import 'dart:math';
import 'package:flame/components.dart';
import 'package:flame/effects.dart';
import 'package:flame/game.dart';
import 'tile.dart';
import 'package:flame/sprite.dart';

class Board extends FlameGame {
  final List<Sprite> sprites;
  static const int rows = 8;
  static const int cols = 8;
  late double tileSize;
  List<List<Tile?>> tiles = [];
  int? selectedRow;
  int? selectedCol;
  bool animating = false;

  Board({required this.sprites});

  @override
  Future<void> onLoad() async {
    super.onLoad();

    tileSize = size.x / cols;
    _initializeGrid();
    _removeInitialMatches();
  }

  void _initializeGrid() {
    for (int row = 0; row < rows; row++) {
      List<Tile?> rowTiles = [];
      for (int col = 0; col < cols; col++) {
        int spriteIndex = _randomElement();
        var tile = Tile(
          sprite: sprites[spriteIndex],
          spriteIndex: spriteIndex,
          size: Vector2.all(tileSize),
          position: Vector2(col * tileSize, row * tileSize),
          row: row,
          col: col,
          onTileTap: handleTileTap,
        );
        rowTiles.add(tile);
        add(tile);
      }
      tiles.add(rowTiles);
    }
  }

  int _randomElement() {
    return Random().nextInt(7);
  }

  void _removeInitialMatches() {
    bool hasMatches;
    do {
      hasMatches = false;
      for (int row = 0; row < rows; row++) {
        for (int col = 0; col < cols; col++) {
          if (_hasMatch(row, col)) {
            int spriteIndex = _randomElement();
            tiles[row][col]!.sprite = sprites[spriteIndex];
            tiles[row][col]!.spriteIndex = spriteIndex;
            hasMatches = true;
          }
        }
      }
    } while (hasMatches);
  }

  void handleTileTap(Tile tappedTile) {
    if (animating) return;

    int row = tappedTile.row;
    int col = tappedTile.col;

    if (selectedRow == null || selectedCol == null) {
      tappedTile.select();
      selectedRow = row;
      selectedCol = col;
    } else {
      tiles[selectedRow!][selectedCol!]?.deselect();
      if (_isAdjacent(selectedRow!, selectedCol!, row, col)) {
        swapTiles(tiles[selectedRow!]![selectedCol!]!, tiles[row]![col]!, true);
        Future.delayed(const Duration(milliseconds: 300), () {
          if (!_checkMatches()) {
            swapTiles(
                tiles[row]![col]!, tiles[selectedRow!]![selectedCol!]!, true);
          }
          selectedRow = null;
          selectedCol = null;
        });
      } else {
        tiles[selectedRow!][selectedCol!]?.deselect();
        tappedTile.select();
        selectedRow = row;
        selectedCol = col;
      }
    }
  }

  bool _isAdjacent(int row1, int col1, int row2, int col2) {
    return (row1 == row2 && (col1 - col2).abs() == 1) ||
        (col1 == col2 && (row1 - row2).abs() == 1);
  }

  void swapTiles(Tile tile1, Tile tile2, bool animate) {
    final tempPosition = tile1.position;
    final tempRow = tile1.row;
    final tempCol = tile1.col;

    tile1.position = tile2.position;
    tile1.row = tile2.row;
    tile1.col = tile2.col;

    tile2.position = tempPosition;
    tile2.row = tempRow;
    tile2.col = tempCol;

    tiles[tile1.row][tile1.col] = tile1;
    tiles[tile2.row][tile2.col] = tile2;

    if (animate) {
      tile1.animateMoveTo(tile1.position, () {});
      tile2.animateMoveTo(tile2.position, () {});
    }
  }

  bool _checkMatches() {
    if (animating) return false;
    animating = true;

    final matches = <List<int>>[];
    for (int row = 0; row < rows; row++) {
      for (int col = 0; col < cols; col++) {
        if (_hasMatch(row, col)) {
          matches.add([row, col]);
        }
      }
    }

    if (matches.isNotEmpty) {
      for (final match in matches) {
        _removeMatchedElements(match[0], match[1]);
      }
      Future.delayed(const Duration(milliseconds: 300), () {
        _applyGravity();
        Future.delayed(const Duration(milliseconds: 300), () {
          _fillEmptySpaces();
          Future.delayed(const Duration(milliseconds: 300), () {
            animating = false;
            _checkMatches();
          });
        });
      });
      return true;
    }
    animating = false;
    return false;
  }

  bool _hasMatch(int row, int col) {
    final value = tiles[row]?[col]?.spriteIndex;

    int count = 1;
    for (int i = col + 1; i < cols && tiles[row]?[i]?.spriteIndex == value; i++)
      count++;
    for (int i = col - 1; i >= 0 && tiles[row]?[i]?.spriteIndex == value; i--)
      count++;
    if (count >= 3) return true;

    count = 1;
    for (int i = row + 1; i < rows && tiles[i]?[col]?.spriteIndex == value; i++)
      count++;
    for (int i = row - 1; i >= 0 && tiles[i]?[col]?.spriteIndex == value; i--)
      count++;
    return count >= 3;
  }

  void _removeMatchedElements(int row, int col) {
    final value = tiles[row]?[col]?.spriteIndex;

    int left = col;
    while (left > 0 && tiles[row]?[left - 1]?.spriteIndex == value) left--;
    int right = col;
    while (right < cols - 1 && tiles[row]?[right + 1]?.spriteIndex == value)
      right++;
    if (right - left + 1 >= 3) {
      for (int i = left; i <= right; i++) {
        if (tiles[row]?[i] != null) {
          _animateRemoveTile(tiles[row]![i]!);
          tiles[row]![i] = null;
        }
      }
    }

    int top = row;
    while (top > 0 && tiles[top - 1]?[col]?.spriteIndex == value) top--;
    int bottom = row;
    while (bottom < rows - 1 && tiles[bottom + 1]?[col]?.spriteIndex == value)
      bottom++;
    if (bottom - top + 1 >= 3) {
      for (int i = top; i <= bottom; i++) {
        if (tiles[i]?[col] != null) {
          _animateRemoveTile(tiles[i]![col]!);
          tiles[i]![col] = null;
        }
      }
    }
  }

  void _animateRemoveTile(Tile tile) {
    tile.animateRemove(() {
      remove(tile);
    });
  }

  void _applyGravity() {
    for (int col = 0; col < cols; col++) {
      for (int row = rows - 1; row >= 0; row--) {
        if (tiles[row]?[col] == null) {
          for (int k = row - 1; k >= 0; k--) {
            if (tiles[k]?[col] != null) {
              tiles[row]![col] = tiles[k]![col]!;
              tiles[k]![col] = null;
              tiles[row]![col]!.row = row;
              tiles[row]![col]!.animateMoveTo(
                  Vector2(col * tileSize, row * tileSize), () {});
              break;
            }
          }
        }
      }
    }
  }

  void _fillEmptySpaces() {
    for (int col = 0; col < cols; col++) {
      for (int row = rows - 1; row >= 0; row--) {
        if (tiles[row]?[col] == null) {
          int spriteIndex = _randomElement();
          var tile = Tile(
            sprite: sprites[spriteIndex],
            spriteIndex: spriteIndex,
            size: Vector2.all(tileSize),
            position: Vector2(col * tileSize, -tileSize),
            row: row,
            col: col,
            onTileTap: handleTileTap,
          );
          tiles[row][col] = tile;
          add(tile);
          tile.animateMoveTo(Vector2(col * tileSize, row * tileSize), () {});
        }
      }
    }
  }
}