import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:image_puzzle/config/device.dart';
import 'package:image_puzzle/play/board.dart';
import 'package:image_puzzle/play/board_painter.dart';
import 'package:image_puzzle/play/piece.dart';
import 'package:logging/logging.dart';
import 'package:provider/provider.dart';
import 'dart:ui' as ui;
import 'package:vector_math/vector_math.dart' as vmath;

final Logger _log = Logger('board_play.dart');

// 移动类型 (不再需要，但保留枚举以防止其他文件引用报错)
enum MoveType {
  group, // 整个群组一起移动
  single, // 单个碎片移动
}

// 操作类型
enum Action {
  revert, // 回归
  swap, // 交换
}

class BoardPlay extends StatefulWidget {
  final int cols;
  final int rows;

  const BoardPlay({super.key, required this.cols, required this.rows});

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

class _BoardPlayState extends State<BoardPlay> with TickerProviderStateMixin {
  final GlobalKey boardKey = GlobalKey();
  Board? board;
  bool _isLoading = true;

  Piece? _draggingPiece;

  // 记录所有动画中的移动项 (位移/交换/归位)
  List<MoveItem>? moveItems;

  // 动画控制器
  late AnimationController _moveAnimationController; // 移动动画（位移）
  late AnimationController _mergeAnimationController; // merge动画（scale）

  // merge 动画的缩放值
  late Animation<double> _mergeScaleAnimation;

  List<PieceGroup>? _mergeGroups;

  @override
  initState() {
    super.initState();
    _moveAnimationController = AnimationController(vsync: this, duration: const Duration(milliseconds: 200));
    _moveAnimationController.addListener(_moveAnimationListener);
    _moveAnimationController.addStatusListener(_moveAnimationStatusListener);

    // 初始化 Merge 动画
    _mergeAnimationController = AnimationController(vsync: this, duration: const Duration(milliseconds: 300)); // 0.4s for scale up/down
    _mergeAnimationController.addListener(_mergeAnimationListener);
    _mergeAnimationController.addStatusListener(_mergeAnimationStatusListener);

    // 缩放值从 1.0 -> 1.1 -> 1.0 (使用 TweenSequence 实现放大再缩小)
    _mergeScaleAnimation =
        TweenSequence<double>([
          TweenSequenceItem(tween: Tween<double>(begin: 1.0, end: 1.06), weight: 50),
          TweenSequenceItem(tween: Tween<double>(begin: 1.06, end: 1.0), weight: 50),
        ]).animate(
          // 应用曲线：用 CurvedAnimation 包装控制器
          CurvedAnimation(
            parent: _mergeAnimationController, // 动画控制器
            curve: Curves.easeInOut, // 曲线类型（先加速后减速）
          ),
        );

    init();
  }

  // 关键修正：动画监听器，只注册一次
  void _moveAnimationListener() {
    if (moveItems == null || moveItems!.isEmpty) {
      return;
    }

    for (var item in moveItems!) {
      item.move();
    }

    board!.invalidate();
  }

  void _moveAnimationStatusListener(AnimationStatus status) {
    if (status == AnimationStatus.completed) {
      // 动画完成，确保所有 piece 都在它们的最终位置（endTransform）
      if (moveItems != null) {
        bool needRebuildGroup = moveItems!.any((item) => item.action == Action.swap);

        // 确保所有 piece 的 transform 最终停留在 endTransform
        for (var item in moveItems!) {
          item.stop();
        }

        if (needRebuildGroup) {
          board!.backupAllGroups();
          board!.rebuildAllGroups();
          final mergeGroups = board!.compareAllGroups();

          // 有新的区块合成，执行 merge 动画，稍稍放大然后再复原
          if (mergeGroups.isNotEmpty) {
            _log.info('Merge animation start for ${mergeGroups.length} groups.');

            // 启动 Merge 动画
            _mergeGroups = mergeGroups;
            _mergeAnimationController.forward(from: 0.0);

            // 如果执行了 merge 动画，将胜利条件检查推迟到 merge 动画完成时
            moveItems = null;
            return;
          }
        }

        // 如果没有 merge 发生，或者 move action 是 revert，检查胜利条件
        if (board!.checkWinCondition()) {
          board!.success();
        }

        moveItems = null;
      }
    }
  }

  // 新增：Merge 动画监听器
  void _mergeAnimationListener() {
    if (_mergeGroups == null || _mergeGroups!.isEmpty || board == null) {
      return;
    }

    // 当前缩放值 (从 1.0 -> 1.1 -> 1.0)
    final double scale = _mergeScaleAnimation.value;

    for (var group in _mergeGroups!) {
      final groupCenter = group.center;
      for (var piece in group.pieces) {
        // 1. 获取碎片归位后的基础位置(纯平移)
        final baseTransform = board!.getTransformByCoordinate(piece.curRow, piece.curCol);

        // 2. 计算碎片左上角到群组中心的偏移量
        final pieceTopLeft = Offset(baseTransform.storage[12], baseTransform.storage[13]);
        final offsetToCenter = groupCenter - pieceTopLeft;

        // 3. 创建围绕群组中心的缩放矩阵
        final scaleMatrix = vmath.Matrix4.identity()
          ..translate(offsetToCenter.dx, offsetToCenter.dy) // 移到群组中心
          ..scale(scale, scale, 1.0) // 缩放
          ..translate(-offsetToCenter.dx, -offsetToCenter.dy); // 移回原位

        // 4. 应用最终变换
        piece.transform = baseTransform * scaleMatrix;
      }
    }

    board!.invalidate();
  }

  // 新增：Merge 动画状态监听器
  void _mergeAnimationStatusListener(AnimationStatus status) {
    if (status == AnimationStatus.completed) {
      if (_mergeGroups != null && _mergeGroups!.isNotEmpty) {
        for (var group in _mergeGroups!) {
          for (var piece in group.pieces) {
            piece.transform = board!.getTransformByCoordinate(piece.curRow, piece.curCol);
          }
        }
      }

      _mergeGroups = null;

      // 检查胜利条件 (现在所有 pieces 都在正确位置且 scale=1.0)
      if (board!.checkWinCondition()) {
        board!.success();
      }

      board!.invalidate();
    }
  }

  init() async {
    Device device = context.read<Device>();

    setState(() {
      _isLoading = true;
    });

    final targetRect = device.targetRect;
    final bestImageSize = device.bestImageSize;

    // TODO: 替换为实际的图片加载逻辑
    final ByteData data = await rootBundle.load('assets/images/test.jpeg');
    final ui.Codec codec = await ui.instantiateImageCodec(
      data.buffer.asUint8List(),
      targetWidth: bestImageSize.width.round(),
      targetHeight: bestImageSize.height.round(),
    );
    final ui.FrameInfo frameInfo = await codec.getNextFrame();
    final image = frameInfo.image;

    board = Board(this, image, widget.cols, widget.rows, targetRect, device);
    board!.start(); // 游戏开始

    setState(() {
      _isLoading = false;
    });
  }

  @override
  void didChangeDependencies() async {
    super.didChangeDependencies();
    _log.info("didChangeDependencies");
  }

  @override
  dispose() {
    _moveAnimationController.removeListener(_moveAnimationListener);
    _moveAnimationController.removeStatusListener(_moveAnimationStatusListener);
    _moveAnimationController.dispose();

    _mergeAnimationController.removeListener(_mergeAnimationListener);
    _mergeAnimationController.removeStatusListener(_mergeAnimationStatusListener);
    _mergeAnimationController.dispose();

    board?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    Device device = context.read<Device>();

    return Scaffold(
      body: Stack(
        children: <Widget>[
          if (!_isLoading) Positioned.fill(child: _buildPuzzleCanvas(device.screenSize.width, device.screenSize.height)),
          Positioned(top: 0, left: 0, right: 0, child: appBar),
          Positioned(
            bottom: 0,
            left: 0,
            right: 0,
            child: Container(
              height: device.bannerHeight,
              color: Colors.green.shade100,
              alignment: Alignment.center,
              child: const Text('Banner 广告区域', style: TextStyle(fontSize: 12)),
            ),
          ),
          if (_isLoading) const Positioned.fill(child: Center(child: CircularProgressIndicator())),
        ],
      ),
    );
  }

  final appBar = SafeArea(
    child: Center(
      child: Padding(
        padding: const EdgeInsets.all(10.0),
        child: Text(
          '关卡1',
          style: TextStyle(color: Colors.white, fontSize: 20, fontWeight: FontWeight.w600),
        ),
      ),
    ),
  );

  Widget _buildPuzzleCanvas(double width, double height) {
    return CustomPaint(
      painter: BoardPainter(board: board!),
      size: Size(width, height),
      child: GestureDetector(
        key: boardKey,
        onPanStart: _onPanStart,
        onPanUpdate: _onPanUpdate,
        onPanEnd: _onPanEnd,
        child: Container(color: Colors.transparent),
      ),
    );
  }

  Offset _globalToLocal(Offset globalPosition) {
    final RenderBox renderBox = boardKey.currentContext!.findRenderObject() as RenderBox;
    return renderBox.globalToLocal(globalPosition);
  }

  void _onPanStart(DragStartDetails details) {
    _log.info('_onPanStart');
    // 动画中断逻辑：如果动画正在进行，立即停止并强制所有 pieces 归位到最终位置
    if (_moveAnimationController.isAnimating && moveItems != null) {
      _log.info('移动动画中断，强制归位/交换');
      for (var item in moveItems!) {
        item.stop();
      }

      bool needRebuildGroup = moveItems!.any((item) => item.action == Action.swap);
      if (needRebuildGroup) {
        board!.backupAllGroups();
        board!.rebuildAllGroups();
        final mergeGroups = board!.compareAllGroups();

        if (mergeGroups.isNotEmpty) {
          // 此时不需要触发 merge 动画，只需确保数据结构正确
        }
      }

      moveItems = null; // 清空动画列表
      _moveAnimationController.stop();
      board!.invalidate(); // 触发一次重绘来显示最终位置
    }

    // 如果 merge 动画正在进行，也应该中断并立即归位
    if (_mergeAnimationController.isAnimating && _mergeGroups != null) {
      _log.info('合并动画中断，强制归位');

      for (var group in _mergeGroups!) {
        for (var piece in group.pieces) {
          piece.transform = board!.getTransformByCoordinate(piece.curRow, piece.curCol);
        }
      }
      _mergeGroups = null;
      _mergeAnimationController.stop();
      board!.invalidate();
    }

    // 停止所有正在运行的动画（如果尚未停止）
    _moveAnimationController.stop();
    _mergeAnimationController.stop();
    moveItems = null;

    final localPosition = _globalToLocal(details.globalPosition);
    final touchedPiece = board?.findPieceAt(localPosition);

    if (touchedPiece != null) {
      _draggingPiece = touchedPiece;

      final draggingGroup = _draggingPiece!.group;
      if (draggingGroup != null) {
        // 将拖拽群组置于 pieces 列表末尾，确保它在 CustomPainter 中被最后绘制（在最上层）
        board!.pieces.removeWhere((p) => draggingGroup.contains(p));
        board!.pieces.addAll(draggingGroup.pieces);
      } else {
        board!.pieces.remove(_draggingPiece);
        board!.pieces.add(_draggingPiece!);
      }
      board!.invalidate();
    }
  }

  void _onPanUpdate(DragUpdateDetails details) {
    _log.info('_onPanUpdate');
    if (_draggingPiece == null) return;

    final Offset delta = details.delta;

    final draggingGroup = _draggingPiece!.group;
    if (draggingGroup != null) {
      // 拖拽过程中，所有群组成员共享相同的位移
      for (var piece in draggingGroup.pieces) {
        piece.applyDelta(delta);
      }
    } else {
      _draggingPiece!.applyDelta(delta);
    }

    board!.invalidate();
  }

  void _onPanEnd(DragEndDetails details) {
    _log.info('_onPanEnd');
    if (_draggingPiece == null) {
      return;
    }

    // 保存当前拖拽结束的碎片，以备动画使用
    Piece leaderPiece = _draggingPiece!;
    _draggingPiece = null; // 结束拖拽

    board!.invalidate();

    /// 交换或归位

    // 获取碎片的中心点，判断中心点是否落到某个piece上
    Piece? targetPiece = board!.findPieceAtExclude(leaderPiece.currentCenter, leaderPiece);

    // 群组特殊处理：如果 leaderPiece 没有落在其他碎片上，检查群组其他成员
    if (targetPiece == null && leaderPiece.group != null) {
      for (var p in leaderPiece.group!.pieces) {
        targetPiece = board!.findPieceAtExclude(p.currentCenter, p);
        if (targetPiece != null) {
          _log.info('推举 ${p.toString()} 为新leader');
          leaderPiece = p; // p 落在有效的其他piece上，推举为leaderPiece
          break;
        }
      }
    }

    // 判断是否可以交换
    if (targetPiece != null && targetPiece != leaderPiece && leaderPiece.canPlaceTo(targetPiece)) {
      _log.info("swap animation start");
      _animateSwap(leaderPiece, targetPiece);
    } else {
      _log.info("revert animation start");
      _animateRevert(leaderPiece);
    }
  }

  // 关键重构：为所有涉及移动的 piece 创建独立的 MoveItem
  void _animateSwap(Piece leaderPiece, Piece targetPiece) {
    List<MoveItem> items = [];

    // 1. 确定涉及移动的所有碎片
    final List<Piece> draggingPieces = leaderPiece.group != null ? leaderPiece.group!.pieces : [leaderPiece];
    final int dr = targetPiece.curRow - leaderPiece.curRow; // 目标位置的行位移
    final int dc = targetPiece.curCol - leaderPiece.curCol; // 目标位置的列位移

    // 2. 识别被替换/推开的碎片
    List<Piece> displacedPieces = [];
    if (leaderPiece.group != null) {
      // 群组交换：找到群组新目标位置上的所有非自身群组的碎片
      for (var p in draggingPieces) {
        final int targetRow = p.curRow + dr;
        final int targetCol = p.curCol + dc;
        final Piece? other = board!.getPieceByCoordinate(targetRow, targetCol);
        if (other != null && !p.isSameGroup(other)) {
          displacedPieces.add(other);
        }
      }
    } else {
      // 单碎片交换：被替换的碎片就是 targetPiece
      displacedPieces.add(targetPiece);
    }

    // 3. 更新逻辑坐标 (curRow, curCol) - 必须在创建动画前完成

    // a. 更新拖拽群组/碎片的位置
    for (var p in draggingPieces) {
      p.curRow += dr;
      p.curCol += dc;
    }

    // b. 更新被推开的碎片的位置 (移入拖拽群组腾出的槽位)
    if (leaderPiece.group == null) {
      // 单碎片交换：targetPiece 移入 leaderPiece 的旧槽位
      targetPiece.curRow -= dr;
      targetPiece.curCol -= dc;
    } else {
      // 群组交换：被推开的碎片向后退 dr/dc 距离，找到空槽位
      for (var p in displacedPieces) {
        int newRow = p.curRow - dr;
        int newCol = p.curCol - dc;

        do {
          final Piece? pieceInSlot = board!.getPieceByCoordinate(newRow, newCol);
          if (pieceInSlot == null) {
            p.curRow = newRow;
            p.curCol = newCol;
            break;
          } else {
            newRow -= dr;
            newCol -= dc;
          }
        } while (newRow >= 0 && newRow < p.rows && newCol >= 0 && newCol < p.cols);
      }
    }

    // 4. 为所有涉及移动的碎片创建 MoveItem

    // a. 拖拽群组/碎片
    for (var p in draggingPieces) {
      // 动画起点：拖拽结束时的实际 Canvas 坐标 (p.transform)
      final startTransform = p.transform;
      // 动画终点：新的逻辑网格坐标
      final endTransform = board!.getTransformByCoordinate(p.curRow, p.curCol);
      final animation = Matrix4Tween(begin: startTransform, end: endTransform).animate(_moveAnimationController);

      items.add(MoveItem(piece: p, animation: animation, startTransform: startTransform, endTransform: endTransform, action: Action.swap));
    }

    // b. 被推开的碎片
    for (var p in displacedPieces) {
      // 动画起点：旧的逻辑网格坐标 (p.transform)
      final startTransform = p.transform;
      // 动画终点：新的逻辑网格坐标
      final endTransform = board!.getTransformByCoordinate(p.curRow, p.curCol);
      final animation = Matrix4Tween(begin: startTransform, end: endTransform).animate(_moveAnimationController);

      items.add(MoveItem(piece: p, animation: animation, startTransform: startTransform, endTransform: endTransform, action: Action.swap));
    }

    // 5. 启动动画
    moveItems = items;
    _moveAnimationController.forward(from: 0.0);
  }

  // 关键重构：为所有涉及归位的 piece 创建独立的 MoveItem
  void _animateRevert(Piece piece) {
    List<MoveItem> items = [];
    final List<Piece> groupPieces = piece.group != null ? piece.group!.pieces : [piece];

    for (var p in groupPieces) {
      // 动画起点：拖拽结束时的实际 Canvas 坐标 (p.transform)
      final startTransform = p.transform;
      // 动画终点：归位位置（即拖拽前所在的逻辑网格坐标）
      final endTransform = board!.getTransformByCoordinate(p.curRow, p.curCol);
      final animation = Matrix4Tween(begin: startTransform, end: endTransform).animate(_moveAnimationController);

      items.add(MoveItem(piece: p, animation: animation, startTransform: startTransform, endTransform: endTransform, action: Action.revert));
    }

    moveItems = items;
    _moveAnimationController.forward(from: 0.0);
  }
}

// 辅助类：用于对 vmath.Matrix4 进行线性插值 (lerp)，实现平滑动画
class Matrix4Tween extends Tween<vmath.Matrix4> {
  Matrix4Tween({required vmath.Matrix4 begin, required vmath.Matrix4 end}) : super(begin: begin, end: end);

  @override
  vmath.Matrix4 lerp(double t) {
    if (begin == null || end == null) return begin ?? end ?? vmath.Matrix4.identity();

    final List<double> lerpedStorage = List.generate(16, (i) {
      // 确保使用 ui.lerpDouble 进行插值
      return ui.lerpDouble(begin!.storage[i], end!.storage[i], t)!;
    });

    return vmath.Matrix4.fromList(lerpedStorage.cast<double>());
  }
}

// 动画辅助类，记录移动信息
class MoveItem {
  // 要移动的piece
  final Piece piece;
  // 动画animation
  final Animation<vmath.Matrix4> animation;
  // 起始位置（拖拽结束时的实际 Canvas 坐标）
  final vmath.Matrix4 startTransform;
  // 结束位置（目标网格槽位的 Canvas 坐标）
  final vmath.Matrix4 endTransform;

  // 移除了 MoveType，因为现在每个 piece 都有自己的 MoveItem
  // final MoveType moveType;

  final Action action;

  MoveItem({required this.piece, required this.animation, required this.startTransform, required this.endTransform, required this.action});

  // 关键修正：直接设置 piece 的 transform 为动画插值
  void move() {
    // 关键修正：直接设置piece的transform为动画插值，而不是累加delta
    piece.transform = animation.value;
  }

  void stop() {
    // 关键修正：动画中断时，直接设置到最终目标位置 (endTransform)
    // 此时 piece 的 curRow/curCol 已经是目标网格坐标
    piece.transform = endTransform;
  }
}