import 'dart:async';
import 'package:get/get.dart';
import '../../../data/services/volcano_asr_service.dart';
import '../../../data/services/volcano_tts_api_service.dart';
import '../../../core/utils/logger.dart';
import '../models/translation_message_model.dart';

class TranslationController extends GetxController {
  // Observable states
  final isListening = false.obs;
  final isTranslating = false.obs;
  final sourceLanguage = "Chinese".obs;
  final targetLanguage = "English".obs;
  final originalText = "".obs;
  final translatedText = "".obs;
  final isUserSpeaking = false.obs;
  final messages = <TranslationMessage>[].obs;
  
  // TTS启用状态
  final isTtsEnabled = true.obs;
  
  // Services
  late final VolcanoAsrService _voiceService;
  late final VolcanoTtsApiService _ttsService;
  
  // Stream subscriptions
  StreamSubscription? _recognitionSubscription;
  
  // Timers
  Timer? _silenceTimer;
  Timer? _speakingCheckTimer;
  
  // State tracking
  bool _hasRecognizedSpeech = false;
  bool _hasFinalResult = false;
  DateTime? _lastSpeechTime;
  Completer<String>? _recognitionCompleter;
  
  // TTS事件订阅
  StreamSubscription? _ttsEventSubscription;
  bool _isTtsSpeaking = false;
  
  @override
  void onInit() {
    super.onInit();
    _initializeServices();
    _startSpeakingCheckTimer();
    
    _ttsService = Get.find<VolcanoTtsApiService>();
    
    // 设置TTS事件监听
    _setupTtsEventListener();
  }
  
  Future<void> _initializeServices() async {
    try {
      _voiceService = Get.find<VolcanoAsrService>();
      _ttsService = Get.find<VolcanoTtsApiService>();
      
      await _voiceService.initialize();
      await startListening();
    } catch (e) {
      Logger.error('Failed to initialize translation services', e);
      Get.snackbar(
        'Error',
        'Failed to initialize translation services: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }
  
  Future<void> startListening() async {
    if (isListening.value) return;
    
    try {
      isListening.value = true;
      originalText.value = '';
      translatedText.value = '';
      _hasRecognizedSpeech = false;
      _hasFinalResult = false;
      
      _recognitionCompleter = Completer<String>();
      
      final success = await _voiceService.startContinuousRecognition();
      if (!success) {
        isListening.value = false;
        throw Exception('Failed to start voice recognition');
      }
      
      _recognitionSubscription = _voiceService.recognitionStream?.listen(
        (event) {
          switch (event.type) {
            case RecognitionEventType.recognizing:
              if (event.text.isNotEmpty) {
                originalText.value = event.text;
                _hasRecognizedSpeech = true;
                _lastSpeechTime = DateTime.now();
                isUserSpeaking.value = true;
                
                // Cancel previous silence timer
                _silenceTimer?.cancel();
                
                // Set new silence timer - if no new recognition results in 2 seconds,
                // consider the user has stopped speaking
                _silenceTimer = Timer(const Duration(seconds: 2), () {
                  if (_hasRecognizedSpeech && !_hasFinalResult) {
                    _processTranslation(event.text);
                  }
                });
                
                // If TTS is playing and user starts speaking, stop TTS
                if (_isTtsSpeaking) {
                  _ttsService.endSession();
                }
              }
              break;
              
            case RecognitionEventType.finalResult:
              _hasFinalResult = true;
              isUserSpeaking.value = false;
              
              if (event.text.isNotEmpty) {
                originalText.value = event.text;
                _hasRecognizedSpeech = true;
                _lastSpeechTime = DateTime.now();
                
                _processTranslation(event.text);
              } else if (_hasRecognizedSpeech) {
                // If final result is empty but we had intermediate results
                _processTranslation(originalText.value);
              }
              
              // Reset for next utterance
              _hasRecognizedSpeech = false;
              _hasFinalResult = false;
              break;
              
            case RecognitionEventType.error:
              Logger.error('Voice recognition error', event.error);
              break;
              
            default:
              break;
          }
        },
        onError: (error) {
          Logger.error('Voice recognition stream error', error);
          isListening.value = false;
          restartListening();
        }
      );
      
    } catch (e) {
      Logger.error('Failed to start listening', e);
      isListening.value = false;
    }
  }
  
  Future<void> _processTranslation(String text) async {
    if (text.isEmpty) return;
    
    try {
      isTranslating.value = true;
      
      // In a real implementation, you would call your translation service here
      // For now, we'll simulate translation with a delay
      await Future.delayed(const Duration(milliseconds: 300));
      
      // Simulate translation (in a real app, call your translation API here)
      final translated = await _simulateTranslation(text);
      translatedText.value = translated;
      
      // Add to messages
      messages.add(TranslationMessage(
        original: text,
        translated: translated,
        timestamp: DateTime.now(),
        isFromUser: true,
      ));
      
      // Speak the translation if TTS is enabled
      if (isTtsEnabled.value) {
        await _synthesizeText(translated);
      }
      
    } catch (e) {
      Logger.error('Translation error', e);
    } finally {
      isTranslating.value = false;
    }
  }
  
  // This is a placeholder - in a real app, you would call your translation API
  Future<String> _simulateTranslation(String text) async {
    // This is just a simulation - replace with actual translation API call
    if (sourceLanguage.value == "Chinese" && targetLanguage.value == "English") {
      // Simulate Chinese to English translation
      if (text.contains('测试')) return 'I am now starting to test the function of translating spoken Chinese into English.';
      return 'Translated from Chinese: $text';
    } else {
      // Simulate English to Chinese translation
      return '翻译自英语: $text';
    }
  }
  
  void switchLanguages() {
    final temp = sourceLanguage.value;
    sourceLanguage.value = targetLanguage.value;
    targetLanguage.value = temp;
    
    // Clear current messages when switching languages
    messages.clear();
  }
  
  Future<void> restartListening() async {
    await stopListening();
    await Future.delayed(const Duration(milliseconds: 500));
    await startListening();
  }
  
  Future<void> stopListening() async {
    if (!isListening.value) return;
    
    try {
      await _recognitionSubscription?.cancel();
      _recognitionSubscription = null;
      
      _silenceTimer?.cancel();
      _silenceTimer = null;
      
      if (_voiceService.isContinuousRecognitionActive()) {
        await _voiceService.stopRecognition();
      }
      
      isListening.value = false;
      isUserSpeaking.value = false;
      _hasRecognizedSpeech = false;
      _hasFinalResult = false;
    } catch (e) {
      Logger.error('Failed to stop listening', e);
    }
  }
  
  void _startSpeakingCheckTimer() {
    _speakingCheckTimer?.cancel();
    _speakingCheckTimer = Timer.periodic(const Duration(milliseconds: 200), (_) {
      _checkIfUserIsSpeaking();
    });
  }
  
  void _checkIfUserIsSpeaking() {
    if (_hasRecognizedSpeech && !_hasFinalResult && _lastSpeechTime != null) {
      final timeSinceLastSpeech = DateTime.now().difference(_lastSpeechTime!);
      if (timeSinceLastSpeech.inMilliseconds < 1000) {
        isUserSpeaking.value = true;
        return;
      }
    }
    
    isUserSpeaking.value = false;
  }
  
  void _setupTtsEventListener() {
    _ttsEventSubscription = _ttsService.eventStream.listen(_handleTtsEvent);
  }
  
  void _handleTtsEvent(Map<String, dynamic> event) {
    final String eventType = event['type'] as String? ?? 'unknown';
    
    switch (eventType) {
      case 'ttsSentenceStart':
        _isTtsSpeaking = true;
        break;
      case 'ttsSentenceEnd':
      case 'sessionFinished':
      case 'connectionFinished':
        _isTtsSpeaking = false;
        break;
      case 'connectionFailed':
      case 'sessionFailed':
        _isTtsSpeaking = false;
        print('TTS错误: ${event['message']}');
        break;
    }
  }
  
  @override
  void onClose() {
    stopListening();
    _speakingCheckTimer?.cancel();
    
    // 取消TTS事件订阅
    _ttsEventSubscription?.cancel();
    
    // 结束TTS会话
    _ttsService.endSession();
    
    super.onClose();
  }
  
  // Add a method to synthesize text using the new TTS service
  Future<void> _synthesizeText(String text) async {
    if (text.isEmpty || !isTtsEnabled.value) return;
    
    try {
      // 如果当前有正在进行的TTS会话，先结束它
      if (_isTtsSpeaking) {
        await _ttsService.endSession();
      }
      
      // 确保连接已建立
      if (!_ttsService.isConnected.value) {
        final connected = await _ttsService.connect();
        if (!connected) {
          print('无法连接到TTS服务');
          return;
        }
      }
      
      // 开始合成
      await _ttsService.synthesize(text, 'zh_female_1'); // 使用默认说话人
    } catch (e) {
      print('TTS播放出错: $e');
    }
  }
  
  // Add a method to toggle TTS
  void toggleTTS() {
    isTtsEnabled.toggle();
    if (!isTtsEnabled.value) {
      _ttsService.endSession();
    }
  }
}