Put reaction and GIF helpers in charge of encoding

lib/helpers/gif_helper.dart

@@ -9,7 +9,7 @@ class GifHelper {
   /// include a trailing slash.
   ///
   /// Returns null if text is not a valid GIF format
-  static String? parseGifId(String text) {
+  static String? parseGif(String text) {
     final trimmed = text.trim();
     final match = RegExp(r'^g:([A-Za-z0-9_-]+)$').firstMatch(trimmed);
     if (match != null) {
@@ -30,4 +30,9 @@ class GifHelper {
     ).firstMatch(trimmed);
     return pageMatch?.group(1);
   }
+  
+  /// Encode a GIF in a format that parseGif() can parse.
+  static String encodeGif(String gifId) {
+    return 'g:$gifId';
+  }
 }

lib/helpers/reaction_helper.dart

@@ -109,4 +109,9 @@ class ReactionHelper {
 
     return ReactionInfo(targetHash: match.group(1)!, emoji: emoji);
   }
+  
+  /// Encode a reaction message that parseReaction() can parse.
+  static String encodeReaction(String hash, String emojiIndex) {
+    return 'r:$hash:$emojiIndex';
+  }
 }

lib/screens/channel_chat_screen.dart

@@ -356,7 +356,7 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
     final settingsService = context.watch<AppSettingsService>();
     final enableTracing = settingsService.settings.enableMessageTracing;
     final isOutgoing = message.isOutgoing;
-    final gifId = GifHelper.parseGifId(message.text);
+    final gifId = GifHelper.parseGif(message.text);
     final poi = _parsePoiMessage(message.text);
     final translatedDisplayText =
         message.translatedText != null &&
@@ -700,7 +700,7 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
     final colorScheme = Theme.of(context).colorScheme;
     final previewTextColor = colorScheme.onSurface.withValues(alpha: 0.7);
 
-    final gifId = GifHelper.parseGifId(replyText);
+    final gifId = GifHelper.parseGif(replyText);
     final poi = _parsePoiMessage(replyText);
 
     Widget contentPreview;
@@ -892,7 +892,7 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
       isScrollControlled: true,
       builder: (context) => GifPicker(
         onGifSelected: (gifId) {
-          _textController.text = 'g:$gifId';
+          _textController.text = GifHelper.encodeGif(gifId);
         },
       ),
     );
@@ -1048,7 +1048,7 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
                 child: ValueListenableBuilder<TextEditingValue>(
                   valueListenable: _textController,
                   builder: (context, value, child) {
-                    final gifId = GifHelper.parseGifId(value.text);
+                    final gifId = GifHelper.parseGif(value.text);
                     if (gifId != null) {
                       return Focus(
                         autofocus: true,
@@ -1316,7 +1316,7 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
       message.senderName,
       message.text,
     );
-    final reactionText = 'r:$hash:$emojiIndex';
+    final reactionText = ReactionHelper.encodeReaction(hash, emojiIndex);
     connector.sendChannelMessage(widget.channel, reactionText);
   }
 

lib/screens/chat_screen.dart

@@ -524,7 +524,7 @@ class _ChatScreenState extends State<ChatScreen> {
               child: ValueListenableBuilder<TextEditingValue>(
                 valueListenable: _textController,
                 builder: (context, value, child) {
-                  final gifId = GifHelper.parseGifId(value.text);
+                  final gifId = GifHelper.parseGif(value.text);
                   if (gifId != null) {
                     return Focus(
                       autofocus: true,
@@ -605,7 +605,7 @@ class _ChatScreenState extends State<ChatScreen> {
       isScrollControlled: true,
       builder: (context) => GifPicker(
         onGifSelected: (gifId) {
-          _textController.text = 'g:$gifId';
+          _textController.text = GifHelper.encodeGif(gifId);
         },
       ),
     );
@@ -1538,7 +1538,7 @@ class _ChatScreenState extends State<ChatScreen> {
       senderName,
       message.text,
     );
-    final reactionText = 'r:$hash:$emojiIndex';
+    final reactionText = ReactionHelper.encodeReaction(hash, emojiIndex);
     connector.sendMessage(_resolveContact(connector), reactionText);
   }
 }
@@ -1568,7 +1568,7 @@ class _MessageBubble extends StatelessWidget {
     final enableTracing = settingsService.settings.enableMessageTracing;
     final isOutgoing = message.isOutgoing;
     final colorScheme = Theme.of(context).colorScheme;
-    final gifId = GifHelper.parseGifId(message.text);
+    final gifId = GifHelper.parseGif(message.text);
     final poi = _parsePoiMessage(message.text);
     final isFailed = message.status == MessageStatus.failed;
     final bubbleColor = isFailed