tic-tac-toe.controller.ts

import { Response, NextFunction } from "express";
import { JumpTo } from "./use-cases/jump-to.use-case";
import { Play } from "./use-cases/play.use-case";
import { Initialize } from "./use-cases/initialize.use-case";
import {
  CellAlreadyTakenException,
  StepDoesNotExistException,
} from "./exceptions";
import { BadRequestException } from "../common/exceptions/bad-request.exception";

export class TicTacToeController {
  constructor(
    private initialize: Initialize,
    private play: Play,
    private jumpTo: JumpTo
  ) {}

  handleInitialize(res: Response) {
    const game = this.initialize.execute();
    res.status(201).json({
      moves: this.getMoves(game.history),
      status: this.getStatus(game.winner, game.xIsNext),
      squares: game.history[game.step],
    });
  }

  handlePlay(res: Response, next: NextFunction, step: number, square: number) {
    try {
      const game = this.play.execute({ step, square });
      res.status(201).json({
        moves: this.getMoves(game.history),
        status: this.getStatus(game.winner, game.xIsNext),
        squares: game.history[game.step],
      });
    } catch (e) {
      if (e instanceof StepDoesNotExistException) {
        return next(
          new BadRequestException({
            error: "step does not exist",
          })
        );
      }

      if (e instanceof CellAlreadyTakenException) {
        return next(
          new BadRequestException({
            error: "cell already taken",
          })
        );
      }

      next(e);
    }
  }

  handleJumpTo(res: Response, next: NextFunction, step: number) {
    try {
      const game = this.jumpTo.execute({ step });
      res.status(201).json({
        moves: this.getMoves(game.history),
        status: this.getStatus(game.winner, game.xIsNext),
        squares: game.history[game.step],
      });
    } catch (e) {
      if (e instanceof StepDoesNotExistException) {
        return next(
          new BadRequestException({
            error: "step does not exist",
          })
        );
      }

      next(e);
    }
  }

  private getMoves(history: string[][]) {
    const moves = history.map((_, move: number) => {
      return {
        move,
        description: move > 0 ? "Go to move #" + move : "Go to game start",
      };
    });

    return moves;
  }

  private getStatus(winner: string | null, xIsNext: boolean) {
    const status = winner
      ? winner === "draw"
        ? "Draw"
        : "Winner: " + winner
      : "Next player: " + (xIsNext ? "X" : "O");

    return status;
  }
}