feat: mvp viode

wei_ai_app/lib/core/services/services.dart

@@ -4,3 +4,5 @@ library services;
 export 'supabase_service.dart';
 export 'chat_service.dart';
 export 'chat_storage_service.dart';
+export 'stt_service.dart';
+export 'tts_service.dart';

wei_ai_app/lib/core/services/stt_service.dart

@@ -0,0 +1,73 @@
+import 'package:speech_to_text/speech_to_text.dart';
+import 'package:flutter/foundation.dart';
+
+class STTService {
+  static final STTService _instance = STTService._internal();
+  factory STTService() => _instance;
+  STTService._internal();
+
+  final SpeechToText _speech = SpeechToText();
+  bool _isInitialized = false;
+  bool _isListening = false;
+
+  bool get isListening => _isListening;
+
+  Future<bool> init() async {
+    if (_isInitialized) return true;
+
+    try {
+      _isInitialized = await _speech.initialize(
+        onError: (error) => debugPrint('❌ STT Error: $error'),
+        onStatus: (status) {
+          debugPrint('🎤 STT Status: $status');
+          if (status == 'listening') _isListening = true;
+          if (status == 'notListening') _isListening = false;
+        },
+      );
+      debugPrint('✅ STT Initialized: $_isInitialized');
+      return _isInitialized;
+    } catch (e) {
+      debugPrint('❌ STT Init failed: $e');
+      return false;
+    }
+  }
+
+  Future<void> listen({
+    required Function(String text) onResult,
+    required Function(String text) onFinalResult,
+    String localeId = 'zh-CN',
+  }) async {
+    if (!_isInitialized) {
+      bool success = await init();
+      if (!success) return;
+    }
+
+    if (_isListening) await stop();
+
+    await _speech.listen(
+      onResult: (result) {
+        if (result.finalResult) {
+          onFinalResult(result.recognizedWords);
+        } else {
+          onResult(result.recognizedWords);
+        }
+      },
+      localeId: localeId,
+      listenFor: const Duration(seconds: 30),
+      pauseFor: const Duration(seconds: 3), // Wait 3s of silence to consider "done"
+      partialResults: true,
+      cancelOnError: true,
+      listenMode: ListenMode.dictation,
+    );
+  }
+
+  Future<void> stop() async {
+    await _speech.stop();
+    _isListening = false;
+  }
+
+  Future<void> cancel() async {
+    await _speech.cancel();
+    _isListening = false;
+  }
+}

wei_ai_app/lib/core/services/tts_service.dart

@@ -0,0 +1,65 @@
+import 'package:flutter_tts/flutter_tts.dart';
+import 'package:flutter/foundation.dart';
+
+class TTSService {
+  static final TTSService _instance = TTSService._internal();
+  factory TTSService() => _instance;
+  TTSService._internal();
+
+  final FlutterTts _flutterTts = FlutterTts();
+  bool _isInitialized = false;
+
+  Future<void> init() async {
+    if (_isInitialized) return;
+
+    try {
+      if (!kIsWeb) {
+        if (defaultTargetPlatform == TargetPlatform.iOS) {
+          await _flutterTts.setSharedInstance(true);
+          await _flutterTts.setIosAudioCategory(
+              IosTextToSpeechAudioCategory.playAndRecord,
+              [
+                IosTextToSpeechAudioCategoryOptions.allowBluetooth,
+                IosTextToSpeechAudioCategoryOptions.allowBluetoothA2DP,
+                IosTextToSpeechAudioCategoryOptions.mixWithOthers,
+                IosTextToSpeechAudioCategoryOptions.defaultToSpeaker
+              ],
+              IosTextToSpeechAudioMode.defaultMode);
+        }
+      }
+
+      await _flutterTts.setLanguage("zh-CN"); // Default to Chinese
+      await _flutterTts.setPitch(1.0);
+      await _flutterTts.setSpeechRate(0.5); // Normal rate
+      
+      _isInitialized = true;
+      debugPrint('✅ TTSService initialized');
+    } catch (e) {
+      debugPrint('❌ TTSService init error: $e');
+    }
+  }
+
+  Future<void> speak(String text) async {
+    if (!_isInitialized) await init();
+    if (text.isEmpty) return;
+    
+    debugPrint('🗣️ TTS Speaking: $text');
+    await _flutterTts.speak(text);
+  }
+
+  Future<void> stop() async {
+    await _flutterTts.stop();
+  }
+
+  void setCompletionHandler(VoidCallback handler) {
+    _flutterTts.setCompletionHandler(handler);
+  }
+  
+  void setStartHandler(VoidCallback handler) {
+    _flutterTts.setStartHandler(handler);
+  }
+
+  void setErrorHandler(Function(dynamic) handler) {
+    _flutterTts.setErrorHandler(handler);
+  }
+}