fix: if there's an error while building transcript in tts card, show error card (#1281)

lib/pangea/widgets/chat/message_speech_to_text_card.dart

@@ -35,6 +35,7 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
   bool _fetchingTranscription = true;
   Object? error;
   STTToken? selectedToken;
+  TextSpan? transcriptText;
 
   String? get l1Code =>
       MatrixState.pangeaController.languageController.activeL1Code();
@@ -70,6 +71,7 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
   }
 
   TextSpan _buildTranscriptText(BuildContext context) {
+    try {
       final Transcript transcript = speechToTextResponse!.transcript;
       final List<InlineSpan> spans = [];
       String remainingFullText = transcript.text;
@@ -79,9 +81,6 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
           text: remainingFullText,
           style: BotStyle.text(
             context,
-          existingStyle: TextStyle(
-            color: Theme.of(context).colorScheme.onSurface,
-          ),
             setColor: false,
           ),
         );
@@ -89,9 +88,11 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
 
       for (final token in transcript.sttTokens) {
         final offset = remainingFullText.indexOf(token.token.text.content);
+        if (offset == -1) continue;
         final length = token.length;
 
         if (remainingFullText.substring(0, offset).trim().isNotEmpty) {
+          remainingFullText = remainingFullText.substring(offset);
           continue;
         }
 
@@ -140,12 +141,21 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
       }
 
       return TextSpan(children: spans);
+    } catch (err, s) {
+      ErrorHandler.logError(e: err, s: s);
+      setState(() => error = err);
+      return const TextSpan(text: '');
+    }
   }
 
   @override
   void initState() {
     super.initState();
-    getSpeechToText();
+    getSpeechToText().then((_) {
+      if (mounted) {
+        setState(() => transcriptText = _buildTranscriptText(context));
+      }
+    });
   }
 
   String? get wordsPerMinuteString =>
@@ -158,7 +168,7 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
     }
 
     // done fetchig but not results means some kind of error
-    if (speechToTextResponse == null) {
+    if (speechToTextResponse == null || error != null) {
       return CardErrorWidget(
         error: error ?? "Failed to fetch speech to text",
         maxWidth: AppConfig.toolbarMinWidth,
@@ -173,7 +183,7 @@ class MessageSpeechToTextCardState extends State<MessageSpeechToTextCard> {
         children: [
           const SizedBox(height: 8),
           RichText(
-            text: _buildTranscriptText(context),
+            text: transcriptText!,
           ),
           if (widget.messageEvent.senderId == Matrix.of(context).client.userID)
             Column(