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

import 'dart:async';
import 'package:flutter/services.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:get_storage/get_storage.dart';
import '../../../core/utils/logger.dart';
import 'package:get/get.dart';
import '../asr_service.dart';

/// Azure 语音识别服务
///
/// 该服务提供了通过平台通道与 Android 上的 Microsoft Speech SDK 交互的接口
class AzureAsrService extends GetxService implements AsrService {
  static final AzureAsrService to = Get.put(AzureAsrService());
  static const MethodChannel _channel = MethodChannel('azure_speech/asr');
  static const EventChannel _eventChannel =
      EventChannel('azure_speech/asr_events');
  final GetStorage _storage = GetStorage();
  bool _isInitialized = false;
  late final String _subscriptionKey;
  late final String _serviceRegion;

  final List<String> _defaultSupportedLanguages = ['zh-CN'];
  @override
  List<String> get supportedLanguages => _defaultSupportedLanguages;

  // 连续识别相关
  bool _isContinuousRecognitionActive = false;
  StreamController<RecognitionEvent>? _eventStreamController;
  StreamSubscription? _eventSubscription;

  // 最新的识别结果
  String _latestRecognizedText = '';
  String get latestRecognizedText => _latestRecognizedText;

  // 最新检测到的语言
  String _latestDetectedLanguage = '';
  String get latestDetectedLanguage => _latestDetectedLanguage;

  AzureAsrService() {
    _loadConfig();
  }

  /// 从环境变量加载配置
  void _loadConfig() {
    final _env = _storage.read("ENV") as Map<String, String>;
    _subscriptionKey = _env['AZURE_SPEECH_KEY'] ?? '';
    _serviceRegion = _env['AZURE_SPEECH_REGION'] ?? '';

    if (_subscriptionKey.isEmpty || _serviceRegion.isEmpty) {
      throw Exception(
          '未找到 Azure 语音服务配置。请在 .env 文件中设置 AZURE_SPEECH_KEY 和 AZURE_SPEECH_REGION');
    }
  }

  /// 设置事件通道
  void _setupEventChannel() {
    _eventSubscription = _eventChannel.receiveBroadcastStream().listen((event) {
      if (event is Map) {
        _handleRecognitionEvent(event);
      }
    }, onError: _handleRecognitionError);
  }

  @override
  Future<bool> initialize({
    List<String>? supportedLanguages,
  }) async {
    try {
      final List<String> languages =
          supportedLanguages ?? _defaultSupportedLanguages;

      // 检查是否需要重新初始化
      if (_isInitialized) {
        await dispose();
      }

      final bool result = await _channel.invokeMethod('initialize', {
        'subscriptionKey': _subscriptionKey,
        'region': _serviceRegion,
        'supportedLanguages': languages,
      });
      _setupEventChannel();

      _isInitialized = result;
      Logger.info('Azure 语音识别服务初始化${result ? '成功' : '失败'}');
      return result;
    } catch (e) {
      Logger.error('Azure 语音识别服务初始化失败: $e');
      _isInitialized = false;
      rethrow;
    }
  }

  @override
  Future<RecognitionEvent> recognizeOnce() async {
    if (!_isInitialized) {
      await initialize();
    }

    try {
      final result = await _channel.invokeMethod('recognizeOnce');

      if (result is Map) {
        final String text = result['text'] as String? ?? '';
        final String detectedLanguage =
            result['detectedLanguage'] as String? ?? '';
        _latestRecognizedText = text;
        _latestDetectedLanguage = detectedLanguage;

        return RecognitionEvent.finalResult(
          text: text,
          detectedLanguage: detectedLanguage,
        );
      } else if (result is String) {
        // 兼容旧版本
        _latestRecognizedText = result;
        return RecognitionEvent.finalResult(text: result);
      }

      throw Exception('无效的识别结果格式');
    } catch (e) {
      Logger.error('语音识别失败: $e');
      return RecognitionEvent.error(e.toString());
    }
  }

  @override
  Future<Stream<RecognitionEvent>> startContinuousRecognition() async {
    if (!_isInitialized) {
      await initialize();
    }

    if (_isContinuousRecognitionActive) {
      await stopContinuousRecognition();
    }

    try {
      _eventStreamController = StreamController<RecognitionEvent>.broadcast();

      // 开始连续识别
      final bool result =
          await _channel.invokeMethod('startContinuousRecognition');

      if (!result) {
        _cleanupEventStream();
        throw Exception('启动连续识别失败');
      }

      _isContinuousRecognitionActive = true;
      return _eventStreamController!.stream;
    } catch (e) {
      Logger.error('开始连续语音识别失败: $e');
      _cleanupEventStream();
      rethrow;
    }
  }

  @override
  Future<bool> stopContinuousRecognition() async {
    if (!_isInitialized || !_isContinuousRecognitionActive) {
      return true;
    }

    try {
      final bool result =
          await _channel.invokeMethod('stopContinuousRecognition');
      _cleanupEventStream();
      return result;
    } catch (e) {
      Logger.error('停止连续语音识别失败: $e');
      _cleanupEventStream();
      rethrow;
    }
  }

  @override
  bool isContinuousRecognitionActive() {
    return _isContinuousRecognitionActive;
  }

  /// 处理来自原生端的识别事件
  void _handleRecognitionEvent(dynamic event) {
    if (event is! Map || _eventStreamController == null) return;

    final Map<dynamic, dynamic> eventMap = event;
    final String eventType = eventMap['type'] as String? ?? '';

    // 添加日志帮助调试
    Logger.debug('收到语音识别事件: $eventType, 数据: $eventMap');

    switch (eventType) {
      case 'result':
        final String text = eventMap['text'] as String? ?? '';
        final String detectedLanguage =
            eventMap['detectedLanguage'] as String? ?? '';
        _latestRecognizedText = text;
        _latestDetectedLanguage = detectedLanguage;
        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.finalResult,
          text: text,
          detectedLanguage: detectedLanguage,
        ));
        break;

      case 'recognizing':
        final String text = eventMap['text'] as String? ?? '';
        final String detectedLanguage =
            eventMap['detectedLanguage'] as String? ?? '';
        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.intermediateResult,
          text: text,
          detectedLanguage: detectedLanguage,
        ));
        break;

      case 'sessionStarted':
        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.sessionStarted,
        ));
        break;

      case 'sessionStopped':
        _isContinuousRecognitionActive = false;
        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.sessionStopped,
        ));
        break;

      case 'canceled':
        _isContinuousRecognitionActive = false;
        final String reason = eventMap['reason'] as String? ?? '';
        final String errorDetails = eventMap['errorDetails'] as String? ?? '';

        if (reason.isNotEmpty || errorDetails.isNotEmpty) {
          Logger.error('识别取消: $reason - $errorDetails');
        }

        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.canceled,
          error: '$reason: $errorDetails',
        ));
        break;

      case 'error':
        final String error = eventMap['message'] as String? ?? '';
        Logger.error('识别错误: $error');
        _eventStreamController?.add(RecognitionEvent(
          type: RecognitionEventType.error,
          error: error,
        ));
        break;
    }
  }

  /// 处理识别事件流错误
  void _handleRecognitionError(Object error) {
    Logger.error('识别事件流错误: $error');
    _eventStreamController?.addError(error);
    _cleanupEventStream();
  }

  /// 清理事件流资源
  void _cleanupEventStream() {
    _eventStreamController?.close();
    _eventStreamController = null;
    _isContinuousRecognitionActive = false;
  }

  @override
  Future<void> dispose() async {
    try {
      if (_isContinuousRecognitionActive) {
        await stopContinuousRecognition();
      }

      // 取消事件订阅
      await _eventSubscription?.cancel();
      _eventSubscription = null;

      // 通知原生端释放资源
      await _channel.invokeMethod('dispose');
      _isInitialized = false;

      Logger.info('Azure 语音识别资源已释放');
    } catch (e) {
      Logger.error('释放语音识别资源失败: $e');
      _cleanupEventStream();
      _isInitialized = false;
    }
  }
}