import 'dart:collection';
import 'dart:typed_data';

import 'package:star_lock/app_settings/app_settings.dart';
import '../../proto/talk_data_h264_frame.pb.dart';

class H264FrameHandler {
  final LinkedHashMap<int, TalkDataH264Frame> _frameBuffer = LinkedHashMap();
  final void Function(List<int> frameData) onCompleteFrame;

  final LinkedHashMap<int, TalkDataH264Frame_FrameTypeE> _frameTypeIndex = LinkedHashMap();

  H264FrameHandler({required this.onCompleteFrame});

  void handleFrame(TalkDataH264Frame frame) {
    // 存储帧
    _frameBuffer[frame.frameSeq] = frame;
    _frameTypeIndex[frame.frameSeq] = frame.frameType;

    // 检查是否可以组装完整的 GOP (Group of Pictures)
    _tryAssembleFrames(frame.frameSeq);
  }

  void _tryAssembleFrames(int currentSeq) {
    final List<int> framesToProcess = [];
    int? startFrameSeq;

    // 从当前帧开始向前找到最近的 I 帧或 P 帧
    for (int seq = currentSeq; seq >= 0; seq--) {
      final frameType = _frameTypeIndex[seq];
      if (frameType == null) continue;
      if (frameType == TalkDataH264Frame_FrameTypeE.I) {
        startFrameSeq = seq;
        break;
      } else if (frameType == TalkDataH264Frame_FrameTypeE.P) {
        if (_frameBuffer.containsKey(_frameBuffer[seq]!.frameSeqI)) {
          startFrameSeq = seq;
          break;
        } else {
          _frameBuffer.remove(seq);
          _frameTypeIndex.remove(seq);
        }
      }
    }

    if (startFrameSeq != null) {
      for (int seq = startFrameSeq; _frameBuffer.containsKey(seq); seq++) {
        framesToProcess.add(seq);
      }

      if (framesToProcess.isNotEmpty) {
        _processFrames(framesToProcess);
      }
    } else {
      _clearOldFrames(currentSeq);
    }
  }

  void _processFrames(List<int> frameSeqs) {
    // 按顺序组装帧数据
    // final List<int> assembledData = [];
    //
    // for (var seq in frameSeqs) {
    //   final frame = _frameBuffer[seq]!;
    //   assembledData.addAll(frame.frameData);
    //
    //   // 处理完后从缓冲区移除
    //   _frameBuffer.remove(seq);
    // }
    //
    // // 回调完整的帧数据
    // onCompleteFrame(assembledData);
    // Calculate the total length of the assembled data
    int totalLength = frameSeqs.fold(
        0, (sum, seq) => sum + _frameBuffer[seq]!.frameData.length);

    // Allocate a buffer for the assembled data
    final assembledData = Uint8List(totalLength);
    int offset = 0;

    for (var seq in frameSeqs) {
      final frame = _frameBuffer[seq]!;
      assembledData.setRange(
          offset, offset + frame.frameData.length, frame.frameData);
      offset += frame.frameData.length;

      // Remove the frame from the buffer after processing
      _frameBuffer.remove(seq);
      _frameTypeIndex.remove(seq);
    }

    // Callback with the complete frame data
    onCompleteFrame(assembledData);
  }

  void clear() {
    _frameBuffer.clear();
  }

  void _clearOldFrames(int currentSeq) {
    // 清理比当前帧序列旧的帧
    _frameBuffer.removeWhere((seq, frame) => seq < currentSeq - 200); // 调整阈值
    _frameTypeIndex.removeWhere((seq, frameType) => seq < currentSeq - 200);
  }
}