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

import 'dart:async';
import 'dart:convert';
import 'dart:typed_data';
import 'package:crypto/crypto.dart';
import 'package:record/record.dart';
import 'package:web_socket_channel/web_socket_channel.dart';
import '../../../core/utils/logger.dart';
import 'package:get/get.dart';
import '../asr_service.dart';

/// 讯飞 语音识别服务
///
class XunfeiAsrService extends GetxService implements AsrService {
  final String baseUrl = 'wss://rtasr.xfyun.cn/v1/ws';
  final int _chunkSize = 1280; // 每次发送的数据大小

  final String appId = '43d87d22';
  final String apiKey = '83f063755e8d342670002f50a4471d42';

  AudioRecorder? recorder;
  Timer? _timer;

  WebSocketChannel? _channel;
  bool isConnected = false; //是否链接

  bool _isInitialized = false;

  final List<String> _defaultSupportedLanguages = ['zh-CN'];
  String _languageStr = 'cn';

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

  @override
  List<String> get supportedLanguages => _defaultSupportedLanguages;

  Uint8List _buff = Uint8List(0); //音频缓存区
  BytesBuilder _originaBytes = BytesBuilder(); //原始音频
  bool isRecording = false;

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

      String languagetoStr = languages.first.split('-')[1].toLowerCase();
      _languageStr = languagetoStr;

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

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

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

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

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

      await recorder?.dispose();
      recorder = AudioRecorder();
      Stream<Uint8List>? stream = await recorder?.startStream(
        const RecordConfig(
          sampleRate: 16000,
          encoder: AudioEncoder.pcm16bits,
          numChannels: 1,
        ),
      );
      isRecording = true;
      stream?.listen((data) {
        if (isRecording) {
          _buff = _appendToBuffer(data);
          _originaBytes.add(data);
        }
      });
      await _tryConnecting();
      _timer = Timer.periodic(const Duration(milliseconds: 40), (timer) async {
        //每40毫秒读取一次数据
        var frame = _getAudioData();
        if (frame.isNotEmpty) {
          _channel?.sink.add(frame);
        }
      });

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

  //写入音频数据到缓存区中
  Uint8List _appendToBuffer(Uint8List newData) {
    var newBuffer = Uint8List(_buff.length + newData.length);
    newBuffer.setAll(0, _buff);
    newBuffer.setAll(_buff.length, newData);
    return newBuffer;
  }

  //读取缓存区中一帧数据
  Uint8List _getAudioData() {
    if (_buff.length >= _chunkSize) {
      // 从缓冲区中读取1280字节的数据
      var data = _buff.sublist(0, _chunkSize);
      // 移除已读取的数据
      _buff = _buff.sublist(_chunkSize);
      return data;
    } else {
      return _buff;
    }
  }

  //尝试连接
  Future<void> _tryConnecting() async {
    try {
      final url = _geturl();
      _channel = WebSocketChannel.connect(Uri.parse(url));
      _channel?.stream.timeout(const Duration(seconds: 10)); //设置超时时间
      await _channel?.ready;
      isConnected = true;
      _channel?.stream.listen(
        (message) {
          _handle(message);
        },
        onError: (error) {
          isConnected = false;
          Logger.error('连接失败: ${error.toString()}');
        },
        onDone: () {
          isConnected = false;
          Logger.error('WebSocket 连接已关闭!');
        },
        cancelOnError: true,
      );
    } catch (e) {
      Logger.error("初始化异常----------------${e.toString()}");
    }
  }

  //处理数据
  void _handle(data) {
    try {
      final result = jsonDecode(data);
      if (result['code'] == "0" && result['data'] != "") {
        final data = jsonDecode(result['data']);
        String msg = "";
        String role = '';

        List rtList = data['cn']['st']['rt'];
        for (var rt in rtList) {
          for (var ws in rt['ws']) {
            for (var ws in ws['cw']) {
              msg += ws['w'];
              if (ws['rl'] != "0") {
                role = ws['rl'];
              }
            }
          }
        }
        Logger.info(
            "识别到的内容 type:${data['cn']['st']['type']} msg:$msg rl:$role");
        if (msg.isNotEmpty) {
          if (data['cn']['st']['type'] == "0") {
            _eventStreamController?.add(RecognitionEvent(
              type: RecognitionEventType.finalResult,
              text: msg,
              role: role,
              audio: _originaBytes.toBytes(),
            ));
            _originaBytes.clear();
          } else {
            _eventStreamController?.add(RecognitionEvent(
              type: RecognitionEventType.intermediateResult,
              text: msg,
              role: role,
            ));
          }
        }
      }
    } catch (e) {
      Logger.error("接受消息异常 ${e.toString()}");
    }
  }

  ///获取链接地址
  String _geturl() {
    // 生成时间戳
    String ts = (DateTime.now().millisecondsSinceEpoch ~/ 1000).toString();
    // 计算 baseString
    String baseString = md5.convert(utf8.encode(appId + ts)).toString();
    // 计算 signa
    var hmacSha1 = Hmac(sha1, utf8.encode(apiKey));
    var signa = hmacSha1.convert(utf8.encode(baseString));
    String signaBase64 = base64Encode(signa.bytes);
    String url = "";
    // 构建 WebSocket URL
    url =
        '$baseUrl?appid=$appId&ts=$ts&lang=$_languageStr&roleType=2&signa=${Uri.encodeComponent(signaBase64)}';
    return url;
  }

  @override
  Future<bool> stopContinuousRecognition() async {
    try {
      await recorder?.stop();
      isRecording = false;
      _timer?.cancel();
      _buff = Uint8List(0);
      _originaBytes = BytesBuilder();
      if (isConnected) {
        _channel?.sink.add(utf8.encode('{"end": true}')); //结束
      }

      _isContinuousRecognitionActive = false;
      return true;
    } catch (e) {
      Logger.error('停止连续语音识别失败: ${e.toString()}');
      rethrow;
    }
  }

  @override
  bool isContinuousRecognitionActive() {
    return _isContinuousRecognitionActive;
  }

  @override
  Future<void> dispose() async {
    try {
      await stopContinuousRecognition();
      recorder?.dispose();
      _channel?.sink.close();

      _eventStreamController?.close();
      _eventStreamController = null;

      _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.toString()}');
      _isInitialized = false;
    }
  }

  @override
  Future<bool> enableRecord(String filePath) {
    // TODO: implement enableRecord
    throw UnimplementedError();
  }

  @override
  Future<bool> stopRecord(bool isSave) {
    // TODO: implement stopRecord
    throw UnimplementedError();
  }

  @override
  Future<bool> pauseRecord() {
    // TODO: implement pauseRecord
    throw UnimplementedError();
  }

  @override
  Future<bool> moveFile(String sourcePath, String destPath) {
    // TODO: implement moveFile
    throw UnimplementedError();
  }

  @override
  Future<bool> renameFile(String filePath, String newName) {
    // TODO: implement renameFile
    throw UnimplementedError();
  }
}