snakesLadders.js

class SnakesLadders {
  constructor() {
    this.board = [
      0,
      0, 36, 0, 0, 0, 0, 7, 23, 0, 0,
      0, 0, 0, 0, 11, -10, 0, 0, 0, 0,
      21, 0, 0, 0, 0, 0, 0, 56, 0, 0,
      0, 0, 0, 0, 0, 8, 0, 0, 0, 0,
      0, 0, 0, 0, 0, -21, 0, 0, -38, 0,
      16, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, -43, 0, -4, 0, 0, 0, 0, 0, 0,
      20, 0, 0, -21, 0, 0, 0, 20, 0, 0,
      0, 0, 0, 0, 0, 0, 7, 0, -21, 0,
      0, -4, 0, 0, -20, 0, 0, 0, -19, 0
    ];
    this.cellByPlayer = {
      1: 0,
      2: 0
    };
    this.player = 1;
    this.winner = 0;
  }

  get cell() {
    return this.cellByPlayer[this.player];
  }

  set cell(val) {
    this.cellByPlayer[this.player] = val;
  }

  switchPlayer() {
    this.player = (this.player === 1) ? 2 : 1;
  }

  play(die1, die2) {
    let result;

    // Возвращаем окончание игры, если победитель уже есть
    if (this.winner !== 0 && this.winner !== this.player) {
      return 'Game over!';
    }

    this.cell += (die1 + die2);

    if (this.cell === 100) {
      this.winner = this.player;
      result = `Player ${this.player} Wins!`;
      this.switchPlayer();
      return result;
    } else if (this.cell > 100) {
      this.cell -= (this.cell - 100) * 2;
    }

    // Поднимаемся по лестнице или скатываемся вниз по змее
    if (this.board[this.cell] !== 0) {
      this.cell += this.board[this.cell];
    }

    result = `Player ${this.player} is on square ${this.cell}`;

    // Сменяем текущего игрока
    // Если выпал повтор, то даем дополнительный ход
    if (die1 !== die2) {
      this.switchPlayer();
    }
    return result;
  }
}