[db] add support for detecting swap repos

Note that those are not really meant to be added to the DB as they are ephemeral by nature.

libs/database/src/main/java/org/fdroid/index/RepoManager.kt

@@ -1,6 +1,7 @@
 package org.fdroid.index
 
 import android.content.Context
+import android.net.Uri
 import androidx.annotation.AnyThread
 import androidx.annotation.UiThread
 import androidx.annotation.WorkerThread
@@ -20,6 +21,7 @@ import org.fdroid.download.DownloaderFactory
 import org.fdroid.download.HttpManager
 import org.fdroid.repo.AddRepoState
 import org.fdroid.repo.RepoAdder
+import org.fdroid.repo.RepoUriGetter
 import java.io.File
 import java.net.Proxy
 import java.util.concurrent.CountDownLatch
@@ -155,4 +157,12 @@ public class RepoManager @JvmOverloads constructor(
         repoAdder.abortAddingRepo()
     }
 
+    /**
+     * Returns true if the given [uri] belongs to a swap repo.
+     */
+    @UiThread
+    public fun isSwapUri(uri: Uri?): Boolean {
+        return uri != null && RepoUriGetter.isSwapUri(uri)
+    }
+
 }

libs/database/src/main/java/org/fdroid/repo/RepoUriGetter.kt

@@ -21,6 +21,7 @@ internal object RepoUriGetter {
             }
         }
         val fingerprint = uri.getQueryParameter("fingerprint")?.lowercase()
+            ?: uri.getQueryParameter("FINGERPRINT")?.lowercase()
 
         val pathSegments = uri.pathSegments
         val normalizedUri = uri.buildUpon().apply {
@@ -53,6 +54,11 @@ internal object RepoUriGetter {
         return NormalizedUri(normalizedUri, fingerprint)
     }
 
+    fun isSwapUri(uri: Uri): Boolean {
+        val swap = uri.getQueryParameter("swap") ?: uri.getQueryParameter("SWAP")
+        return swap != null && uri.scheme?.lowercase() == "http"
+    }
+
     private fun getFdroidLinkUri(uri: Uri): Uri {
         val tmpUri = uri.buildUpon().encodedQuery(uri.encodedFragment).build()
         return Uri.parse(tmpUri.getQueryParameter("repo"))