bubbletwist/lib/game/board.dart

import 'dart:math';

import 'package:bubbletwist/game/stone/quad_special_stone.dart';
import 'package:bubbletwist/game/stone/special_stone.dart';
import 'package:bubbletwist/game/stone/triple_special_stone.dart';

import '../enums/stone_color.dart';
import 'game.dart';
import 'stone/penta_special_stone.dart';
import 'stone/stone.dart';
import 'stone/stone_location.dart';

class Board {
  static const int boardSize = 8;
  final Game game;
  late final List<List<Stone?>> stones =
      List.generate(boardSize, (i) => List.generate(boardSize, (j) => Stone()));
  bool specialStonesEnabled = false;

  Board(this.game) {
    // The map generates with pairs of 3+ stones already in place.
    // To fix that we just let the game remove all 3+ stone pairs until none are left
    while (checkBoard()) {}
  }

  void updateBoard() {
    game.updateBoard();
  }

  bool swapStones(StoneLocation sl1, StoneLocation sl2) {
    // Check if the two stones that have been clicked are next to each other
    if (!(sl1.row >= sl2.row - 1 && sl1.row <= sl2.row + 1) ||
        !(sl1.column >= sl2.column - 1 && sl1.column <= sl2.column + 1)) {
      return false; // If they are not next to each other just abort
    }

    final s1 = game.getStone(sl1);
    final ss1 = s1 is PentaSpecialStone ? s1 : null;
    if (ss1 != null) {
      ss1.stoneColor = getStone(sl2)!.stoneColor;
      performSpecialStone(ss1, sl1);
      return true;
    }

    final s2 = game.getStone(sl2);
    final ss2 = s2 is PentaSpecialStone ? s2 : null;
    if (ss2 != null) {
      ss2.stoneColor = getStone(sl1)!.stoneColor;
      performSpecialStone(ss2, sl2);
      return true;
    }

    // Swap stones
    swap(sl1, sl2);
    if (checkBoard()) {
      // Check if swapping was a valid move
      // If Swap is valid, Stones have been removed and others have to fall down
      applyGravity();
      while (checkBoard()) {
        // Then we have to keep checking until no more 3+ stones are created by falling stones
        applyGravity();
      }
      return true;
    } else {
      // If Swap is invalid, the stones get swapped back
      swap(sl1, sl2);
      return false;
    }
  }

  bool checkBoard() {
    bool stuffDeleted = false;

    // FOR HORIZONTALS
    for (int row = 0; row < boardSize; ++row) {
      // First go through each row
      int startPosition = 0;
      int counter = 1;
      for (int column = 1; column < boardSize; ++column) {
        // And then through each column
        if (stones[row][column] == null || stones[row][column - 1] == null) {
          // Ignore deleted stones
          continue;
        }

        final colorsAreSame = stones[row][column]!.stoneColor ==
            stones[row][column - 1]!.stoneColor;

        // If both stones have the same color increase counter
        if (colorsAreSame) {
          counter++;
        }
        // If they are not the same color or we reach the end of the Board,
        // check the counter to see if the last 3+ stones had the same color
        if (!colorsAreSame || column == boardSize - 1) {
          if (counter >= 3) {
            // And if we had 3+ stones, remove them
            if (game.isRunning()) {
              game.addPoints(counter);
              game.addTime(3);
            }
            for (int k = 0; k < counter; ++k) {
              final st = StoneLocation(row: row, column: startPosition + k);
              removeStone(st);
              stuffDeleted = true;
            }
            if (counter == 3 && game.isRunning() && specialStonesEnabled) {
              stones[row][startPosition] = TripleSpecialStone(this);
            }
            if (counter == 4 && game.isRunning() && specialStonesEnabled) {
              stones[row][startPosition] = QuadSpecialStone(this, false);
            }
            if (counter == 5 && game.isRunning() && specialStonesEnabled) {
              stones[row][startPosition] = PentaSpecialStone(this);
            }
          }
          // Reset counter and start position after each color change
          counter = 1;
          startPosition = column;
        }
      }
    }

    // FOR VERTICALS
    for (int column = 0; column < boardSize; ++column) {
      // First go through each column
      int startPosition = 0;
      int counter = 1;
      for (int row = 1; row < boardSize; ++row) {
        // And then through each row
        if (stones[row][column] == null || stones[row - 1][column] == null) {
          // Ignore deleted stones
          continue;
        }

        // If both stones have the same color increase counter
        final colorsAreSame = stones[row][column]!.stoneColor ==
            stones[row - 1][column]!.stoneColor;
        if (colorsAreSame) {
          counter++;
        }
        // If they are not the same color or we reach the end of the Board,
        // check the counter to see if the last 3+ stones had the same color
        if (!colorsAreSame || row == boardSize - 1) {
          if (counter >= 3) {
            //And if we had 3+ stones, remove them
            if (game.isRunning()) {
              game.addPoints(counter);
              game.addTime(3);
            }
            for (int k = 0; k < counter; ++k) {
              final st = StoneLocation(row: startPosition + k, column: column);
              removeStone(st);
              stuffDeleted = true;
            }
            if (counter == 3 && game.isRunning() && specialStonesEnabled) {
              stones[startPosition][column] = TripleSpecialStone(this);
            }
            if (counter == 4 && game.isRunning() && specialStonesEnabled) {
              stones[startPosition][column] = QuadSpecialStone(this, true);
            }
            if (counter == 5 && game.isRunning() && specialStonesEnabled) {
              stones[startPosition][column] = PentaSpecialStone(this);
            }
          }
          // Reset counter and start position after each color change
          counter = 1;
          startPosition = row;
        }
      }
    }
    if (stuffDeleted) {
      // If stuff has been deleted we have to update the Gui
      game.updateBoard();
    }
    return stuffDeleted;
  }

  void removeStone(StoneLocation sl) {
    if (sl.row < 0 ||
        sl.row >= boardSize ||
        sl.column < 0 ||
        sl.column >= boardSize) {
      return;
    }
    if (!game.isRunning()) {
      // If game is not running, just give the stones a new color
      stones[sl.row][sl.column]!.stoneColor =
          StoneColors.values[Random().nextInt(StoneColors.values.length - 1)];
    } else {
      // Otherwise mark stones as deleted
      stones[sl.row][sl.column] = null;
    }
  }

  void applyGravity() {
    bool stonesHaveFallenDown;
    // Move Stones down 1 row if the stone below them is marked as deleted
    do {
      stonesHaveFallenDown = false;
      for (int column = 0; column < boardSize; ++column) {
        for (int row = boardSize - 1; row > 0; --row) {
          if (stones[row][column] == null) {
            if (stones[row - 1][column] == null) {
              continue;
            }
            stones[row][column] = stones[row - 1][column];
            stones[row - 1][column] = null;
            stonesHaveFallenDown = true;
          }
        }
      }
    } while (
        stonesHaveFallenDown); // Continue doing so until all deleted Stones are at the top most position

    // Then generate new stones that rain from the sky)
    for (int i = 0; i < boardSize; i++) {
      for (int j = 0; j < boardSize; j++) {
        if (stones[i][j] == null) {
          stones[i][j] = Stone();
        }
      }
    }
    game.updateBoard();
  }

  void performSpecialStone(SpecialStone ss, StoneLocation sl) {
    //Delete Stones
    ss.performSpecialStoneAction();
    removeStone(sl);
    //show Deleted Stones
    updateBoard();
    //Make Stones fall down into new "holes"
    applyGravity();
    updateBoard(); //Show the Gravity Effect
    while (checkBoard()) {
      // Then we have to keep checking until no more 3+ stones are created by falling stones
      applyGravity();
    }
  }

  void swap(StoneLocation sl1, StoneLocation sl2) {
    final tmp = stones[sl1.row][sl1.column];
    stones[sl1.row][sl1.column] = stones[sl2.row][sl2.column];
    stones[sl2.row][sl2.column] = tmp;
    game.updateBoard();
  }

  Stone? getStone(StoneLocation sl) {
    return stones[sl.row][sl.column];
  }
}