liangchengyou / wow_english

import 'dart:async';

import 'package:common_utils/common_utils.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:video_player/video_player.dart';
import 'package:wow_english/common/extension/string_extension.dart';
import 'package:wow_english/common/utils/video_playback_diagnostics.dart';
import 'package:wow_english/common/utils/video_rendering_preference.dart';
import 'package:wow_english/pages/video/lookvideo/bloc/look_video_bloc.dart';
import 'package:wow_english/route/route.dart';

import '../../../section/subsection/base_section/event.dart';
import '../../../section/subsection/base_section/state.dart';
import 'video_opera_widget.dart';

class VideoWidget extends StatefulWidget {
  const VideoWidget(
      {super.key,
      this.videoUrl = '',
      this.typeTitle,
      this.courseLessonId = '',
      this.isTopic = false});

  final String videoUrl;
  final String? typeTitle;
  final String courseLessonId;
  final bool isTopic;

  @override
  State<StatefulWidget> createState() {
    return _VideoWidgetState();
  }
}

class _VideoWidgetState extends State<VideoWidget> {
  VideoPlayerController? _controller;
  String _currentTime = '00:00';
  String _totalTime = '00:00';
  double _playDegree = 0.0;
  bool _hiddenTipView = false;
  Object? _loadError;
  Timer? _bufferingTimer;
  int _loadGeneration = 0;
  VoidCallback? _diagnosticListener;
  bool _bufferingWarningShown = false;
  TimerUtil? timerUtil;

  String formatDuration(Duration duration) {
    String hours = duration.inHours.toString().padLeft(2, '0');
    String minutes =
        duration.inMinutes.remainder(60).toString().padLeft(2, '0');
    String seconds =
        duration.inSeconds.remainder(60).toString().padLeft(2, '0');
    return "$hours:$minutes:$seconds";
  }

  void _addListener() {
    _controller!.addListener(() {
      if (_controller!.value.isInitialized) {
        if (_controller!.value.isPlaying) {
          setState(() {
            double currentSecond = getCurrentPositionSeconds().toDouble();
            int totalSecond =
                _controller!.value.duration.inMinutes.remainder(60) * 60 +
                    _controller!.value.duration.inSeconds.remainder(60);
            _currentTime = formatDuration(_controller!.value.position);
            _playDegree = currentSecond / totalSecond;
            if (_playDegree > 1.0) {
              _playDegree = 1.0;
            }
            if (_playDegree < 0) {
              _playDegree = 0.0;
            }
          });
        } else if (widget.isTopic &&
            //受限于video_player库没有唯一的播放完成状态标识，发现isBuffering=false的时候暂时是安全唯一的
            _controller?.value.isBuffering == false &&
            _controller!.value.isCompleted &&
            _controller!.value.position.inSeconds ==
                _controller!.value.duration.inSeconds) {
          final lookVideoBloc = context.read<LookVideoBloc>();
          lookVideoBloc.sectionComplete(
              () {
                popPage(data: {
                  'courseLessonId': widget.courseLessonId,
                  'currentTime': getCurrentPositionSeconds(),
                  'isCompleted': true,
                  'nextSection': widget.isTopic
                });
              } as VoidCallback, againSectionTap: (() {
            if (mounted && !lookVideoBloc.isClosed) {
              lookVideoBloc.add(SectionAgainEvent());
            }
          }), context: context);
        }
      }
    });
  }

  //开始倒计时
  void startTimer() {
    if (timerUtil == null) {
      timerUtil = TimerUtil(mInterval: 1000, mTotalTime: 1000 * 10);
      timerUtil!.setOnTimerTickCallback((int tick) {
        double currentTick = tick / 1000;
        if (currentTick.toInt() == 0) {
          //倒计时结束
          setState(() {
            _hiddenTipView = true;
          });
          timerUtil!.cancel();
          timerUtil = null;
        }
      });
      timerUtil!.startCountDown();
    }
  }

  //取消倒计时
  void cancelTimer() {
    timerUtil!.cancel();
    timerUtil = null;
  }

  void actionType(OperationType type) async {
    if (type == OperationType.back) {
      if (widget.courseLessonId.isEmpty) {
        popPage();
      } else {
        if (_controller == null) {
          popPage();
          return;
        }
        popPage(data: {
          'courseLessonId': widget.courseLessonId,
          'currentTime': getCurrentPositionSeconds(),
        });
      }
    } else if (type == OperationType.playState) {
      if (_controller!.value.isPlaying) {
        _controller!.pause();
      } else {
        _controller!.play();
      }
      setState(() {});
    }
  }

  @override
  void initState() {
    super.initState();
    unawaited(_initializeVideo());
  }

  Future<void> _initializeVideo() async {
    final generation = ++_loadGeneration;
    _bufferingTimer?.cancel();
    _bufferingWarningShown = false;
    final oldController = _controller;
    if (oldController != null) {
      if (_diagnosticListener != null) {
        oldController.removeListener(_diagnosticListener!);
      }
    }
    _diagnosticListener = null;
    _controller = null;
    _loadError = null;
    if (oldController != null) {
      await VideoPlaybackDiagnostics.disposeController(
        oldController,
        context: '课程视频切换',
      );
    }
    if (!mounted || generation != _loadGeneration) return;
    final url = widget.videoUrl.trim();
    if (url.isEmpty) {
      _loadError = StateError('课程视频地址为空');
      VideoPlaybackDiagnostics.show('课程视频地址为空');
      if (mounted) setState(() {});
      return;
    }
    final controller = VideoPlayerController.networkUrl(
      Uri.parse(url),
      viewType: VideoRenderingPreference.viewType,
    );
    _controller = controller;
    if (mounted) setState(() {});
    var stage = '视频初始化';
    try {
      await controller
          .initialize()
          .timeout(VideoPlaybackDiagnostics.initializeTimeout);
      if (!mounted ||
          generation != _loadGeneration ||
          controller != _controller) {
        await controller.dispose();
        return;
      }
      stage = '播放器配置';
      await controller
          .setLooping(!widget.isTopic)
          .timeout(VideoPlaybackDiagnostics.commandTimeout);
      await controller
          .setVolume(1)
          .timeout(VideoPlaybackDiagnostics.commandTimeout);
      _addListener();
      _diagnosticListener = _onDiagnosticChanged;
      controller.addListener(_diagnosticListener!);
      _updateBufferingWatch(controller);
      await controller.play().timeout(VideoPlaybackDiagnostics.commandTimeout);
      if (!mounted || generation != _loadGeneration) return;
      startTimer();
      setState(() {
        _currentTime = formatDuration(controller.value.position);
        _totalTime = formatDuration(controller.value.duration);
      });
    } catch (error) {
      final failedCurrentController = controller == _controller;
      if (failedCurrentController) {
        _bufferingTimer?.cancel();
        _bufferingTimer = null;
        controller.removeListener(_diagnosticListener ?? _onDiagnosticChanged);
      }
      await VideoPlaybackDiagnostics.disposeController(
        controller,
        context: '课程视频初始化失败($stage)',
      );
      if (!mounted ||
          generation != _loadGeneration ||
          !failedCurrentController) {
        return;
      }
      _controller = null;
      final message = VideoPlaybackDiagnostics.messageFor(error, stage: stage);
      debugPrint('课程视频加载失败(stage=$stage): $error');
      VideoPlaybackDiagnostics.show(message);
      setState(() => _loadError = error);
    }
  }

  void _onDiagnosticChanged() {
    final controller = _controller;
    if (!mounted || controller == null) return;
    _updateBufferingWatch(controller);
    if (controller.value.hasError && _loadError == null) {
      final error = controller.value.errorDescription ?? '未知播放器错误';
      debugPrint('课程视频播放失败: $error');
      VideoPlaybackDiagnostics.show(
        VideoPlaybackDiagnostics.messageFor(error, stage: '视频播放/解码'),
      );
      setState(() => _loadError = error);
    }
  }

  void _updateBufferingWatch(VideoPlayerController controller) {
    if (!controller.value.isBuffering) {
      _bufferingTimer?.cancel();
      _bufferingTimer = null;
      _bufferingWarningShown = false;
      return;
    }
    if (_bufferingTimer != null || _bufferingWarningShown) return;
    _bufferingTimer = Timer(VideoPlaybackDiagnostics.bufferingWarningDelay, () {
      _bufferingTimer = null;
      if (!mounted ||
          controller != _controller ||
          !controller.value.isBuffering) {
        return;
      }
      _bufferingWarningShown = true;
      final error = controller.value.errorDescription;
      final message = error == null
          ? '视频持续缓冲，网络或设备解码可能异常'
          : VideoPlaybackDiagnostics.messageFor(error, stage: '视频播放/解码');
      debugPrint('课程视频持续缓冲: $message ${error ?? ''}');
      VideoPlaybackDiagnostics.show(message);
    });
  }

  @override
  Widget build(BuildContext context) {
    return BlocListener<LookVideoBloc, BaseSectionState>(
      listener: (context, state) async {
        if (state is SectionAgainState) {
          final controller = _controller;
          if (controller?.value.isInitialized == true) {
            await controller!.seekTo(Duration.zero);
            await controller.play();
          }
        }
      },
      child: GestureDetector(
        onTap: () {
          if (_loadError != null || _controller?.value.isInitialized != true) {
            return;
          }
          setState(() {
            _hiddenTipView = !_hiddenTipView;
            if (!_hiddenTipView) {
              startTimer();
            } else {
              if (timerUtil!.isActive()) {
                cancelTimer();
              }
            }
          });
        },
        onDoubleTap: () {
          if (_controller?.value.isInitialized == true) {
            if (_controller!.value.isPlaying) {
              _controller!.pause();
            } else {
              _controller!.play();
            }
            setState(() {});
          }
        },
        child: Center(
          child: _loadError != null
              ? Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    const Text('视频加载失败，请重试'),
                    const SizedBox(height: 8),
                    ElevatedButton(
                      onPressed: _initializeVideo,
                      child: const Text('重试'),
                    ),
                  ],
                )
              : _controller?.value.isInitialized == true
                  ? Stack(
                      alignment: Alignment.center,
                      children: [
                        SizedBox(
                          height: double.infinity,
                          width: double.infinity,
                          child: AspectRatio(
                            aspectRatio: _controller!.value.aspectRatio,
                            child: VideoPlayer(_controller!),
                          ),
                        ),
                        Offstage(
                          offstage: _hiddenTipView,
                          child: VideoOperaWidget(
                            title: widget.typeTitle ?? 'song',
                            degree: _playDegree,
                            totalTime: _totalTime,
                            currentTime: _currentTime,
                            isPlay: _controller!.value.isPlaying,
                            actionEvent: (OperationType type) {
                              actionType(type);
                            },
                            sliderChangeEvent: (double degree) {
                              int totalSecond = _controller!
                                          .value.duration.inMinutes
                                          .remainder(60) *
                                      60 +
                                  _controller!.value.duration.inSeconds
                                      .remainder(60);
                              int positionSecond =
                                  (totalSecond * degree).toInt();
                              _controller!
                                  .seekTo(Duration(seconds: positionSecond));
                            },
                          ),
                        ),
                        Offstage(
                          offstage: _controller!.value.isPlaying,
                          child: IconButton(
                            onPressed: () {
                              _controller!.play();
                            },
                            icon: Image.asset(
                              'video_stop'.assetPng,
                              width: 70.w,
                              height: 70.h,
                            ),
                          ),
                        )
                      ],
                    )
                  : Container(
                      color: Colors.white,
                      child: const CircularProgressIndicator(),
                      // Text(
                      //   '视频加载中....',
                      //   style: TextStyle(fontSize: 20.sp, color: Colors.black),
                      // ),
                    ),
        ),
      ),
    );
  }

  @override
  void dispose() {
    _loadGeneration++;
    _bufferingTimer?.cancel();
    if (_diagnosticListener != null) {
      _controller?.removeListener(_diagnosticListener!);
    }
    final controller = _controller;
    if (controller != null) {
      unawaited(VideoPlaybackDiagnostics.disposeController(
        controller,
        context: '课程视频页面退出',
      ));
    }
    if (timerUtil != null) {
      timerUtil!.cancel();
      timerUtil = null;
    }
    super.dispose();
  }

  ///获取当前进度秒数
  int getCurrentPositionSeconds() {
    return (_controller!.value.position.inMinutes.remainder(60) * 60 +
        _controller!.value.position.inSeconds.remainder(60));
  }
}