deepvoice_client/lib/data/services/flutter_asr_service.dart

import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:get/get.dart';
// 移除 speech_to_text 依赖
// import 'package:speech_to_text/speech_to_text.dart';
// import 'package:speech_to_text/speech_recognition_result.dart';
import '../../core/utils/logger.dart';

/// ASR状态枚举
enum AsrState {
  notInitialized, // 未初始化
  initialized,    // 已初始化
  listening,      // 正在监听
  notListening,   // 未监听
  error           // 错误状态
}

/// 监听模式枚举（与 speech_to_text 兼容）
enum ListenMode {
  deviceDefault,
  dictation,
  search,
  confirmation,
}

/// 本地名称类（与 speech_to_text 兼容）
class LocaleName {
  final String name;
  final String localeId;
  
  LocaleName(this.name, this.localeId);
}

/// Flutter ASR服务，负责本地语音转文本功能
/// 注意：此实现为空实现，不再依赖 speech_to_text 插件
class FlutterAsrService extends GetxService {
  // 当前ASR状态
  final Rx<AsrState> _asrState = AsrState.notInitialized.obs;
  AsrState get asrState => _asrState.value;
  
  // 可用的语音识别语言
  final RxList<LocaleName> _locales = <LocaleName>[].obs;
  List<LocaleName> get locales => _locales;
  
  // 当前选择的语言
  final RxString _currentLocale = ''.obs;
  String get currentLocale => _currentLocale.value;
  
  // 识别结果
  final RxString _lastWords = ''.obs;
  String get lastWords => _lastWords.value;
  
  // 识别准确度
  final RxDouble _confidence = 0.0.obs;
  double get confidence => _confidence.value;
  
  // 是否可用
  final RxBool _isAvailable = false.obs;
  bool get isAvailable => _isAvailable.value;
  
  // 是否正在监听
  bool _isListening = false;
  bool get isListening => _isListening;
  
  // 识别结果流
  final _recognitionResultsController = StreamController<String>.broadcast();
  Stream<String> get recognitionResults => _recognitionResultsController.stream;
  
  @override
  void onInit() {
    super.onInit();
    _initSpeech();
  }
  
  /// 初始化语音识别
  Future<void> _initSpeech() async {
    try {
      // 空实现，不再使用 speech_to_text
      _isAvailable.value = false;
      _asrState.value = AsrState.error;
      
      // 添加一个默认语言
      _locales.add(LocaleName('中文 (简体)', 'zh-CN'));
      _currentLocale.value = 'zh-CN';
      
      Logger.info('FlutterAsrService 已初始化（空实现）');
    } catch (e) {
      _asrState.value = AsrState.error;
      _isAvailable.value = false;
      Logger.error('语音识别初始化失败: $e');
    }
  }
  
  /// 开始监听
  /// 
  /// [listenFor] 监听时长，默认30秒
  /// [pauseFor] 暂停时长，默认3秒，超过此时长无语音输入会自动停止
  /// [partialResults] 是否返回部分结果，默认true
  /// [onDevice] 是否使用设备本地识别，默认false
  /// [listenMode] 监听模式，默认设备默认模式
  Future<bool> startListening({
    Duration listenFor = const Duration(seconds: 30),
    Duration pauseFor = const Duration(seconds: 3),
    bool partialResults = true,
    bool onDevice = false,
    ListenMode listenMode = ListenMode.deviceDefault,
  }) async {
    // 空实现，不再使用 speech_to_text
    Logger.error('FlutterAsrService 为空实现，不支持语音识别');
    return false;
  }
  
  /// 停止监听
  Future<void> stopListening() async {
    // 空实现，不再使用 speech_to_text
    _isListening = false;
    _asrState.value = AsrState.notListening;
  }
  
  /// 取消监听
  Future<void> cancelListening() async {
    // 空实现，不再使用 speech_to_text
    _isListening = false;
    _lastWords.value = '';
    _confidence.value = 0.0;
    _asrState.value = AsrState.notListening;
  }
  
  /// 设置当前语言
  void setLocale(String localeId) {
    if (_currentLocale.value != localeId) {
      _currentLocale.value = localeId;
      Logger.info('设置语音识别语言: $localeId');
    }
  }
  
  @override
  void onClose() {
    _recognitionResultsController.close();
    super.onClose();
  }
}