deepvoice_client/lib/data/services/speech_impl/flutter_tts_service.dart

import 'dart:async';
import 'dart:collection';
import 'package:flutter/foundation.dart';
import 'package:get/get.dart';
import 'package:flutter_tts/flutter_tts.dart';
import '../../../core/utils/logger.dart';
import '../tts_service.dart';

/// Flutter TTS服务，负责基本的文本转语音功能
/// 
/// 使用flutter_tts插件实现TtsService接口
class FlutterTtsService extends GetxService implements TtsService {
  static final FlutterTtsService to = Get.put(FlutterTtsService());
  
  // flutter_tts实例
  late final FlutterTts _flutterTts;
  
  // 支持的语音列表
  final List<String> _supportedVoices = [];
  List<String> get supportedVoices => _supportedVoices;
  
  // 当前语音
  final RxString _currentVoice = ''.obs;
  @override
  String get currentVoice => _currentVoice.value;
  
  // 播放状态
  final RxBool _isSpeaking = false.obs;
  @override
  bool get isSpeaking => _isSpeaking.value;
  
  // 文本队列
  final Queue<_SpeechItem> _textQueue = Queue<_SpeechItem>();
  bool _isProcessingQueue = false;
  
  // 事件流控制器
  final StreamController<TtsEvent> _eventController = StreamController<TtsEvent>.broadcast();
  @override
  Stream<TtsEvent> get onEvent => _eventController.stream;
  
  // 语言
  String _language = 'zh-CN';
  
  // 流式文本缓冲区
  String _streamBuffer = '';
  
  // 当前参数设置
  double _volume = 1.0;
  double _rate = 0.5;
  double _pitch = 1.0;
  
  FlutterTtsService() {
    _flutterTts = FlutterTts();
    _initTts();
  }
  
  /// 初始化TTS
  Future<void> _initTts() async {
    try {
      // 设置完成回调
      _flutterTts.setCompletionHandler(() {
        _isSpeaking.value = false;
        _eventController.add(TtsEvent(type: TtsEventType.completed));
      });
      
      // 设置开始回调
      _flutterTts.setStartHandler(() {
        _isSpeaking.value = true;
        _eventController.add(TtsEvent(type: TtsEventType.started));
      });
      
      // 设置错误回调
      _flutterTts.setErrorHandler((msg) {
        _isSpeaking.value = false;
        _eventController.add(TtsEvent.error(msg));
        Logger.error('TTS错误: $msg');
      });
      
      // 设置取消回调
      _flutterTts.setCancelHandler(() {
        _isSpeaking.value = false;
        _eventController.add(TtsEvent(type: TtsEventType.canceled));
      });
      
      // 设置默认语言
      await _flutterTts.setLanguage(_language);
      
      // 设置音量
      await _flutterTts.setVolume(_volume);
      
      // 设置语速
      await _flutterTts.setSpeechRate(_rate);
      
      // 设置音调
      await _flutterTts.setPitch(_pitch);
      
      Logger.info('FlutterTtsService 已初始化');
    } catch (e) {
      Logger.error('TTS初始化失败: ${e.toString()}');
    }
  }
  
  @override
  Future<bool> initialize({
    List<String>? supportedLanguages,
  }) async {
    try {
      // 获取可用的语音
      await _loadVoices();
      
      // 更新支持的语言列表（如果提供）
      if (supportedLanguages != null && supportedLanguages.isNotEmpty) {
        _language = supportedLanguages.first;
        await _flutterTts.setLanguage(_language);
      }
      
      Logger.info('FlutterTtsService 初始化成功');
      Logger.info('支持的语音: ${_supportedVoices.join(", ")}');
      return true;
    } catch (e) {
      Logger.error('TTS初始化失败: ${e.toString()}');
      return false;
    }
  }
  
  /// 加载可用的语音
  Future<void> _loadVoices() async {
    try {
      _supportedVoices.clear();
      
      // 获取可用的语音
      final voices = await _flutterTts.getVoices;
      
      if (voices != null && voices is List) {
        for (final voice in voices) {
          if (voice is Map && voice.containsKey('name')) {
            _supportedVoices.add(voice['name'].toString());
          }
        }
      }
      
      // 如果没有找到语音，添加默认语音
      if (_supportedVoices.isEmpty) {
        _supportedVoices.add('default');
      }
      
      // 设置默认语音
      if (_currentVoice.value.isEmpty && _supportedVoices.isNotEmpty) {
        _currentVoice.value = _supportedVoices.first;
      }
    } catch (e) {
      Logger.error('加载TTS语音失败: ${e.toString()}');
      
      // 添加默认语音
      if (_supportedVoices.isEmpty) {
        _supportedVoices.add('default');
        _currentVoice.value = 'default';
      }
    }
  }
  
  @override
  Future<bool> setVoice(String voiceName) async {
    try {
      // 检查语音是否存在
      if (!_supportedVoices.contains(voiceName) && voiceName != 'default') {
        Logger.warning('语音不存在: $voiceName，使用默认语音');
        voiceName = _supportedVoices.isNotEmpty ? _supportedVoices.first : 'default';
      }
      
      // 设置语音
      await _flutterTts.setVoice({"name": voiceName});
      _currentVoice.value = voiceName;
      
      Logger.info('设置TTS语音: $voiceName');
      return true;
    } catch (e) {
      Logger.error('设置TTS语音失败: ${e.toString()}');
      return false;
    }
  }

  /// 设置语音参数
  Future<bool> setSpeechParams({double? rate, double? pitch, double? volume}) async {
    try {
      if (volume != null) {
        await _flutterTts.setVolume(volume);
        _volume = volume;
      }
      
      if (rate != null) {
        await _flutterTts.setSpeechRate(rate);
        _rate = rate;
      }
      
      if (pitch != null) {
        await _flutterTts.setPitch(pitch);
        _pitch = pitch;
      }
      
      return true;
    } catch (e) {
      Logger.error('设置语音参数失败: ${e.toString()}');
      
      // 发送错误事件
      _eventController.add(TtsEvent.error('设置语音参数失败: $e'));
      
      return false;
    }
  }
  
  @override
  Future<bool> speakOnce(String text) async {
    if (text.isEmpty) return false;
    
    try {
      // 如果正在播放，先停止
      if (_isSpeaking.value) {
        await stop();
      }
      
      // 播放文本
      await _flutterTts.speak(text);
      
      return true;
    } catch (e) {
      // 发送错误事件
      _eventController.add(TtsEvent.error(e.toString()));
      
      Logger.error('TTS播放失败: ${e.toString()}');
      return false;
    }
  }
  
  @override
  Future<bool> speakStream(String text) async {
    if (text.isEmpty) return false;
    
    try {
      // 添加文本到缓冲区
      _streamBuffer += text;
      
      // 如果缓冲区为空，直接返回
      if (_streamBuffer.isEmpty) return true;
      
      // 使用正则表达式匹配句子，包括结束符号
      // 匹配任意字符，直到遇到句子结束符号
      final sentenceRegex = RegExp(
        r'([^。.！!？?；;：\n\r]+[。.！!？?；;：:\n\r]|[^。.！!？?；;：\n\r]+(?:\.{3,}|…)|[^。.！!？?；;：\n\r]+["」』])'
      );
      
      bool hasProcessed = false;
      
      // 查找所有完整句子
      final matches = sentenceRegex.allMatches(_streamBuffer);
      final List<String> sentences = [];
      int lastMatchEnd = 0;
      
      for (final match in matches) {
        // 提取完整句子（包含结束符号）
        final sentence = match.group(1)?.trim();
        if (sentence != null && sentence.isNotEmpty) {
          sentences.add(sentence);
          lastMatchEnd = match.end;
        }
      }
      
      // 处理找到的句子
      for (final sentence in sentences) {
        _textQueue.add(_SpeechItem(
          text: sentence,
          rate: _rate,
          pitch: _pitch,
          volume: _volume,
        ));
        hasProcessed = true;
      }
      
      // 更新缓冲区，只保留未完成的部分
      if (lastMatchEnd > 0) {
        _streamBuffer = _streamBuffer.substring(lastMatchEnd);
      }
      
      // 如果处理了文本并且队列未在处理中，开始处理队列
      if (hasProcessed && !_isProcessingQueue) {
        _processQueue();
      }
      
      return true;
    } catch (e) {
      Logger.error('处理流式文本失败: ${e.toString()}');
      
      // 发送错误事件
      _eventController.add(TtsEvent.error(e.toString()));
      
      return false;
    }
  }
  
  @override
  Future<bool> flushStream() async {
    if (_textQueue.isEmpty && _streamBuffer.isEmpty) return true;
    
    try {
      // 处理缓冲区中可能的完整句子
      await speakStream('');
      
      // 如果缓冲区仍有剩余文本，将其添加到播放队列
      if (_streamBuffer.isNotEmpty && _streamBuffer.trim().isNotEmpty) {
        _textQueue.add(_SpeechItem(
          text: _streamBuffer,
          rate: _rate,
          pitch: _pitch,
          volume: _volume,
        ));
        
        // 清空缓冲区
        _streamBuffer = '';
        
        // 如果队列未在处理中，开始处理队列
        if (!_isProcessingQueue) {
          _processQueue();
        }
      }
      
      Logger.info('等待TTS队列播放完成，剩余${_textQueue.length}条');
      
      // 等待队列处理完成
      while (_isProcessingQueue || _isSpeaking.value) {
        await Future.delayed(const Duration(milliseconds: 100));
      }
      
      Logger.info('TTS队列播放完成');
      return true;
    } catch (e) {
      Logger.error('等待TTS队列播放完成失败: ${e.toString()}');
      
      // 发送错误事件
      _eventController.add(TtsEvent.error(e.toString()));
      
      return false;
    }
  }
  
  /// 处理队列中的文本
  Future<void> _processQueue() async {
    if (_isProcessingQueue) return;
    
    _isProcessingQueue = true;
    
    try {
      while (_textQueue.isNotEmpty) {
        if (!_isSpeaking.value) {
          final item = _textQueue.removeFirst();
          
          // 如果参数有变化，更新参数
          if (item.rate != _rate || item.pitch != _pitch || item.volume != _volume) {
            await setSpeechParams(
              rate: item.rate,
              pitch: item.pitch,
              volume: item.volume,
            );
          }
          
          // 播放文本
          await _flutterTts.speak(item.text);
          
          // 等待开始播放
          int attempts = 0;
          while (!_isSpeaking.value && attempts < 10) {
            await Future.delayed(const Duration(milliseconds: 50));
            attempts++;
          }
          
          // 等待播放完成
          while (_isSpeaking.value) {
            await Future.delayed(const Duration(milliseconds: 100));
          }
        } else {
          // 等待一小段时间再检查队列
          await Future.delayed(const Duration(milliseconds: 100));
        }
      }
    } catch (e) {
      Logger.error('TTS处理队列失败: ${e.toString()}');
      
      // 发送错误事件
      _eventController.add(TtsEvent.error(e.toString()));
    } finally {
      _isProcessingQueue = false;
    }
  }
  
  @override
  Future<bool> stop() async {
    try {
      Logger.info('尝试停止TTS播放...');
      
      // 清空队列
      _textQueue.clear();
      _streamBuffer = '';
      
      // 如果正在播放，停止播放
      if (_isSpeaking.value) {
        // 先重置状态标志，避免处理队列循环继续等待
        _isProcessingQueue = false;
        
        // 执行停止
        final result = await _flutterTts.stop();
        Logger.info('TTS停止结果: $result');
        
        // 短暂延迟等待状态更新
        await Future.delayed(const Duration(milliseconds: 100));
        
        // 强制更新状态
        _isSpeaking.value = false;
        
        // 发送取消事件
        _eventController.add(TtsEvent(type: TtsEventType.canceled));
      }
      
      Logger.info('TTS停止播放完成');
      return true;
    } catch (e) {
      Logger.error('TTS停止播放失败: ${e.toString()}');
      
      // 即使出错也尝试强制重置状态
      _isSpeaking.value = false;
      _isProcessingQueue = false;
      
      return false;
    }
  }
  
  @override
  Future<void> dispose() async {
    try {
      await stop();
      _textQueue.clear();
      
      // 关闭事件流控制器
      await _eventController.close();
      
      Logger.info('TTS资源已释放');
    } catch (e) {
      Logger.error('释放TTS资源失败: ${e.toString()}');
    }
  }

  /// 处理AI返回的文本流，将其转换为语音
  /// 
  /// [textStream] 文本流
  /// 返回一个Future，当流处理完成时完成
  Future<bool> processAiTextStream(Stream<String> textStream) async {
    try {
      await for (final text in textStream) {
        if (text.isEmpty) continue;
        await speakStream(text);
      }
      
      // 处理完流后，刷新缓冲区中的剩余文本
      await flushStream();
      return true;
    } catch (e) {
      Logger.error('处理文本流时出错: ${e.toString()}');
      return false;
    }
  }
}

/// 语音合成项目
class _SpeechItem {
  final String text;
  final double rate;
  final double pitch;
  final double volume;
  
  _SpeechItem({
    required this.text,
    this.rate = 0.5,
    this.pitch = 1.0,
    this.volume = 1.0,
  });
}