import 'dart:async';

import 'package:fis_common/event/event_type.dart';
import 'package:fis_common/func/func_proxy.dart';
import 'package:fis_measure/interfaces/process/player/play_controller.dart';
import 'package:fis_ui/index.dart';
import 'package:fis_vid/data_channel/channel.dart';
import 'package:fis_vid/data_host/data_host.dart';
import 'package:flutter/foundation.dart';
import 'package:vid/us/vid_us_image.dart';
import 'package:vid/us/vid_us_probe.dart';

import 'enums.dart';
import 'events.dart';

/// Vid播放器控制器
class VidPlayerControllerNoSharing extends ChangeNotifier
    implements IPlayerController {
  /// Vid播放器控制器
  ///
  /// [dataHost] Vid文件宿主
  VidPlayerControllerNoSharing({
    required VidDataHost dataHost,
  }) {
    _dataHost = dataHost;
    eventHandler = FEventHandler<VidPlayerEvent>();
    frameUpdated = FEventHandler<VidUsImage>();
    firstFrameLoaded = FEventHandler<VidUsImage>();
    frameLoadStateChanged = FEventHandler<bool>();
    errorOccured = FEventHandler<String?>();
  }

  // ignore: constant_identifier_names
  static const _CAN_PLAY_STATUS_ARR = [
    VidPlayStatus.ready,
    VidPlayStatus.pause
  ];

  // ignore: constant_identifier_names
  static const _HAS_VIEW_STATUS_ARR = [VidPlayStatus.play, VidPlayStatus.pause];

  @override
  var eventHandler = FEventHandler<VidPlayerEvent>();

  var currentFrameHandler = FEventHandler<VidUsImage>();

  @override
  late final FEventHandler<VidUsImage> frameUpdated;
  @override
  late final FEventHandler<VidUsImage> firstFrameLoaded;
  @override
  late final FEventHandler<bool> frameLoadStateChanged;
  @override
  late final FEventHandler<String?> errorOccured;

  late final VidDataHost _dataHost;

  _PlayAssistant? _playAssistant;
  double _speed = 1.0;
  VidPlayStatus _status = VidPlayStatus.init;
  int _frameIndex = -1;
  VidUsImage? _frame;
  bool _disposed = false;

  ///该图像是否需要获取测量项和注释项
  bool ifNeedInit = true;

  @override
  bool get disposed => _disposed;

  /// Current play speed
  double get currentSpeed => _speed;

  @override
  VidPlayStatus get status => _status;

  @override
  VidUsImage? get currentFrame => _frame;

  /// Whether the player is playing
  bool get playing => status == VidPlayStatus.play;

  /// Whether the player can play
  bool get canPlay => _CAN_PLAY_STATUS_ARR.contains(status);

  /// Whether the player should has view
  @override
  bool get hasView => _HAS_VIEW_STATUS_ARR.contains(status);

  /// Current viewed frame index
  int get currentFrameIndex => _frameIndex;

  /// Total frames count of current vid
  int get totalFramesCount => _dataHost.frameCount;

  double get frameRate => _dataHost.probe.frameRate;

  bool get isSingleFrame => totalFramesCount == 1;

  /// 是否播放结束
  bool get isEndOfPlay => currentFrameIndex == totalFramesCount - 1;

  /// 当前播放器亮度 初始值为 0
  double get brightness => _brightness;
  double _brightness = 0.0;

  /// 当前播放器对比度 初始值为 1
  double get contrast => _contrast;
  double _contrast = 1.0;

  /// Set play speed [0.5~2]
  ///
  /// [speed] speed value [0.5~2]
  void setSpeed(double speed) {
    if (speed < 0.5 || speed > 2) return;

    _speed = speed;
    eventHandler.emit(this, VidPlayerSpeedChangeEvent(currentSpeed));
  }

  @override
  Future<bool> load() async {
    ifNeedInit = true;
    final info = await _dataHost.load();
    final result = info != null;
    if (result) {
      _setStatus(VidPlayStatus.ready);
    } else {
      _setStatus(VidPlayStatus.loadFail);
    }
    return result;
  }

  @override
  void play() {
    if (playing) return;
    if (!canPlay) return;

    if (isEndOfPlay) {
      _frameIndex = -1;
    }
    if (isSingleFrame) {
      gotoFrame(0);
      _setStatus(VidPlayStatus.pause);
    } else {
      _playAssistant ??= _PlayAssistant(this);
      _playAssistant!.play();

      _setStatus(VidPlayStatus.play);
    }
  }

  @override
  void pause() {
    if (!playing) {
      if (_status != VidPlayStatus.pause) {
        _setStatus(VidPlayStatus.pause);
      }
      return;
    }

    _playAssistant?.pause();
    _setStatus(VidPlayStatus.pause);
  }

  /// 主动播放结束
  void playOver() {
    pause();
    eventHandler.emit(this, VidPlayerPlayOverEvent());
  }

  /// Pause and view next frame
  Future<bool> gotoNextFrame() {
    pause();
    return gotoFrame(currentFrameIndex + 1);
  }

  /// Pause and view prev frame
  Future<bool> gotoPrevFrame() {
    pause();
    return gotoFrame(currentFrameIndex - 1);
  }

  /// View target indexed frame
  ///
  /// [index] frame index
  Future<bool> gotoFrame(int index) async {
    if (index < 0 || index >= totalFramesCount) return false;
    if (index == currentFrameIndex) return true;
    _frameIndex = index;
    _updateFrame();
    return true;
  }

  /// Set frame brightness
  ///
  /// [value] brightness value
  void setBrightness(int value) {
    final brightnessCount = value / 100;
    if (brightnessCount < -1 || brightnessCount > 1) {
      return;
    }
    if (kIsMobile) {
      _brightness = brightnessCount * 255;
    } else {
      _brightness = brightnessCount;
    }
    final fliterMatrix = <double>[
      contrast, 0, 0, 0, brightness, // red
      0, contrast, 0, 0, brightness, // green
      0, 0, contrast, 0, brightness, // blue
      0, 0, 0, 1, 0, // alpha // alpha
    ];
    eventHandler.emit(this, VidPlayerFilterChangeEvent(fliterMatrix));
    _updateFrame();
  }

  /// Set frame contrast
  ///
  /// [value] contrast value
  void setContrast(int value) {
    double contrastCount = 1;
    if (value < 0) {
      contrastCount = (value + 100) / 100;
    } else if (value >= 0) {
      contrastCount = value / 100 * 9 + 1;
    }
    if (contrastCount < 0 || contrastCount > 10) {
      return;
    }
    _contrast = contrastCount;
    final fliterMatrix = <double>[
      contrast, 0, 0, 0, brightness, // red
      0, contrast, 0, 0, brightness, // green
      0, 0, contrast, 0, brightness, // blue
      0, 0, 0, 1, 0, // alpha
    ];
    eventHandler.emit(this, VidPlayerFilterChangeEvent(fliterMatrix));
    _updateFrame();
  }

  void setFilterMatrix(List<double> matrix) {
    eventHandler.emit(this, VidPlayerFilterChangeEvent(matrix));
  }

  /// 重置图像增益
  void resetTone() {
    setBrightness(0);
    setContrast(0);
    eventHandler.emit(this, VidPlayResetToneEvent());
  }

  void _updateFrame() {
    _handleUpdateFrame
        .throttle(
          timeout: _playAssistant?._playIntervalMillSeconds ?? 200,
        )
        .call();
  }

  /// [Carotid] ✅用于设置颈动脉单帧展示
  void set2DMeasureFrame(VidUsImage _frame) {
    eventHandler.emit(
      this,
      VidPlayerFrameIndexChangeEvent(
        currentFrameIndex,
        _frame.imageData,
        _frame.width,
        _frame.height,
      ),
    );
  }

  /// [Carotid] ✅用于重置播放器
  void resetCurrentFrame() {
    _frameIndex = -1;
    play();
  }

  Future<void> _handleUpdateFrame() async {
    if (_disposed) return;

    _frame = await _dataHost.getFrame(currentFrameIndex);
    emitFrameUpdate();
  }

  void emitFrameUpdate() {
    if (ifNeedInit) {
      currentFrameHandler.emit(this, _frame!);
      ifNeedInit = false;
    }

    eventHandler.emit(
      this,
      VidPlayerFrameIndexChangeEvent(
        currentFrameIndex,
        _frame!.imageData,
        _frame!.width,
        _frame!.height,
      ),
    );
  }

  void _setStatus(VidPlayStatus value) {
    _status = value;
    _notifyStatus();
  }

  void _notifyStatus() {
    eventHandler.emit(this, VidPlayerStatusChangeEvent(status));
  }

  void _stop({bool needNotify = true}) {
    _playAssistant?.pause();
    if (needNotify) {
      _setStatus(VidPlayStatus.stop);
    }
  }

  @override
  void dispose() {
    _dataHost.release();
    _disposed = true;
    _stop(needNotify: false);
    eventHandler.dispose();
    super.dispose();
  }

  /// 已禁用，请通过eventHandler监听事件
  @override
  void addListener(VoidCallback listener) {
    throw UnsupportedError(
        "method `addListener` has been limited.Pls use `eventHandler.addListener`.");
  }

  /// 已禁用，请通过eventHandler监听事件
  @override
  void removeListener(VoidCallback listener) {
    throw UnsupportedError(
        "method `removeListener` has been limited.Pls use `eventHandler.removeListener`.");
  }

  @override
  VidDataChannel get dataChannel => throw UnimplementedError();

  @override
  Future<bool> locateTo(int index) {
    pause();
    return gotoFrame(index);
  }

  @override
  String get url => _dataHost.url;

  VidUsProbe get probe => _dataHost.probe;
}

class _PlayAssistant {
  _PlayAssistant(this.owner);

  final VidPlayerControllerNoSharing owner;

  bool _ready = false;

  late double _frameRate;

  int get _playInterval => 1000 * 1000 ~/ _frameRate;

  int get _playIntervalMillSeconds => _playInterval ~/ 1000.0;

  Timer? _timer;

  void play() {
    if (!_ready) {
      _prepare();
    }
    if (_timer != null) {
      pause();
    }
    final duration = Duration(microseconds: _playInterval);
    // final duration = const Duration(milliseconds: 1000 ~/ 10);
    _timer = Timer.periodic(duration, (timer) {
      // print('play at  ${DateTime.now()}');
      owner.gotoFrame(owner.currentFrameIndex + 1);
      if (owner.currentFrameIndex == owner.totalFramesCount - 1) {
        owner.playOver();
      }
    });
  }

  void pause() {
    _timer?.cancel();
    _timer = null;
    print('stop at ${DateTime.now()}');
  }

  void _prepare() {
    _frameRate = owner._dataHost.probe.frameRate;
    _ready = true;
  }
}