[API break] Move all the tools in the tools directory instead of common.

The `common` name is from the time where kiwix was only one repository
for all the project (android, desktop, server...).

Now we have split the repositories and kiwix-lib is the "common" repo,
the "common" directory is somehow nonsense.

src/tools/regexTools.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2011 Emmanuel Engelhart <kelson@kiwix.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU  General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <tools/regexTools.h>
+
+std::map<std::string, icu::RegexMatcher*> regexCache;
+
+icu::RegexMatcher* buildRegex(const std::string& regex)
+{
+  icu::RegexMatcher* matcher;
+  auto itr = regexCache.find(regex);
+
+  /* Regex is in cache */
+  if (itr != regexCache.end()) {
+    matcher = itr->second;
+  }
+
+  /* Regex needs to be parsed (and cached) */
+  else {
+    UErrorCode status = U_ZERO_ERROR;
+    icu::UnicodeString uregex(regex.c_str());
+    matcher = new icu::RegexMatcher(uregex, UREGEX_CASE_INSENSITIVE, status);
+    regexCache[regex] = matcher;
+  }
+
+  return matcher;
+}
+
+/* todo */
+void freeRegexCache()
+{
+}
+bool matchRegex(const std::string& content, const std::string& regex)
+{
+  ucnv_setDefaultName("UTF-8");
+  icu::UnicodeString ucontent(content.c_str());
+  auto matcher = buildRegex(regex);
+  matcher->reset(ucontent);
+  return matcher->find();
+}
+
+std::string replaceRegex(const std::string& content,
+                         const std::string& replacement,
+                         const std::string& regex)
+{
+  ucnv_setDefaultName("UTF-8");
+  icu::UnicodeString ucontent(content.c_str());
+  icu::UnicodeString ureplacement(replacement.c_str());
+  auto matcher = buildRegex(regex);
+  matcher->reset(ucontent);
+  UErrorCode status = U_ZERO_ERROR;
+  auto uresult = matcher->replaceAll(ureplacement, status);
+  std::string tmp;
+  uresult.toUTF8String(tmp);
+  return tmp;
+}
+
+std::string appendToFirstOccurence(const std::string& content,
+                                   const std::string regex,
+                                   const std::string& replacement)
+{
+  ucnv_setDefaultName("UTF-8");
+  icu::UnicodeString ucontent(content.c_str());
+  icu::UnicodeString ureplacement(replacement.c_str());
+  auto matcher = buildRegex(regex);
+  matcher->reset(ucontent);
+
+  if (matcher->find()) {
+    UErrorCode status = U_ZERO_ERROR;
+    ucontent.insert(matcher->end(status), ureplacement);
+    std::string tmp;
+    ucontent.toUTF8String(tmp);
+    return tmp;
+  }
+
+  return content;
+}