语音消息功能实现

// 状态变量
final AudioRecorder _audioRecorder = AudioRecorder();
bool _isRecording = false;
String? _recordingPath;
DateTime? _recordingStartTime;
 
// 开始录音
Future<void> _startRecording() async {
  final status = await Permission.microphone.request();
  if (!status.isGranted) {
    showAppToast(context, '需要麦克风权限');
    return;
  }
  
  // 生成临时文件路径
  final dir = await getTemporaryDirectory();
  final timestamp = DateTime.now().millisecondsSinceEpoch;
  _recordingPath = '${dir.path}/voice_$timestamp.m4a';
  _recordingStartTime = DateTime.now();
  
  // 开始录音
  await _audioRecorder.start(
    const RecordConfig(
      encoder: AudioEncoder.aacLc,
      bitRate: 128000,
      sampleRate: 44100,
    ),
    path: _recordingPath!,
  );
  
  setState(() => _isRecording = true);
}
 
// 停止录音并发送
Future<void> _stopRecordingAndSend() async {
  if (!_isRecording) return;
  
  final path = await _audioRecorder.stop();
  final duration = DateTime.now().difference(_recordingStartTime!).inMilliseconds;
  
  setState(() => _isRecording = false);
  
  // 太短不发送
  if (duration < 500) {
    showAppToast(context, '录音太短');
    return;
  }
  
  if (path != null) {
    await _sendVoiceMessage(path, duration);
  }
}

Future<void> _sendVoiceMessage(String filePath, int durationMs) async {
  final appState = context.read<AppState>();
  final tempId = const Uuid().v4();
  final now = DateTime.now();
  final fileName = 'voice_${now.millisecondsSinceEpoch}.m4a';
  
  // 1. 创建临时消息（乐观更新）
  final tempMessage = SendMessage(
    id: tempId,
    type: SendMessageType.voice,
    duration: durationMs,
    createdAt: now,
  );
  
  setState(() {
    _messages.add(tempMessage);
    _pendingMessageIds.add(tempId);
  });
  _scrollToBottom();
  
  // 2. 复用文件上传
  final result = await appState.api.uploadByPath(
    filePath: filePath,
    fileName: fileName,
    remotePath: '/录音/$fileName',
    skipMetadata: true,  // 语音不需要提取元数据
  );
  
  if (!result.isSuccess) {
    _markMessageFailed(tempId, tempMessage);
    return;
  }
  
  // 3. 轮询上传进度
  final taskId = result.data!.taskId;
  while (true) {
    final progress = await appState.api.getUploadProgress(taskId);
    if (!progress.isSuccess) break;
    
    if (progress.data!.isDone) {
      if (progress.data!.fileId != null) {
        // 4. 上传完成，发送消息
        await appState.api.addSendMessage(
          sessionId: widget.session.id,
          type: 'voice',
          fileId: progress.data!.fileId,
          duration: durationMs,
        );
        
        _pendingMessageIds.remove(tempId);
        _refreshMessages();
        return;
      }
      break;
    }
    
    await Future.delayed(const Duration(milliseconds: 500));
  }
  
  _markMessageFailed(tempId, tempMessage);
}

Widget _buildVoiceContent(SendMessage message) {
  final isPlaying = _playingMessageId == message.id;
  final durationMs = message.duration ?? 0;
  final durationSec = (durationMs / 1000).ceil();
  
  return GestureDetector(
    onTap: () => _playVoice(message),
    child: Container(
      constraints: const BoxConstraints(minWidth: 100, maxWidth: 200),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          // 播放/暂停按钮
          Container(
            width: 36,
            height: 36,
            decoration: BoxDecoration(
              color: Colors.white.withAlpha(50),
              shape: BoxShape.circle,
            ),
            child: Icon(
              isPlaying ? Icons.pause : Icons.play_arrow,
              color: Colors.white,
              size: 24,
            ),
          ),
          const SizedBox(width: 8),
          // 时长显示
          Text(
            '$durationSec"',
            style: const TextStyle(color: Colors.white, fontSize: 14),
          ),
          const SizedBox(width: 8),
          // 音频波形图标
          Icon(
            Icons.graphic_eq,
            color: Colors.white.withAlpha(180),
            size: 20,
          ),
        ],
      ),
    ),
  );
}

final AudioPlayer _audioPlayer = AudioPlayer();
String? _playingMessageId;
 
Future<void> _playVoice(SendMessage message) async {
  if (message.fileId == null) return;
  
  final appState = context.read<AppState>();
  
  // 如果正在播放同一条，停止播放
  if (_playingMessageId == message.id) {
    await _audioPlayer.stop();
    setState(() => _playingMessageId = null);
    return;
  }
  
  // 停止当前播放
  await _audioPlayer.stop();
  
  try {
    // 获取流式播放 URL 和请求头（包含 token）
    final streamUrl = appState.api.getStreamUrl(message.fileId!);
    final headers = appState.api.getStreamHeaders();
    
    setState(() => _playingMessageId = message.id);
    
    // 使用 AudioSource.uri 支持请求头
    await _audioPlayer.setAudioSource(
      AudioSource.uri(
        Uri.parse(streamUrl),
        headers: headers,
      ),
    );
    _audioPlayer.play();
    
    // 监听播放完成
    _audioPlayer.playerStateStream.listen((state) {
      if (state.processingState == ProcessingState.completed) {
        if (mounted) setState(() => _playingMessageId = null);
      }
    });
  } catch (e) {
    setState(() => _playingMessageId = null);
    showAppToast(context, '播放失败: $e');
  }
}

// 在输入区域，加号按钮后面
const SizedBox(width: 8),
// 麦克风按钮 - 按住录音
GestureDetector(
  onLongPressStart: (_) => _startRecording(),
  onLongPressEnd: (_) => _stopRecordingAndSend(),
  onLongPressCancel: () => _cancelRecording(),
  child: AnimatedContainer(
    duration: const Duration(milliseconds: 200),
    width: plusButtonSize,
    height: plusButtonSize,
    decoration: BoxDecoration(
      color: _isRecording ? Colors.red : overlayColor,
      shape: BoxShape.circle,
    ),
    child: Center(
      child: Icon(
        _isRecording ? Icons.stop : Icons.mic,
        color: Colors.white,
        size: 20,
      ),
    ),
  ),
),

// addSendMessage 请求验证
if req.Type != "text" && req.Type != "file" && req.Type != "voice" {
    c.JSON(http.StatusBadRequest, gin.H{"error": "type must be 'text', 'file' or 'voice'"})
    return
}

// 更新会话预览
if req.Type == "voice" {
    session.LastMessagePreview = "[语音]"
}

await _audioPlayer.setAudioSource(
  AudioSource.uri(Uri.parse(streamUrl), headers: headers),
);