null)?.use { cursor ->
-                if (cursor.moveToNext())
-                    return cursor.getString(0)
-            }
-            null
-        } catch(e: Exception) {
-            throw CalendarStorageException("Couldn't read local (last known) CTag", e)
-        }
-
-    @Throws(CalendarStorageException::class)
-    override fun setCTag(cTag: String?) {
-        try {
-            val values = ContentValues(1)
-            values.put(COLUMN_CTAG, cTag)
-            provider.client.update(taskListSyncUri(), values, null, null)
-        } catch (e: Exception) {
-            throw CalendarStorageException("Couldn't write local (last known) CTag", e)
-        }
-    }
-
-
-    object Factory: AndroidTaskListFactory<LocalTaskList> {
-
-        override fun newInstance(account: Account, provider: TaskProvider, id: Long) =
-                LocalTaskList(account, provider, id)
-
-    }
-
-}
@@ -1,74 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import at.bitfire.davdroid.App
-
-open class DefaultsProvider(
-        private val allowOverride: Boolean = true
-): Provider {
-
-    open val booleanDefaults = mapOf(
-            Pair(App.DISTRUST_SYSTEM_CERTIFICATES, false),
-            Pair(App.OVERRIDE_PROXY, false)
-    )
-
-    open val intDefaults = mapOf(
-            Pair(App.OVERRIDE_PROXY_PORT, App.OVERRIDE_PROXY_PORT_DEFAULT)
-    )
-
-    open val longDefaults = mapOf<String, Long>()
-
-    open val stringDefaults = mapOf(
-            Pair(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT)
-    )
-
-
-    override fun close() {
-    }
-
-    override fun forceReload() {
-    }
-
-
-    private fun hasKey(key: String) =
-            booleanDefaults.containsKey(key) ||
-            intDefaults.containsKey(key) ||
-            longDefaults.containsKey(key) ||
-            stringDefaults.containsKey(key)
-
-    override fun has(key: String): Pair<Boolean, Boolean> {
-        val has = hasKey(key)
-        return Pair(has, allowOverride || !has)
-    }
-
-
-    override fun getBoolean(key: String) =
-            Pair(booleanDefaults[key], allowOverride || !booleanDefaults.containsKey(key))
-
-    override fun getInt(key: String) =
-            Pair(intDefaults[key], allowOverride || !intDefaults.containsKey(key))
-
-    override fun getLong(key: String) =
-            Pair(longDefaults[key], allowOverride || !longDefaults.containsKey(key))
-
-    override fun getString(key: String) =
-            Pair(stringDefaults[key], allowOverride || !stringDefaults.containsKey(key))
-
-
-    override fun isWritable(key: String) = Pair(false, allowOverride || !hasKey(key))
-
-    override fun putBoolean(key: String, value: Boolean?) = false
-    override fun putInt(key: String, value: Int?) = false
-    override fun putLong(key: String, value: Long?) = false
-    override fun putString(key: String, value: String?) = false
-
-    override fun remove(key: String) = false
-
-}
@@ -1,38 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import java.io.Closeable
-
-interface Provider: Closeable {
-
-    fun forceReload()
-
-    fun has(key: String): Pair<Boolean, Boolean>
-
-    fun getBoolean(key: String): Pair<Boolean?, Boolean>
-    fun getInt(key: String): Pair<Int?, Boolean>
-    fun getLong(key: String): Pair<Long?, Boolean>
-    fun getString(key: String): Pair<String?, Boolean>
-
-    fun isWritable(key: String): Pair<Boolean, Boolean>
-
-    fun putBoolean(key: String, value: Boolean?): Boolean
-    fun putInt(key: String, value: Int?): Boolean
-    fun putLong(key: String, value: Long?): Boolean
-    fun putString(key: String, value: String?): Boolean
-
-    fun remove(key: String): Boolean
-
-
-    interface Observer {
-        fun onReload()
-    }
-
-}
@@ -1,276 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import android.annotation.TargetApi
-import android.app.Service
-import android.content.ComponentName
-import android.content.Context
-import android.content.Intent
-import android.content.ServiceConnection
-import android.os.Build
-import android.os.Handler
-import android.os.IBinder
-import android.os.Looper
-import at.bitfire.davdroid.log.Logger
-import java.io.Closeable
-import java.lang.ref.WeakReference
-import java.util.*
-import java.util.logging.Level
-
-class Settings: Service(), Provider.Observer {
-
-    private val providers = LinkedList<Provider>()
-    private val observers = LinkedList<WeakReference<ISettingsObserver>>()
-
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    override fun onCreate() {
-        Logger.log.info("Initializing Settings service")
-
-        // always add a defaults provider first
-        providers.add(DefaultsProvider())
-
-        // always add a provider for local preferences
-        providers.add(SharedPreferencesProvider(this))
-    }
-
-    override fun onDestroy() {
-        Logger.log.info("Shutting down Settings service")
-        providers.forEach { it.close() }
-        providers.clear()
-    }
-
-    override fun onTrimMemory(level: Int) {
-        stopSelf()
-    }
-
-
-    fun forceReload() {
-        providers.forEach { it.forceReload() }
-    }
-
-    override fun onReload() {
-        observers.forEach {
-            Handler(Looper.getMainLooper()).post {
-                it.get()?.onSettingsChanged()
-            }
-        }
-    }
-
-
-    private fun has(key: String): Boolean {
-        Logger.log.fine("Looking for setting $key")
-        var result = false
-        for (provider in providers)
-            try {
-                val (value, further) = provider.has(key)
-                Logger.log.finer("${provider::class.java.simpleName}: has $key = $value, continue: $further")
-                if (value) {
-                    result = true
-                    break
-                }
-                if (!further)
-                    break
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't look up setting in $provider", e)
-            }
-        Logger.log.fine("Looking for setting $key -> $result")
-        return result
-    }
-
-    private fun<T> getValue(key: String, reader: (Provider) -> Pair<T?, Boolean>): T? {
-        Logger.log.fine("Looking up setting $key")
-        var result: T? = null
-        for (provider in providers)
-            try {
-                val (value, further) = reader(provider)
-                Logger.log.finer("${provider::class.java.simpleName}: value = $value, continue: $further")
-                value?.let { result = it }
-                if (!further)
-                    break
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't read setting from $provider", e)
-            }
-        Logger.log.fine("Looked up setting $key -> $result")
-        return result
-    }
-
-    fun getBoolean(key: String) =
-            getValue(key, { provider -> provider.getBoolean(key) })
-
-    fun getInt(key: String) =
-            getValue(key, { provider -> provider.getInt(key) })
-
-    fun getLong(key: String) =
-            getValue(key, { provider -> provider.getLong(key) })
-
-    fun getString(key: String) =
-            getValue(key, { provider -> provider.getString(key) })
-
-
-    fun isWritable(key: String): Boolean {
-        for (provider in providers) {
-            val (value, further) = provider.isWritable(key)
-            if (value)
-                return true
-            if (!further)
-                return false
-        }
-        return false
-    }
-
-    private fun<T> putValue(key: String, value: T?, writer: (Provider) -> Boolean): Boolean {
-        Logger.log.fine("Trying to write setting $key = $value")
-        for (provider in providers) {
-            val (writable, further) = provider.isWritable(key)
-            Logger.log.finer("${provider::class.java.simpleName}: writable = $writable, continue: $further")
-            if (writable)
-                return try {
-                    writer(provider)
-                } catch (e: Exception) {
-                    Logger.log.log(Level.SEVERE, "Couldn't write setting to $provider", e)
-                    false
-                }
-            if (!further)
-                return false
-        }
-        return false
-    }
-
-    fun putBoolean(key: String, value: Boolean?) =
-            putValue(key, value, { provider -> provider.putBoolean(key, value) })
-
-    fun putInt(key: String, value: Int?) =
-            putValue(key, value, { provider -> provider.putInt(key, value) })
-
-    fun putLong(key: String, value: Long?) =
-            putValue(key, value, { provider -> provider.putLong(key, value) })
-
-    fun putString(key: String, value: String?) =
-            putValue(key, value, { provider -> provider.putString(key, value) })
-
-    fun remove(key: String): Boolean {
-        var deleted = false
-        providers.forEach { deleted = deleted || it.remove(key) }
-        return deleted
-    }
-
-
-    val binder = object: ISettings.Stub() {
-
-        override fun forceReload() =
-               this@Settings.forceReload()
-
-        override fun has(key: String) =
-                this@Settings.has(key)
-
-        override fun getBoolean(key: String, defaultValue: Boolean) =
-                this@Settings.getBoolean(key) ?: defaultValue
-
-        override fun getInt(key: String, defaultValue: Int) =
-                this@Settings.getInt(key) ?: defaultValue
-
-        override fun getLong(key: String, defaultValue: Long) =
-                this@Settings.getLong(key) ?: defaultValue
-
-        override fun getString(key: String, defaultValue: String?) =
-                this@Settings.getString(key) ?: defaultValue
-
-        override fun isWritable(key: String) =
-                this@Settings.isWritable(key)
-
-        override fun remove(key: String) =
-                this@Settings.remove(key)
-
-        override fun putBoolean(key: String, value: Boolean) =
-                this@Settings.putBoolean(key, value)
-
-        override fun putString(key: String, value: String?) =
-                this@Settings.putString(key, value)
-
-        override fun putInt(key: String, value: Int) =
-                this@Settings.putInt(key, value)
-
-        override fun putLong(key: String, value: Long) =
-                this@Settings.putLong(key, value)
-
-        override fun registerObserver(observer: ISettingsObserver) {
-            observers += WeakReference(observer)
-        }
-
-        override fun unregisterObserver(observer: ISettingsObserver) {
-            observers.removeAll { it.get() == observer }
-        }
-
-    }
-
-    override fun onBind(intent: Intent?) = binder
-
-
-    class Stub(
-            delegate: ISettings,
-            private val context: Context,
-            private val serviceConn: ServiceConnection
-    ): ISettings by delegate, Closeable {
-
-        override fun close() {
-            try {
-                context.unbindService(serviceConn)
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't unbind Settings service", e)
-            }
-        }
-
-    }
-
-    companion object {
-
-        fun getInstance(context: Context): Stub? {
-            if (Looper.getMainLooper().thread == Thread.currentThread())
-                throw IllegalStateException("Must not be called from main thread")
-
-            var service: ISettings? = null
-            val serviceLock = Object()
-            val serviceConn = object: ServiceConnection {
-                override fun onServiceConnected(name: ComponentName, binder: IBinder) {
-                    synchronized(serviceLock) {
-                        service = ISettings.Stub.asInterface(binder)
-                        serviceLock.notify()
-                    }
-                }
-                override fun onServiceDisconnected(name: ComponentName) {
-                    service = null
-                }
-            }
-
-            if (!context.bindService(Intent(context, Settings::class.java), serviceConn, Context.BIND_AUTO_CREATE or Context.BIND_IMPORTANT))
-                return null
-
-            synchronized(serviceLock) {
-                if (service == null)
-                    try {
-                        serviceLock.wait()
-                    } catch(e: InterruptedException) {
-                    }
-
-                if (service == null) {
-                    try {
-                        context.unbindService(serviceConn)
-                    } catch (e: IllegalArgumentException) {
-                    }
-                    return null
-                }
-            }
-
-            return Stub(service!!, context, serviceConn)
-        }
-
-    }
-
-}
@@ -1,120 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.settings
-
-import android.content.Context
-import android.content.Context.MODE_PRIVATE
-import android.content.SharedPreferences
-import android.preference.PreferenceManager
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.ServiceDB
-
-class SharedPreferencesProvider(
-        context: Context
-): Provider {
-
-    companion object {
-        private val META_VERSION = "version"
-        private val CURRENT_VERSION = 0
-    }
-
-    private val preferences = PreferenceManager.getDefaultSharedPreferences(context)
-
-    init {
-        val meta = context.getSharedPreferences("meta", MODE_PRIVATE)
-        val version = meta.getInt(META_VERSION, -1)
-        if (version == -1) {
-            // first call, check whether to migrate from SQLite database (DAVdroid <1.9)
-            firstCall(context)
-            meta.edit().putInt(META_VERSION, CURRENT_VERSION).apply()
-        }
-    }
-
-    override fun close() {
-    }
-
-    override fun forceReload() {
-    }
-
-
-    override fun has(key: String) =
-            Pair(preferences.contains(key), true)
-
-    private fun<T> getValue(key: String, reader: (SharedPreferences) -> T): Pair<T?, Boolean> {
-        if (preferences.contains(key))
-            return Pair(
-                    try { reader(preferences) } catch(e: ClassCastException) { null },
-                    true)
-
-        return Pair(null, true)
-    }
-
-    override fun getBoolean(key: String): Pair<Boolean?, Boolean> =
-            getValue(key, { preferences -> preferences.getBoolean(key, /* will never be used: */ false) })
-
-    override fun getInt(key: String): Pair<Int?, Boolean> =
-            getValue(key, { preferences -> preferences.getInt(key, /* will never be used: */ -1) })
-
-    override fun getLong(key: String): Pair<Long?, Boolean> =
-            getValue(key, { preferences -> preferences.getLong(key, /* will never be used: */ -1) })
-
-    override fun getString(key: String): Pair<String?, Boolean> =
-            getValue(key, { preferences -> preferences.getString(key, /* will never be used: */ null) })
-
-
-    override fun isWritable(key: String) =
-            Pair(true, true)
-
-    private fun<T> putValue(key: String, value: T?, writer: (SharedPreferences.Editor, T) -> Unit): Boolean {
-        if (value == null)
-            return remove(key)
-        else {
-            Logger.log.fine("Writing setting $key = $value")
-            val edit = preferences.edit()
-            writer(edit, value)
-            edit.apply()
-            return true
-        }
-    }
-
-    override fun putBoolean(key: String, value: Boolean?) =
-            putValue(key, value, { editor, v -> editor.putBoolean(key, v) })
-
-    override fun putInt(key: String, value: Int?) =
-            putValue(key, value, { editor, v -> editor.putInt(key, v) })
-
-    override fun putLong(key: String, value: Long?) =
-            putValue(key, value, { editor, v -> editor.putLong(key, v) })
-
-    override fun putString(key: String, value: String?) =
-            putValue(key, value, { editor, v -> editor.putString(key, v) })
-
-    override fun remove(key: String): Boolean {
-        Logger.log.fine("Removing setting $key")
-        preferences.edit()
-                .remove(key)
-                .apply()
-        return true
-    }
-
-
-    private fun firstCall(context: Context) {
-        // remove possible artifacts from DAVdroid <1.9
-        val edit = preferences.edit()
-        edit.remove("override_proxy")
-        edit.remove("proxy_host")
-        edit.remove("proxy_port")
-        edit.remove("log_to_external_storage")
-        edit.apply()
-
-        // open ServiceDB to upgrade it and possibly migrate settings
-        ServiceDB.OpenHelper(context).use { it.readableDatabase }
-    }
-
-}
@@ -0,0 +1,88 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.AbstractAccountAuthenticator;
+import android.accounts.Account;
+import android.accounts.AccountAuthenticatorResponse;
+import android.accounts.AccountManager;
+import android.accounts.NetworkErrorException;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.IBinder;
+
+import at.bitfire.davdroid.ui.setup.LoginActivity;
+
+public class AccountAuthenticatorService extends Service {
+	private static AccountAuthenticator accountAuthenticator;
+
+	private AccountAuthenticator getAuthenticator() {
+		if (accountAuthenticator != null)
+			return accountAuthenticator;
+		return accountAuthenticator = new AccountAuthenticator(this);
+	}
+	
+	@Override
+	public IBinder onBind(Intent intent) {
+		if (intent.getAction().equals(android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT))
+			return getAuthenticator().getIBinder(); 
+		return null;
+	}
+	
+	
+	private static class AccountAuthenticator extends AbstractAccountAuthenticator {
+		final Context context;
+		
+		public AccountAuthenticator(Context context) {
+			super(context);
+			this.context = context;
+		}
+
+		@Override
+		public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType,
+				String[] requiredFeatures, Bundle options) throws NetworkErrorException {
+			Intent intent = new Intent(context, LoginActivity.class);
+			intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
+			Bundle bundle = new Bundle();
+			bundle.putParcelable(AccountManager.KEY_INTENT, intent);
+			return bundle;
+		}
+
+		@Override
+		public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException {
+			return null;
+		}
+
+		@Override
+		public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
+			return null;
+		}
+
+        @Override
+		public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+			return null;
+		}
+
+		@Override
+		public String getAuthTokenLabel(String authTokenType) {
+			return null;
+		}
+
+		@Override
+		public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException {
+			return null;
+		}
+
+		@Override
+		public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+			return null;
+		}
+	}
+}
@@ -1,117 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.*
-import android.app.Service
-import android.content.Context
-import android.content.Intent
-import android.database.DatabaseUtils
-import android.os.Bundle
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.ui.setup.LoginActivity
-import at.bitfire.vcard4android.ContactsStorageException
-import java.util.*
-import java.util.logging.Level
-
-
-/**
- * Account authenticator for the main DAVdroid account type.
- *
- * Gets started when a DAVdroid account is removed, too, so it also watches for account removals
- * and contains the corresponding cleanup code.
- */
-class AccountAuthenticatorService: Service(), OnAccountsUpdateListener {
-
-    companion object {
-
-        fun cleanupAccounts(context: Context) {
-            Logger.log.info("Cleaning up orphaned accounts")
-
-            ServiceDB.OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.writableDatabase
-
-                val sqlAccountNames = LinkedList<String>()
-                val accountNames = HashSet<String>()
-                val accountManager = AccountManager.get(context)
-                for (account in accountManager.getAccountsByType(context.getString(R.string.account_type))) {
-                    sqlAccountNames.add(DatabaseUtils.sqlEscapeString(account.name))
-                    accountNames += account.name
-                }
-
-                // delete orphaned address book accounts
-                accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))
-                        .map { LocalAddressBook(context, it, null) }
-                        .forEach {
-                            try {
-                                if (!accountNames.contains(it.getMainAccount().name))
-                                    it.delete()
-                            } catch(e: ContactsStorageException) {
-                                Logger.log.log(Level.SEVERE, "Couldn't get address book main account", e)
-                            }
-                        }
-
-                // delete orphaned services in DB
-                if (sqlAccountNames.isEmpty())
-                    db.delete(ServiceDB.Services._TABLE, null, null)
-                else
-                    db.delete(ServiceDB.Services._TABLE, "${ServiceDB.Services.ACCOUNT_NAME} NOT IN (${sqlAccountNames.joinToString(",")})", null)
-            }
-        }
-
-    }
-
-
-    private lateinit var accountManager: AccountManager
-    private lateinit var accountAuthenticator: AccountAuthenticator
-
-    override fun onCreate() {
-        accountManager = AccountManager.get(this)
-        accountManager.addOnAccountsUpdatedListener(this, null, true)
-
-        accountAuthenticator = AccountAuthenticator(this)
-    }
-
-    override fun onDestroy() {
-        super.onDestroy()
-        accountManager.removeOnAccountsUpdatedListener(this)
-    }
-
-    override fun onBind(intent: Intent?) =
-            accountAuthenticator.iBinder.takeIf { intent?.action == android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT }
-
-
-    override fun onAccountsUpdated(accounts: Array<out Account>?) {
-        cleanupAccounts(this)
-    }
-
-
-    private class AccountAuthenticator(
-            val context: Context
-    ): AbstractAccountAuthenticator(context) {
-
-        override fun addAccount(response: AccountAuthenticatorResponse?, accountType: String?, authTokenType: String?, requiredFeatures: Array<String>?, options: Bundle?): Bundle {
-            val intent = Intent(context, LoginActivity::class.java)
-            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response)
-            val bundle = Bundle(1)
-            bundle.putParcelable(AccountManager.KEY_INTENT, intent)
-            return bundle
-        }
-
-        override fun editProperties(response: AccountAuthenticatorResponse?, accountType: String?)  = null
-        override fun getAuthTokenLabel(p0: String?) = null
-        override fun confirmCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Bundle?) = null
-        override fun updateCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
-        override fun getAuthToken(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
-        override fun hasFeatures(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Array<out String>?) = null
-
-    }
-}
@@ -1,24 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.content.ContentProvider
-import android.content.ContentValues
-import android.net.Uri
-
-class AddressBookProvider: ContentProvider() {
-
-    override fun onCreate() = false
-    override fun insert(p0: Uri?, p1: ContentValues?) = null
-    override fun query(p0: Uri?, p1: Array<out String>?, p2: String?, p3: Array<out String>?, p4: String?) = null
-    override fun update(p0: Uri?, p1: ContentValues?, p2: String?, p3: Array<out String>?) = 0
-    override fun delete(p0: Uri?, p1: String?, p2: Array<out String>?) = 0
-    override fun getType(p0: Uri?) = null
-
-}
@@ -1,135 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.accounts.AccountManager
-import android.content.*
-import android.database.DatabaseUtils
-import android.os.Bundle
-import android.provider.ContactsContract
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.vcard4android.ContactsStorageException
-import java.util.logging.Level
-
-class AddressBooksSyncAdapterService: SyncAdapterService() {
-
-    override fun syncAdapter() = AddressBooksSyncAdapter(this)
-
-
-	protected class AddressBooksSyncAdapter(
-            context: Context
-    ): SyncAdapter(context) {
-
-        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, addressBooksProvider: ContentProviderClient, syncResult: SyncResult) {
-            val contactsProvider = context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)
-            if (contactsProvider == null) {
-                Logger.log.severe("Couldn't access contacts provider")
-                syncResult.databaseError = true
-                return
-            }
-
-            try {
-                val accountSettings = AccountSettings(context, settings, account)
-
-                /* don't run sync if
-                   - sync conditions (e.g. "sync only in WiFi") are not met AND
-                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
-                 */
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
-                    return
-
-                updateLocalAddressBooks(contactsProvider, account)
-
-                val accountManager = AccountManager.get(context)
-                for (addressBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))) {
-                    Logger.log.log(Level.INFO, "Running sync for address book", addressBookAccount)
-                    val syncExtras = Bundle(extras)
-                    syncExtras.putBoolean(ContentResolver.SYNC_EXTRAS_IGNORE_SETTINGS, true)
-                    syncExtras.putBoolean(ContentResolver.SYNC_EXTRAS_IGNORE_BACKOFF, true)
-                    ContentResolver.requestSync(addressBookAccount, ContactsContract.AUTHORITY, syncExtras)
-                }
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't sync address books", e)
-            }
-
-            Logger.log.info("Address book sync complete")
-        }
-
-        private fun updateLocalAddressBooks(provider: ContentProviderClient, account: Account) {
-            ServiceDB.OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.readableDatabase
-
-                fun getService() =
-                        db.query(ServiceDB.Services._TABLE, arrayOf(ServiceDB.Services.ID),
-                            "${ServiceDB.Services.ACCOUNT_NAME}=? AND ${ServiceDB.Services.SERVICE}=?",
-                            arrayOf(account.name, ServiceDB.Services.SERVICE_CARDDAV), null, null, null)?.use { c ->
-                            if (c.moveToNext())
-                                c.getLong(0)
-                            else
-                                null
-                        }
-
-                fun remoteAddressBooks(service: Long?): MutableMap<String, CollectionInfo> {
-                    val collections = mutableMapOf<String, CollectionInfo>()
-                    service?.let {
-                        db.query(Collections._TABLE, null,
-                            Collections.SERVICE_ID + "=? AND " + Collections.SYNC, arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                            while (cursor.moveToNext()) {
-                                val values = ContentValues(cursor.columnCount)
-                                DatabaseUtils.cursorRowToContentValues(cursor, values)
-                                val info = CollectionInfo(values)
-                                collections[info.url] = info
-                            }
-                        }
-                    }
-                    return collections
-                }
-
-                // enumerate remote and local address books
-                val service = getService()
-                val remote = remoteAddressBooks(service)
-
-                // delete/update local address books
-                for (addressBook in LocalAddressBook.find(context, provider, account)) {
-                    val url = addressBook.getURL()
-                    val info = remote[url]
-                    if (info == null) {
-                        Logger.log.log(Level.INFO, "Deleting obsolete local address book", url)
-                        addressBook.delete()
-                    } else {
-                        // remote CollectionInfo found for this local collection, update data
-                        try {
-                            Logger.log.log(Level.FINE, "Updating local address book $url", info)
-                            addressBook.update(info)
-                        } catch(e: ContactsStorageException) {
-                            Logger.log.log(Level.WARNING, "Couldn't rename address book account", e)
-                        }
-                        // we already have a local address book for this remote collection, don't take into consideration anymore
-                        remote -= url
-                    }
-                }
-
-                // create new local address books
-                for ((_, info) in remote) {
-                    Logger.log.log(Level.INFO, "Adding local address book", info)
-                    LocalAddressBook.create(context, provider, account, info)
-                }
-            }
-        }
-
-    }
-
-}
@@ -0,0 +1,223 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.Context;
+import android.content.SyncResult;
+import android.os.Bundle;
+
+import org.apache.commons.codec.Charsets;
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.logging.Level;
+
+import at.bitfire.dav4android.DavCalendar;
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.exception.DavException;
+import at.bitfire.dav4android.exception.HttpException;
+import at.bitfire.dav4android.property.CalendarData;
+import at.bitfire.dav4android.property.GetCTag;
+import at.bitfire.dav4android.property.GetContentType;
+import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.ArrayUtils;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.resource.LocalCalendar;
+import at.bitfire.davdroid.resource.LocalEvent;
+import at.bitfire.davdroid.resource.LocalResource;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.Event;
+import at.bitfire.ical4android.InvalidCalendarException;
+import at.bitfire.vcard4android.ContactsStorageException;
+import lombok.Cleanup;
+import okhttp3.HttpUrl;
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+import okhttp3.ResponseBody;
+
+public class CalendarSyncManager extends SyncManager {
+
+    protected static final int MAX_MULTIGET = 20;
+
+
+    public CalendarSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult result, LocalCalendar calendar) throws InvalidAccountException {
+        super(context, account, settings, extras, authority, result, "calendar/" + calendar.getId());
+        localCollection = calendar;
+    }
+
+    @Override
+    protected int notificationId() {
+        return Constants.NOTIFICATION_CALENDAR_SYNC;
+    }
+
+    @Override
+    protected String getSyncErrorTitle() {
+        return context.getString(R.string.sync_error_calendar, account.name);
+    }
+
+
+    @Override
+    protected void prepare() {
+        collectionURL = HttpUrl.parse(localCalendar().getName());
+        davCollection = new DavCalendar(httpClient, collectionURL);
+    }
+
+    @Override
+    protected void queryCapabilities() throws DavException, IOException, HttpException {
+        davCollection.propfind(0, GetCTag.NAME);
+    }
+
+    @Override
+    protected void prepareDirty() throws CalendarStorageException, ContactsStorageException {
+        super.prepareDirty();
+
+        localCalendar().processDirtyExceptions();
+    }
+
+    @Override
+    protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException {
+        LocalEvent local = (LocalEvent)resource;
+        App.log.log(Level.FINE, "Preparing upload of event " + local.getFileName(), new Object[] { local.getEvent() });
+        return RequestBody.create(
+                DavCalendar.MIME_ICALENDAR,
+                local.getEvent().toStream().toByteArray()
+        );
+    }
+
+    @Override
+    protected void listRemote() throws IOException, HttpException, DavException {
+        // calculate time range limits
+        Date limitStart = null;
+        Integer pastDays = settings.getTimeRangePastDays();
+        if (pastDays != null) {
+            Calendar calendar = Calendar.getInstance();
+            calendar.add(Calendar.DAY_OF_MONTH, -pastDays);
+            limitStart = calendar.getTime();
+        }
+
+        // fetch list of remote VEVENTs and build hash table to index file name
+        davCalendar().calendarQuery("VEVENT", limitStart, null);
+
+        remoteResources = new HashMap<>(davCollection.members.size());
+        for (DavResource iCal : davCollection.members) {
+            String fileName = iCal.fileName();
+            App.log.fine("Found remote VEVENT: " + fileName);
+            remoteResources.put(fileName, iCal);
+        }
+    }
+
+    @Override
+    protected void downloadRemote() throws IOException, HttpException, DavException, CalendarStorageException {
+        App.log.info("Downloading " + toDownload.size() + " events (" + MAX_MULTIGET + " at once)");
+
+        // download new/updated iCalendars from server
+        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return;
+            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
+
+            if (bunch.length == 1) {
+                // only one contact, use GET
+                DavResource remote = bunch[0];
+
+                ResponseBody body = remote.get("text/calendar");
+                String eTag = ((GetETag)remote.properties.get(GetETag.NAME)).eTag;
+
+                Charset charset = Charsets.UTF_8;
+                MediaType contentType = body.contentType();
+                if (contentType != null)
+                    charset = contentType.charset(Charsets.UTF_8);
+
+                @Cleanup InputStream stream = body.byteStream();
+                processVEvent(remote.fileName(), eTag, stream, charset);
+
+            } else {
+                // multiple contacts, use multi-get
+                List<HttpUrl> urls = new LinkedList<>();
+                for (DavResource remote : bunch)
+                    urls.add(remote.location);
+                davCalendar().multiget(urls.toArray(new HttpUrl[urls.size()]));
+
+                // process multiget results
+                for (DavResource remote : davCollection.members) {
+                    String eTag;
+                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                    if (getETag != null)
+                        eTag = getETag.eTag;
+                    else
+                        throw new DavException("Received multi-get response without ETag");
+
+                    Charset charset = Charsets.UTF_8;
+                    GetContentType getContentType = (GetContentType)remote.properties.get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.type != null) {
+                        MediaType type = MediaType.parse(getContentType.type);
+                        if (type != null)
+                            charset = type.charset(Charsets.UTF_8);
+                    }
+
+                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
+                    if (calendarData == null || calendarData.iCalendar == null)
+                        throw new DavException("Received multi-get response without address data");
+
+                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
+                    processVEvent(remote.fileName(), eTag, stream, charset);
+                }
+            }
+        }
+    }
+
+
+    // helpers
+
+    private LocalCalendar localCalendar() { return ((LocalCalendar)localCollection); }
+    private DavCalendar davCalendar() { return (DavCalendar)davCollection; }
+
+    private void processVEvent(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException {
+        Event[] events;
+        try {
+            events = Event.fromStream(stream, charset);
+        } catch (InvalidCalendarException e) {
+            App.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e);
+            return;
+        }
+
+        if (events.length == 1) {
+            Event newData = events[0];
+
+            // delete local event, if it exists
+            LocalEvent localEvent = (LocalEvent)localResources.get(fileName);
+            if (localEvent != null) {
+                App.log.info("Updating " + fileName + " in local calendar");
+                localEvent.setETag(eTag);
+                localEvent.update(newData);
+                syncResult.stats.numUpdates++;
+            } else {
+                App.log.info("Adding " + fileName + " to local calendar");
+                localEvent = new LocalEvent(localCalendar(), newData, fileName, eTag);
+                localEvent.add();
+                syncResult.stats.numInserts++;
+            }
+        } else
+            App.log.severe("Received VCALENDAR with not exactly one VEVENT with UID, but without RECURRENCE-ID; ignoring " + fileName);
+    }
+
+}
@@ -1,210 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.content.ContentProviderClient
-import android.content.Context
-import android.content.SyncResult
-import android.os.Bundle
-import at.bitfire.dav4android.DavCalendar
-import at.bitfire.dav4android.exception.DavException
-import at.bitfire.dav4android.property.CalendarData
-import at.bitfire.dav4android.property.GetCTag
-import at.bitfire.dav4android.property.GetETag
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.Constants
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.resource.LocalCalendar
-import at.bitfire.davdroid.resource.LocalEvent
-import at.bitfire.davdroid.resource.LocalResource
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.ical4android.Event
-import at.bitfire.ical4android.InvalidCalendarException
-import okhttp3.HttpUrl
-import okhttp3.RequestBody
-import org.apache.commons.collections4.ListUtils
-import java.io.ByteArrayOutputStream
-import java.io.Reader
-import java.io.StringReader
-import java.util.*
-import java.util.logging.Level
-
-/**
- * Synchronization manager for CalDAV collections; handles events ({@code VEVENT}).
- */
-class CalendarSyncManager(
-        context: Context,
-        settings: ISettings,
-        account: Account,
-        accountSettings: AccountSettings,
-        extras: Bundle,
-        authority: String,
-        syncResult: SyncResult,
-        val provider: ContentProviderClient,
-        val localCalendar: LocalCalendar
-): SyncManager(context, settings, account, accountSettings, extras, authority, syncResult, "calendar/${localCalendar.id}") {
-
-    companion object {
-        private val MAX_MULTIGET = 20
-    }
-
-    init {
-        localCollection = localCalendar
-    }
-
-    override fun notificationId() = Constants.NOTIFICATION_CALENDAR_SYNC
-
-    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_calendar, account.name)!!
-
-
-    override fun prepare(): Boolean {
-        collectionURL = HttpUrl.parse(localCalendar.name ?: return false) ?: return false
-        davCollection = DavCalendar(httpClient.okHttpClient, collectionURL)
-        return true
-    }
-
-    override fun queryCapabilities() {
-        davCollection.propfind(0, GetCTag.NAME)
-    }
-
-    override fun prepareDirty() {
-        super.prepareDirty()
-        localCalendar.processDirtyExceptions()
-    }
-
-    override fun prepareUpload(resource: LocalResource): RequestBody {
-        if (resource is LocalEvent) {
-            val event = requireNotNull(resource.event)
-            Logger.log.log(Level.FINE, "Preparing upload of event ${resource.fileName}", event)
-
-            val os = ByteArrayOutputStream()
-            event.write(os)
-
-            return RequestBody.create(
-                    DavCalendar.MIME_ICALENDAR,
-                    os.toByteArray()
-            )
-        } else
-            throw IllegalArgumentException("resource must be a LocalEvent")
-    }
-
-    override fun listRemote() {
-        // calculate time range limits
-        var limitStart: Date? = null
-        accountSettings.getTimeRangePastDays()?.let { pastDays ->
-            val calendar = Calendar.getInstance()
-            calendar.add(Calendar.DAY_OF_MONTH, -pastDays)
-            limitStart = calendar.time
-        }
-
-        // fetch list of remote VEVENTs and build hash table to index file name
-        val calendar = davCalendar()
-        currentDavResource = calendar
-        calendar.calendarQuery("VEVENT", limitStart, null)
-
-        remoteResources = HashMap(davCollection.members.size)
-        for (iCal in davCollection.members) {
-            val fileName = iCal.fileName()
-            Logger.log.fine("Found remote VEVENT: $fileName")
-            remoteResources[fileName] = iCal
-        }
-
-        currentDavResource = null
-    }
-
-    override fun downloadRemote() {
-        Logger.log.info("Downloading ${toDownload.size} events ($MAX_MULTIGET at once)")
-
-        // download new/updated iCalendars from server
-        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
-            abortIfCancelled()
-            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
-
-            if (bunch.size == 1) {
-                // only one contact, use GET
-                val remote = bunch.first()
-                currentDavResource = remote
-
-                val body = remote.get("text/calendar")
-
-                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
-                val eTag = remote.properties[GetETag::class.java]
-                if (eTag == null || eTag.eTag.isNullOrEmpty())
-                    throw DavException("Received CalDAV GET response without ETag for ${remote.location}")
-
-                body.charStream()?.use { reader ->
-                    processVEvent(remote.fileName(), eTag.eTag!!, reader)
-                }
-
-            } else {
-                // multiple contacts, use multi-get
-                val calendar = davCalendar()
-                currentDavResource = calendar
-                calendar.multiget(bunch.map { it.location })
-
-                // process multiget results
-                for (remote in davCollection.members) {
-                    currentDavResource = remote
-
-                    val eTag = remote.properties[GetETag::class.java]?.eTag
-                            ?: throw DavException("Received multi-get response without ETag")
-
-                    val calendarData = remote.properties[CalendarData::class.java]
-                    val iCalendar = calendarData?.iCalendar
-                            ?: throw DavException("Received multi-get response without event data")
-
-                    processVEvent(remote.fileName(), eTag, StringReader(iCalendar))
-                }
-            }
-
-            currentDavResource = null
-        }
-    }
-
-
-    // helpers
-
-    private fun davCalendar() = davCollection as DavCalendar
-
-    private fun processVEvent(fileName: String, eTag: String, reader: Reader) {
-        val events: List<Event>
-        try {
-            events = Event.fromReader(reader)
-        } catch (e: InvalidCalendarException) {
-            Logger.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e)
-            return
-        }
-
-        if (events.size == 1) {
-            val newData = events.first()
-
-            // delete local event, if it exists
-            val localEvent = localResources[fileName] as LocalEvent?
-            currentLocalResource = localEvent
-            if (localEvent != null) {
-                Logger.log.info("Updating $fileName in local calendar")
-                localEvent.eTag = eTag
-                localEvent.update(newData)
-                syncResult.stats.numUpdates++
-            } else {
-                Logger.log.info("Adding $fileName to local calendar")
-                val newEvent = LocalEvent(localCalendar, newData, fileName, eTag)
-                currentLocalResource = newEvent
-                newEvent.add()
-                syncResult.stats.numInserts++
-            }
-        } else
-            Logger.log.severe("Received VCALENDAR with not exactly one VEVENT with UID, but without RECURRENCE-ID; ignoring $fileName")
-
-        currentLocalResource = null
-    }
-
-}
@@ -0,0 +1,148 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.AbstractThreadedSyncAdapter;
+import android.content.ContentProviderClient;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.SyncResult;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Bundle;
+import android.provider.CalendarContract;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import at.bitfire.davdroid.model.ServiceDB.Services;
+import at.bitfire.davdroid.resource.LocalCalendar;
+import at.bitfire.ical4android.CalendarStorageException;
+import lombok.Cleanup;
+
+public class CalendarsSyncAdapterService extends SyncAdapterService {
+
+    @Override
+    protected AbstractThreadedSyncAdapter syncAdapter() {
+        return new SyncAdapter(this);
+    }
+
+
+	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
+
+        public SyncAdapter(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
+            super.onPerformSync(account, extras, authority, provider, syncResult);
+
+            try {
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
+                updateLocalCalendars(provider, account, settings);
+
+                for (LocalCalendar calendar : (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, CalendarContract.Calendars.SYNC_EVENTS + "!=0", null)) {
+                    App.log.info("Synchronizing calendar #"  + calendar.getId() + ", URL: " + calendar.getName());
+                    CalendarSyncManager syncManager = new CalendarSyncManager(getContext(), account, settings, extras, authority, syncResult, calendar);
+                    syncManager.performSync();
+                }
+            } catch (CalendarStorageException e) {
+                App.log.log(Level.SEVERE, "Couldn't enumerate local calendars", e);
+                syncResult.databaseError = true;
+            } catch (InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            }
+
+            App.log.info("Calendar sync complete");
+        }
+
+        private void updateLocalCalendars(ContentProviderClient provider, Account account, AccountSettings settings) throws CalendarStorageException {
+            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+            try {
+                // enumerate remote and local calendars
+                SQLiteDatabase db = dbHelper.getReadableDatabase();
+                Long service = getService(db, account);
+                Map<String, CollectionInfo> remote = remoteCalendars(db, service);
+
+                LocalCalendar[] local = (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, null, null);
+
+                boolean updateColors = settings.getManageCalendarColors();
+
+                // delete obsolete local calendar
+                for (LocalCalendar calendar : local) {
+                    String url = calendar.getName();
+                    if (!remote.containsKey(url)) {
+                        App.log.fine("Deleting obsolete local calendar " + url);
+                        calendar.delete();
+                    } else {
+                        // remote CollectionInfo found for this local collection, update data
+                        CollectionInfo info = remote.get(url);
+                        App.log.fine("Updating local calendar " + url + " with " + info);
+                        calendar.update(info, updateColors);
+                        // we already have a local calendar for this remote collection, don't take into consideration anymore
+                        remote.remove(url);
+                    }
+                }
+
+                // create new local calendars
+                for (String url : remote.keySet()) {
+                    CollectionInfo info = remote.get(url);
+                    App.log.info("Adding local calendar list " + info);
+                    LocalCalendar.create(account, provider, info);
+                }
+            } finally {
+                dbHelper.close();
+            }
+        }
+
+        @Nullable
+        Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
+            @Cleanup Cursor c = db.query(Services._TABLE, new String[] { Services.ID },
+                    Services.ACCOUNT_NAME + "=? AND " + Services.SERVICE + "=?", new String[] { account.name, Services.SERVICE_CALDAV }, null, null, null);
+            if (c.moveToNext())
+                return c.getLong(0);
+            else
+                return null;
+        }
+
+        @NonNull
+        private Map<String, CollectionInfo> remoteCalendars(@NonNull SQLiteDatabase db, Long service) {
+            Map<String, CollectionInfo> collections = new LinkedHashMap<>();
+            if (service != null) {
+                @Cleanup Cursor cursor = db.query(Collections._TABLE, null,
+                        Collections.SERVICE_ID + "=? AND " + Collections.SUPPORTS_VEVENT + "!=0 AND " + Collections.SYNC,
+                        new String[] { String.valueOf(service) }, null, null, null);
+                while (cursor.moveToNext()) {
+                    ContentValues values = new ContentValues();
+                    DatabaseUtils.cursorRowToContentValues(cursor, values);
+                    CollectionInfo info = CollectionInfo.fromDB(values);
+                    collections.put(info.url, info);
+                }
+            }
+            return collections;
+        }
+    }
+
+}
@@ -1,127 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.content.*
-import android.database.DatabaseUtils
-import android.os.Bundle
-import android.provider.CalendarContract
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.resource.LocalCalendar
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.ical4android.AndroidCalendar
-import java.util.logging.Level
-
-class CalendarsSyncAdapterService: SyncAdapterService() {
-
-    override fun syncAdapter() = CalendarsSyncAdapter(this)
-
-
-	class CalendarsSyncAdapter(
-            context: Context
-    ): SyncAdapter(context) {
-
-        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
-            try {
-                val accountSettings = AccountSettings(context, settings, account)
-
-                /* don't run sync if
-                   - sync conditions (e.g. "sync only in WiFi") are not met AND
-                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
-                 */
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
-                    return
-
-                if (accountSettings.getEventColors())
-                    AndroidCalendar.insertColors(provider, account)
-                else
-                    AndroidCalendar.removeColors(provider, account)
-
-                updateLocalCalendars(provider, account, accountSettings)
-
-                for (calendar in AndroidCalendar.find(account, provider, LocalCalendar.Factory, "${CalendarContract.Calendars.SYNC_EVENTS}!=0", null)) {
-                    Logger.log.info("Synchronizing calendar #${calendar.id}, URL: ${calendar.name}")
-                    CalendarSyncManager(context, settings, account, accountSettings, extras, authority, syncResult, provider, calendar).use {
-                        it.performSync()
-                    }
-                }
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't sync calendars", e)
-            }
-            Logger.log.info("Calendar sync complete")
-        }
-
-        private fun updateLocalCalendars(provider: ContentProviderClient, account: Account, settings: AccountSettings) {
-            ServiceDB.OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.readableDatabase
-
-                fun getService() =
-                        db.query(ServiceDB.Services._TABLE, arrayOf(ServiceDB.Services.ID),
-                                "${ServiceDB.Services.ACCOUNT_NAME}=? AND ${ServiceDB.Services.SERVICE}=?",
-                                arrayOf(account.name, ServiceDB.Services.SERVICE_CALDAV), null, null, null)?.use { c ->
-                            if (c.moveToNext())
-                                c.getLong(0)
-                            else
-                                null
-                        }
-
-                fun remoteCalendars(service: Long?): MutableMap<String, CollectionInfo> {
-                    val collections = mutableMapOf<String, CollectionInfo>()
-                    service?.let {
-                        db.query(Collections._TABLE, null,
-                                "${Collections.SERVICE_ID}=? AND ${Collections.SUPPORTS_VEVENT}!=0 AND ${Collections.SYNC}",
-                                arrayOf(service.toString()), null, null, null).use { cursor ->
-                            while (cursor.moveToNext()) {
-                                val values = ContentValues(cursor.columnCount)
-                                DatabaseUtils.cursorRowToContentValues(cursor, values)
-                                val info = CollectionInfo(values)
-                                collections[info.url] = info
-                            }
-                        }
-                    }
-                    return collections
-                }
-
-                // enumerate remote and local calendars
-                val service = getService()
-                val remote = remoteCalendars(service)
-
-                // delete/update local calendars
-                val updateColors = settings.getManageCalendarColors()
-
-                for (calendar in AndroidCalendar.find(account, provider, LocalCalendar.Factory, null, null))
-                    calendar.name?.let { url ->
-                        val info = remote[url]
-                        if (info == null) {
-                            Logger.log.log(Level.INFO, "Deleting obsolete local calendar", url)
-                            calendar.delete()
-                        } else {
-                            // remote CollectionInfo found for this local collection, update data
-                            Logger.log.log(Level.FINE, "Updating local calendar $url", info)
-                            calendar.update(info, updateColors)
-                            // we already have a local calendar for this remote collection, don't take into consideration anymore
-                            remote -= url
-                        }
-                    }
-
-                // create new local calendars
-                for ((_, info) in remote) {
-                    Logger.log.log(Level.INFO, "Adding local calendar", info)
-                    LocalCalendar.create(account, provider, info)
-                }
-            }
-        }
-
-    }
-
-}
@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.AbstractThreadedSyncAdapter;
+import android.content.ContentProviderClient;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.SyncResult;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import lombok.Cleanup;
+
+public class ContactsSyncAdapterService extends SyncAdapterService {
+
+    @Override
+    protected AbstractThreadedSyncAdapter syncAdapter() {
+        return new ContactsSyncAdapter(this);
+    }
+
+
+	private static class ContactsSyncAdapter extends SyncAdapter {
+
+        public ContactsSyncAdapter(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
+            super.onPerformSync(account, extras, authority, provider, syncResult);
+
+            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+            try {
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
+                SQLiteDatabase db = dbHelper.getReadableDatabase();
+                Long service = getService(db, account);
+                if (service != null) {
+                    CollectionInfo remote = remoteAddressBook(db, service);
+                    if (remote != null)
+                        try {
+                            ContactsSyncManager syncManager = new ContactsSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, remote);
+                            syncManager.performSync();
+                        } catch(InvalidAccountException e) {
+                            App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+                        }
+                    else
+                        App.log.info("No address book collection selected for synchronization");
+                } else
+                    App.log.info("No CardDAV service found in DB");
+            } catch (InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            } finally {
+                dbHelper.close();
+            }
+
+            App.log.info("Address book sync complete");
+        }
+
+        @Nullable
+        private Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
+            @Cleanup Cursor c = db.query(ServiceDB.Services._TABLE, new String[] { ServiceDB.Services.ID },
+                    ServiceDB.Services.ACCOUNT_NAME + "=? AND " + ServiceDB.Services.SERVICE + "=?", new String[] { account.name, ServiceDB.Services.SERVICE_CARDDAV }, null, null, null);
+            if (c.moveToNext())
+                return c.getLong(0);
+            else
+                return null;
+        }
+
+        @Nullable
+        private CollectionInfo remoteAddressBook(@NonNull SQLiteDatabase db, long service) {
+            @Cleanup Cursor c = db.query(Collections._TABLE, null,
+                    Collections.SERVICE_ID + "=? AND " + Collections.SYNC, new String[] { String.valueOf(service) }, null, null, null);
+            if (c.moveToNext()) {
+                ContentValues values = new ContentValues();
+                DatabaseUtils.cursorRowToContentValues(c, values);
+                return CollectionInfo.fromDB(values);
+            } else
+                return null;
+        }
+
+    }
+
+}
@@ -1,75 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.content.ContentProviderClient
-import android.content.ContentResolver
-import android.content.Context
-import android.content.SyncResult
-import android.os.Bundle
-import android.provider.ContactsContract
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.settings.ISettings
-import java.util.logging.Level
-
-class ContactsSyncAdapterService: SyncAdapterService() {
-
-    companion object {
-        val PREVIOUS_GROUP_METHOD = "previous_group_method"
-    }
-
-    override fun syncAdapter() = ContactsSyncAdapter(this)
-
-
-	class ContactsSyncAdapter(
-            context: Context
-    ): SyncAdapter(context) {
-
-        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
-            try {
-                val addressBook = LocalAddressBook(context, account, provider)
-                val accountSettings = AccountSettings(context, settings, addressBook.getMainAccount())
-
-                // handle group method change
-                val groupMethod = accountSettings.getGroupMethod().name
-                accountSettings.accountManager.getUserData(account, PREVIOUS_GROUP_METHOD)?.let { previousGroupMethod ->
-                    if (previousGroupMethod != groupMethod) {
-                        Logger.log.info("Group method changed, deleting all local contacts/groups")
-
-                        // delete all local contacts and groups so that they will be downloaded again
-                        provider.delete(addressBook.syncAdapterURI(ContactsContract.RawContacts.CONTENT_URI), null, null)
-                        provider.delete(addressBook.syncAdapterURI(ContactsContract.Groups.CONTENT_URI), null, null)
-
-                        // reset CTag
-                        addressBook.setCTag(null)
-                    }
-                }
-                accountSettings.accountManager.setUserData(account, PREVIOUS_GROUP_METHOD, groupMethod)
-
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
-                    return
-
-                Logger.log.info("Synchronizing address book: ${addressBook.getURL()}")
-                Logger.log.info("Taking settings from: ${addressBook.getMainAccount()}")
-
-                ContactsSyncManager(context, settings, account, accountSettings, extras, authority, syncResult, provider, addressBook).use {
-                    it.performSync()
-                }
-            } catch(e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't sync contacts", e)
-            }
-            Logger.log.info("Contacts sync complete")
-        }
-
-    }
-
-}
@@ -0,0 +1,342 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.ContentProviderClient;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.SyncResult;
+import android.os.Bundle;
+import android.provider.ContactsContract;
+
+import org.apache.commons.codec.Charsets;
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.logging.Level;
+
+import at.bitfire.dav4android.DavAddressBook;
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.exception.DavException;
+import at.bitfire.dav4android.exception.HttpException;
+import at.bitfire.dav4android.property.AddressData;
+import at.bitfire.dav4android.property.GetCTag;
+import at.bitfire.dav4android.property.GetContentType;
+import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.dav4android.property.SupportedAddressData;
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.ArrayUtils;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.HttpClient;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.resource.LocalAddressBook;
+import at.bitfire.davdroid.resource.LocalContact;
+import at.bitfire.davdroid.resource.LocalGroup;
+import at.bitfire.davdroid.resource.LocalResource;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.vcard4android.Contact;
+import at.bitfire.vcard4android.ContactsStorageException;
+import ezvcard.VCardVersion;
+import ezvcard.util.IOUtils;
+import lombok.Cleanup;
+import lombok.RequiredArgsConstructor;
+import okhttp3.HttpUrl;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+
+public class ContactsSyncManager extends SyncManager {
+    protected static final int MAX_MULTIGET = 10;
+
+    final private ContentProviderClient provider;
+    final private CollectionInfo remote;
+    private boolean hasVCard4;
+
+
+    public ContactsSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, ContentProviderClient provider, SyncResult result, CollectionInfo remote) throws InvalidAccountException {
+        super(context, account, settings, extras, authority, result, "addressBook");
+        this.provider = provider;
+        this.remote = remote;
+    }
+
+    @Override
+    protected int notificationId() {
+        return Constants.NOTIFICATION_CONTACTS_SYNC;
+    }
+
+    @Override
+    protected String getSyncErrorTitle() {
+        return context.getString(R.string.sync_error_contacts, account.name);
+    }
+
+
+    @Override
+    protected void prepare() throws ContactsStorageException {
+        // prepare local address book
+        localCollection = new LocalAddressBook(account, provider);
+        LocalAddressBook localAddressBook = localAddressBook();
+
+        String url = remote.url;
+        String lastUrl = localAddressBook.getURL();
+        if (!url.equals(lastUrl)) {
+            App.log.info("Selected address book has changed from " + lastUrl + " to " + url + ", deleting all local contacts");
+            localAddressBook.deleteAll();
+        }
+
+        // set up Contacts Provider Settings
+        ContentValues settings = new ContentValues(2);
+        settings.put(ContactsContract.Settings.SHOULD_SYNC, 1);
+        settings.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1);
+        localAddressBook.updateSettings(settings);
+
+        collectionURL = HttpUrl.parse(url);
+        davCollection = new DavAddressBook(httpClient, collectionURL);
+
+        processChangedGroups();
+    }
+
+    @Override
+    protected void queryCapabilities() throws DavException, IOException, HttpException {
+        // prepare remote address book
+        hasVCard4 = false;
+        davCollection.propfind(0, SupportedAddressData.NAME, GetCTag.NAME);
+        SupportedAddressData supportedAddressData = (SupportedAddressData) davCollection.properties.get(SupportedAddressData.NAME);
+        if (supportedAddressData != null)
+            for (MediaType type : supportedAddressData.types)
+                if ("text/vcard; version=4.0".equalsIgnoreCase(type.toString()))
+                    hasVCard4 = true;
+        App.log.info("Server advertises VCard/4 support: " + hasVCard4);
+    }
+
+    @Override
+    protected RequestBody prepareUpload(LocalResource resource) throws IOException, ContactsStorageException {
+        LocalContact local = (LocalContact)resource;
+        App.log.log(Level.FINE, "Preparing upload of contact " + local.getFileName(), new Object[] { local.getContact() });
+        return RequestBody.create(
+                hasVCard4 ? DavAddressBook.MIME_VCARD4 : DavAddressBook.MIME_VCARD3_UTF8,
+                local.getContact().toStream(hasVCard4 ? VCardVersion.V4_0 : VCardVersion.V3_0).toByteArray()
+        );
+    }
+
+    @Override
+    protected void listRemote() throws IOException, HttpException, DavException {
+        // fetch list of remote VCards and build hash table to index file name
+
+        try {
+            davAddressBook().addressbookQuery();
+        } catch(HttpException e) {
+            /*  non-successful responses to CARDDAV:addressbook-query with empty filter, tested on 2015/10/21
+             *  fastmail.com                 403 Forbidden (DAV:error CARDDAV:supported-filter)
+             *  mailbox.org (OpenXchange)    400 Bad Request
+             *  SOGo                         207 Multi-status, but without entries       http://www.sogo.nu/bugs/view.php?id=3370
+             *  Zimbra ZCS                   500 Server Error                            https://bugzilla.zimbra.com/show_bug.cgi?id=101902
+             */
+            if (e.status == 400 || e.status == 403 || e.status == 500 || e.status == 501) {
+                App.log.log(Level.WARNING, "Server error on REPORT addressbook-query, falling back to PROPFIND", e);
+                davAddressBook().propfind(1, GetETag.NAME);
+            } else
+                // no defined fallback, pass through exception
+                throw e;
+        }
+
+        remoteResources = new HashMap<>(davCollection.members.size());
+        for (DavResource vCard : davCollection.members) {
+            String fileName = vCard.fileName();
+            App.log.fine("Found remote VCard: " + fileName);
+            remoteResources.put(fileName, vCard);
+        }
+    }
+
+    @Override
+    protected void downloadRemote() throws IOException, HttpException, DavException, ContactsStorageException {
+        App.log.info("Downloading " + toDownload.size() + " contacts (" + MAX_MULTIGET + " at once)");
+
+        // prepare downloader which may be used to download external resource like contact photos
+        Contact.Downloader downloader = new ResourceDownloader(collectionURL);
+
+        // download new/updated VCards from server
+        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return;
+
+            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
+
+            if (bunch.length == 1) {
+                // only one contact, use GET
+                DavResource remote = bunch[0];
+
+                ResponseBody body = remote.get("text/vcard;version=4.0, text/vcard;charset=utf-8;q=0.8, text/vcard;q=0.5");
+                String eTag = ((GetETag) remote.properties.get(GetETag.NAME)).eTag;
+
+                Charset charset = Charsets.UTF_8;
+                MediaType contentType = body.contentType();
+                if (contentType != null)
+                    charset = contentType.charset(Charsets.UTF_8);
+
+                @Cleanup InputStream stream = body.byteStream();
+                processVCard(remote.fileName(), eTag, stream, charset, downloader);
+
+            } else {
+                // multiple contacts, use multi-get
+                List<HttpUrl> urls = new LinkedList<>();
+                for (DavResource remote : bunch)
+                    urls.add(remote.location);
+                davAddressBook().multiget(urls.toArray(new HttpUrl[urls.size()]), hasVCard4);
+
+                // process multiget results
+                for (DavResource remote : davCollection.members) {
+                    String eTag;
+                    GetETag getETag = (GetETag) remote.properties.get(GetETag.NAME);
+                    if (getETag != null)
+                        eTag = getETag.eTag;
+                    else
+                        throw new DavException("Received multi-get response without ETag");
+
+                    Charset charset = Charsets.UTF_8;
+                    GetContentType getContentType = (GetContentType) remote.properties.get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.type != null) {
+                        MediaType type = MediaType.parse(getContentType.type);
+                        if (type != null)
+                            charset = type.charset(Charsets.UTF_8);
+                    }
+
+                    AddressData addressData = (AddressData) remote.properties.get(AddressData.NAME);
+                    if (addressData == null || addressData.vCard == null)
+                        throw new DavException("Received multi-get response without address data");
+
+                    @Cleanup InputStream stream = new ByteArrayInputStream(addressData.vCard.getBytes());
+                    processVCard(remote.fileName(), eTag, stream, charset, downloader);
+                }
+            }
+        }
+    }
+
+    @Override
+    protected void saveSyncState() throws CalendarStorageException, ContactsStorageException {
+        super.saveSyncState();
+        ((LocalAddressBook)localCollection).setURL(remote.url);
+    }
+
+
+    // helpers
+
+    private DavAddressBook davAddressBook() { return (DavAddressBook)davCollection; }
+    private LocalAddressBook localAddressBook() { return (LocalAddressBook)localCollection; }
+
+    private void processChangedGroups() throws ContactsStorageException {
+        LocalAddressBook addressBook = localAddressBook();
+
+        // groups with DELETED=1: remove group finally
+        for (LocalGroup group : addressBook.getDeletedGroups()) {
+            long groupId = group.getId();
+            App.log.fine("Finally removing group #" + groupId);
+            // remove group memberships, but not as sync adapter (should marks contacts as DIRTY)
+            // NOTE: doesn't work that way because Contact Provider removes the group memberships even for DELETED groups
+            // addressBook.removeGroupMemberships(groupId, false);
+            group.delete();
+        }
+
+        // groups with DIRTY=1: mark all memberships as dirty, then clean DIRTY flag of group
+        for (LocalGroup group : addressBook.getDirtyGroups()) {
+            long groupId = group.getId();
+            App.log.fine("Marking members of modified group #" + groupId + " as dirty");
+            addressBook.markMembersDirty(groupId);
+            group.clearDirty();
+        }
+    }
+
+    private void processVCard(String fileName, String eTag, InputStream stream, Charset charset, Contact.Downloader downloader) throws IOException, ContactsStorageException {
+        Contact[] contacts = Contact.fromStream(stream, charset, downloader);
+        if (contacts.length == 1) {
+            Contact newData = contacts[0];
+
+            // update local contact, if it exists
+            LocalContact localContact = (LocalContact)localResources.get(fileName);
+            if (localContact != null) {
+                App.log.info("Updating " + fileName + " in local address book");
+                localContact.eTag = eTag;
+                localContact.update(newData);
+                syncResult.stats.numUpdates++;
+            } else {
+                App.log.info("Adding " + fileName + " to local address book");
+                localContact = new LocalContact(localAddressBook(), newData, fileName, eTag);
+                localContact.add();
+                syncResult.stats.numInserts++;
+            }
+        } else
+            App.log.severe("Received VCard with not exactly one VCARD, ignoring " + fileName);
+    }
+
+
+    // downloader helper class
+
+    @RequiredArgsConstructor
+    private class ResourceDownloader implements Contact.Downloader {
+        final HttpUrl baseUrl;
+
+        @Override
+        public byte[] download(String url, String accepts) {
+            HttpUrl httpUrl = HttpUrl.parse(url);
+
+            if (httpUrl == null) {
+                App.log.log(Level.SEVERE, "Invalid external resource URL", url);
+                return null;
+            }
+
+            String host = httpUrl.host();
+            if (host == null) {
+                App.log.log(Level.SEVERE, "External resource URL doesn't specify a host name", url);
+                return null;
+            }
+
+            OkHttpClient resourceClient = HttpClient.create();
+
+            // authenticate only against a certain host, and only upon request
+            resourceClient = HttpClient.addAuthentication(resourceClient, baseUrl.host(), settings.username(), settings.password());
+
+            // allow redirects
+            resourceClient = resourceClient.newBuilder()
+                    .followRedirects(true)
+                    .build();
+
+            try {
+                Response response = resourceClient.newCall(new Request.Builder()
+                        .get()
+                        .url(httpUrl)
+                        .build()).execute();
+
+                ResponseBody body = response.body();
+                if (body != null) {
+                    @Cleanup InputStream stream = body.byteStream();
+                    if (response.isSuccessful() && stream != null) {
+                        return IOUtils.toByteArray(stream);
+                    } else
+                        App.log.severe("Couldn't download external resource");
+                }
+            } catch(IOException e) {
+                App.log.log(Level.SEVERE, "Couldn't download external resource", e);
+            }
+            return null;
+        }
+    }
+
+}
@@ -1,508 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.content.*
-import android.os.Build
-import android.os.Bundle
-import android.os.RemoteException
-import android.provider.ContactsContract.Groups
-import android.support.v4.app.NotificationCompat
-import at.bitfire.dav4android.DavAddressBook
-import at.bitfire.dav4android.exception.DavException
-import at.bitfire.dav4android.property.*
-import at.bitfire.davdroid.*
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.resource.LocalContact
-import at.bitfire.davdroid.resource.LocalGroup
-import at.bitfire.davdroid.resource.LocalResource
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.davdroid.ui.NotificationUtils
-import at.bitfire.vcard4android.BatchOperation
-import at.bitfire.vcard4android.Contact
-import at.bitfire.vcard4android.ContactsStorageException
-import at.bitfire.vcard4android.GroupMethod
-import ezvcard.VCardVersion
-import okhttp3.HttpUrl
-import okhttp3.Request
-import okhttp3.RequestBody
-import org.apache.commons.collections4.ListUtils
-import java.io.*
-import java.util.*
-import java.util.logging.Level
-
-/**
- * Synchronization manager for CardDAV collections; handles contacts and groups.
- *
- * Group handling differs according to the {@link #groupMethod}. There are two basic methods to
- * handle/manage groups:
- *
- *     1. CATEGORIES: groups memberships are attached to each contact and represented as
- *     "category". When a group is dirty or has been deleted, all its members have to be set to
- *     dirty, too (because they have to be uploaded without the respective category). This
- *     is done in [prepareDirty]. Empty groups can be deleted without further processing,
- *     which is done in [postProcess] because groups may become empty after downloading
- *     updated remote contacts.
- *
- *     2. Groups as separate VCards: individual and group contacts (with a list of member UIDs) are
- *     distinguished. When a local group is dirty, its members don't need to be set to dirty.
- *
- *         * However, when a contact is dirty, it has
- *         to be checked whether its group memberships have changed. In this case, the respective
- *         groups have to be set to dirty. For instance, if contact A is in group G and H, and then
- *         group membership of G is removed, the contact will be set to dirty because of the changed
- *         [android.provider.ContactsContract.CommonDataKinds.GroupMembership]. DAVdroid will
- *         then have to check whether the group memberships have actually changed, and if so,
- *         all affected groups have to be set to dirty. To detect changes in group memberships,
- *         DAVdroid always mirrors all [android.provider.ContactsContract.CommonDataKinds.GroupMembership]
- *         data rows in respective [at.bitfire.vcard4android.CachedGroupMembership] rows.
- *         If the cached group memberships are not the same as the current group member ships, the
- *         difference set (in our example G, because its in the cached memberships, but not in the
- *         actual ones) is marked as dirty. This is done in [prepareDirty].
- *
- *         * When downloading remote contacts, groups (+ member information) may be received
- *         by the actual members. Thus, the member lists have to be cached until all VCards
- *         are received. This is done by caching the member UIDs of each group in
- *         [LocalGroup.COLUMN_PENDING_MEMBERS]. In [postProcess],
- *         these "pending memberships" are assigned to the actual contacts and then cleaned up.
- */
-class ContactsSyncManager(
-        context: Context,
-        settings: ISettings,
-        account: Account,
-        accountSettings: AccountSettings,
-        extras: Bundle,
-        authority: String,
-        syncResult: SyncResult,
-        val provider: ContentProviderClient,
-        private val localAddressBook: LocalAddressBook
-): SyncManager(context, settings, account, accountSettings, extras, authority, syncResult, "addressBook") {
-
-    companion object {
-        private val MAX_MULTIGET = 10
-    }
-
-    private val readOnly = localAddressBook.getReadOnly()
-    private var numDiscarded = 0
-
-    private var hasVCard4 = false
-    private val groupMethod = accountSettings.getGroupMethod()
-
-
-    init {
-        localCollection = localAddressBook
-    }
-
-    override fun notificationId() = Constants.NOTIFICATION_CONTACTS_SYNC
-
-    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_contacts, account.name)!!
-
-
-    override fun prepare(): Boolean {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
-            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-            val reallyDirty = localAddressBook.verifyDirty()
-            val deleted = localAddressBook.getDeleted().size
-            if (extras.containsKey(ContentResolver.SYNC_EXTRAS_UPLOAD) && reallyDirty == 0 && deleted == 0) {
-                Logger.log.info("This sync was called to up-sync dirty/deleted contacts, but no contacts have been changed")
-                return false
-            }
-        }
-
-        collectionURL = HttpUrl.parse(localAddressBook.getURL()) ?: return false
-        davCollection = DavAddressBook(httpClient.okHttpClient, collectionURL)
-
-        return true
-    }
-
-    override fun queryCapabilities() {
-        // prepare remote address book
-        davCollection.propfind(0, SupportedAddressData.NAME, GetCTag.NAME)
-
-        val properties = davCollection.properties
-        properties[SupportedAddressData::class.java]?.let {
-            hasVCard4 = it.hasVCard4()
-        }
-        Logger.log.info("Server advertises VCard/4 support: $hasVCard4")
-
-        Logger.log.info("Contact group method: $groupMethod")
-        // in case of GROUP_VCARDs, treat groups as contacts in the local address book
-        localAddressBook.includeGroups = groupMethod == GroupMethod.GROUP_VCARDS
-    }
-
-    override fun processLocallyDeleted() {
-        if (readOnly) {
-            for (group in localAddressBook.getDeletedGroups()) {
-                Logger.log.warning("Restoring locally deleted group (read-only address book!)")
-                group.resetDeleted()
-                numDiscarded++
-            }
-
-            for (contact in localAddressBook.getDeletedContacts()) {
-                Logger.log.warning("Restoring locally deleted contact (read-only address book!)")
-                contact.resetDeleted()
-                numDiscarded++
-            }
-
-            if (numDiscarded > 0)
-                notifyDiscardedChange()
-        } else
-            // mirror deletions to remote collection (DELETE)
-            super.processLocallyDeleted()
-    }
-
-    override fun prepareDirty() {
-        // generate UID/file name for newly created contacts
-        super.prepareDirty()
-
-        if (readOnly) {
-            for (group in localAddressBook.getDirtyGroups()) {
-                Logger.log.warning("Resetting locally modified group to ETag=null (read-only address book!)")
-                group.clearDirty(null)
-                numDiscarded++
-            }
-
-            for (contact in localAddressBook.getDirtyContacts()) {
-                Logger.log.warning("Resetting locally modified contact to ETag=null (read-only address book!)")
-                contact.clearDirty(null)
-                numDiscarded++
-            }
-
-            if (numDiscarded > 0)
-                notifyDiscardedChange()
-
-        } else {
-            if (groupMethod == GroupMethod.CATEGORIES) {
-                /* groups memberships are represented as contact CATEGORIES */
-
-                // groups with DELETED=1: set all members to dirty, then remove group
-                for (group in localAddressBook.getDeletedGroups()) {
-                    Logger.log.fine("Finally removing group $group")
-                    // useless because Android deletes group memberships as soon as a group is set to DELETED:
-                    // group.markMembersDirty()
-                    group.delete()
-                }
-
-                // groups with DIRTY=1: mark all memberships as dirty, then clean DIRTY flag of group
-                for (group in localAddressBook.getDirtyGroups()) {
-                    Logger.log.fine("Marking members of modified group $group as dirty")
-                    group.markMembersDirty()
-                    group.clearDirty(null)
-                }
-            } else {
-                /* groups as separate VCards: there are group contacts and individual contacts */
-
-                // mark groups with changed members as dirty
-                val batch = BatchOperation(localAddressBook.provider!!)
-                for (contact in localAddressBook.getDirtyContacts())
-                    try {
-                        Logger.log.fine("Looking for changed group memberships of contact ${contact.fileName}")
-                        val cachedGroups = contact.getCachedGroupMemberships()
-                        val currentGroups = contact.getGroupMemberships()
-                        for (groupID in cachedGroups disjunct currentGroups) {
-                            Logger.log.fine("Marking group as dirty: $groupID")
-                            batch.enqueue(BatchOperation.Operation(
-                                    ContentProviderOperation.newUpdate(localAddressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)))
-                                    .withValue(Groups.DIRTY, 1)
-                                    .withYieldAllowed(true)
-                            ))
-                        }
-                    } catch(e: FileNotFoundException) {
-                    }
-                batch.commit()
-            }
-        }
-    }
-
-    private fun notifyDiscardedChange() {
-        val notification = NotificationCompat.Builder(context, NotificationUtils.CHANNEL_SYNC_STATUS)
-                .setSmallIcon(R.drawable.ic_delete_notification)
-                .setLargeIcon(App.getLauncherBitmap(context))
-                .setContentTitle(context.getString(R.string.sync_contacts_read_only_address_book))
-                .setContentText(context.resources.getQuantityString(R.plurals.sync_contacts_local_contact_changes_discarded, numDiscarded, numDiscarded))
-                .setSubText(account.name)
-                .setCategory(NotificationCompat.CATEGORY_ERROR)
-                .setPriority(NotificationCompat.PRIORITY_LOW)
-                .setLocalOnly(true)
-                .setAutoCancel(true)
-                .build()
-        notificationManager.notify("discarded_${account.name}", 0, notification)
-    }
-
-    override fun prepareUpload(resource: LocalResource): RequestBody {
-        val contact: Contact
-        if (resource is LocalContact) {
-            contact = resource.contact!!
-
-            if (groupMethod == GroupMethod.CATEGORIES) {
-                // add groups as CATEGORIES
-                for (groupID in resource.getGroupMemberships()) {
-                    try {
-                        provider.query(
-                                localAddressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)),
-                                arrayOf(Groups.TITLE), null, null, null
-                        )?.use { cursor ->
-                            if (cursor.moveToNext()) {
-                                val title = cursor.getString(0)
-                                if (!title.isNullOrEmpty())
-                                    contact.categories.add(title)
-                            }
-                        }
-                    } catch(e: RemoteException) {
-                        throw ContactsStorageException("Couldn't find group for adding CATEGORIES", e)
-                    }
-                }
-            }
-        } else if (resource is LocalGroup)
-            contact = resource.contact!!
-        else
-            throw IllegalArgumentException("resource must be a LocalContact or a LocalGroup")
-
-        Logger.log.log(Level.FINE, "Preparing upload of VCard ${resource.fileName}", contact)
-
-        val os = ByteArrayOutputStream()
-        contact.write(if (hasVCard4) VCardVersion.V4_0 else VCardVersion.V3_0, groupMethod, os)
-
-        return RequestBody.create(
-                if (hasVCard4) DavAddressBook.MIME_VCARD4 else DavAddressBook.MIME_VCARD3_UTF8,
-                os.toByteArray()
-        )
-    }
-
-    override fun listRemote() {
-        val addressBook = davAddressBook()
-        currentDavResource = addressBook
-
-        // fetch list of remote VCards and build hash table to index file name
-        addressBook.propfind(1, ResourceType.NAME, GetETag.NAME)
-
-        remoteResources = HashMap(davCollection.members.size)
-        for (vCard in davCollection.members) {
-            // ignore member collections
-            var ignore = false
-            vCard.properties[ResourceType::class.java]?.let { type ->
-                if (type.types.contains(ResourceType.COLLECTION))
-                    ignore = true
-            }
-            if (ignore)
-                continue
-
-            val fileName = vCard.fileName()
-            Logger.log.fine("Found remote VCard: $fileName")
-            remoteResources[fileName] = vCard
-        }
-
-        currentDavResource = null
-    }
-
-    override fun downloadRemote() {
-        Logger.log.info("Downloading ${toDownload.size} contacts ($MAX_MULTIGET at once)")
-
-        // prepare downloader which may be used to download external resource like contact photos
-        val downloader = ResourceDownloader(collectionURL)
-
-        // download new/updated VCards from server
-        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
-            abortIfCancelled()
-            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
-
-            if (bunch.size == 1) {
-                // only one contact, use GET
-                val remote = bunch.first()
-                currentDavResource = remote
-
-                val body = remote.get("text/vcard;version=4.0, text/vcard;charset=utf-8;q=0.8, text/vcard;q=0.5")
-
-                // CardDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc6352#section-6.3.2.3]
-                val eTag = remote.properties[GetETag::class.java]
-                if (eTag == null || eTag.eTag.isNullOrEmpty())
-                    throw DavException("Received CardDAV GET response without ETag for ${remote.location}")
-
-                body.charStream().use { reader ->
-                    processVCard(remote.fileName(), eTag.eTag!!, reader, downloader)
-                }
-
-            } else {
-                // multiple contacts, use multi-get
-                val addressBook = davAddressBook()
-                currentDavResource = addressBook
-                addressBook.multiget(bunch.map { it.location }, hasVCard4)
-
-                // process multi-get results
-                for (remote in davCollection.members) {
-                    currentDavResource = remote
-
-                    val eTag = remote.properties[GetETag::class.java]?.eTag
-                            ?: throw DavException("Received multi-get response without ETag")
-
-                    val addressData = remote.properties[AddressData::class.java]
-                    val vCard = addressData?.vCard
-                            ?: throw DavException("Received multi-get response without address data")
-
-                    processVCard(remote.fileName(), eTag, StringReader(vCard), downloader)
-                }
-            }
-
-            currentDavResource = null
-        }
-    }
-
-    override fun postProcess() {
-        if (groupMethod == GroupMethod.CATEGORIES) {
-            /* VCard3 group handling: groups memberships are represented as contact CATEGORIES */
-
-            // remove empty groups
-            Logger.log.info("Removing empty groups")
-            localAddressBook.removeEmptyGroups()
-
-        } else {
-            /* VCard4 group handling: there are group contacts and individual contacts */
-            Logger.log.info("Assigning memberships of downloaded contact groups")
-            LocalGroup.applyPendingMemberships(localAddressBook)
-        }
-    }
-
-
-    // helpers
-
-    private fun davAddressBook() = davCollection as DavAddressBook
-
-    private fun processVCard(fileName: String, eTag: String, reader: Reader, downloader: Contact.Downloader) {
-        Logger.log.info("Processing CardDAV resource $fileName")
-        val contacts = Contact.fromReader(reader, downloader)
-        if (contacts.isEmpty()) {
-            Logger.log.warning("Received VCard without data, ignoring")
-            return
-        } else if (contacts.size > 1)
-            Logger.log.warning("Received multiple VCards, using first one")
-
-        val newData = contacts.first()
-
-        if (groupMethod == GroupMethod.CATEGORIES && newData.group) {
-            Logger.log.warning("Received group VCard although group method is CATEGORIES. Saving as regular contact")
-            newData.group = false
-        }
-
-        // update local contact, if it exists
-        var local = localResources[fileName]
-        currentLocalResource = local
-        if (local != null) {
-            Logger.log.log(Level.INFO, "Updating $fileName in local address book", newData)
-
-            if (local is LocalGroup && newData.group) {
-                // update group
-                local.eTag = eTag
-                local.updateFromServer(newData)
-                syncResult.stats.numUpdates++
-
-            } else if (local is LocalContact && !newData.group) {
-                // update contact
-                local.eTag = eTag
-                local.update(newData)
-                syncResult.stats.numUpdates++
-
-            } else {
-                // group has become an individual contact or vice versa
-                local.delete()
-                local = null
-            }
-        }
-
-        if (local == null) {
-            if (newData.group) {
-                Logger.log.log(Level.INFO, "Creating local group", newData)
-                val group = LocalGroup(localAddressBook, newData, fileName, eTag)
-                currentLocalResource = group
-                group.create()
-
-                local = group
-            } else {
-                Logger.log.log(Level.INFO, "Creating local contact", newData)
-                val contact = LocalContact(localAddressBook, newData, fileName, eTag)
-                currentLocalResource = contact
-                contact.create()
-
-                local = contact
-            }
-            syncResult.stats.numInserts++
-        }
-
-        if (groupMethod == GroupMethod.CATEGORIES && local is LocalContact) {
-            // VCard3: update group memberships from CATEGORIES
-            currentLocalResource = local
-
-            val batch = BatchOperation(provider)
-            Logger.log.log(Level.FINE, "Removing contact group memberships")
-            local.removeGroupMemberships(batch)
-
-            for (category in local.contact!!.categories) {
-                val groupID = localAddressBook.findOrCreateGroup(category)
-                Logger.log.log(Level.FINE, "Adding membership in group $category ($groupID)")
-                local.addToGroup(batch, groupID)
-            }
-
-            batch.commit()
-        }
-
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O && local is LocalContact)
-            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-            local.updateHashCode(null)
-
-        currentLocalResource = null
-    }
-
-
-    // downloader helper class
-
-    private inner class ResourceDownloader(
-            val baseUrl: HttpUrl
-    ): Contact.Downloader {
-
-        override fun download(url: String, accepts: String): ByteArray? {
-            val httpUrl = HttpUrl.parse(url)
-            if (httpUrl == null) {
-                Logger.log.log(Level.SEVERE, "Invalid external resource URL", url)
-                return null
-            }
-
-            val host = httpUrl.host()
-            if (host == null) {
-                Logger.log.log(Level.SEVERE, "External resource URL doesn't specify a host name", url)
-                return null
-            }
-
-            // authenticate only against a certain host, and only upon request
-            val builder = HttpClient.Builder(context, baseUrl.host(), accountSettings.credentials())
-
-            // allow redirects
-            builder.followRedirects(true)
-
-            val client = builder.build()
-            try {
-                val response = client.okHttpClient.newCall(Request.Builder()
-                        .get()
-                        .url(httpUrl)
-                        .build()).execute()
-
-                if (response.isSuccessful)
-                    return response.body()?.bytes()
-                else
-                    Logger.log.warning("Couldn't download external resource")
-            } catch(e: IOException) {
-                Logger.log.log(Level.SEVERE, "Couldn't download external resource", e)
-            } finally {
-                client.close()
-            }
-            return null
-        }
-    }
-
-}
@@ -1,53 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.AbstractAccountAuthenticator
-import android.accounts.Account
-import android.accounts.AccountAuthenticatorResponse
-import android.accounts.AccountManager
-import android.app.Service
-import android.content.Context
-import android.content.Intent
-import android.os.Bundle
-import at.bitfire.davdroid.ui.AccountsActivity
-
-class NullAuthenticatorService: Service() {
-
-    private lateinit var accountAuthenticator: AccountAuthenticator
-
-    override fun onCreate() {
-        accountAuthenticator = AccountAuthenticator(this)
-    }
-
-    override fun onBind(intent: Intent?) =
-            accountAuthenticator.iBinder.takeIf { intent?.action == android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT }
-
-
-    private class AccountAuthenticator(
-            val context: Context
-    ): AbstractAccountAuthenticator(context) {
-
-        override fun addAccount(response: AccountAuthenticatorResponse?, accountType: String?, authTokenType: String?, requiredFeatures: Array<String>?, options: Bundle?): Bundle {
-            val intent = Intent(context, AccountsActivity::class.java)
-            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response)
-            val bundle = Bundle(1)
-            bundle.putParcelable(AccountManager.KEY_INTENT, intent)
-            return bundle
-        }
-
-        override fun editProperties(response: AccountAuthenticatorResponse?, accountType: String?) = null
-        override fun getAuthTokenLabel(p0: String?) = null
-        override fun confirmCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Bundle?) = null
-        override fun updateCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
-        override fun getAuthToken(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
-        override fun hasFeatures(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Array<out String>?) = null
-
-    }
-
-}
@@ -0,0 +1,115 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.AbstractThreadedSyncAdapter;
+import android.content.ContentProviderClient;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SyncResult;
+import android.graphics.drawable.BitmapDrawable;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.app.NotificationCompat;
+
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.ui.PermissionsActivity;
+
+public abstract class SyncAdapterService extends Service {
+
+    abstract protected AbstractThreadedSyncAdapter syncAdapter();
+
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        return syncAdapter().getSyncAdapterBinder();
+    }
+
+
+    public static abstract class SyncAdapter extends AbstractThreadedSyncAdapter {
+
+        public SyncAdapter(Context context) {
+            super(context, false);
+        }
+
+        @Override
+        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
+            App.log.info("Sync for " + authority + " has been initiated");
+
+            // required for dav4android (ServiceLoader)
+            Thread.currentThread().setContextClassLoader(getContext().getClassLoader());
+        }
+
+        @Override
+        public void onSecurityException(Account account, Bundle extras, String authority, SyncResult syncResult) {
+            App.log.log(Level.WARNING, "Security exception when opening content provider for " +  authority);
+            syncResult.databaseError = true;
+
+            Intent intent = new Intent(getContext(), PermissionsActivity.class);
+            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+            Notification notify = new NotificationCompat.Builder(getContext())
+                    .setSmallIcon(R.drawable.ic_error_light)
+                    .setLargeIcon(((BitmapDrawable)getContext().getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .setContentTitle(getContext().getString(R.string.sync_error_permissions))
+                    .setContentText(getContext().getString(R.string.sync_error_permissions_text))
+                    .setContentIntent(PendingIntent.getActivity(getContext(), 0, intent, PendingIntent.FLAG_CANCEL_CURRENT))
+                    .setCategory(NotificationCompat.CATEGORY_ERROR)
+                    .setLocalOnly(true)
+                    .build();
+            NotificationManager nm = (NotificationManager)getContext().getSystemService(NOTIFICATION_SERVICE);
+            nm.notify(Constants.NOTIFICATION_PERMISSIONS, notify);
+        }
+
+        protected boolean checkSyncConditions(@NonNull AccountSettings settings) {
+            if (settings.getSyncWifiOnly()) {
+                ConnectivityManager cm = (ConnectivityManager)getContext().getSystemService(CONNECTIVITY_SERVICE);
+                NetworkInfo network = cm.getActiveNetworkInfo();
+                if (network == null) {
+                    App.log.info("No network available, stopping");
+                    return false;
+                }
+                if (network.getType() != ConnectivityManager.TYPE_WIFI || !network.isConnected()) {
+                    App.log.info("Not on connected WiFi, stopping");
+                    return false;
+                }
+
+                String onlySSID = settings.getSyncWifiOnlySSID();
+                if (onlySSID != null) {
+                    onlySSID = "\"" + onlySSID + "\"";
+                    WifiManager wifi = (WifiManager)getContext().getSystemService(WIFI_SERVICE);
+                    WifiInfo info = wifi.getConnectionInfo();
+                    if (info == null || !onlySSID.equals(info.getSSID())) {
+                        App.log.info("Connected to wrong WiFi network (" + info.getSSID() + ", required: " + onlySSID + "), ignoring");
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }
+
+    }
+
+}
@@ -1,120 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.app.PendingIntent
-import android.app.Service
-import android.content.*
-import android.net.ConnectivityManager
-import android.net.wifi.WifiManager
-import android.os.Bundle
-import android.support.v4.app.NotificationCompat
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.App
-import at.bitfire.davdroid.Constants
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.davdroid.settings.Settings
-import at.bitfire.davdroid.ui.NotificationUtils
-import at.bitfire.davdroid.ui.PermissionsActivity
-import java.util.*
-import java.util.logging.Level
-
-abstract class SyncAdapterService: Service() {
-
-    companion object {
-        val runningSyncs = Collections.synchronizedSet(mutableSetOf<Pair<String, Account>>())!!
-    }
-
-    abstract protected fun syncAdapter(): AbstractThreadedSyncAdapter
-
-    override fun onBind(intent: Intent?) = syncAdapter().syncAdapterBinder!!
-
-
-    abstract class SyncAdapter(
-            context: Context
-    ): AbstractThreadedSyncAdapter(context, false) {
-
-        abstract fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult)
-
-        override fun onPerformSync(account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
-            Logger.log.log(Level.INFO, "$authority sync of $account has been initiated", extras.keySet().joinToString(", "))
-
-            // prevent multiple syncs of the same authority to be run for the same account
-            val currentSync = Pair(authority, account)
-            if (!runningSyncs.add(currentSync)) {
-                Logger.log.warning("There's already another $authority sync running for $account, aborting")
-                return
-            }
-
-            try {
-                // required for dav4android (ServiceLoader)
-                Thread.currentThread().contextClassLoader = context.classLoader
-
-                // load app settings
-                Settings.getInstance(context).use { settings ->
-                    if (settings == null) {
-                        syncResult.databaseError = true
-                        Logger.log.severe("Couldn't connect to Settings service, aborting sync")
-                        return
-                    }
-
-                    sync(settings, account, extras, authority, provider, syncResult)
-                }
-                Logger.log.info("Sync for $authority complete")
-            } finally {
-                runningSyncs -= currentSync
-            }
-        }
-
-        override fun onSecurityException(account: Account, extras: Bundle, authority: String, syncResult: SyncResult) {
-            Logger.log.log(Level.WARNING, "Security exception when opening content provider for $authority")
-            syncResult.databaseError = true
-
-            val intent = Intent(context, PermissionsActivity::class.java)
-            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
-
-            val notify = NotificationCompat.Builder(context, NotificationUtils.CHANNEL_SYNC_PROBLEMS)
-                    .setSmallIcon(R.drawable.ic_sync_error_notification)
-                    .setLargeIcon(App.getLauncherBitmap(context))
-                    .setContentTitle(context.getString(R.string.sync_error_permissions))
-                    .setContentText(context.getString(R.string.sync_error_permissions_text))
-                    .setContentIntent(PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
-                    .setCategory(NotificationCompat.CATEGORY_ERROR)
-                    .build()
-            val nm = NotificationUtils.createChannels(context)
-            nm.notify(Constants.NOTIFICATION_PERMISSIONS, notify)
-        }
-
-        protected fun checkSyncConditions(settings: AccountSettings): Boolean {
-            if (settings.getSyncWifiOnly()) {
-                val connectivityManager = context.getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager
-                val network = connectivityManager.activeNetworkInfo
-                if (network == null || network.type != ConnectivityManager.TYPE_WIFI || !network.isConnected) {
-                    Logger.log.info("Not on connected WiFi, stopping")
-                    return false
-                }
-
-                settings.getSyncWifiOnlySSIDs()?.let { onlySSIDs ->
-                    val wifi = context.applicationContext.getSystemService(WIFI_SERVICE) as WifiManager
-                    val info = wifi.connectionInfo
-                    if (info == null || !onlySSIDs.contains(info.ssid.trim('"'))) {
-                        Logger.log.info("Connected to wrong WiFi network (${info.ssid}), ignoring")
-                        return false
-                    }
-                }
-            }
-            return true
-        }
-
-    }
-
-}
@@ -0,0 +1,438 @@
+    /*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.annotation.TargetApi;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SyncResult;
+import android.graphics.drawable.BitmapDrawable;
+import android.net.Uri;
+import android.os.Bundle;
+import android.support.v7.app.NotificationCompat;
+import android.text.TextUtils;
+
+import java.io.IOException;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.logging.Level;
+
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.exception.ConflictException;
+import at.bitfire.dav4android.exception.DavException;
+import at.bitfire.dav4android.exception.HttpException;
+import at.bitfire.dav4android.exception.PreconditionFailedException;
+import at.bitfire.dav4android.exception.ServiceUnavailableException;
+import at.bitfire.dav4android.exception.UnauthorizedException;
+import at.bitfire.dav4android.property.GetCTag;
+import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.HttpClient;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.resource.LocalCollection;
+import at.bitfire.davdroid.resource.LocalResource;
+import at.bitfire.davdroid.ui.AccountSettingsActivity;
+import at.bitfire.davdroid.ui.DebugInfoActivity;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.vcard4android.ContactsStorageException;
+import okhttp3.HttpUrl;
+import okhttp3.OkHttpClient;
+import okhttp3.RequestBody;
+
+abstract public class SyncManager {
+
+    protected final int SYNC_PHASE_PREPARE = 0,
+                        SYNC_PHASE_QUERY_CAPABILITIES = 1,
+                        SYNC_PHASE_PROCESS_LOCALLY_DELETED = 2,
+                        SYNC_PHASE_PREPARE_DIRTY = 3,
+                        SYNC_PHASE_UPLOAD_DIRTY = 4,
+                        SYNC_PHASE_CHECK_SYNC_STATE = 5,
+                        SYNC_PHASE_LIST_LOCAL = 6,
+                        SYNC_PHASE_LIST_REMOTE = 7,
+                        SYNC_PHASE_COMPARE_LOCAL_REMOTE = 8,
+                        SYNC_PHASE_DOWNLOAD_REMOTE = 9,
+                        SYNC_PHASE_SAVE_SYNC_STATE = 10;
+
+    protected final NotificationManager notificationManager;
+    protected final String uniqueCollectionId;
+
+    protected final Context context;
+    protected final Account account;
+    protected final Bundle extras;
+    protected final String authority;
+    protected final SyncResult syncResult;
+
+    protected final AccountSettings settings;
+    protected LocalCollection localCollection;
+
+    protected OkHttpClient httpClient;
+    protected HttpUrl collectionURL;
+    protected DavResource davCollection;
+
+
+    /** remote CTag at the time of {@link #listRemote()} */
+    protected String remoteCTag = null;
+
+    /** sync-able resources in the local collection, as enumerated by {@link #listLocal()} */
+    protected Map<String, LocalResource> localResources;
+
+    /** sync-able resources in the remote collection, as enumerated by {@link #listRemote()} */
+    protected Map<String, DavResource> remoteResources;
+
+    /** resources which have changed on the server, as determined by {@link #compareLocalRemote()} */
+    protected Set<DavResource> toDownload;
+
+
+
+    public SyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) throws InvalidAccountException {
+        this.context = context;
+        this.account = account;
+        this.settings = settings;
+        this.extras = extras;
+        this.authority = authority;
+        this.syncResult = syncResult;
+
+        // create HttpClient with given logger
+        httpClient = HttpClient.create(context, account);
+
+        // dismiss previous error notifications
+        this.uniqueCollectionId = uniqueCollectionId;
+        notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
+        notificationManager.cancel(uniqueCollectionId, notificationId());
+    }
+
+    protected abstract int notificationId();
+    protected abstract String getSyncErrorTitle();
+
+    @TargetApi(21)
+    public void performSync() {
+        int syncPhase = SYNC_PHASE_PREPARE;
+        try {
+            App.log.info("Preparing synchronization");
+            prepare();
+
+            if (Thread.interrupted())
+                return;
+            syncPhase = SYNC_PHASE_QUERY_CAPABILITIES;
+            App.log.info("Querying capabilities");
+            queryCapabilities();
+
+            syncPhase = SYNC_PHASE_PROCESS_LOCALLY_DELETED;
+            App.log.info("Processing locally deleted entries");
+            processLocallyDeleted();
+
+            if (Thread.interrupted())
+                return;
+            syncPhase = SYNC_PHASE_PREPARE_DIRTY;
+            App.log.info("Locally preparing dirty entries");
+            prepareDirty();
+
+            syncPhase = SYNC_PHASE_UPLOAD_DIRTY;
+            App.log.info("Uploading dirty entries");
+            uploadDirty();
+
+            syncPhase = SYNC_PHASE_CHECK_SYNC_STATE;
+            App.log.info("Checking sync state");
+            if (checkSyncState()) {
+                syncPhase = SYNC_PHASE_LIST_LOCAL;
+                App.log.info("Listing local entries");
+                listLocal();
+
+                if (Thread.interrupted())
+                    return;
+                syncPhase = SYNC_PHASE_LIST_REMOTE;
+                App.log.info("Listing remote entries");
+                listRemote();
+
+                if (Thread.interrupted())
+                    return;
+                syncPhase = SYNC_PHASE_COMPARE_LOCAL_REMOTE;
+                App.log.info("Comparing local/remote entries");
+                compareLocalRemote();
+
+                syncPhase = SYNC_PHASE_DOWNLOAD_REMOTE;
+                App.log.info("Downloading remote entries");
+                downloadRemote();
+
+                syncPhase = SYNC_PHASE_SAVE_SYNC_STATE;
+                App.log.info("Saving sync state");
+                saveSyncState();
+            } else
+                App.log.info("Remote collection didn't change, skipping remote sync");
+
+        } catch (IOException|ServiceUnavailableException e) {
+            App.log.log(Level.WARNING, "I/O exception during sync, trying again later", e);
+            syncResult.stats.numIoExceptions++;
+
+            if (e instanceof ServiceUnavailableException) {
+                Date retryAfter = ((ServiceUnavailableException) e).retryAfter;
+                if (retryAfter != null) {
+                    // how many seconds to wait? getTime() returns ms, so divide by 1000
+                    syncResult.delayUntil = (retryAfter.getTime() - new Date().getTime()) / 1000;
+                }
+            }
+
+        } catch(Exception|OutOfMemoryError e) {
+            final int messageString;
+
+            if (e instanceof UnauthorizedException) {
+                App.log.log(Level.SEVERE, "Not authorized anymore", e);
+                messageString = R.string.sync_error_unauthorized;
+                syncResult.stats.numAuthExceptions++;
+            } else if (e instanceof HttpException || e instanceof DavException) {
+                App.log.log(Level.SEVERE, "HTTP/DAV Exception during sync", e);
+                messageString = R.string.sync_error_http_dav;
+                syncResult.stats.numParseExceptions++;
+            } else if (e instanceof CalendarStorageException || e instanceof ContactsStorageException) {
+                App.log.log(Level.SEVERE, "Couldn't access local storage", e);
+                messageString = R.string.sync_error_local_storage;
+                syncResult.databaseError = true;
+            } else {
+                App.log.log(Level.SEVERE, "Unknown sync error", e);
+                messageString = R.string.sync_error;
+                syncResult.stats.numParseExceptions++;
+            }
+
+            final Intent detailsIntent;
+            if (e instanceof UnauthorizedException) {
+                detailsIntent = new Intent(context, AccountSettingsActivity.class);
+                detailsIntent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account);
+            } else {
+                detailsIntent = new Intent(context, DebugInfoActivity.class);
+                detailsIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e);
+                detailsIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account);
+                detailsIntent.putExtra(DebugInfoActivity.KEY_AUTHORITY, authority);
+                detailsIntent.putExtra(DebugInfoActivity.KEY_PHASE, syncPhase);
+            }
+
+            // to make the PendingIntent unique
+            detailsIntent.setData(Uri.parse("uri://" + getClass().getName() + "/" + uniqueCollectionId));
+
+            NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
+            builder .setSmallIcon(R.drawable.ic_error_light)
+                    .setLargeIcon(((BitmapDrawable)context.getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .setContentTitle(getSyncErrorTitle())
+                    .setContentIntent(PendingIntent.getActivity(context, 0, detailsIntent, PendingIntent.FLAG_CANCEL_CURRENT))
+                    .setCategory(NotificationCompat.CATEGORY_ERROR)
+                    .setLocalOnly(true);
+
+            try {
+                String[] phases = context.getResources().getStringArray(R.array.sync_error_phases);
+                String message = context.getString(messageString, phases[syncPhase]);
+                builder.setContentText(message);
+            } catch (IndexOutOfBoundsException ex) {
+                // should never happen
+            }
+
+            notificationManager.notify(uniqueCollectionId, notificationId(), builder.build());
+        }
+    }
+
+
+    abstract protected void prepare() throws ContactsStorageException;
+
+    abstract protected void queryCapabilities() throws IOException, HttpException, DavException, CalendarStorageException, ContactsStorageException;
+
+    /**
+     * Process locally deleted entries (DELETE them on the server as well).
+     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
+     */
+    protected void processLocallyDeleted() throws CalendarStorageException, ContactsStorageException {
+        // Remove locally deleted entries from server (if they have a name, i.e. if they were uploaded before),
+        // but only if they don't have changed on the server. Then finally remove them from the local address book.
+        LocalResource[] localList = localCollection.getDeleted();
+        for (LocalResource local : localList) {
+            if (Thread.interrupted())
+                return;
+
+            final String fileName = local.getFileName();
+            if (!TextUtils.isEmpty(fileName)) {
+                App.log.info(fileName + " has been deleted locally -> deleting from server");
+                try {
+                    new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
+                            .delete(local.getETag());
+                } catch (IOException|HttpException e) {
+                    App.log.warning("Couldn't delete " + fileName + " from server; ignoring (may be downloaded again)");
+                }
+            } else
+                App.log.info("Removing local record #" + local.getId() + " which has been deleted locally and was never uploaded");
+            local.delete();
+            syncResult.stats.numDeletes++;
+        }
+    }
+
+    protected void prepareDirty() throws CalendarStorageException, ContactsStorageException {
+        // assign file names and UIDs to new contacts so that we can use the file name as an index
+        for (LocalResource local : localCollection.getWithoutFileName()) {
+            String uuid = UUID.randomUUID().toString();
+            App.log.info("Found local record #" + local.getId() + " without file name; assigning file name/UID based on " + uuid);
+            local.updateFileNameAndUID(uuid);
+        }
+    }
+
+    abstract protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException, ContactsStorageException;
+
+    /**
+     * Uploads dirty records to the server, using a PUT request for each record.
+     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
+     */
+    protected void uploadDirty() throws IOException, HttpException, CalendarStorageException, ContactsStorageException {
+        // upload dirty contacts
+        for (LocalResource local : localCollection.getDirty()) {
+            if (Thread.interrupted())
+                return;
+
+            final String fileName = local.getFileName();
+
+            DavResource remote = new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build());
+
+            // generate entity to upload (VCard, iCal, whatever)
+            RequestBody body = prepareUpload(local);
+
+            try {
+
+                if (local.getETag() == null) {
+                    App.log.info("Uploading new record " + fileName);
+                    remote.put(body, null, true);
+                } else {
+                    App.log.info("Uploading locally modified record " + fileName);
+                    remote.put(body, local.getETag(), false);
+                }
+
+            } catch (ConflictException|PreconditionFailedException e) {
+                // we can't interact with the user to resolve the conflict, so we treat 409 like 412
+                App.log.log(Level.INFO, "Resource has been modified on the server before upload, ignoring", e);
+            }
+
+            String eTag = null;
+            GetETag newETag = (GetETag) remote.properties.get(GetETag.NAME);
+            if (newETag != null) {
+                eTag = newETag.eTag;
+                App.log.fine("Received new ETag=" + eTag + " after uploading");
+            } else
+                App.log.fine("Didn't receive new ETag after uploading, setting to null");
+
+            local.clearDirty(eTag);
+        }
+    }
+
+    /**
+     * Checks the current sync state (e.g. CTag) and whether synchronization from remote is required.
+     * @return <ul>
+     *      <li><code>true</code>   if the remote collection has changed, i.e. synchronization from remote is required</li>
+     *      <li><code>false</code>  if the remote collection hasn't changed</li>
+     * </ul>
+     */
+    protected boolean checkSyncState() throws CalendarStorageException, ContactsStorageException {
+        // check CTag (ignore on manual sync)
+        GetCTag getCTag = (GetCTag)davCollection.properties.get(GetCTag.NAME);
+        if (getCTag != null)
+            remoteCTag = getCTag.cTag;
+
+        String localCTag = null;
+        if (extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL))
+            App.log.info("Manual sync, ignoring CTag");
+        else
+            localCTag = localCollection.getCTag();
+
+        if (remoteCTag != null && remoteCTag.equals(localCTag)) {
+            App.log.info("Remote collection didn't change (CTag=" + remoteCTag + "), no need to query children");
+            return false;
+        } else
+            return true;
+    }
+
+    /**
+     * Lists all local resources which should be taken into account for synchronization into {@link #localResources}.
+     */
+    protected void listLocal() throws CalendarStorageException, ContactsStorageException {
+        // fetch list of local contacts and build hash table to index file name
+        LocalResource[] localList = localCollection.getAll();
+        localResources = new HashMap<>(localList.length);
+        for (LocalResource resource : localList) {
+            App.log.fine("Found local resource: " + resource.getFileName());
+            localResources.put(resource.getFileName(), resource);
+        }
+    }
+
+    /**
+     * Lists all members of the remote collection which should be taken into account for synchronization into {@link #remoteResources}.
+     */
+    abstract protected void listRemote() throws IOException, HttpException, DavException;
+
+    /**
+     * Compares {@link #localResources} and {@link #remoteResources} by file name and ETag:
+     * <ul>
+     *     <li>Local resources which are not available in the remote collection (anymore) will be removed.</li>
+     *     <li>Resources whose remote ETag has changed will be added into {@link #toDownload}</li>
+     * </ul>
+     */
+    protected void compareLocalRemote() throws IOException, HttpException, DavException, CalendarStorageException, ContactsStorageException {
+        /* check which contacts
+           1. are not present anymore remotely -> delete immediately on local side
+           2. updated remotely -> add to downloadNames
+           3. added remotely  -> add to downloadNames
+         */
+        toDownload = new HashSet<>();
+        for (String localName : localResources.keySet()) {
+            DavResource remote = remoteResources.get(localName);
+            if (remote == null) {
+                App.log.info(localName + " is not on server anymore, deleting");
+                localResources.get(localName).delete();
+                syncResult.stats.numDeletes++;
+            } else {
+                // contact is still on server, check whether it has been updated remotely
+                GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                if (getETag == null || getETag.eTag == null)
+                    throw new DavException("Server didn't provide ETag");
+                String localETag = localResources.get(localName).getETag(),
+                        remoteETag = getETag.eTag;
+                if (remoteETag.equals(localETag))
+                    syncResult.stats.numSkippedEntries++;
+                else {
+                    App.log.info(localName + " has been changed on server (current ETag=" + remoteETag + ", last known ETag=" + localETag + ")");
+                    toDownload.add(remote);
+                }
+
+                // remote entry has been seen, remove from list
+                remoteResources.remove(localName);
+            }
+        }
+
+        // add all unseen (= remotely added) remote contacts
+        if (!remoteResources.isEmpty()) {
+            App.log.info("New resources have been found on the server: " + TextUtils.join(", ", remoteResources.keySet()));
+            toDownload.addAll(remoteResources.values());
+        }
+    }
+
+    /**
+     * Downloads the remote resources in {@link #toDownload} and stores them locally.
+     * Must check Thread.interrupted() periodically to allow quick sync cancellation.
+     */
+    abstract protected void downloadRemote() throws IOException, HttpException, DavException, ContactsStorageException, CalendarStorageException;
+
+    protected void saveSyncState() throws CalendarStorageException, ContactsStorageException {
+        /* Save sync state (CTag). It doesn't matter if it has changed during the sync process
+           (for instance, because another client has uploaded changes), because this will simply
+           cause all remote entries to be listed at the next sync. */
+        App.log.info("Saving CTag=" + remoteCTag);
+        localCollection.setCTag(remoteCTag);
+    }
+
+}
@@ -1,494 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.app.PendingIntent
-import android.content.ContentResolver
-import android.content.Context
-import android.content.Intent
-import android.content.SyncResult
-import android.net.Uri
-import android.os.Bundle
-import android.support.v4.app.NotificationCompat
-import at.bitfire.dav4android.DavResource
-import at.bitfire.dav4android.exception.*
-import at.bitfire.dav4android.property.GetCTag
-import at.bitfire.dav4android.property.GetETag
-import at.bitfire.davdroid.*
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.resource.LocalCollection
-import at.bitfire.davdroid.resource.LocalResource
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.davdroid.ui.AccountSettingsActivity
-import at.bitfire.davdroid.ui.DebugInfoActivity
-import at.bitfire.davdroid.ui.NotificationUtils
-import at.bitfire.ical4android.CalendarStorageException
-import at.bitfire.vcard4android.ContactsStorageException
-import okhttp3.HttpUrl
-import okhttp3.RequestBody
-import java.io.Closeable
-import java.io.IOException
-import java.io.InterruptedIOException
-import java.security.cert.CertificateException
-import java.util.*
-import java.util.logging.Level
-import javax.net.ssl.SSLHandshakeException
-
-abstract class SyncManager(
-        val context: Context,
-        val settings: ISettings,
-        val account: Account,
-        val accountSettings: AccountSettings,
-        val extras: Bundle,
-        val authority: String,
-        val syncResult: SyncResult,
-        val uniqueCollectionId: String
-): Closeable {
-
-    companion object {
-
-        val SYNC_PHASE_PREPARE = 0
-        val SYNC_PHASE_QUERY_CAPABILITIES = 1
-        val SYNC_PHASE_PROCESS_LOCALLY_DELETED = 2
-        val SYNC_PHASE_PREPARE_DIRTY = 3
-        val SYNC_PHASE_UPLOAD_DIRTY = 4
-        val SYNC_PHASE_CHECK_SYNC_STATE = 5
-        val SYNC_PHASE_LIST_LOCAL = 6
-        val SYNC_PHASE_LIST_REMOTE = 7
-        val SYNC_PHASE_COMPARE_LOCAL_REMOTE = 8
-        val SYNC_PHASE_DOWNLOAD_REMOTE = 9
-        val SYNC_PHASE_POST_PROCESSING = 10
-        val SYNC_PHASE_SAVE_SYNC_STATE = 11
-
-        infix fun <T> Set<T>.disjunct(other: Set<T>) = (this - other) union (other - this)
-
-    }
-
-    protected val notificationManager = NotificationUtils.createChannels(context)
-
-    protected lateinit var localCollection: LocalCollection<*>
-
-    protected val httpClient = HttpClient.Builder(context, settings, accountSettings).build()
-    protected lateinit var collectionURL: HttpUrl
-    protected lateinit var davCollection: DavResource
-
-
-    /** current sync phase */
-    private var syncPhase: Int = SYNC_PHASE_PREPARE
-
-    /** state information for debug info (local resource) */
-    protected var currentLocalResource: LocalResource? = null
-
-    /** state information for debug info (remote resource) */
-    protected var currentDavResource: DavResource? = null
-
-
-    /** remote CTag at the time of {@link #listRemote()} */
-    protected var remoteCTag: String? = null
-
-    /** sync-able resources in the local collection, as enumerated by {@link #listLocal()} */
-    protected lateinit var localResources: MutableMap<String, LocalResource>
-
-    /** sync-able resources in the remote collection, as enumerated by {@link #listRemote()} */
-    protected lateinit var remoteResources: MutableMap<String, DavResource>
-
-    /** resources which have changed on the server, as determined by {@link #compareLocalRemote()} */
-    protected val toDownload = mutableSetOf<DavResource>()
-
-
-    protected abstract fun notificationId(): Int
-    protected abstract fun getSyncErrorTitle(): String
-
-    @Suppress("UNUSED_VALUE")
-    fun performSync() {
-        // dismiss previous error notifications
-        notificationManager.cancel(uniqueCollectionId, notificationId())
-
-        try {
-            Logger.log.info("Preparing synchronization")
-            if (!prepare()) {
-                Logger.log.info("No reason to synchronize, aborting")
-                return
-            }
-
-            abortIfCancelled()
-            syncPhase = SYNC_PHASE_QUERY_CAPABILITIES
-            Logger.log.info("Querying capabilities")
-            queryCapabilities()
-
-            syncPhase = SYNC_PHASE_PROCESS_LOCALLY_DELETED
-            Logger.log.info("Processing locally deleted entries")
-            processLocallyDeleted()
-
-            abortIfCancelled()
-            syncPhase = SYNC_PHASE_PREPARE_DIRTY
-            Logger.log.info("Locally preparing dirty entries")
-            prepareDirty()
-
-            syncPhase = SYNC_PHASE_UPLOAD_DIRTY
-            Logger.log.info("Uploading dirty entries")
-            uploadDirty()
-
-            syncPhase = SYNC_PHASE_CHECK_SYNC_STATE
-            Logger.log.info("Checking sync state")
-            if (checkSyncState()) {
-                syncPhase = SYNC_PHASE_LIST_LOCAL
-                Logger.log.info("Listing local resources")
-                listLocal()
-
-                abortIfCancelled()
-                syncPhase = SYNC_PHASE_LIST_REMOTE
-                Logger.log.info("Listing remote resources")
-                listRemote()
-
-                abortIfCancelled()
-                syncPhase = SYNC_PHASE_COMPARE_LOCAL_REMOTE
-                Logger.log.info("Comparing local/remote entries")
-                compareLocalRemote()
-
-                syncPhase = SYNC_PHASE_DOWNLOAD_REMOTE
-                Logger.log.info("Downloading remote entries")
-                downloadRemote()
-
-                syncPhase = SYNC_PHASE_POST_PROCESSING
-                Logger.log.info("Post-processing")
-                postProcess()
-
-                syncPhase = SYNC_PHASE_SAVE_SYNC_STATE
-                Logger.log.info("Saving sync state")
-                saveSyncState()
-            } else
-                Logger.log.info("Remote collection didn't change, skipping remote sync")
-
-        } catch (e: InterruptedException) {
-            // re-throw to SyncAdapterService
-            throw e
-        } catch (e: InterruptedIOException) {
-            throw e
-
-        } catch (e: SSLHandshakeException) {
-            Logger.log.log(Level.WARNING, "SSL handshake failed", e)
-
-            // when a certificate is rejected by cert4android, the cause will be a CertificateException
-            if (!BuildConfig.customCerts || e.cause !is CertificateException)
-                notifyException(e)
-        } catch (e: IOException) {
-            Logger.log.log(Level.WARNING, "I/O exception during sync, trying again later", e)
-            syncResult.stats.numIoExceptions++
-        } catch (e: ServiceUnavailableException) {
-            Logger.log.log(Level.WARNING, "Got 503 Service unavailable, trying again later", e)
-            syncResult.stats.numIoExceptions++
-            e.retryAfter?.let { retryAfter ->
-                // how many seconds to wait? getTime() returns ms, so divide by 1000
-                syncResult.delayUntil = (retryAfter.time - Date().time) / 1000
-            }
-        } catch (e: Throwable) {
-            notifyException(e)
-        }
-    }
-
-    private fun notifyException(e: Throwable) {
-        val messageString: Int
-
-        when (e) {
-            is UnauthorizedException -> {
-                Logger.log.log(Level.SEVERE, "Not authorized anymore", e)
-                messageString = R.string.sync_error_unauthorized
-                syncResult.stats.numAuthExceptions++
-            }
-            is HttpException, is DavException -> {
-                Logger.log.log(Level.SEVERE, "HTTP/DAV Exception during sync", e)
-                messageString = R.string.sync_error_http_dav
-                syncResult.stats.numParseExceptions++
-            }
-            is CalendarStorageException, is ContactsStorageException -> {
-                Logger.log.log(Level.SEVERE, "Couldn't access local storage", e)
-                messageString = R.string.sync_error_local_storage
-                syncResult.databaseError = true
-            }
-            else -> {
-                Logger.log.log(Level.SEVERE, "Unknown sync error", e)
-                messageString = R.string.sync_error
-                syncResult.stats.numParseExceptions++
-            }
-        }
-
-        val detailsIntent: Intent
-        if (e is UnauthorizedException) {
-            detailsIntent = Intent(context, AccountSettingsActivity::class.java)
-            detailsIntent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account)
-        } else {
-            detailsIntent = Intent(context, DebugInfoActivity::class.java)
-            detailsIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e)
-            detailsIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account)
-            detailsIntent.putExtra(DebugInfoActivity.KEY_AUTHORITY, authority)
-            detailsIntent.putExtra(DebugInfoActivity.KEY_PHASE, syncPhase)
-            currentLocalResource?.let { detailsIntent.putExtra(DebugInfoActivity.KEY_LOCAL_RESOURCE, it.toString()) }
-            currentDavResource?.let { detailsIntent.putExtra(DebugInfoActivity.KEY_REMOTE_RESOURCE, it.toString()) }
-        }
-
-        // to make the PendingIntent unique
-        detailsIntent.data = Uri.parse("uri://${javaClass.name}/$uniqueCollectionId")
-
-        val builder = NotificationCompat.Builder(context, NotificationUtils.CHANNEL_SYNC_PROBLEMS)
-        builder .setSmallIcon(R.drawable.ic_sync_error_notification)
-                .setLargeIcon(App.getLauncherBitmap(context))
-                .setContentTitle(getSyncErrorTitle())
-                .setContentIntent(PendingIntent.getActivity(context, 0, detailsIntent, PendingIntent.FLAG_CANCEL_CURRENT))
-                .setCategory(NotificationCompat.CATEGORY_ERROR)
-
-        try {
-            val phases = context.resources.getStringArray(R.array.sync_error_phases)
-            val message = context.getString(messageString, phases[syncPhase])
-            builder.setContentText(message)
-        } catch (ex: IndexOutOfBoundsException) {
-            // should never happen
-        }
-
-        notificationManager.notify(uniqueCollectionId, notificationId(), builder.build())
-    }
-
-    /**
-     * Throws an [InterruptedException] if the current thread has been interrupted,
-     * most probably because synchronization was cancelled by the user.
-     * @throws InterruptedException (which will be catched by [performSync])
-     * */
-    protected fun abortIfCancelled() {
-        if (Thread.interrupted())
-            throw InterruptedException("Sync was cancelled")
-    }
-
-    override fun close() {
-        httpClient.close()
-    }
-
-
-    /** Prepares synchronization (for instance, allocates necessary resources).
-     * @return whether actual synchronization is required / can be made. true = synchronization
-     *         shall be continued, false = synchronization can be skipped */
-    abstract protected fun prepare(): Boolean
-
-    abstract protected fun queryCapabilities()
-
-    /**
-     * Process locally deleted entries (DELETE them on the server as well).
-     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
-     */
-    protected open fun processLocallyDeleted() {
-        // Remove locally deleted entries from server (if they have a name, i.e. if they were uploaded before),
-        // but only if they don't have changed on the server. Then finally remove them from the local address book.
-        val localList = localCollection.getDeleted()
-        for (local in localList) {
-            if (Thread.interrupted())
-                return
-
-            currentLocalResource = local
-
-            val fileName = local.fileName
-            if (fileName != null) {
-                Logger.log.info("$fileName has been deleted locally -> deleting from server")
-
-                val remote = DavResource(httpClient.okHttpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
-                currentDavResource = remote
-                try {
-                    remote.delete(local.eTag)
-                } catch (e: HttpException) {
-                    Logger.log.warning("Couldn't delete $fileName from server; ignoring (may be downloaded again)")
-                }
-            } else
-                Logger.log.info("Removing local record #${local.id} which has been deleted locally and was never uploaded")
-            local.delete()
-            syncResult.stats.numDeletes++
-
-            currentLocalResource = null
-            currentDavResource = null
-        }
-    }
-
-    protected open fun prepareDirty() {
-        // assign file names and UIDs to new contacts so that we can use the file name as an index
-        Logger.log.info("Looking for contacts/groups without file name")
-        for (local in localCollection.getWithoutFileName()) {
-            currentLocalResource = local
-
-            Logger.log.fine("Found local record #${local.id} without file name; generating file name/UID if necessary")
-            local.prepareForUpload()
-
-            currentLocalResource = null
-        }
-    }
-
-    abstract protected fun prepareUpload(resource: LocalResource): RequestBody
-
-    /**
-     * Uploads dirty records to the server, using a PUT request for each record.
-     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
-     */
-    protected open fun uploadDirty() {
-        // upload dirty contacts
-        for (local in localCollection.getDirty()) {
-            if (Thread.interrupted())
-                return
-
-            currentLocalResource = local
-            val fileName = local.fileName
-
-            val remote = DavResource(httpClient.okHttpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
-            currentDavResource = remote
-
-            // generate entity to upload (VCard, iCal, whatever)
-            val body = prepareUpload(local)
-
-            try {
-                if (local.eTag == null) {
-                    Logger.log.info("Uploading new record $fileName")
-                    remote.put(body, null, true)
-                } else {
-                    Logger.log.info("Uploading locally modified record $fileName")
-                    remote.put(body, local.eTag, false)
-                }
-            } catch(e: ConflictException) {
-                // we can't interact with the user to resolve the conflict, so we treat 409 like 412
-                Logger.log.log(Level.INFO, "Edit conflict, ignoring", e)
-            } catch(e: PreconditionFailedException) {
-                Logger.log.log(Level.INFO, "Resource has been modified on the server before upload, ignoring", e)
-            }
-
-            val newETag = remote.properties[GetETag::class.java]
-            val eTag: String?
-            if (newETag != null) {
-                eTag = newETag.eTag
-                Logger.log.fine("Received new ETag=$eTag after uploading")
-            } else {
-                Logger.log.fine("Didn't receive new ETag after uploading, setting to null")
-                eTag = null
-            }
-
-            local.clearDirty(eTag)
-
-            currentLocalResource = null
-            currentDavResource = null
-        }
-    }
-
-    /**
-     * Checks the current sync state (e.g. CTag) and whether synchronization from remote is required.
-     * @return <ul>
-     *      <li><code>true</code>   if the remote collection has changed, i.e. synchronization from remote is required</li>
-     *      <li><code>false</code>  if the remote collection hasn't changed</li>
-     * </ul>
-     */
-    protected open fun checkSyncState(): Boolean {
-        // check CTag (ignore on manual sync)
-        davCollection.properties[GetCTag::class.java]?.let { remoteCTag = it.cTag }
-
-        val localCTag = if (extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL)) {
-            Logger.log.info("Manual sync, ignoring CTag")
-            null
-        } else
-            localCollection.getCTag()
-
-        return if (remoteCTag != null && remoteCTag == localCTag) {
-            Logger.log.info("Remote collection didn't change (CTag=$remoteCTag), no need to query children")
-            false
-        } else
-            true
-    }
-
-    /**
-     * Lists all local resources which should be taken into account for synchronization into {@link #localResources}.
-     */
-    protected open fun listLocal() {
-        // fetch list of local contacts and build hash table to index file name
-        val localList = localCollection.getAll()
-        val resources = HashMap<String, LocalResource>(localList.size)
-        for (resource in localList) {
-            Logger.log.fine("Found local resource: ${resource.fileName}")
-            resource.fileName?.let { resources[it] = resource }
-        }
-        localResources = resources
-        Logger.log.info("Found ${localResources.size} local resources")
-    }
-
-    /**
-     * Lists all members of the remote collection which should be taken into account for synchronization into {@link #remoteResources}.
-     */
-    abstract protected fun listRemote()
-
-    /**
-     * Compares {@link #localResources} and {@link #remoteResources} by file name and ETag:
-     * <ul>
-     *     <li>Local resources which are not available in the remote collection (anymore) will be removed.</li>
-     *     <li>Resources whose remote ETag has changed will be added into {@link #toDownload}</li>
-     * </ul>
-     */
-    protected open fun compareLocalRemote() {
-        /* check which contacts
-           1. are not present anymore remotely -> delete immediately on local side
-           2. updated remotely -> add to downloadNames
-           3. added remotely  -> add to downloadNames
-         */
-        toDownload.clear()
-        for ((name,local) in localResources) {
-            val remote = remoteResources[name]
-            currentDavResource = remote
-
-            if (remote == null) {
-                Logger.log.info("$name is not on server anymore, deleting")
-                currentLocalResource = local
-                local.delete()
-                syncResult.stats.numDeletes++
-            } else {
-                // contact is still on server, check whether it has been updated remotely
-                val localETag = local.eTag
-                val getETag = remote.properties[GetETag::class.java]
-                val remoteETag = getETag?.eTag ?: throw DavException("Server didn't provide ETag")
-                if (remoteETag == localETag) {
-                    Logger.log.fine("$name has not been changed on server (ETag still $remoteETag)")
-                    syncResult.stats.numSkippedEntries++
-                } else {
-                    Logger.log.info("$name has been changed on server (current ETag=$remoteETag, last known ETag=$localETag)")
-                    toDownload.add(remote)
-                }
-
-                // remote entry has been seen, remove from list
-                remoteResources.remove(name)
-
-                currentDavResource = null
-                currentLocalResource = null
-            }
-        }
-
-        // add all unseen (= remotely added) remote contacts
-        if (remoteResources.isNotEmpty()) {
-            Logger.log.info("New resources have been found on the server: ${remoteResources.keys.joinToString(", ")}")
-            toDownload.addAll(remoteResources.values)
-        }
-    }
-
-    /**
-     * Downloads the remote resources in {@link #toDownload} and stores them locally.
-     * Must check Thread.interrupted() periodically to allow quick sync cancellation.
-     */
-    abstract protected fun downloadRemote()
-
-    /**
-     * For post-processing of entries, for instance assigning groups.
-     */
-    protected open fun postProcess() {}
-
-    protected open fun saveSyncState() {
-        /* Save sync state (CTag). It doesn't matter if it has changed during the sync process
-           (for instance, because another client has uploaded changes), because this will simply
-           cause all remote entries to be listed at the next sync. */
-        Logger.log.info("Saving CTag=$remoteCTag")
-        localCollection.setCTag(remoteCTag)
-    }
-
-}
@@ -0,0 +1,152 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.AbstractThreadedSyncAdapter;
+import android.content.ContentProviderClient;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.SyncResult;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import org.dmfs.provider.tasks.TaskContract;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import at.bitfire.davdroid.model.ServiceDB.Services;
+import at.bitfire.davdroid.resource.LocalTaskList;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.TaskProvider;
+import lombok.Cleanup;
+
+public class TasksSyncAdapterService extends SyncAdapterService {
+
+    @Override
+    protected AbstractThreadedSyncAdapter syncAdapter() {
+        return new SyncAdapter(this);
+    }
+
+
+	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
+
+        public SyncAdapter(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient providerClient, SyncResult syncResult) {
+            super.onPerformSync(account, extras, authority, providerClient, syncResult);
+
+            try {
+                @Cleanup TaskProvider provider = TaskProvider.acquire(getContext().getContentResolver(), TaskProvider.ProviderName.OpenTasks);
+                if (provider == null)
+                    throw new CalendarStorageException("Couldn't access OpenTasks provider");
+
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
+                updateLocalTaskLists(provider, account, settings);
+
+                for (LocalTaskList taskList : (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, TaskContract.TaskLists.SYNC_ENABLED + "!=0", null)) {
+                    App.log.info("Synchronizing task list #" + taskList.getId() + " [" + taskList.getSyncId() + "]");
+                    TasksSyncManager syncManager = new TasksSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, taskList);
+                    syncManager.performSync();
+                }
+            } catch (CalendarStorageException e) {
+                App.log.log(Level.SEVERE, "Couldn't enumerate local task lists", e);
+            } catch (InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            }
+
+            App.log.info("Task sync complete");
+        }
+
+        private void updateLocalTaskLists(TaskProvider provider, Account account, AccountSettings settings) throws CalendarStorageException {
+            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+            try {
+                // enumerate remote and local task lists
+                SQLiteDatabase db = dbHelper.getReadableDatabase();
+                Long service = getService(db, account);
+                Map<String, CollectionInfo> remote = remoteTaskLists(db, service);
+                LocalTaskList[] local = (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
+
+                boolean updateColors = settings.getManageCalendarColors();
+
+                // delete obsolete local task lists
+                for (LocalTaskList list : local) {
+                    String url = list.getSyncId();
+                    if (!remote.containsKey(url)) {
+                        App.log.fine("Deleting obsolete local task list" + url);
+                        list.delete();
+                    } else {
+                        // remote CollectionInfo found for this local collection, update data
+                        CollectionInfo info = remote.get(url);
+                        App.log.fine("Updating local task list " + url + " with " + info);
+                        list.update(info, updateColors);
+                        // we already have a local task list for this remote collection, don't take into consideration anymore
+                        remote.remove(url);
+                    }
+                }
+
+                // create new local task lists
+                for (String url : remote.keySet()) {
+                    CollectionInfo info = remote.get(url);
+                    App.log.info("Adding local task list " + info);
+                    LocalTaskList.create(account, provider, info);
+                }
+            } finally {
+                dbHelper.close();
+            }
+        }
+
+        @Nullable
+        Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
+            @Cleanup Cursor c = db.query(Services._TABLE, new String[] { Services.ID },
+                    Services.ACCOUNT_NAME + "=? AND " + Services.SERVICE + "=?", new String[] { account.name, Services.SERVICE_CALDAV }, null, null, null);
+            if (c.moveToNext())
+                return c.getLong(0);
+            else
+                return null;
+        }
+
+        @NonNull
+        private Map<String, CollectionInfo> remoteTaskLists(@NonNull SQLiteDatabase db, Long service) {
+            Map<String, CollectionInfo> collections = new LinkedHashMap<>();
+            if (service != null) {
+                @Cleanup Cursor cursor = db.query(Collections._TABLE, null,
+                        Collections.SERVICE_ID + "=? AND " + Collections.SUPPORTS_VTODO + "!=0 AND " + Collections.SYNC,
+                        new String[] { String.valueOf(service) }, null, null, null);
+                while (cursor.moveToNext()) {
+                    ContentValues values = new ContentValues();
+                    DatabaseUtils.cursorRowToContentValues(cursor, values);
+                    CollectionInfo info = CollectionInfo.fromDB(values);
+                    collections.put(info.url, info);
+                }
+            }
+            return collections;
+        }
+    }
+
+}
@@ -1,159 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.app.NotificationManager
-import android.app.PendingIntent
-import android.content.*
-import android.content.pm.PackageManager
-import android.database.DatabaseUtils
-import android.graphics.drawable.BitmapDrawable
-import android.net.Uri
-import android.os.Bundle
-import android.support.v4.app.NotificationCompat
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.Constants
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.model.ServiceDB.Services
-import at.bitfire.davdroid.resource.LocalTaskList
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.davdroid.ui.NotificationUtils
-import at.bitfire.ical4android.AndroidTaskList
-import at.bitfire.ical4android.TaskProvider
-import org.dmfs.tasks.contract.TaskContract
-import java.util.logging.Level
-
-/**
- * Synchronization manager for CalDAV collections; handles tasks ({@code VTODO}).
- */
-class TasksSyncAdapterService: SyncAdapterService() {
-
-    override fun syncAdapter() = TasksSyncAdapter(this)
-
-
-	class TasksSyncAdapter(
-            context: Context
-    ): SyncAdapter(context) {
-
-        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
-            try {
-                val taskProvider = TaskProvider.fromProviderClient(context, provider)
-                val accountSettings = AccountSettings(context, settings, account)
-                /* don't run sync if
-                   - sync conditions (e.g. "sync only in WiFi") are not met AND
-                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
-                 */
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
-                    return
-
-                updateLocalTaskLists(taskProvider, account, accountSettings)
-
-                for (taskList in AndroidTaskList.find(account, taskProvider, LocalTaskList.Factory, "${TaskContract.TaskLists.SYNC_ENABLED}!=0", null)) {
-                    Logger.log.info("Synchronizing task list #${taskList.id} [${taskList.syncId}]")
-                    TasksSyncManager(context, settings, account, accountSettings, extras, authority, syncResult, taskProvider, taskList).use {
-                        it.performSync()
-                    }
-                }
-            } catch (e: TaskProvider.ProviderTooOldException) {
-                val nm = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
-                val notify = NotificationCompat.Builder(context, NotificationUtils.CHANNEL_SYNC_PROBLEMS)
-                        .setSmallIcon(R.drawable.ic_sync_error_notification)
-                        .setContentTitle(context.getString(R.string.sync_error_opentasks_too_old))
-                        .setContentText(context.getString(R.string.sync_error_opentasks_required_version, e.provider.minVersionName, e.installedVersionName))
-                        .setCategory(NotificationCompat.CATEGORY_ERROR)
-
-                try {
-                    val icon = context.packageManager.getApplicationIcon(e.provider.packageName)
-                    if (icon is BitmapDrawable)
-                        notify.setLargeIcon(icon.bitmap)
-                } catch(ignored: PackageManager.NameNotFoundException) {}
-
-                val intent = Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=${e.provider.packageName}"))
-                if (intent.resolveActivity(context.packageManager) != null)
-                    notify  .setContentIntent(PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
-                            .setAutoCancel(true)
-
-                nm.notify(Constants.NOTIFICATION_TASK_SYNC, notify.build())
-                syncResult.databaseError = true
-            } catch (e: Exception) {
-                Logger.log.log(Level.SEVERE, "Couldn't sync task lists", e)
-                syncResult.databaseError = true
-            }
-
-            Logger.log.info("Task sync complete")
-        }
-
-        private fun updateLocalTaskLists(provider: TaskProvider, account: Account, settings: AccountSettings) {
-            ServiceDB.OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.readableDatabase
-
-                fun getService() =
-                        db.query(Services._TABLE, arrayOf(Services.ID),
-                                "${Services.ACCOUNT_NAME}=? AND ${Services.SERVICE}=?",
-                                arrayOf(account.name, Services.SERVICE_CALDAV), null, null, null)?.use { c ->
-                            if (c.moveToNext())
-                                c.getLong(0)
-                            else
-                                null
-                        }
-
-                fun remoteTaskLists(service: Long?): MutableMap<String, CollectionInfo> {
-                    val collections = mutableMapOf<String, CollectionInfo>()
-                    service?.let {
-                        db.query(Collections._TABLE, null,
-                                "${Collections.SERVICE_ID}=? AND ${Collections.SUPPORTS_VTODO}!=0 AND ${Collections.SYNC}",
-                                arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                            while (cursor.moveToNext()) {
-                                val values = ContentValues(cursor.columnCount)
-                                DatabaseUtils.cursorRowToContentValues(cursor, values)
-                                val info = CollectionInfo(values)
-                                collections[info.url] = info
-                            }
-                        }
-                    }
-                    return collections
-                }
-
-                // enumerate remote and local task lists
-                val service = getService()
-                val remote = remoteTaskLists(service)
-
-                // delete/update local task lists
-                val updateColors = settings.getManageCalendarColors()
-
-                for (list in AndroidTaskList.find(account, provider, LocalTaskList.Factory, null, null))
-                    list.syncId?.let { url ->
-                        val info = remote[url]
-                        if (info == null) {
-                            Logger.log.fine("Deleting obsolete local task list $url")
-                            list.delete()
-                        } else {
-                            // remote CollectionInfo found for this local collection, update data
-                            Logger.log.log(Level.FINE, "Updating local task list $url", info)
-                            list.update(info, updateColors)
-                            // we already have a local task list for this remote collection, don't take into consideration anymore
-                            remote -= url
-                        }
-                    }
-
-                // create new local task lists
-                for ((_,info) in remote) {
-                    Logger.log.log(Level.INFO, "Adding local task list", info)
-                    LocalTaskList.create(account, provider, info)
-                }
-            }
-        }
-
-    }
-
-}
@@ -0,0 +1,208 @@
+/*
+ * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter;
+
+import android.accounts.Account;
+import android.content.Context;
+import android.content.SyncResult;
+import android.os.Bundle;
+
+import org.apache.commons.codec.Charsets;
+import org.apache.commons.lang3.StringUtils;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.logging.Level;
+
+import at.bitfire.dav4android.DavCalendar;
+import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.exception.DavException;
+import at.bitfire.dav4android.exception.HttpException;
+import at.bitfire.dav4android.property.CalendarData;
+import at.bitfire.dav4android.property.GetCTag;
+import at.bitfire.dav4android.property.GetContentType;
+import at.bitfire.dav4android.property.GetETag;
+import at.bitfire.davdroid.AccountSettings;
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.ArrayUtils;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.InvalidAccountException;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.resource.LocalResource;
+import at.bitfire.davdroid.resource.LocalTask;
+import at.bitfire.davdroid.resource.LocalTaskList;
+import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.InvalidCalendarException;
+import at.bitfire.ical4android.Task;
+import at.bitfire.ical4android.TaskProvider;
+import lombok.Cleanup;
+import okhttp3.HttpUrl;
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+import okhttp3.ResponseBody;
+
+public class TasksSyncManager extends SyncManager {
+
+    protected static final int MAX_MULTIGET = 30;
+
+    final protected TaskProvider provider;
+
+
+    public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException {
+        super(context, account, settings, extras, authority, result, "taskList/" + taskList.getId());
+        this.provider = provider;
+        localCollection = taskList;
+    }
+
+    @Override
+    protected int notificationId() {
+        return Constants.NOTIFICATION_TASK_SYNC;
+    }
+
+    @Override
+    protected String getSyncErrorTitle() {
+        return context.getString(R.string.sync_error_tasks, account.name);
+    }
+
+
+    @Override
+    protected void prepare() {
+        collectionURL = HttpUrl.parse(localTaskList().getSyncId());
+        davCollection = new DavCalendar(httpClient, collectionURL);
+    }
+
+    @Override
+    protected void queryCapabilities() throws DavException, IOException, HttpException {
+        davCollection.propfind(0, GetCTag.NAME);
+    }
+
+    @Override
+    protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException {
+        LocalTask local = (LocalTask)resource;
+        App.log.log(Level.FINE, "Preparing upload of task " + local.getFileName(), new Object[] { local.getTask() });
+        return RequestBody.create(
+                DavCalendar.MIME_ICALENDAR,
+                local.getTask().toStream().toByteArray()
+        );
+    }
+
+    @Override
+    protected void listRemote() throws IOException, HttpException, DavException {
+        // fetch list of remote VTODOs and build hash table to index file name
+        davCalendar().calendarQuery("VTODO", null, null);
+        remoteResources = new HashMap<>(davCollection.members.size());
+        for (DavResource vCard : davCollection.members) {
+            String fileName = vCard.fileName();
+            App.log.fine("Found remote VTODO: " + fileName);
+            remoteResources.put(fileName, vCard);
+        }
+    }
+
+    @Override
+    protected void downloadRemote() throws IOException, HttpException, DavException, CalendarStorageException {
+        App.log.info("Downloading " + toDownload.size() + " tasks (" + MAX_MULTIGET + " at once)");
+
+        // download new/updated iCalendars from server
+        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return;
+
+            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
+
+            if (bunch.length == 1) {
+                // only one contact, use GET
+                DavResource remote = bunch[0];
+
+                ResponseBody body = remote.get("text/calendar");
+                String eTag = ((GetETag)remote.properties.get(GetETag.NAME)).eTag;
+
+                Charset charset = Charsets.UTF_8;
+                MediaType contentType = body.contentType();
+                if (contentType != null)
+                    charset = contentType.charset(Charsets.UTF_8);
+
+                @Cleanup InputStream stream = body.byteStream();
+                processVTodo(remote.fileName(), eTag, stream, charset);
+
+            } else {
+                // multiple contacts, use multi-get
+                List<HttpUrl> urls = new LinkedList<>();
+                for (DavResource remote : bunch)
+                    urls.add(remote.location);
+                davCalendar().multiget(urls.toArray(new HttpUrl[urls.size()]));
+
+                // process multiget results
+                for (DavResource remote : davCollection.members) {
+                    String eTag;
+                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                    if (getETag != null)
+                        eTag = getETag.eTag;
+                    else
+                        throw new DavException("Received multi-get response without ETag");
+
+                    Charset charset = Charsets.UTF_8;
+                    GetContentType getContentType = (GetContentType)remote.properties.get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.type != null) {
+                        MediaType type = MediaType.parse(getContentType.type);
+                        if (type != null)
+                            charset = type.charset(Charsets.UTF_8);
+                    }
+
+                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
+                    if (calendarData == null || calendarData.iCalendar == null)
+                        throw new DavException("Received multi-get response without address data");
+
+                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
+                    processVTodo(remote.fileName(), eTag, stream, charset);
+                }
+            }
+        }
+    }
+
+
+    // helpers
+
+    private LocalTaskList localTaskList() { return ((LocalTaskList)localCollection); }
+    private DavCalendar davCalendar() { return (DavCalendar)davCollection; }
+
+    private void processVTodo(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException {
+        Task[] tasks;
+        try {
+            tasks = Task.fromStream(stream, charset);
+        } catch (InvalidCalendarException e) {
+            App.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e);
+            return;
+        }
+
+        if (tasks.length == 1) {
+            Task newData = tasks[0];
+
+            // update local task, if it exists
+            LocalTask localTask = (LocalTask)localResources.get(fileName);
+            if (localTask != null) {
+                App.log.info("Updating " + fileName + " in local tasklist");
+                localTask.setETag(eTag);
+                localTask.update(newData);
+                syncResult.stats.numUpdates++;
+            } else {
+                App.log.info("Adding " + fileName + " to local task list");
+                localTask = new LocalTask(localTaskList(), newData, fileName, eTag);
+                localTask.add();
+                syncResult.stats.numInserts++;
+            }
+        } else
+            App.log.severe("Received VCALENDAR with not exactly one VTODO; ignoring " + fileName);
+    }
+
+}
@@ -1,191 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter
-
-import android.accounts.Account
-import android.content.Context
-import android.content.SyncResult
-import android.os.Bundle
-import at.bitfire.dav4android.DavCalendar
-import at.bitfire.dav4android.exception.DavException
-import at.bitfire.dav4android.property.CalendarData
-import at.bitfire.dav4android.property.GetCTag
-import at.bitfire.dav4android.property.GetETag
-import at.bitfire.davdroid.AccountSettings
-import at.bitfire.davdroid.Constants
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.resource.LocalResource
-import at.bitfire.davdroid.resource.LocalTask
-import at.bitfire.davdroid.resource.LocalTaskList
-import at.bitfire.davdroid.settings.ISettings
-import at.bitfire.ical4android.InvalidCalendarException
-import at.bitfire.ical4android.Task
-import at.bitfire.ical4android.TaskProvider
-import okhttp3.HttpUrl
-import okhttp3.RequestBody
-import org.apache.commons.collections4.ListUtils
-import java.io.ByteArrayOutputStream
-import java.io.Reader
-import java.io.StringReader
-import java.util.*
-import java.util.logging.Level
-
-class TasksSyncManager(
-        context: Context,
-        settings: ISettings,
-        account: Account,
-        accountSettings: AccountSettings,
-        extras: Bundle,
-        authority: String,
-        syncResult: SyncResult,
-        val provider: TaskProvider,
-        val localTaskList: LocalTaskList
-): SyncManager(context, settings, account, accountSettings, extras, authority, syncResult, "taskList/${localTaskList.id}") {
-
-    val MAX_MULTIGET = 30
-
-
-    init {
-        localCollection = localTaskList
-    }
-
-    override fun notificationId() = Constants.NOTIFICATION_TASK_SYNC
-
-    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_tasks, account.name)!!
-
-
-    override fun prepare(): Boolean {
-        collectionURL = HttpUrl.parse(localTaskList.syncId ?: return false) ?: return false
-        davCollection = DavCalendar(httpClient.okHttpClient, collectionURL)
-        return true
-    }
-
-    override fun queryCapabilities() {
-        davCollection.propfind(0, GetCTag.NAME)
-    }
-
-    override fun prepareUpload(resource: LocalResource): RequestBody {
-        if (resource is LocalTask) {
-            val task = requireNotNull(resource.task)
-            Logger.log.log(Level.FINE, "Preparing upload of task ${resource.fileName}", task)
-
-            val os = ByteArrayOutputStream()
-            task.write(os)
-
-            return RequestBody.create(
-                    DavCalendar.MIME_ICALENDAR,
-                    os.toByteArray()
-            )
-        } else
-            throw IllegalArgumentException("resource must be a LocalTask")
-    }
-
-    override fun listRemote() {
-        // fetch list of remote VTODOs and build hash table to index file name
-        val calendar = davCalendar()
-        currentDavResource = calendar
-        calendar.calendarQuery("VTODO", null, null)
-
-        remoteResources = HashMap(davCollection.members.size)
-        for (vCard in davCollection.members) {
-            val fileName = vCard.fileName()
-            Logger.log.fine("Found remote VTODO: $fileName")
-            remoteResources[fileName] = vCard
-        }
-
-        currentDavResource = null
-    }
-
-    override fun downloadRemote() {
-        Logger.log.info("Downloading ${toDownload.size} tasks ($MAX_MULTIGET at once)")
-
-        // download new/updated iCalendars from server
-        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
-            abortIfCancelled()
-            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
-
-            if (bunch.size == 1) {
-                // only one contact, use GET
-                val remote = bunch.first()
-                currentDavResource = remote
-
-                val body = remote.get("text/calendar")
-
-                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
-                val eTag = remote.properties[GetETag::class.java]
-                if (eTag == null || eTag.eTag.isNullOrEmpty())
-                    throw DavException("Received CalDAV GET response without ETag for ${remote.location}")
-
-                body.charStream().use { reader ->
-                    processVTodo(remote.fileName(), eTag.eTag!!, reader)
-                }
-
-            } else {
-                // multiple contacts, use multi-get
-                val calendar = davCalendar()
-                currentDavResource = calendar
-                calendar.multiget(bunch.map { it.location })
-
-                // process multiget results
-                for (remote in davCollection.members) {
-                    currentDavResource = remote
-
-                    val eTag = remote.properties[GetETag::class.java]?.eTag
-                            ?: throw DavException("Received multi-get response without ETag")
-
-                    val calendarData = remote.properties[CalendarData::class.java]
-                    val iCalendar = calendarData?.iCalendar
-                            ?: throw DavException("Received multi-get response without task data")
-
-                    processVTodo(remote.fileName(), eTag, StringReader(iCalendar))
-                }
-            }
-
-            currentDavResource = null
-        }
-    }
-
-
-    // helpers
-
-    private fun davCalendar() = davCollection as DavCalendar
-
-    private fun processVTodo(fileName: String, eTag: String, reader: Reader) {
-        val tasks: List<Task>
-        try {
-            tasks = Task.fromReader(reader)
-        } catch (e: InvalidCalendarException) {
-            Logger.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e)
-            return
-        }
-
-        if (tasks.size == 1) {
-            val newData = tasks.first()
-
-            // update local task, if it exists
-            val localTask = localResources[fileName] as LocalTask?
-            currentLocalResource = localTask
-            if (localTask != null) {
-                Logger.log.info("Updating $fileName in local tasklist")
-                localTask.eTag = eTag
-                localTask.update(newData)
-                syncResult.stats.numUpdates++
-            } else {
-                Logger.log.info("Adding $fileName to local task list")
-                val newTask = LocalTask(localTaskList, newData, fileName, eTag)
-                currentLocalResource = newTask
-                newTask.add()
-                syncResult.stats.numInserts++
-            }
-        } else
-            Logger.log.severe("Received VCALENDAR with not exactly one VTODO; ignoring $fileName")
-    }
-
-}
@@ -0,0 +1,220 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.ui;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.design.widget.TabLayout;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentManager;
+import android.support.v4.app.FragmentPagerAdapter;
+import android.support.v4.app.LoaderManager;
+import android.support.v4.content.AsyncTaskLoader;
+import android.support.v4.content.Loader;
+import android.support.v4.view.ViewPager;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.Toolbar;
+import android.text.Html;
+import android.text.Spanned;
+import android.text.util.Linkify;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import org.apache.commons.lang3.time.DateFormatUtils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.davdroid.R;
+import ezvcard.Ezvcard;
+import ezvcard.util.IOUtils;
+import lombok.Cleanup;
+import lombok.RequiredArgsConstructor;
+
+public class AboutActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_about);
+
+        setSupportActionBar((Toolbar)findViewById(R.id.toolbar));
+        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+        ViewPager viewPager = (ViewPager)findViewById(R.id.viewpager);
+        viewPager.setAdapter(new TabsAdapter(getSupportFragmentManager()));
+
+        TabLayout tabLayout = (TabLayout)findViewById(R.id.tabs);
+        tabLayout.setupWithViewPager(viewPager);
+    }
+
+
+    @RequiredArgsConstructor
+    private static class ComponentInfo {
+        final String   title, version, website, copyright;
+        final int licenseInfo;
+        final String licenseTextFile;
+    }
+
+    private final static ComponentInfo components[] = {
+            new ComponentInfo(
+                    "DAVdroid", BuildConfig.VERSION_NAME, "https://davdroid.bitfire.at",
+                    "© " + DateFormatUtils.format(BuildConfig.buildTime, "yyyy") + " Ricki Hirner, Bernhard Stockmann (bitfire web engineering)",
+                    R.string.about_license_info_no_warranty, "gpl-3.0-standalone.html"
+            ), new ComponentInfo(
+                    "AmbilWarna", null, "https://github.com/yukuku/ambilwarna",
+                    "© Yuku", R.string.about_license_info_no_warranty, "apache2.html"
+            ), new ComponentInfo(
+                    "Apache Commons", null, "http://commons.apache.org/",
+                    "Apache Software Foundation", R.string.about_license_info_no_warranty, "apache2.html"
+            ), new ComponentInfo(
+                    "dnsjava", null, "http://dnsjava.org/",
+                    "© Brian Wellington", R.string.about_license_info_no_warranty, "bsd.html"
+            ), new ComponentInfo(
+                    "ez-vcard", Ezvcard.VERSION, "https://github.com/mangstadt/ez-vcard",
+                    "© Michael Angstadt", R.string.about_license_info_no_warranty, "bsd.html"
+            ), new ComponentInfo(
+                    "ical4j", "2.x", "http://ical4j.github.io/",
+                    "© Ben Fortuna", R.string.about_license_info_no_warranty, "bsd-3clause.html"
+            ), new ComponentInfo(
+                    "MemorizingTrustManager", null, "https://github.com/ge0rg/MemorizingTrustManager",
+                    "© Georg Lukas", R.string.about_license_info_no_warranty, "mit.html"
+            ), new ComponentInfo(
+                    "OkHttp", null, "https://square.github.io/okhttp/",
+                    "© Square, Inc.", R.string.about_license_info_no_warranty, "apache2.html"
+            ), new ComponentInfo(
+                    "Project Lombok", null, "https://projectlombok.org/",
+                    "© The Project Lombok Authors", R.string.about_license_info_no_warranty, "mit.html"
+            )
+    };
+
+
+    private static class TabsAdapter extends FragmentPagerAdapter {
+        public TabsAdapter(FragmentManager fm) {
+            super(fm);
+        }
+
+        @Override
+        public int getCount() {
+            return components.length;
+        }
+
+        @Override
+        public CharSequence getPageTitle(int position) {
+            return components[position].title;
+        }
+
+        @Override
+        public Fragment getItem(int position) {
+            return ComponentFragment.instantiate(position);
+        }
+    }
+
+    public static class ComponentFragment extends Fragment implements LoaderManager.LoaderCallbacks<Spanned> {
+        private static final String
+                KEY_POSITION = "position",
+                KEY_FILE_NAME = "fileName";
+
+        public static ComponentFragment instantiate(int position) {
+            ComponentFragment frag = new ComponentFragment();
+            Bundle args = new Bundle(1);
+            args.putInt(KEY_POSITION, position);
+            frag.setArguments(args);
+            return frag;
+        }
+
+        @Nullable
+        @Override
+        @SuppressLint("SetTextI18n")
+        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+            ComponentInfo info = components[getArguments().getInt(KEY_POSITION)];
+
+            View v = inflater.inflate(R.layout.about_component, container, false);
+
+            TextView tv = (TextView)v.findViewById(R.id.title);
+            tv.setText(info.title + (info.version != null ? (" " + info.version) : ""));
+
+            tv = (TextView)v.findViewById(R.id.website);
+            tv.setAutoLinkMask(Linkify.WEB_URLS);
+            tv.setText(info.website);
+
+            tv = (TextView)v.findViewById(R.id.copyright);
+            tv.setText(info.copyright);
+
+            tv = (TextView)v.findViewById(R.id.license_info);
+            tv.setText(info.licenseInfo);
+
+            // load and format license text
+            Bundle args = new Bundle(1);
+            args.putString(KEY_FILE_NAME, info.licenseTextFile);
+            getLoaderManager().initLoader(0, args, this);
+
+            return v;
+        }
+
+        @Override
+        public Loader<Spanned> onCreateLoader(int id, Bundle args) {
+            return new LicenseLoader(getContext(), args.getString(KEY_FILE_NAME));
+        }
+
+        @Override
+        public void onLoadFinished(Loader<Spanned> loader, Spanned license) {
+            if (getView() != null) {
+                TextView tv = (TextView)getView().findViewById(R.id.license_text);
+                if (tv != null) {
+                    tv.setAutoLinkMask(Linkify.EMAIL_ADDRESSES | Linkify.WEB_URLS);
+                    tv.setText(license);
+                }
+            }
+        }
+
+        @Override
+        public void onLoaderReset(Loader<Spanned> loader) {
+        }
+    }
+
+    private static class LicenseLoader extends AsyncTaskLoader<Spanned> {
+        final String fileName;
+        Spanned content;
+
+        LicenseLoader(Context context, String fileName) {
+            super(context);
+            this.fileName = fileName;
+        }
+
+        @Override
+        protected void onStartLoading() {
+            if (content == null)
+                forceLoad();
+            else
+                deliverResult(content);
+        }
+
+        @Override
+        public Spanned loadInBackground() {
+            App.log.fine("Loading license file " + fileName);
+            try {
+                @Cleanup InputStream is = getContext().getResources().getAssets().open(fileName);
+                byte[] raw = IOUtils.toByteArray(is);
+                return content = Html.fromHtml(new String(raw));
+            } catch (IOException e) {
+                App.log.log(Level.SEVERE, "Couldn't read license file", e);
+                return null;
+            }
+        }
+    }
+
+}
@@ -1,219 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui
-
-import android.annotation.SuppressLint
-import android.content.Context
-import android.os.Bundle
-import android.support.v4.app.Fragment
-import android.support.v4.app.FragmentManager
-import android.support.v4.app.FragmentPagerAdapter
-import android.support.v4.app.LoaderManager
-import android.support.v4.content.AsyncTaskLoader
-import android.support.v4.content.Loader
-import android.support.v7.app.AppCompatActivity
-import android.text.Html
-import android.text.Spanned
-import android.text.util.Linkify
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import at.bitfire.davdroid.BuildConfig
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import ezvcard.Ezvcard
-import kotlinx.android.synthetic.main.about_component.view.*
-import kotlinx.android.synthetic.main.activity_about.*
-import org.apache.commons.io.IOUtils
-import java.io.IOException
-import java.util.*
-import java.util.logging.Level
-
-class AboutActivity: AppCompatActivity() {
-
-    private class ComponentInfo(
-            val title: String?,
-            val version: String?,
-            val website: String,
-            val copyright: String,
-            val licenseInfo: Int?,
-            val licenseTextFile: String?
-    )
-
-    private lateinit var components: Array<ComponentInfo>
-
-
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-
-        components = arrayOf(
-            ComponentInfo(
-                    null, BuildConfig.VERSION_NAME, getString(R.string.homepage_url),
-                    "Ricki Hirner, Bernhard Stockmann (bitfire web engineering)",
-                    null, null
-            ), ComponentInfo(
-                    "AmbilWarna", null, "https://github.com/yukuku/ambilwarna",
-                    "Yuku", R.string.about_license_info_no_warranty, "apache2.html"
-            ), ComponentInfo(
-                    "Apache Commons", null, "http://commons.apache.org/",
-                    "Apache Software Foundation", R.string.about_license_info_no_warranty, "apache2.html"
-            ), ComponentInfo(
-                    "dnsjava", null, "http://dnsjava.org/",
-                    "Brian Wellington", R.string.about_license_info_no_warranty, "bsd.html"
-            ), ComponentInfo(
-                    "ez-vcard", Ezvcard.VERSION, "https://github.com/mangstadt/ez-vcard",
-                    "Michael Angstadt", R.string.about_license_info_no_warranty, "bsd.html"
-            ), ComponentInfo(
-                    "ical4j", "2.x", "https://ical4j.github.io/",
-                    "Ben Fortuna", R.string.about_license_info_no_warranty, "bsd-3clause.html"
-            ), ComponentInfo(
-                    "OkHttp", null, "https://square.github.io/okhttp/",
-                    "Square, Inc.", R.string.about_license_info_no_warranty, "apache2.html"
-            ), ComponentInfo(
-                    "Project Lombok", null, "https://projectlombok.org/",
-                    "The Project Lombok Authors", R.string.about_license_info_no_warranty, "mit.html"
-            )
-        )
-
-        setContentView(R.layout.activity_about)
-
-        setSupportActionBar(toolbar)
-        supportActionBar?.setDisplayHomeAsUpEnabled(true)
-
-        viewpager.adapter = TabsAdapter(supportFragmentManager)
-        tabs.setupWithViewPager(viewpager)
-    }
-
-
-    private inner class TabsAdapter(
-            fm: FragmentManager
-    ): FragmentPagerAdapter(fm) {
-
-        override fun getCount() = components.size
-
-        override fun getPageTitle(position: Int) =
-                components[position].title ?: getString(R.string.app_name)!!
-
-        override fun getItem(position: Int) = ComponentFragment.instantiate(position)
-    }
-
-
-    class ComponentFragment: Fragment(), LoaderManager.LoaderCallbacks<Spanned> {
-
-        companion object {
-            val KEY_POSITION = "position"
-            val KEY_FILE_NAME = "fileName"
-
-            fun instantiate(position: Int): ComponentFragment {
-                val frag = ComponentFragment()
-                val args = Bundle(1)
-                args.putInt(KEY_POSITION, position)
-                frag.arguments = args
-                return frag
-            }
-        }
-
-        private val licenseFragmentLoader = ServiceLoader.load(ILicenseFragment::class.java)!!.firstOrNull()
-
-
-        @SuppressLint("SetTextI18n")
-        override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-            val info = (activity as AboutActivity).components[arguments!!.getInt(KEY_POSITION)]
-
-            val v = inflater.inflate(R.layout.about_component, container, false)
-
-            var title = info.title ?: getString(R.string.app_name)
-            info.version?.let { title += " ${info.version}" }
-            v.title.text = title
-
-            v.website.autoLinkMask = Linkify.WEB_URLS
-            v.website.text = info.website
-
-            v.copyright.text = "© ${info.copyright}"
-
-            if (info.licenseInfo == null && info.licenseTextFile == null) {
-                // No license text, so this must be the app's tab. Show the license fragment here, if available.
-                licenseFragmentLoader?.let { factory ->
-                    fragmentManager!!.beginTransaction()
-                            .add(R.id.license_fragment, factory.getFragment())
-                            .commit()
-                }
-                v.license_terms.visibility = View.GONE
-
-            } else {
-                // show license info
-                if (info.licenseInfo == null)
-                    v.license_info.visibility = View.GONE
-                else
-                    v.license_info.setText(info.licenseInfo)
-
-                // load and format license text
-                if (info.licenseTextFile == null) {
-                    v.license_header.visibility = View.GONE
-                    v.license_text.visibility = View.GONE
-                } else {
-                    val args = Bundle(1)
-                    args.putString(KEY_FILE_NAME, info.licenseTextFile)
-                    loaderManager.initLoader(0, args, this)
-                }
-            }
-
-
-            return v
-        }
-
-        override fun onCreateLoader(id: Int, args: Bundle) =
-                LicenseLoader(activity!!, args.getString(KEY_FILE_NAME))
-
-        override fun onLoadFinished(loader: Loader<Spanned>, license: Spanned?) {
-            view?.let { v ->
-                v.license_text.autoLinkMask = Linkify.EMAIL_ADDRESSES or Linkify.WEB_URLS
-                v.license_text.text = license
-            }
-        }
-
-        override fun onLoaderReset(loader: Loader<Spanned>) {}
-    }
-
-    class LicenseLoader(
-            context: Context,
-            val fileName: String
-    ): AsyncTaskLoader<Spanned>(context) {
-
-        private var content: Spanned? = null
-
-        override fun onStartLoading() {
-            if (content != null)
-                deliverResult(content)
-            else
-                forceLoad()
-        }
-
-        override fun loadInBackground(): Spanned? {
-            Logger.log.fine("Loading license file $fileName")
-            try {
-                context.resources.assets.open(fileName).use {
-                    content = Html.fromHtml(IOUtils.toString(it, Charsets.UTF_8))
-                    return content
-                }
-            } catch(e: IOException) {
-                Logger.log.log(Level.SEVERE, "Couldn't read license file", e)
-                return null
-            }
-        }
-    }
-
-
-    interface ILicenseFragment {
-
-        fun getFragment(): Fragment
-
-    }
-
-}
@@ -0,0 +1,566 @@
+/*
+ * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.ui;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.accounts.AccountManagerCallback;
+import android.accounts.AccountManagerFuture;
+import android.accounts.AuthenticatorException;
+import android.accounts.OperationCanceledException;
+import android.app.LoaderManager;
+import android.content.AsyncTaskLoader;
+import android.content.ComponentName;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.content.Loader;
+import android.content.ServiceConnection;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.provider.CalendarContract;
+import android.provider.ContactsContract;
+import android.support.annotation.NonNull;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.AlertDialog;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.CardView;
+import android.support.v7.widget.Toolbar;
+import android.text.TextUtils;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AbsListView;
+import android.widget.AdapterView;
+import android.widget.ArrayAdapter;
+import android.widget.CheckBox;
+import android.widget.ListView;
+import android.widget.PopupMenu;
+import android.widget.ProgressBar;
+import android.widget.RadioButton;
+import android.widget.TextView;
+
+import org.apache.commons.lang3.BooleanUtils;
+
+import java.io.IOException;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.logging.Level;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.DavService;
+import at.bitfire.davdroid.R;
+import at.bitfire.davdroid.model.CollectionInfo;
+import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.model.ServiceDB.Collections;
+import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
+import at.bitfire.davdroid.model.ServiceDB.Services;
+import at.bitfire.ical4android.TaskProvider;
+import lombok.Cleanup;
+
+public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenuItemClickListener, PopupMenu.OnMenuItemClickListener, LoaderManager.LoaderCallbacks<AccountActivity.AccountInfo> {
+    public static final String EXTRA_ACCOUNT = "account";
+
+    private Account account;
+    private AccountInfo accountInfo;
+
+    ListView listCalDAV, listCardDAV;
+    Toolbar tbCardDAV, tbCalDAV;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        account = getIntent().getParcelableExtra(EXTRA_ACCOUNT);
+        setTitle(account.name);
+
+        setContentView(R.layout.activity_account);
+
+        Drawable icMenu = Build.VERSION.SDK_INT >= 21 ? getDrawable(R.drawable.ic_menu_light) :
+                getResources().getDrawable(R.drawable.ic_menu_light);
+
+        // CardDAV toolbar
+        tbCardDAV = (Toolbar)findViewById(R.id.carddav_menu);
+        tbCardDAV.setOverflowIcon(icMenu);
+        tbCardDAV.inflateMenu(R.menu.carddav_actions);
+        tbCardDAV.setOnMenuItemClickListener(this);
+
+        // CalDAV toolbar
+        tbCalDAV = (Toolbar)findViewById(R.id.caldav_menu);
+        tbCalDAV.setOverflowIcon(icMenu);
+        tbCalDAV.inflateMenu(R.menu.caldav_actions);
+        tbCalDAV.setOnMenuItemClickListener(this);
+
+        // load CardDAV/CalDAV collections
+        getLoaderManager().initLoader(0, getIntent().getExtras(), this);
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.activity_account, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.sync_now:
+                requestSync();
+                break;
+            case R.id.settings:
+                Intent intent = new Intent(this, AccountSettingsActivity.class);
+                intent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account);
+                startActivity(intent);
+                break;
+            case R.id.delete_account:
+                new AlertDialog.Builder(AccountActivity.this)
+                        .setIcon(R.drawable.ic_error_dark)
+                        .setTitle(R.string.account_delete_confirmation_title)
+                        .setMessage(R.string.account_delete_confirmation_text)
+                        .setNegativeButton(android.R.string.no, null)
+                        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                deleteAccount();
+                            }
+                        })
+                        .show();
+                break;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+        return true;
+    }
+
+    @Override
+    public boolean onMenuItemClick(MenuItem item) {
+        Intent intent;
+        switch (item.getItemId()) {
+            case R.id.refresh_address_books:
+                if (accountInfo.carddav != null) {
+                    intent = new Intent(this, DavService.class);
+                    intent.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
+                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, accountInfo.carddav.id);
+                    startService(intent);
+                }
+                break;
+            case R.id.create_address_book:
+                intent = new Intent(this, CreateAddressBookActivity.class);
+                intent.putExtra(CreateAddressBookActivity.EXTRA_ACCOUNT, account);
+                startActivity(intent);
+                break;
+            case R.id.refresh_calendars:
+                if (accountInfo.caldav != null) {
+                    intent = new Intent(this, DavService.class);
+                    intent.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
+                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, accountInfo.caldav.id);
+                    startService(intent);
+                }
+                break;
+            case R.id.create_calendar:
+                intent = new Intent(this, CreateCalendarActivity.class);
+                intent.putExtra(CreateCalendarActivity.EXTRA_ACCOUNT, account);
+                startActivity(intent);
+                break;
+        }
+        return false;
+    }
+
+
+    private AdapterView.OnItemClickListener onItemClickListener = new AdapterView.OnItemClickListener() {
+        @Override
+        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+            final ListView list = (ListView)parent;
+            final ArrayAdapter<CollectionInfo> adapter = (ArrayAdapter)list.getAdapter();
+            final CollectionInfo info = adapter.getItem(position);
+
+            boolean nowChecked = !info.selected;
+
+            if (list.getChoiceMode() == AbsListView.CHOICE_MODE_SINGLE)
+                // clear all other checked items
+                for (int i = adapter.getCount()-1; i >= 0; i--)
+                    adapter.getItem(i).selected = false;
+
+            OpenHelper dbHelper = new OpenHelper(AccountActivity.this);
+            try {
+                SQLiteDatabase db = dbHelper.getWritableDatabase();
+                db.beginTransactionNonExclusive();
+
+                if (list.getChoiceMode() == AbsListView.CHOICE_MODE_SINGLE) {
+                    // disable all other collections
+                    ContentValues values = new ContentValues(1);
+                    values.put(Collections.SYNC, 0);
+                    db.update(Collections._TABLE, values, Collections.SERVICE_ID + "=?", new String[] { String.valueOf(info.serviceID) });
+                }
+
+                ContentValues values = new ContentValues(1);
+                values.put(Collections.SYNC, nowChecked ? 1 : 0);
+                db.update(Collections._TABLE, values, Collections.ID + "=?", new String[] { String.valueOf(info.id) });
+
+                db.setTransactionSuccessful();
+                db.endTransaction();
+
+                info.selected = nowChecked;
+                adapter.notifyDataSetChanged();
+            } finally {
+                dbHelper.close();
+            }
+        }
+    };
+
+    private AdapterView.OnItemLongClickListener onItemLongClickListener = new AdapterView.OnItemLongClickListener() {
+        @Override
+        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
+            final ListView list = (ListView)parent;
+            final ArrayAdapter<CollectionInfo> adapter = (ArrayAdapter)list.getAdapter();
+            final CollectionInfo info = adapter.getItem(position);
+
+            PopupMenu popup = new PopupMenu(AccountActivity.this, view);
+            popup.inflate(R.menu.account_collection_operations);
+            popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
+                @Override
+                public boolean onMenuItemClick(MenuItem item) {
+                    switch (item.getItemId()) {
+                        case R.id.delete_collection:
+                            DeleteCollectionFragment.ConfirmDeleteCollectionFragment.newInstance(account, info).show(getSupportFragmentManager(), null);
+                            break;
+                    }
+                    return true;
+                }
+            });
+            popup.show();
+
+            // long click was handled
+            return true;
+        }
+    };
+
+
+    /* LOADERS AND LOADED DATA */
+
+    protected static class AccountInfo {
+        ServiceInfo carddav, caldav;
+
+        public static class ServiceInfo {
+            long id;
+            boolean refreshing;
+
+            boolean hasHomeSets;
+            List<CollectionInfo> collections;
+        }
+    }
+
+    @Override
+    public Loader<AccountInfo> onCreateLoader(int id, Bundle args) {
+        return new AccountLoader(this, account.name);
+    }
+
+    public void reload() {
+        getLoaderManager().restartLoader(0, getIntent().getExtras(), this);
+    }
+
+    @Override
+    public void onLoadFinished(Loader<AccountInfo> loader, final AccountInfo info) {
+        accountInfo = info;
+
+        if (accountInfo == null) {
+            // account doesn't exist anymore
+            finish();
+            return;
+        }
+
+        CardView card = (CardView)findViewById(R.id.carddav);
+        if (info.carddav != null) {
+            ProgressBar progress = (ProgressBar)findViewById(R.id.carddav_refreshing);
+            progress.setVisibility(info.carddav.refreshing ? View.VISIBLE : View.GONE);
+
+            listCardDAV = (ListView)findViewById(R.id.address_books);
+            listCardDAV.setEnabled(!info.carddav.refreshing);
+            listCardDAV.setAlpha(info.carddav.refreshing ? 0.5f : 1);
+
+            tbCardDAV.getMenu().findItem(R.id.create_address_book).setEnabled(info.carddav.hasHomeSets);
+
+            AddressBookAdapter adapter = new AddressBookAdapter(this);
+            adapter.addAll(info.carddav.collections);
+            listCardDAV.setAdapter(adapter);
+            listCardDAV.setOnItemClickListener(onItemClickListener);
+            listCardDAV.setOnItemLongClickListener(onItemLongClickListener);
+        } else
+            card.setVisibility(View.GONE);
+
+        card = (CardView)findViewById(R.id.caldav);
+        if (info.caldav != null) {
+            ProgressBar progress = (ProgressBar)findViewById(R.id.caldav_refreshing);
+            progress.setVisibility(info.caldav.refreshing ? View.VISIBLE : View.GONE);
+
+            listCalDAV = (ListView)findViewById(R.id.calendars);
+            listCalDAV.setEnabled(!info.caldav.refreshing);
+            listCalDAV.setAlpha(info.caldav.refreshing ? 0.5f : 1);
+
+            tbCalDAV.getMenu().findItem(R.id.create_calendar).setEnabled(info.caldav.hasHomeSets);
+
+            final CalendarAdapter adapter = new CalendarAdapter(this);
+            adapter.addAll(info.caldav.collections);
+            listCalDAV.setAdapter(adapter);
+            listCalDAV.setOnItemClickListener(onItemClickListener);
+            listCalDAV.setOnItemLongClickListener(onItemLongClickListener);
+        } else
+            card.setVisibility(View.GONE);
+    }
+
+    @Override
+    public void onLoaderReset(Loader<AccountInfo> loader) {
+        if (listCardDAV != null)
+            listCardDAV.setAdapter(null);
+
+        if (listCalDAV != null)
+            listCalDAV.setAdapter(null);
+    }
+
+
+    private static class AccountLoader extends AsyncTaskLoader<AccountInfo> implements DavService.RefreshingStatusListener, ServiceConnection {
+        private final String accountName;
+        private final OpenHelper dbHelper;
+        private DavService.InfoBinder davService;
+
+        public AccountLoader(Context context, String accountName) {
+            super(context);
+            this.accountName = accountName;
+            dbHelper = new OpenHelper(context);
+        }
+
+        @Override
+        protected void onStartLoading() {
+            getContext().bindService(new Intent(getContext(), DavService.class), this, Context.BIND_AUTO_CREATE);
+        }
+
+        @Override
+        protected void onStopLoading() {
+            davService.removeRefreshingStatusListener(this);
+            getContext().unbindService(this);
+        }
+
+        @Override
+        public void onServiceConnected(ComponentName name, IBinder service) {
+            davService = (DavService.InfoBinder)service;
+            davService.addRefreshingStatusListener(this, false);
+
+            forceLoad();
+        }
+
+        @Override
+        public void onServiceDisconnected(ComponentName name) {
+            davService = null;
+        }
+
+        @Override
+        public void onDavRefreshStatusChanged(long id, boolean refreshing) {
+            forceLoad();
+        }
+
+        @Override
+        public AccountInfo loadInBackground() {
+            AccountInfo info = new AccountInfo();
+            try {
+                SQLiteDatabase db = dbHelper.getReadableDatabase();
+
+                @Cleanup Cursor cursor = db.query(
+                        Services._TABLE,
+                        new String[] { Services.ID, Services.SERVICE },
+                        Services.ACCOUNT_NAME + "=?", new String[] { accountName },
+                        null, null, null);
+
+                if (cursor.getCount() == 0)
+                    // no services, account not useable
+                    return null;
+
+                while (cursor.moveToNext()) {
+                    long id = cursor.getLong(0);
+                    String service = cursor.getString(1);
+                    if (Services.SERVICE_CARDDAV.equals(service)) {
+                        info.carddav = new AccountInfo.ServiceInfo();
+                        info.carddav.id = id;
+                        info.carddav.refreshing = davService.isRefreshing(id);
+                        info.carddav.hasHomeSets = hasHomeSets(db, id);
+                        info.carddav.collections = readCollections(db, id);
+
+                    } else if (Services.SERVICE_CALDAV.equals(service)) {
+                        info.caldav = new AccountInfo.ServiceInfo();
+                        info.caldav.id = id;
+                        info.caldav.refreshing = davService.isRefreshing(id);
+                        info.caldav.hasHomeSets = hasHomeSets(db, id);
+                        info.caldav.collections = readCollections(db, id);
+                    }
+                }
+            } finally {
+                dbHelper.close();
+            }
+            return info;
+        }
+
+        private boolean hasHomeSets(@NonNull SQLiteDatabase db, long service) {
+            @Cleanup Cursor cursor = db.query(ServiceDB.HomeSets._TABLE, null, ServiceDB.HomeSets.SERVICE_ID + "=?",
+                    new String[] { String.valueOf(service) }, null, null, null);
+            return cursor.getCount() > 0;
+        }
+
+        private List<CollectionInfo> readCollections(@NonNull SQLiteDatabase db, long service) {
+            List<CollectionInfo> collections = new LinkedList<>();
+            @Cleanup Cursor cursor = db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?",
+                    new String[] { String.valueOf(service) }, null, null, Collections.SUPPORTS_VEVENT + " DESC," + Collections.DISPLAY_NAME);
+            while (cursor.moveToNext()) {
+                ContentValues values = new ContentValues();
+                DatabaseUtils.cursorRowToContentValues(cursor, values);
+                collections.add(CollectionInfo.fromDB(values));
+            }
+            return collections;
+        }
+    }
+
+
+    /* LIST ADAPTERS */
+
+    public static class AddressBookAdapter extends ArrayAdapter<CollectionInfo> {
+        public AddressBookAdapter(Context context) {
+            super(context, R.layout.account_carddav_item);
+        }
+
+        @Override
+        public View getView(int position, View v, ViewGroup parent) {
+            if (v == null)
+                v = LayoutInflater.from(getContext()).inflate(R.layout.account_carddav_item, parent, false);
+
+            final CollectionInfo info = getItem(position);
+
+            RadioButton checked = (RadioButton)v.findViewById(R.id.checked);
+            checked.setChecked(info.selected);
+
+            TextView tv = (TextView)v.findViewById(R.id.title);
+            tv.setText(TextUtils.isEmpty(info.displayName) ? info.url : info.displayName);
+
+            tv = (TextView)v.findViewById(R.id.description);
+            if (TextUtils.isEmpty(info.description))
+                tv.setVisibility(View.GONE);
+            else {
+                tv.setVisibility(View.VISIBLE);
+                tv.setText(info.description);
+            }
+
+            tv = (TextView)v.findViewById(R.id.read_only);
+            tv.setVisibility(info.readOnly ? View.VISIBLE : View.GONE);
+
+            return v;
+        }
+    }
+
+    public static class CalendarAdapter extends ArrayAdapter<CollectionInfo> {
+        public CalendarAdapter(Context context) {
+            super(context, R.layout.account_caldav_item);
+        }
+
+        @Override
+        public View getView(final int position, View v, ViewGroup parent) {
+            if (v == null)
+                v = LayoutInflater.from(getContext()).inflate(R.layout.account_caldav_item, parent, false);
+
+            final CollectionInfo info = getItem(position);
+
+            CheckBox checked = (CheckBox)v.findViewById(R.id.checked);
+            checked.setChecked(info.selected);
+
+            View vColor = v.findViewById(R.id.color);
+            if (info.color != null) {
+                vColor.setVisibility(View.VISIBLE);
+                vColor.setBackgroundColor(info.color);
+            } else
+                vColor.setVisibility(View.GONE);
+
+            TextView tv = (TextView)v.findViewById(R.id.title);
+            tv.setText(TextUtils.isEmpty(info.displayName) ? info.url : info.displayName);
+
+            tv = (TextView)v.findViewById(R.id.description);
+            if (TextUtils.isEmpty(info.description))
+                tv.setVisibility(View.GONE);
+            else {
+                tv.setVisibility(View.VISIBLE);
+                tv.setText(info.description);
+            }
+
+            tv = (TextView)v.findViewById(R.id.read_only);
+            tv.setVisibility(info.readOnly ? View.VISIBLE : View.GONE);
+
+            tv = (TextView)v.findViewById(R.id.events);
+            tv.setVisibility(BooleanUtils.isTrue(info.supportsVEVENT) ? View.VISIBLE : View.GONE);
+
+            tv = (TextView)v.findViewById(R.id.tasks);
+            tv.setVisibility(BooleanUtils.isTrue(info.supportsVTODO) ? View.VISIBLE : View.GONE);
+
+            return v;
+        }
+    }
+
+
+    /* USER ACTIONS */
+
+    private void deleteAccount() {
+        AccountManager accountManager = AccountManager.get(this);
+
+        if (Build.VERSION.SDK_INT >= 22)
+            accountManager.removeAccount(account, this, new AccountManagerCallback<Bundle>() {
+                @Override
+                public void run(AccountManagerFuture<Bundle> future) {
+                    try {
+                        if (future.getResult().getBoolean(AccountManager.KEY_BOOLEAN_RESULT))
+                            finish();
+                    } catch(OperationCanceledException|IOException|AuthenticatorException e) {
+                        App.log.log(Level.SEVERE, "Couldn't remove account", e);
+                    }
+                }
+            }, null);
+        else
+            accountManager.removeAccount(account, new AccountManagerCallback<Boolean>() {
+                @Override
+                public void run(AccountManagerFuture<Boolean> future) {
+                    try {
+                        if (future.getResult())
+                            finish();
+                    } catch (OperationCanceledException|IOException|AuthenticatorException e) {
+                        App.log.log(Level.SEVERE, "Couldn't remove account", e);
+                    }
+                }
+            }, null);
+    }
+
+    private void requestSync() {
+        String authorities[] = {
+                ContactsContract.AUTHORITY,
+                CalendarContract.AUTHORITY,
+                TaskProvider.ProviderName.OpenTasks.authority
+        };
+
+        for (String authority : authorities) {
+            Bundle extras = new Bundle();
+            extras.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);        // manual sync
+            extras.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);     // run immediately (don't queue)
+            ContentResolver.requestSync(account, authority, extras);
+        }
+
+        Snackbar.make(findViewById(R.id.parent), R.string.account_synchronizing_now, Snackbar.LENGTH_LONG).show();
+    }
+
+}
@@ -1,761 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui
-
-import android.Manifest
-import android.accounts.Account
-import android.accounts.AccountManager
-import android.app.Dialog
-import android.app.LoaderManager
-import android.content.*
-import android.content.pm.PackageManager
-import android.database.DatabaseUtils
-import android.database.sqlite.SQLiteDatabase
-import android.net.Uri
-import android.os.Build
-import android.os.Bundle
-import android.os.IBinder
-import android.provider.CalendarContract
-import android.provider.ContactsContract
-import android.support.design.widget.Snackbar
-import android.support.v4.app.ActivityCompat
-import android.support.v4.app.DialogFragment
-import android.support.v4.content.ContextCompat
-import android.support.v7.app.AlertDialog
-import android.support.v7.app.AppCompatActivity
-import android.support.v7.widget.Toolbar
-import android.view.*
-import android.widget.*
-import at.bitfire.davdroid.DavService
-import at.bitfire.davdroid.R
-import at.bitfire.davdroid.log.Logger
-import at.bitfire.davdroid.model.CollectionInfo
-import at.bitfire.davdroid.model.ServiceDB
-import at.bitfire.davdroid.model.ServiceDB.*
-import at.bitfire.davdroid.model.ServiceDB.Collections
-import at.bitfire.davdroid.resource.LocalAddressBook
-import at.bitfire.davdroid.resource.LocalTaskList
-import at.bitfire.ical4android.TaskProvider
-import at.bitfire.vcard4android.ContactsStorageException
-import kotlinx.android.synthetic.main.account_caldav_item.view.*
-import kotlinx.android.synthetic.main.activity_account.*
-import java.util.*
-import java.util.logging.Level
-
-class AccountActivity: AppCompatActivity(), Toolbar.OnMenuItemClickListener, PopupMenu.OnMenuItemClickListener, LoaderManager.LoaderCallbacks<AccountActivity.AccountInfo> {
-
-    companion object {
-        @JvmField val EXTRA_ACCOUNT = "account"
-
-        private fun requestSync(context: Context, account: Account) {
-            val authorities = arrayOf(
-                    context.getString(R.string.address_books_authority),
-                    CalendarContract.AUTHORITY,
-                    TaskProvider.ProviderName.OpenTasks.authority
-            )
-
-            for (authority in authorities) {
-                val extras = Bundle(2)
-                extras.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true)        // manual sync
-                extras.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true)     // run immediately (don't queue)
-                ContentResolver.requestSync(account, authority, extras)
-            }
-        }
-
-    }
-
-    lateinit var account: Account
-    private var accountInfo: AccountInfo? = null
-
-
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-
-        account = intent.getParcelableExtra(EXTRA_ACCOUNT)
-        title = account.name
-
-        setContentView(R.layout.activity_account)
-
-        val icMenu = if (Build.VERSION.SDK_INT >= 21)
-            getDrawable(R.drawable.ic_menu_light)
-        else
-            resources.getDrawable(R.drawable.ic_menu_light)
-
-        // CardDAV toolbar
-        carddav_menu.overflowIcon = icMenu
-        carddav_menu.inflateMenu(R.menu.carddav_actions)
-        carddav_menu.setOnMenuItemClickListener(this)
-
-        // CalDAV toolbar
-        caldav_menu.overflowIcon = icMenu
-        caldav_menu.inflateMenu(R.menu.caldav_actions)
-        caldav_menu.setOnMenuItemClickListener(this)
-
-        // Webcal toolbar
-        webcal_menu.overflowIcon = icMenu
-        webcal_menu.inflateMenu(R.menu.webcal_actions)
-        webcal_menu.setOnMenuItemClickListener(this)
-
-        // load CardDAV/CalDAV collections
-        loaderManager.initLoader(0, null, this)
-    }
-
-    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
-        if (grantResults.any { it == PackageManager.PERMISSION_GRANTED })
-            // we've got additional permissions; try to load everything again
-            reload()
-    }
-
-    override fun onCreateOptionsMenu(menu: Menu): Boolean {
-        menuInflater.inflate(R.menu.activity_account, menu)
-        return true
-    }
-
-    override fun onPrepareOptionsMenu(menu: Menu): Boolean {
-        val itemRename = menu.findItem(R.id.rename_account)
-        // renameAccount is available for API level 21+
-        itemRename.isVisible = Build.VERSION.SDK_INT >= 21
-        return super.onPrepareOptionsMenu(menu)
-    }
-
-    override fun onOptionsItemSelected(item: MenuItem): Boolean {
-        when (item.itemId) {
-            R.id.sync_now ->
-                requestSync()
-            R.id.settings -> {
-                val intent = Intent(this, AccountSettingsActivity::class.java)
-                intent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account)
-                startActivity(intent)
-            }
-            R.id.rename_account ->
-                RenameAccountFragment.newInstance(account).show(supportFragmentManager, null)
-            R.id.delete_account -> {
-                AlertDialog.Builder(this)
-                        .setIcon(R.drawable.ic_error_dark)
-                        .setTitle(R.string.account_delete_confirmation_title)
-                        .setMessage(R.string.account_delete_confirmation_text)
-                        .setNegativeButton(android.R.string.no, null)
-                        .setPositiveButton(android.R.string.yes, { _, _ ->
-                            deleteAccount()
-                        })
-                        .show()
-            }
-            else ->
-                return super.onOptionsItemSelected(item)
-        }
-        return true
-    }
-
-    override fun onMenuItemClick(item: MenuItem): Boolean {
-        when (item.itemId) {
-            R.id.refresh_address_books ->
-                accountInfo?.carddav?.let { carddav ->
-                    val intent = Intent(this, DavService::class.java)
-                    intent.action = DavService.ACTION_REFRESH_COLLECTIONS
-                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, carddav.id)
-                    startService(intent)
-                }
-            R.id.create_address_book -> {
-                val intent = Intent(this, CreateAddressBookActivity::class.java)
-                intent.putExtra(CreateAddressBookActivity.EXTRA_ACCOUNT, account)
-                startActivity(intent)
-            }
-            R.id.refresh_calendars ->
-                accountInfo?.caldav?.let { caldav ->
-                    val intent = Intent(this, DavService::class.java)
-                    intent.action = DavService.ACTION_REFRESH_COLLECTIONS
-                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, caldav.id)
-                    startService(intent)
-                }
-            R.id.create_calendar -> {
-                val intent = Intent(this, CreateCalendarActivity::class.java)
-                intent.putExtra(CreateCalendarActivity.EXTRA_ACCOUNT, account)
-                startActivity(intent)
-            }
-        }
-        return false
-    }
-
-
-    private val onItemClickListener = AdapterView.OnItemClickListener { parent, view, position, _ ->
-        if (!view.isEnabled)
-            return@OnItemClickListener
-
-        val list = parent as ListView
-        val adapter = list.adapter as ArrayAdapter<CollectionInfo>
-        val info = adapter.getItem(position)
-        val nowChecked = !info.selected
-
-        OpenHelper(this).use { dbHelper ->
-            val db = dbHelper.writableDatabase
-            db.beginTransactionNonExclusive()
-
-            val values = ContentValues(1)
-            values.put(Collections.SYNC, if (nowChecked) 1 else 0)
-            db.update(Collections._TABLE, values, "${Collections.ID}=?", arrayOf(info.id.toString()))
-
-            db.setTransactionSuccessful()
-            db.endTransaction()
-        }
-
-        info.selected = nowChecked
-        adapter.notifyDataSetChanged()
-
-        if (nowChecked && info.type == CollectionInfo.Type.ADDRESS_BOOK && info.readOnly)
-            Snackbar.make(parent, R.string.account_read_only_address_book_selected, Snackbar.LENGTH_LONG).show()
-    }
-
-    private val onActionOverflowListener = { anchor: View, info: CollectionInfo ->
-        val popup = PopupMenu(this, anchor, Gravity.RIGHT)
-        popup.inflate(R.menu.account_collection_operations)
-
-        with(popup.menu.findItem(R.id.force_read_only)) {
-            if (info.readOnly)
-                isVisible = false
-            else
-                isChecked = info.forceReadOnly
-        }
-
-        popup.setOnMenuItemClickListener({ item ->
-            when (item.itemId) {
-                R.id.force_read_only -> {
-                    val nowChecked = !item.isChecked
-                    OpenHelper(this).use { dbHelper ->
-                        val db = dbHelper.writableDatabase
-                        db.beginTransactionNonExclusive()
-
-                        val values = ContentValues(1)
-                        values.put(Collections.FORCE_READ_ONLY, nowChecked)
-                        db.update(Collections._TABLE, values, "${Collections.ID}=?", arrayOf(info.id.toString()))
-
-                        db.setTransactionSuccessful()
-                        db.endTransaction()
-                        reload()
-                    }
-                }
-                R.id.delete_collection ->
-                    DeleteCollectionFragment.ConfirmDeleteCollectionFragment.newInstance(account, info).show(supportFragmentManager, null)
-            }
-            true
-        })
-        popup.show()
-
-        // long click was handled
-        true
-    }
-
-    private val webcalOnItemClickListener = AdapterView.OnItemClickListener { parent, _, position, _ ->
-        val info = parent.getItemAtPosition(position) as CollectionInfo
-        var uri = Uri.parse(info.source)
-
-        val nowChecked = !info.selected
-        if (nowChecked) {
-            // subscribe to Webcal feed
-            when {
-                uri.scheme.equals("http", true) -> uri = uri.buildUpon().scheme("webcal").build()
-                uri.scheme.equals("https", true) -> uri = uri.buildUpon().scheme("webcals").build()
-            }
-
-            val intent = Intent(Intent.ACTION_VIEW, uri)
-            info.displayName?.let { intent.putExtra("title", it) }
-            info.color?.let { intent.putExtra("color", it) }
-            if (packageManager.resolveActivity(intent, 0) != null)
-                startActivity(intent)
-            else {
-                val snack = Snackbar.make(parent, R.string.account_no_webcal_handler_found, Snackbar.LENGTH_LONG)
-
-                val installIntent = Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=at.bitfire.icsdroid"))
-                if (packageManager.resolveActivity(installIntent, 0) != null)
-                    snack.setAction(R.string.account_install_icsdroid, {
-                        startActivity(installIntent)
-                    })
-
-                snack.show()
-            }
-        } else {
-            // unsubscribe from Webcal feed
-            if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_CALENDAR) == PackageManager.PERMISSION_GRANTED)
-                contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
-                    try {
-                        provider.delete(CalendarContract.Calendars.CONTENT_URI, "${CalendarContract.Calendars.NAME}=?", arrayOf(info.source))
-                        reload()
-                    } finally {
-                        provider.release()
-                    }
-                }
-        }
-    }
-
-
-    /* LOADERS AND LOADED DATA */
-
-    class AccountInfo {
-        var carddav: ServiceInfo? = null
-        var caldav: ServiceInfo? = null
-
-        class ServiceInfo {
-            var id: Long? = null
-            var refreshing = false
-
-            var hasHomeSets = false
-            var collections = listOf<CollectionInfo>()
-        }
-    }
-
-    override fun onCreateLoader(id: Int, args: Bundle?) =
-            AccountLoader(this, account)
-
-    fun reload() {
-        loaderManager.restartLoader(0, null, this)
-    }
-
-    override fun onLoadFinished(loader: Loader<AccountInfo>, info: AccountInfo?) {
-        accountInfo = info
-
-        carddav.visibility = info?.carddav?.let { carddav ->
-            carddav_refreshing.visibility = if (carddav.refreshing) View.VISIBLE else View.GONE
-
-            address_books.isEnabled = !carddav.refreshing
-            address_books.alpha = if (carddav.refreshing) 0.5f else 1f
-
-            carddav_menu.menu.findItem(R.id.create_address_book).isEnabled = carddav.hasHomeSets
-
-            val adapter = AddressBookAdapter(this)
-            adapter.addAll(carddav.collections)
-            address_books.adapter = adapter
-            address_books.onItemClickListener = onItemClickListener
-
-            View.VISIBLE
-        } ?: View.GONE
-
-        caldav.visibility = info?.caldav?.let { caldav ->
-            caldav_refreshing.visibility = if (caldav.refreshing) View.VISIBLE else View.GONE
-
-            calendars.isEnabled = !caldav.refreshing
-            calendars.alpha = if (caldav.refreshing) 0.5f else 1f
-
-            caldav_menu.menu.findItem(R.id.create_calendar).isEnabled = caldav.hasHomeSets
-
-            val adapter = CalendarAdapter(this)
-            adapter.addAll(caldav.collections.filter { it.type == CollectionInfo.Type.CALENDAR })
-            calendars.adapter = adapter
-            calendars.onItemClickListener = onItemClickListener
-
-            View.VISIBLE
-        } ?: View.GONE
-
-        webcal.visibility = info?.caldav?.let {
-            val collections = it.collections.filter { it.type == CollectionInfo.Type.WEBCAL }
-
-            val adapter = CalendarAdapter(this)
-            adapter.addAll(collections)
-            webcals.adapter = adapter
-            webcals.onItemClickListener = webcalOnItemClickListener
-
-            if (collections.isNotEmpty())
-                View.VISIBLE
-            else
-                View.GONE
-        } ?: View.GONE
-
-        // ask for permissions
-        val requiredPermissions = mutableSetOf<String>()
-        info?.carddav?.let { carddav ->
-            if (carddav.collections.any { it.type == CollectionInfo.Type.ADDRESS_BOOK }) {
-                requiredPermissions += Manifest.permission.READ_CONTACTS
-                requiredPermissions += Manifest.permission.WRITE_CONTACTS
-            }
-        }
-
-        info?.caldav?.let { caldav ->
-            if (caldav.collections.any { it.type == CollectionInfo.Type.CALENDAR }) {
-                requiredPermissions += Manifest.permission.READ_CALENDAR
-                requiredPermissions += Manifest.permission.WRITE_CALENDAR
-
-                if (LocalTaskList.tasksProviderAvailable(this)) {
-                    requiredPermissions += TaskProvider.PERMISSION_READ_TASKS
-                    requiredPermissions += TaskProvider.PERMISSION_WRITE_TASKS
-                }
-            }
-            if (caldav.collections.any { it.type == CollectionInfo.Type.WEBCAL })
-                requiredPermissions += Manifest.permission.READ_CALENDAR
-        }
-
-        val askPermissions = requiredPermissions.filter { ActivityCompat.checkSelfPermission(this, it) != PackageManager.PERMISSION_GRANTED }
-        if (askPermissions.isNotEmpty())
-            ActivityCompat.requestPermissions(this, askPermissions.toTypedArray(), 0)
-    }
-
-    override fun onLoaderReset(loader: Loader<AccountInfo>) {
-        address_books?.adapter = null
-        calendars?.adapter = null
-    }
-
-
-    class AccountLoader(
-            context: Context,
-            val account: Account
-    ): AsyncTaskLoader<AccountInfo>(context), DavService.RefreshingStatusListener, SyncStatusObserver {
-
-        private var syncStatusListener: Any? = null
-
-        private var davServiceConn: ServiceConnection? = null
-        private var davService: DavService.InfoBinder? = null
-
-        override fun onStartLoading() {
-            // get notified when sync status changes
-            if (syncStatusListener == null)
-                syncStatusListener = ContentResolver.addStatusChangeListener(ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE, this)
-
-            // bind to DavService to get notified when it's running
-            if (davServiceConn == null) {
-                davServiceConn = object: ServiceConnection {
-                    override fun onServiceConnected(name: ComponentName, service: IBinder) {
-                        // get notified when DavService is running
-                        davService = service as DavService.InfoBinder
-                        service.addRefreshingStatusListener(this@AccountLoader, false)
-
-                        onContentChanged()
-                    }
-
-                    override fun onServiceDisconnected(name: ComponentName) {
-                        davService = null
-                    }
-                }
-                context.bindService(Intent(context, DavService::class.java), davServiceConn, Context.BIND_AUTO_CREATE)
-            } else
-                forceLoad()
-        }
-
-        override fun onReset() {
-            ContentResolver.removeStatusChangeListener(syncStatusListener)
-
-            davService?.removeRefreshingStatusListener(this)
-            davServiceConn?.let {
-                context.unbindService(it)
-                davServiceConn = null
-            }
-        }
-
-        override fun onDavRefreshStatusChanged(id: Long, refreshing: Boolean) =
-                onContentChanged()
-
-        override fun onStatusChanged(which: Int) =
-                onContentChanged()
-
-        override fun loadInBackground(): AccountInfo {
-            val info = AccountInfo()
-
-            OpenHelper(context).use { dbHelper ->
-                val db = dbHelper.readableDatabase
-                db.query(
-                        Services._TABLE,
-                        arrayOf(Services.ID, Services.SERVICE),
-                        "${Services.ACCOUNT_NAME}=?", arrayOf(account.name),
-                        null, null, null).use { cursor ->
-                    while (cursor.moveToNext()) {
-                        val id = cursor.getLong(0)
-                        when (cursor.getString(1)) {
-                            Services.SERVICE_CARDDAV -> {
-                                val carddav = AccountInfo.ServiceInfo()
-                                info.carddav = carddav
-                                carddav.id = id
-                                carddav.refreshing =
-                                        davService?.isRefreshing(id) ?: false ||
-                                        ContentResolver.isSyncActive(account, context.getString(R.string.address_books_authority))
-
-                                val accountManager = AccountManager.get(context)
-                                for (addrBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))) {
-                                    val addressBook = LocalAddressBook(context, addrBookAccount, null)
-                                    try {
-                                        if (account == addressBook.getMainAccount())
-                                            carddav.refreshing = carddav.refreshing || ContentResolver.isSyncActive(addrBookAccount, ContactsContract.AUTHORITY)
-                                    } catch(e: ContactsStorageException) {
-                                    }
-                                }
-
-                                carddav.hasHomeSets = hasHomeSets(db, id)
-                                carddav.collections = readCollections(db, id)
-                            }
-                            Services.SERVICE_CALDAV -> {
-                                val caldav = AccountInfo.ServiceInfo()
-                                info.caldav = caldav
-                                caldav.id = id
-                                caldav.refreshing =
-                                        davService?.isRefreshing(id) ?: false ||
-                                        ContentResolver.isSyncActive(account, CalendarContract.AUTHORITY) ||
-                                        ContentResolver.isSyncActive(account, TaskProvider.ProviderName.OpenTasks.authority)
-                                caldav.hasHomeSets = hasHomeSets(db, id)
-                                caldav.collections = readCollections(db, id)
-                            }
-                        }
-                    }
-                }
-            }
-
-            return info
-        }
-
-        private fun hasHomeSets(db: SQLiteDatabase, service: Long): Boolean {
-            db.query(ServiceDB.HomeSets._TABLE, null, "${ServiceDB.HomeSets.SERVICE_ID}=?",
-                    arrayOf(service.toString()), null, null, null)?.use { cursor ->
-                return cursor.count > 0
-            }
-            return false
-        }
-
-        private fun readCollections(db: SQLiteDatabase, service: Long): List<CollectionInfo>  {
-            val collections = LinkedList<CollectionInfo>()
-            db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?", arrayOf(service.toString()),
-                    null, null, "${Collections.SUPPORTS_VEVENT} DESC,${Collections.DISPLAY_NAME}").use { cursor ->
-                while (cursor.moveToNext()) {
-                    val values = ContentValues(cursor.columnCount)
-                    DatabaseUtils.cursorRowToContentValues(cursor, values)
-                    collections.add(CollectionInfo(values))
-                }
-            }
-
-            // Webcal: check whether calendar is already subscribed by ICSdroid
-            // (or any other app that stores the URL in Calendars.NAME)
-            val webcalCollections = collections.filter { it.type == CollectionInfo.Type.WEBCAL }
-            if (webcalCollections.isNotEmpty() && ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CALENDAR) == PackageManager.PERMISSION_GRANTED)
-                context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
-                    try {
-                        for (info in webcalCollections) {
-                            provider.query(CalendarContract.Calendars.CONTENT_URI, null,
-                                    "${CalendarContract.Calendars.NAME}=?", arrayOf(info.source), null)?.use { cursor ->
-                                if (cursor.moveToNext())
-                                    info.selected = true
-                            }
-                        }
-                    } finally {
-                        provider.release()
-                    }
-                }
-
-            return collections
-        }
-
-    }
-
-
-    /* LIST ADAPTERS */
-
-    class AddressBookAdapter(
-            context: Context
-    ): ArrayAdapter<CollectionInfo>(context, R.layout.account_carddav_item) {
-        override fun getView(position: Int, v: View?, parent: ViewGroup?): View {
-            val v = v ?: LayoutInflater.from(context).inflate(R.layout.account_carddav_item, parent, false)
-            val info = getItem(position)
-
-            val checked: CheckBox = v.findViewById(R.id.checked)
-            checked.isChecked = info.selected
-
-            var tv: TextView = v.findViewById(R.id.title)
-            tv.text = if (!info.displayName.isNullOrBlank()) info.displayName else info.url
-
-            tv = v.findViewById(R.id.description)
-            if (info.description.isNullOrBlank())
-                tv.visibility = View.GONE
-            else {
-                tv.visibility = View.VISIBLE
-                tv.text = info.description
-            }
-
-            v.findViewById<ImageView>(R.id.read_only).visibility =
-                    if (info.readOnly || info.forceReadOnly) View.VISIBLE else View.GONE
-
-            v.findViewById<ImageView>(R.id.action_overflow).setOnClickListener({ view ->
-                (context as? AccountActivity)?.let {
-                    it.onActionOverflowListener(view, info)
-                }
-            })
-
-            return v
-        }
-    }
-
-    class CalendarAdapter(
-            context: Context
-    ): ArrayAdapter<CollectionInfo>(context, R.layout.account_caldav_item) {
-        override fun getView(position: Int, v: View?, parent: ViewGroup?): View {
-            val v = v ?: LayoutInflater.from(context).inflate(R.layout.account_caldav_item, parent, false)
-            val info = getItem(position)
-
-            val enabled = info.selected || info.supportsVEVENT || info.supportsVTODO
-            v.isEnabled = enabled
-            v.checked.isEnabled = enabled
-
-            val checked: CheckBox = v.findViewById(R.id.checked)
-            checked.isChecked = info.selected
-
-            val vColor: View = v.findViewById(R.id.color)
-            vColor.visibility = info.color?.let {
-                vColor.setBackgroundColor(it)
-                View.VISIBLE
-            } ?: View.INVISIBLE
-
-            var tv: TextView = v.findViewById(R.id.title)
-            tv.text = if (!info.displayName.isNullOrBlank()) info.displayName else info.url
-
-            tv = v.findViewById(R.id.description)
-            if (info.description.isNullOrBlank())
-                tv.visibility = View.GONE
-            else {
-                tv.visibility = View.VISIBLE
-                tv.text = info.description
-            }
-
-            v.findViewById<ImageView>(R.id.read_only).visibility =
-                    if (info.readOnly || info.forceReadOnly) View.VISIBLE else View.GONE
-
-            v.findViewById<ImageView>(R.id.events).visibility =
-                    if (info.supportsVEVENT) View.VISIBLE else View.GONE
-
-            v.findViewById<ImageView>(R.id.tasks).visibility =
-                    if (info.supportsVTODO) View.VISIBLE else View.GONE
-
-            val overflow = v.findViewById<ImageView>(R.id.action_overflow)
-            if (info.type == CollectionInfo.Type.WEBCAL)
-                overflow.visibility = View.GONE
-            else
-                overflow.setOnClickListener({ view ->
-                    (context as? AccountActivity)?.let {
-                        it.onActionOverflowListener(view, info)
-                    }
-                })
-
-            return v
-        }
-    }
-
-
-    /* DIALOG FRAGMENTS */
-
-    class RenameAccountFragment: DialogFragment() {
-
-        companion object {
-
-            val ARG_ACCOUNT = "account"
-
-            fun newInstance(account: Account): RenameAccountFragment {
-                val fragment = RenameAccountFragment()
-                val args = Bundle(1)
-                args.putParcelable(ARG_ACCOUNT, account)
-                fragment.arguments = args
-                return fragment
-            }
-
-        }
-
-        override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
-            val oldAccount: Account = arguments!!.getParcelable(ARG_ACCOUNT)
-
-            val editText = EditText(activity)
-            editText.setText(oldAccount.name)
-
-            return AlertDialog.Builder(activity!!)
-                    .setTitle(R.string.account_rename)
-                    .setMessage(R.string.account_rename_new_name)
-                    .setView(editText)
-                    .setPositiveButton(R.string.account_rename_rename, DialogInterface.OnClickListener { _, _ ->
-                        val newName = editText.text.toString()
-
-                        if (newName == oldAccount.name)
-                            return@OnClickListener
-
-                        val accountManager = AccountManager.get(activity)
-                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
-                            accountManager.renameAccount(oldAccount, newName, { _ ->
-                                Logger.log.info("Updating account name references")
-
-                                // cancel maybe running synchronization
-                                ContentResolver.cancelSync(oldAccount, null)
-                                for (addrBookAccount in accountManager.getAccountsByType(getString(R.string.account_type_address_book)))
-                                    ContentResolver.cancelSync(addrBookAccount, null)
-
-                                // update account name references in database
-                                OpenHelper(activity!!).use { dbHelper ->
-                                    ServiceDB.onRenameAccount(dbHelper.writableDatabase, oldAccount.name, newName)
-                                }
-
-                                // update main account of address book accounts
-                                try {
-                                    for (addrBookAccount in accountManager.getAccountsByType(getString(R.string.account_type_address_book))) {
-                                        val provider = activity!!.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)
-                                        try {
-                                            if (provider != null) {
-                                                val addressBook = LocalAddressBook(activity!!, addrBookAccount, provider)
-                                                if (oldAccount == addressBook.getMainAccount())
-                                                    addressBook.setMainAccount(Account(newName, oldAccount.type))
-                                            }
-                                        } finally {
-                                            if (Build.VERSION.SDK_INT >= 24)
-                                                provider?.close()
-                                            else
-                                                provider?.release()
-                                        }
-
-                                    }
-                                } catch(e: ContactsStorageException) {
-                                    Logger.log.log(Level.SEVERE, "Couldn't update address book accounts", e)
-                                }
-
-                                // calendar provider doesn't allow changing account_name of Events
-                                // (all events will have to be downloaded again)
-
-                                // update account_name of local tasks
-                                try {
-                                    LocalTaskList.onRenameAccount(activity!!.contentResolver, oldAccount.name, newName)
-                                } catch(e: Exception) {
-                                    Logger.log.log(Level.SEVERE, "Couldn't propagate new account name to tasks provider", e)
-                                }
-
-                                // synchronize again
-                                requestSync(activity!!, Account(newName, oldAccount.type))
-                            }, null)
-                        activity!!.finish()
-                    })
-                    .setNegativeButton(android.R.string.cancel, { _, _ -> })
-                    .create()
-        }
-    }
-
-
-    /* USER ACTIONS */
-
-    private fun deleteAccount() {
-        val accountManager = AccountManager.get(this)
-
-        if (Build.VERSION.SDK_INT >= 22)
-            accountManager.removeAccount(account, this, { future ->
-                try {
-                    if (future.result.getBoolean(AccountManager.KEY_BOOLEAN_RESULT))
-                        finish()
-                } catch(e: Exception) {
-                    Logger.log.log(Level.SEVERE, "Couldn't remove account", e)
-                }
-            }, null)
-        else
-            accountManager.removeAccount(account, { future ->
-                try {
-                    if (future.result)
-                        finish()
-                } catch (e: Exception) {
-                    Logger.log.log(Level.SEVERE, "Couldn't remove account", e)
-                }
-            }, null)
-    }
-
-    private fun requestSync() {
-        requestSync(this, account)
-        Snackbar.make(findViewById(R.id.parent), R.string.account_synchronizing_now, Snackbar.LENGTH_LONG).show()
-    }
-
-}