deepvoice_client/lib/modules/opus_test/controllers/opus_test_controller.dart

import 'dart:async';
import 'dart:io';
import 'dart:typed_data';
import 'package:file_picker/file_picker.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:path_provider/path_provider.dart';
import 'package:just_audio/just_audio.dart';
import 'package:jl_opus/jl_opus.dart';
import 'package:permission_handler/permission_handler.dart';

class OpusTestController extends GetxController {
  // 选中的文件
  final selectedFiles = <PlatformFile>[].obs;

  // 扫描到的外部存储文件
  final externalFiles = <PlatformFile>[].obs;
  // 是否携带协议头
  final hasHeader = false.obs;

  // 数据包长度
  final packetLength = '80'.obs;

  // 采样率选项
  final sampleRateOptions = [8000, 16000, 24000, 32000, 44100, 48000];
  final selectedSampleRate = 16000.obs;

  // 通道数量
  final isMono = true.obs;

  // 播放状态
  final isPlaying = false.obs;
  final isDecoding = false.obs;
  final statusMessage = ''.obs;

  // 播放器
  final player = AudioPlayer();

  // 临时文件路径
  String? tempPcmPath;

  // 杰理OPUS解码器
  late JlOpus jlOpus;
  StreamSubscription? _eventSubscription;

  @override
  void onInit() {
    super.onInit();
    requestPermissions();
    _initOpusDecoder();
  }

  @override
  void onClose() {
    player.dispose();
    _eventSubscription?.cancel();
    jlOpus.dispose();
    super.onClose();
  }

  // 初始化OPUS解码器
  Future<void> _initOpusDecoder() async {
    jlOpus = JlOpus();

    // 监听解码器事件
    _eventSubscription = jlOpus.eventStream.listen((event) {
      switch (event.event) {
        case 'onStart':
          statusMessage.value = '开始${event.type == "file" ? "文件" : "流"}解码...';
          break;
        case 'onComplete':
          if (event.type == 'file') {
            statusMessage.value = '解码完成: ${event.filePath}';
          } else {
            statusMessage.value = '流解码完成';
          }
          break;
        case 'onError':
          statusMessage.value =
              '解码错误: [${event.errorCode}] ${event.errorMessage}';
          isDecoding.value = false;
          break;
      }
    });

    // 初始化OPUS解码器
    final initialized = await jlOpus.initOpusDecoder();
    if (!initialized) {
      statusMessage.value = 'OPUS解码器初始化失败';
    }
  }

  // 请求必要权限
  Future<void> requestPermissions() async {
    if (Platform.isAndroid) {
      await Permission.storage.request();
    }
  }

  // 加载外部存储文件
  Future<void> loadExternalFiles() async {
    try {
      externalFiles.clear();
      statusMessage.value = '正在扫描外部存储...';

      // 获取外部存储目录
      final directories = await getExternalStorageDirectories();
      if (directories == null || directories.isEmpty) {
        statusMessage.value = '未找到外部存储目录';
        return;
      }

      // 遍历所有外部存储目录
      for (final directory in directories) {
        final dirPath = directory.path;
        final dir = Directory(dirPath);

        // 检查目录是否存在
        if (await dir.exists()) {
          // 递归列出所有文件
          final files = await dir.list(recursive: true).toList();

          for (var entity in files) {
            if (entity is File) {
              final path = entity.path.toLowerCase();
              if (path.endsWith('.opus')) {
                final fileSize = await entity.length();
                externalFiles.add(PlatformFile(
                  name: entity.path.split('/').last,
                  path: entity.path,
                  size: fileSize,
                ));
              }
            }
          }
        }
      }

      statusMessage.value = '扫描完成，找到 ${externalFiles.length} 个Opus文件';
    } catch (e) {
      statusMessage.value = '扫描失败: $e';
    }
  }

  // 选择文件
  Future<void> pickFiles() async {
    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: ['opus'],
        allowMultiple: false,
      );

      if (result != null && result.files.isNotEmpty) {
        selectedFiles.clear();
        selectedFiles.add(result.files.first);
        statusMessage.value = '已选择文件：${result.files.first.name}';
      }
    } catch (e) {
      statusMessage.value = '选择文件失败: $e';
    }
  }

  // 从外部文件列表中选择文件
  void selectExternalFile(PlatformFile file) {
    selectedFiles.clear();
    selectedFiles.add(file);
    statusMessage.value = '已选择文件: ${file.name}';
  }

  // 切换通道模式
  void toggleChannel(bool isSingleChannel) {
    isMono.value = isSingleChannel;
  }

  // 设置采样率
  void setSampleRate(int rate) {
    selectedSampleRate.value = rate;
  }

  // 设置数据包长度
  void setPacketLength(String length) {
    packetLength.value = length;
  }

  // 切换是否携带协议头
  void toggleHeader(bool value) {
    hasHeader.value = value;
  }

  // 播放音频
  Future<void> playAudio() async {
    if (isPlaying.value) {
      await player.stop();
      isPlaying.value = false;
      statusMessage.value = '已停止播放';
      return;
    }

    if (selectedFiles.isEmpty) {
      statusMessage.value = '请先选择Opus文件';
      return;
    }

    try {
      isDecoding.value = true;
      statusMessage.value = '正在解码...';

      // 使用杰理OPUS库进行解码
      final inPath = selectedFiles.first.path!;

      // 创建WAV输出文件路径
      final tempDir = await getTemporaryDirectory();
      final wavFileName =
          'decoded_opus_${DateTime.now().millisecondsSinceEpoch}.wav';
      final outPath = '${tempDir.path}/$wavFileName';

      // 创建解码参数
      final option = OpusOption(
        hasHeader: hasHeader.value,
        channel: isMono.value ? 1 : 2,
        sampleRate: selectedSampleRate.value,
        packetSize: int.tryParse(packetLength.value) ?? 40,
      );

      // 解码文件
      final pcmPath = await jlOpus.decodeOpusFile(inPath, outPath, option);
      if (pcmPath == null) {
        statusMessage.value = '解码失败';
        isDecoding.value = false;
        return;
      }

      tempPcmPath = pcmPath;

      // 将PCM文件转换为WAV文件
      final wavFile = await _convertPcmToWav(
          pcmPath,
          '${tempDir.path}/$wavFileName',
          selectedSampleRate.value,
          isMono.value ? 1 : 2);

      statusMessage.value = '解码完成，准备播放';

      // 播放WAV文件
      await player.setFilePath(wavFile.path);
      await player.play();
      isPlaying.value = true;
      statusMessage.value = '正在播放解码后的音频';

      // 监听播放完成
      player.playerStateStream.listen((state) {
        if (state.processingState == ProcessingState.completed) {
          isPlaying.value = false;
          statusMessage.value = '播放完成';
        }
      });
    } catch (e) {
      statusMessage.value = '解码或播放失败: $e';
    } finally {
      isDecoding.value = false;
    }
  }

  // 将PCM转换为WAV格式
  Future<File> _convertPcmToWav(
      String pcmPath, String wavPath, int sampleRate, int channels) async {
    final pcmFile = File(pcmPath);
    final pcmData = await pcmFile.readAsBytes();

    // 创建WAV文件 (44字节头部 + PCM数据)
    final wavSize = 44 + pcmData.length;
    final wavData = ByteData(wavSize);

    // 写入WAV头部
    _writeWavHeader(wavData, pcmData.length, sampleRate, channels);

    // 写入PCM数据
    for (int i = 0; i < pcmData.length; i++) {
      wavData.setUint8(44 + i, pcmData[i]);
    }

    // 保存为WAV文件
    final wavFile = File(wavPath);
    await wavFile.writeAsBytes(wavData.buffer.asUint8List());

    return wavFile;
  }

  // 写入WAV头部到ByteData
  void _writeWavHeader(
      ByteData data, int pcmLength, int sampleRate, int channels) {
    final bytesPerSample = 2; // 16位PCM
    final byteRate = sampleRate * channels * bytesPerSample;
    final blockAlign = channels * bytesPerSample;

    // "RIFF"标识
    data.setUint8(0, 0x52); // 'R'
    data.setUint8(1, 0x49); // 'I'
    data.setUint8(2, 0x46); // 'F'
    data.setUint8(3, 0x46); // 'F'

    // 文件大小 (减去8个字节的RIFF头部和大小字段)
    data.setUint32(4, 36 + pcmLength, Endian.little);

    // "WAVE"标识
    data.setUint8(8, 0x57); // 'W'
    data.setUint8(9, 0x41); // 'A'
    data.setUint8(10, 0x56); // 'V'
    data.setUint8(11, 0x45); // 'E'

    // "fmt "子块
    data.setUint8(12, 0x66); // 'f'
    data.setUint8(13, 0x6D); // 'm'
    data.setUint8(14, 0x74); // 't'
    data.setUint8(15, 0x20); // ' '

    // 子块大小 (16 for PCM)
    data.setUint32(16, 16, Endian.little);

    // 音频格式 (1 表示PCM)
    data.setUint16(20, 1, Endian.little);

    // 通道数量
    data.setUint16(22, channels, Endian.little);

    // 采样率
    data.setUint32(24, sampleRate, Endian.little);

    // 字节率 = 采样率 * 通道数 * 每样本字节数
    data.setUint32(28, byteRate, Endian.little);

    // 块对齐 = 通道数 * 每样本字节数
    data.setUint16(32, blockAlign, Endian.little);

    // 每个样本位数
    data.setUint16(34, bytesPerSample * 8, Endian.little);

    // "data"子块
    data.setUint8(36, 0x64); // 'd'
    data.setUint8(37, 0x61); // 'a'
    data.setUint8(38, 0x74); // 't'
    data.setUint8(39, 0x61); // 'a'

    // 数据大小
    data.setUint32(40, pcmLength, Endian.little);
  }
}

// PCM音频源
class PCMAudioSource extends StreamAudioSource {
  final Uint8List pcmData;
  final int sampleRate;
  final int channels;

  PCMAudioSource({
    required this.pcmData,
    this.sampleRate = 16000,
    this.channels = 1,
  });

  @override
  Future<StreamAudioResponse> request([int? start, int? end]) async {
    start = start ?? 0;
    end = end ?? pcmData.length;

    // 转换PCM到WAV格式
    final wavHeader = _createWavHeader(pcmData.length, sampleRate, channels);
    final wavData = Uint8List(wavHeader.length + pcmData.length);
    wavData.setRange(0, wavHeader.length, wavHeader);
    wavData.setRange(
        wavHeader.length, wavHeader.length + pcmData.length, pcmData);

    // 调整请求范围来适应WAV头部
    int adjustedStart = start;
    int adjustedEnd = end;

    if (start < wavHeader.length) {
      adjustedStart = start;
    } else {
      adjustedStart = start + wavHeader.length;
    }

    if (end <= wavHeader.length) {
      adjustedEnd = end;
    } else {
      adjustedEnd = end + wavHeader.length;
      adjustedEnd = adjustedEnd > wavData.length ? wavData.length : adjustedEnd;
    }

    return StreamAudioResponse(
      sourceLength: wavData.length,
      contentLength: adjustedEnd - adjustedStart,
      offset: adjustedStart,
      stream: Stream.value(wavData.sublist(adjustedStart, adjustedEnd)),
      contentType: 'audio/wav',
    );
  }

  // 创建WAV头部
  Uint8List _createWavHeader(int dataLength, int sampleRate, int channels) {
    final bytesPerSample = 2; // 16位PCM
    final byteRate = sampleRate * channels * bytesPerSample;
    final blockAlign = channels * bytesPerSample;

    final header = ByteData(44); // WAV头部固定44字节

    // "RIFF"标识
    header.setUint8(0, 0x52); // 'R'
    header.setUint8(1, 0x49); // 'I'
    header.setUint8(2, 0x46); // 'F'
    header.setUint8(3, 0x46); // 'F'

    // 文件大小 (减去8个字节的RIFF头部和大小字段)
    header.setUint32(4, 36 + dataLength, Endian.little);

    // "WAVE"标识
    header.setUint8(8, 0x57); // 'W'
    header.setUint8(9, 0x41); // 'A'
    header.setUint8(10, 0x56); // 'V'
    header.setUint8(11, 0x45); // 'E'

    // "fmt "子块
    header.setUint8(12, 0x66); // 'f'
    header.setUint8(13, 0x6D); // 'm'
    header.setUint8(14, 0x74); // 't'
    header.setUint8(15, 0x20); // ' '

    // 子块大小 (16 for PCM)
    header.setUint32(16, 16, Endian.little);

    // 音频格式 (1 表示PCM)
    header.setUint16(20, 1, Endian.little);

    // 通道数量
    header.setUint16(22, channels, Endian.little);

    // 采样率
    header.setUint32(24, sampleRate, Endian.little);

    // 字节率 = 采样率 * 通道数 * 每样本字节数
    header.setUint32(28, byteRate, Endian.little);

    // 块对齐 = 通道数 * 每样本字节数
    header.setUint16(32, blockAlign, Endian.little);

    // 每个样本位数
    header.setUint16(34, bytesPerSample * 8, Endian.little);

    // "data"子块
    header.setUint8(36, 0x64); // 'd'
    header.setUint8(37, 0x61); // 'a'
    header.setUint8(38, 0x74); // 't'
    header.setUint8(39, 0x61); // 'a'

    // 数据大小
    header.setUint32(40, dataLength, Endian.little);

    return header.buffer.asUint8List();
  }
}