utility.dart

import 'package:minigames/src/games/tictactoe/tac_ai.dart';

class TacUtility {
  //region utility
  static bool isBoardFull(List<int> board) {
    for (var val in board) {
      if (val == TacAI.EMPTY_SPACE) return false;
    }

    return true;
  }

  static bool isMoveLegal(List<int> board, int move) {
    if (move < 0 || move >= board.length || board[move] != TacAI.EMPTY_SPACE)
      return false;

    return true;
  }

  /// Returns the current state of the board [winning player, draw or no winners yet]
  static int evaluateBoard(List<int> board) {
    for (var list in TacAI.WIN_CONDITIONS_LIST) {
      if (board[list[0]] !=
              TacAI.EMPTY_SPACE && // if a player has played here AND
          board[list[0]] ==
              board[list[1]] && // if all three positions are of the same player
          board[list[0]] == board[list[2]]) {
        return board[list[0]];
      }
    }

    if (isBoardFull(board)) {
      return TacAI.DRAW;
    }

    return TacAI.NO_WINNERS_YET;
  }

  /// Returns the opposite player from the current one.
  static int flipPlayer(int currentPlayer) {
    return -1 * currentPlayer;
  }
}