chore: update Emote-only expressions

- update the emote base regex
- use calcUnlocalizedBody for emote computation
- update documentation about emote computation
- add source for the emote regex

Signed-off-by: The one with the braid <[email protected]>

lib/src/event.dart

@@ -988,29 +988,27 @@ class Event extends MatrixEvent {
       content['formatted_body'] is String;
 
   // regexes to fetch the number of emotes, including emoji, and if the message consists of only those
-  // to match an emoji we can use the following regex:
-  // (?:\x{00a9}|\x{00ae}|[\x{2600}-\x{27bf}]|[\x{2b00}-\x{2bff}]|\x{d83c}[\x{d000}-\x{dfff}]|\x{d83d}[\x{d000}-\x{dfff}]|\x{d83e}[\x{d000}-\x{dfff}])[\x{fe00}-\x{fe0f}]?
-  // we need to replace \x{0000} with \u0000, the comment is left in the other format to be able to paste into regex101.com
+  // to match an emoji we can use the following regularly updated regex : https://stackoverflow.com/a/67705964
   // to see if there is a custom emote, we use the following regex: <img[^>]+data-mx-(?:emote|emoticon)(?==|>|\s)[^>]*>
-  // now we combind the two to have four regexes:
+  // now we combined the two to have four regexes:
   // 1. are there only emoji, or whitespace
   // 2. are there only emoji, emotes, or whitespace
   // 3. count number of emoji
   // 4- count number of emoji or emotes
   static final RegExp _onlyEmojiRegex = RegExp(
-      r'^((?:\u00a9|\u00ae|[\u2600-\u27bf]|[\u2b00-\u2bff]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])[\ufe00-\ufe0f]?|\s)*$',
+      r'^((?:\x{00a9}|\x{00ae}|\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])?|\s)*$',
       caseSensitive: false,
       multiLine: false);
   static final RegExp _onlyEmojiEmoteRegex = RegExp(
-      r'^((?:\u00a9|\u00ae|[\u2600-\u27bf]|[\u2b00-\u2bff]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])[\ufe00-\ufe0f]?|<img[^>]+data-mx-(?:emote|emoticon)(?==|>|\s)[^>]*>|\s)*$',
+      r'^((?:\x{00a9}|\x{00ae}|\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])?|<img[^>]+data-mx-(?:emote|emoticon)(?==|>|\s)[^>]*>|\s)*$',
       caseSensitive: false,
       multiLine: false);
   static final RegExp _countEmojiRegex = RegExp(
-      r'((?:\u00a9|\u00ae|[\u2600-\u27bf]|[\u2b00-\u2bff]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])[\ufe00-\ufe0f]?)',
+      r'((?:\x{00a9}|\x{00ae}|\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])?)',
       caseSensitive: false,
       multiLine: false);
   static final RegExp _countEmojiEmoteRegex = RegExp(
-      r'((?:\u00a9|\u00ae|[\u2600-\u27bf]|[\u2b00-\u2bff]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])[\ufe00-\ufe0f]?|<img[^>]+data-mx-(?:emote|emoticon)(?==|>|\s)[^>]*>)',
+      r'((?:\x{00a9}|\x{00ae}|\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])?|<img[^>]+data-mx-(?:emote|emoticon)(?==|>|\s)[^>]*>)',
       caseSensitive: false,
       multiLine: false);
 
@@ -1019,10 +1017,7 @@ class Event extends MatrixEvent {
   /// This is useful to determine if stand-alone emotes should be displayed bigger.
   bool get onlyEmotes {
     if (isRichMessage) {
-      final formattedTextStripped = formattedText.replaceAll(
-          RegExp('<mx-reply>.*</mx-reply>',
-              caseSensitive: false, multiLine: false, dotAll: true),
-          '');
+      final formattedTextStripped = calcUnlocalizedBody(hideReply: true);
       return _onlyEmojiEmoteRegex.hasMatch(formattedTextStripped);
     } else {
       return _onlyEmojiRegex.hasMatch(plaintextBody);
@@ -1035,10 +1030,7 @@ class Event extends MatrixEvent {
   /// WARNING: This does **not** test if there are only emotes. Use `event.onlyEmotes` for that!
   int get numberEmotes {
     if (isRichMessage) {
-      final formattedTextStripped = formattedText.replaceAll(
-          RegExp('<mx-reply>.*</mx-reply>',
-              caseSensitive: false, multiLine: false, dotAll: true),
-          '');
+      final formattedTextStripped = calcUnlocalizedBody(hideReply: true);
       return _countEmojiEmoteRegex.allMatches(formattedTextStripped).length;
     } else {
       return _countEmojiRegex.allMatches(plaintextBody).length;