/*
	author: leeenx
	@ 贪吃蛇的 control 类 
*/

// 游戏通用ticker
import ticker from "../lib/utils/ticker";

// timer
import timer from "../lib/utils/timer";

// 随机打散数组
import randomList from "../lib/utils/randomList";

// 事件
import Events from "../lib/utils/events";

// control 类
export default class control {
  // 构建函数
  constructor(model, view) {
    this.model = model;
    this.view = view;

    // 挂载一个 speed 属性
    Reflect.defineProperty(this, "speed", {
      get: function () {
        return this.speedScalar || 1;
      },
      set: function (value) {
        if (this.speedScalar !== value) {
          this.speedScalar = value;
          this.interval = 300 / this.speedScalar;
          // 更新 timer
          timer.set(this.intervalID, { delay: this.interval });
        }
      },
    });

    // tickHandle 绑定当前 this
    this.tickHandle = this.tickHandle.bind(this);

    // this.update 绑定 this
    this.update = this.update.bind(this);

    // 挂载事件对象
    this.event = new Events();

    // 四个方向
    this.fourDirections = ["left", "up", "right", "down"];
  }

  // 初始化
  init(config = {}) {
    // 添加 ticker
    ticker.addEventListener("tick", this.tickHandle);
    // 默认暂停 ticker
    this.pause();

    let {
      width = 640,
      height = 640,
      row = 50,
      column = 50,
      border = 0x999999,
      color = 0x000000, // 蛇的节点颜色
      food = color, // 食物颜色
      min = 3, // 初始长度
      speed = 1, // 速度标量
    } = config;

    // 存一份 config 到 this
    this.config = config;

    // 初始化 model
    this.model.init({ row, column, min });

    // view.data
    let data = {
      zone: this.model.zone,
      snake: this.model.snake,
      food: this.model.food,
    };

    // 初始化 view
    this.view.init({ width, height, row, column, border, color, food, data });

    // interval 的间隔
    this.interval = 300 / this.speedScalar;

    // 定时更新view
    this.intervalID = timer.setInterval(this.update, this.interval);

    // 速度标量
    this.speed = speed;

    // 蛇长度
    this.length = this.model.snake.length;

    // 初始化食物
    this.food = this.model.food;

    // 用户操作的方向列表
    this.directions = [];

    // 总计时
    if (config.time > 0) {
      let time = config.time / 1000;
      timer.setTimeout(() => this.gameover("timeout"), config.time);
      // 倒数
      timer.setInterval(() => this.event.dispatch("countdown", --time), 1000);
    }
  }
  // 销毁
  destroy() {
    // 移除 ticker
    ticker.removeEventListener("tick", this.tickHandle);
    // 清空 timer
    timer.clean();
    // 销毁 model
    this.model.destroy();
    // 销毁 view
    this.view.destroy();
    // GAMEOVER
    this.GAMEOVER = false;
  }

  // 转向
  turn(direction) {
    // 只保存第一次方向操作
    if (this.fourDirections.indexOf[direction] === -1) return;
    let directionA = direction,
      directionB = this.directions[0] || this.direction;
    // 给操作列表加个容积 5
    if (
      this.directions.length < 5 &&
      directionA !== directionB &&
      !this.isAdverse(directionA, directionB)
    ) {
      this.directions.unshift(directionA);
    }
  }

  // 判断两个方向是否相反
  isAdverse(directionA, directionB) {
    let indexA = this.fourDirections.indexOf(directionA),
      indexB = this.fourDirections.indexOf(directionB);
    if (Math.abs(indexA - indexB) === 2) {
      return true;
    }
    return false;
  }

  // 暂停
  pause() {
    if (this.GAMEOVER) return;
    ticker.pause();
  }

  // 恢复
  resume() {
    if (this.GAMEOVER) return;
    ticker.resume();
  }

  // start
  start() {
    if (this.GAMEOVER) return;
    // 蛇的随机运动方向
    let { leader, zone } = this.model;
    // 控制方向的变量是 this.direction。this.nextDirection 表示下一个方向
    this.directions.push(
      randomList(
        this.fourDirections.filter(
          (item) => leader[item] !== -1 && zone[leader[item]].fill === undefined
        ),
        1
      )
    );

    this.update();
  }

  // 重新开始
  restart() {
    this.destroy();
    this.init(this.config);
    this.start();
    this.event.dispatch("restart");
  }

  // gameover
  gameover(type) {
    if (this.GAMEOVER) return;
    this.event.dispatch("gameover", type);
    this.pause();
    this.GAMEOVER = true;
  }

  // update
  update() {
    // this.direction 表示蛇头节点的运动方向
    this.direction = this.directions.pop() || this.direction;
    this.model.move(this.direction);
    if (this.model.bar !== undefined) {
      // gameover
      this.gameover(this.model.bar);
    }
    let data = { snake: this.model.snake, food: this.model.food };
    if (this.model.dirty) {
      // model 有变化
      let hasEatEvent = false;
      if (this.food !== this.model.food) {
        this.food = this.model.food;
        hasEatEvent = true;
        this.event.dispatch("before-eat");
        this.length = this.model.snake.length;
      }
      this.view.update(data);
      hasEatEvent && this.event.dispatch("eat");
      this.model.cleanDirty();
    }
  }

  // tickHandle
  tickHandle() {
    timer.update(ticker.paused, ticker.elapsedMS * 1000);
    if (!ticker.paused) {
      this.view.updateTicker();
    }
  }
}