import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flame/game.dart';
import 'package:flame/components.dart' hide Block;
import 'package:flame/events.dart';
import 'package:flame_forge2d/flame_forge2d.dart';
import 'app_theme.dart';
import 'levels.dart';
import 'managers.dart';
import 'game_components.dart';

// --- Physics Engine ---
class LineInkGuideGame extends Forge2DGame with DragCallbacks {
  final LevelConfig config;
  final ValueNotifier<double> inkNotifier = ValueNotifier(0);
  final ValueNotifier<int> starCountNotifier = ValueNotifier(0);
  final ValueNotifier<int?> winNotifier = ValueNotifier(null);
  final ValueNotifier<bool> failNotifier = ValueNotifier(false);
  final ValueNotifier<AchievementDef?> achievementNotifier = ValueNotifier(
    null,
  );

  final List<Vector2> _drawPoints = [];
  DrawingPreview? _preview;
  bool _simulating = false;
  int _collected = 0;
  DateTime? _runStartTime;

  // 公共访问器，供组件使用
  int get collected => _collected;
  set collected(int value) => _collected = value;
  bool get simulating => _simulating;
  set simulating(bool value) => _simulating = value;

  LineInkGuideGame({required this.config}) : super(gravity: Vector2(0, 0));

  @override
  Color backgroundColor() => AppTheme.paperBg;

  Ball? _ball;
  List<Star> _stars = [];
  Goal? _goal;
  List<Block> _blocks = [];

  @override
  Future<void> onLoad() async {
    await super.onLoad();
    camera.viewfinder.anchor = Anchor.topLeft;
    _updateZoom();
    _initializeLevel();
  }

  void _initializeLevel() {
    world.removeAll(world.children);
    world.add(BackgroundGrid());

    // Add Entities
    _ball = Ball(config.ballPos);
    world.add(_ball!);
    _stars.clear();
    for (var sPos in config.stars) {
      final star = Star(sPos);
      _stars.add(star);
      world.add(star);
    }
    _goal = Goal(config.goalPos);
    world.add(_goal!);
    _blocks.clear();
    for (var blockShape in config.blocks) {
      final block = Block(blockShape);
      _blocks.add(block);
      world.add(block);
    }

    // Borders
    world.add(Boundary(Vector2(0, 0), Vector2(20, 0)));
    world.add(Boundary(Vector2(0, 0), Vector2(0, 60)));
    world.add(Boundary(Vector2(20, 0), Vector2(20, 60)));

    // 初始化状态
    _simulating = false;
    _collected = 0;
    starCountNotifier.value = 0;
    inkNotifier.value = config.ink;
    winNotifier.value = null;
    failNotifier.value = false;
    _runStartTime = null;
    _drawPoints.clear();
    world.gravity = Vector2(0, 0);
  }

  void _updateZoom() {
    camera.viewfinder.zoom = size.x / 20;
  }

  @override
  void onGameResize(Vector2 size) {
    super.onGameResize(size);
    _updateZoom();
  }

  void resetLevel() {
    _simulating = false;
    _collected = 0;
    starCountNotifier.value = 0;
    inkNotifier.value = config.ink;
    winNotifier.value = null;
    failNotifier.value = false;
    _runStartTime = null;
    _drawPoints.clear();

    // 停止重力
    world.gravity = Vector2(0, 0);
    _preview?.removeFromParent();

    // 移除所有用户绘制的线条
    final linesToRemove = <UserLine>[];
    for (var child in world.children) {
      if (child is UserLine) {
        linesToRemove.add(child);
      }
    }
    for (var line in linesToRemove) {
      line.removeFromParent();
    }

    // 重置小球位置和速度
    if (_ball != null && _ball!.isMounted) {
      _ball!.body.setTransform(config.ballPos, 0);
      _ball!.body.linearVelocity = Vector2.zero();
      _ball!.body.angularVelocity = 0;
    }

    // 移除所有现有星星并重新添加
    final starsToRemove = <Star>[];
    for (var child in world.children) {
      if (child is Star) {
        starsToRemove.add(child);
      }
    }
    for (var star in starsToRemove) {
      star.removeFromParent();
    }

    // 重新添加所有星星
    _stars.clear();
    for (var sPos in config.stars) {
      final star = Star(sPos);
      _stars.add(star);
      world.add(star);
    }
  }

  void startSimulation() {
    if (_simulating) return;
    if (winNotifier.value != null || failNotifier.value) return;
    _simulating = true;
    world.gravity = Vector2(0, 32);
    _preview?.removeFromParent();
    _runStartTime = DateTime.now();
  }

  @override
  void onDragStart(DragStartEvent event) {
    super.onDragStart(event);
    if (_simulating || inkNotifier.value <= 0) return;
    _drawPoints.clear();
    _drawPoints.add(screenToWorld(event.localPosition));
    world.add(_preview = DrawingPreview(_drawPoints));
  }

  @override
  void onDragUpdate(DragUpdateEvent event) {
    super.onDragUpdate(event);
    if (_simulating || inkNotifier.value <= 0) return;
    final p = screenToWorld(event.localEndPosition);
    if (_drawPoints.isEmpty) return;
    double d = (p - _drawPoints.last).length;
    if (d > 0.25 && inkNotifier.value - (d * 10) > 0) {
      _drawPoints.add(p);
      inkNotifier.value -= d * 10;
    }
  }

  @override
  void onDragEnd(DragEndEvent event) {
    super.onDragEnd(event);
    _preview?.removeFromParent();
    if (_drawPoints.length > 1) world.add(UserLine(List.from(_drawPoints)));
    _drawPoints.clear();
  }

  bool get isSimulating => simulating;

  Duration? get currentRunDuration =>
      _runStartTime == null ? null : DateTime.now().difference(_runStartTime!);

  void onBallOutOfBounds() {
    if (!_simulating || winNotifier.value != null || failNotifier.value) {
      return;
    }
    _simulating = false;
    failNotifier.value = true;
    _runStartTime = null;
  }

  void notifyAchievement(AchievementDef def) {
    achievementNotifier.value = def;
    Future.delayed(const Duration(seconds: 2), () {
      if (achievementNotifier.value == def) {
        achievementNotifier.value = null;
      }
    });
  }
}