class Game {
    constructor() {
        this.canvas = document.body.createChild('canvas', 'pacman-game');
        this.ctx = this.canvas.getContext('2d');

        this.loadMap();
        this.onResize();

        this.gameObjects = [];

        this.paused = false;
        this.gameOver = false;

        this.init();
    }

    init() {
        this.gameObjects.push(new Player(this, this.map.spawn.x + 0.5, this.map.spawn.y + 0.5));

        this.gameObjects.push(new Ghost(this, 5.5, 6.5));
        // this.gameObjects.push(new Ghost(this, 3.5, 20.5));
        // this.gameObjects.push(new Ghost(this, 10.5, 7.5));
        // this.gameObjects.push(new Ghost(this, 19.5, 12.5));

        this.registerKeyListeners();
        this.registerWindowListeners();
    }

    registerKeyListeners() {
        window.addEventListener('keydown', (event) => {
            const key = event.key;

            switch (key) {
                case 'ArrowLeft':
                    this.getPlayer().changeDir({x: -1, y: 0});
                    break;
                case 'ArrowUp':
                    this.getPlayer().changeDir({x: 0, y: -1});
                    break;
                case 'ArrowRight':
                    this.getPlayer().changeDir({x: 1, y: 0});
                    break;
                case 'ArrowDown':
                    this.getPlayer().changeDir({x: 0, y: 1});
                    break;
            }
        });
    }

    registerWindowListeners() {
        window.addEventListener('resize', (event) => {
            this.onResize();
        });
    }

    onResize() {
        this.calculateConf(window.innerWidth, window.innerHeight);

        this.canvas.width = this.conf.tileSize * this.map.width;
        this.canvas.height = this.conf.tileSize * this.map.height;

        this.canvas.style.width = this.canvas.width + 'px';
        this.canvas.style.height = this.canvas.height + 'px';
    }

    loadMap() {
        const mapLoader = new MapLoader("levels/level1.pacmap");
        mapLoader.start();
        this.map = mapLoader.getMap();
    }

    calculateConf(width, height) {
        this.conf = {
            tileSize: calculateTileSize(width, height, this.map.width, this.map.height),
        };
    }

    getGameObjectsByType(type) {
        return this.gameObjects.filter(object => object instanceof type);
    }

    getPlayer() {
        return this.getGameObjectsByType(Player)[0];
    }

    draw() {
        this.ctx.clearRect(0, 0, this.canvas.clientWidth, this.canvas.clientHeight);

        this.map.draw(this.ctx, this.conf);

        this.gameObjects.forEach(object => {
            object.draw(this.ctx, this.conf);
        });

        requestAnimationFrame(() => this.draw());
    }

    update(lastUpdate) {
        const updateTime = Date.now();
        const deltaTime = updateTime - lastUpdate || 16;

        this.gameObjects.forEach(object => {
            object.update(deltaTime);
        });

        if (!this.paused && !this.gameOver)
            requestAnimationFrame(() => this.update(updateTime));
    }

    start() {
        this.draw();
        this.update();
    }
}