//imports here

public class Game extends Canvas implements Runnable {

    public static JFrame frame;
    public static Screen screen;
    public static Level level;
    public static KeyHandel key;
    public static Entity player;

    public static final String gameTitle = "TITLE";
    public static final String gameThreadName = "Game Thread";

    public static final int windowWidth = 800;
    public static final int windowHeight = windowWidth / 16 * 9;
    public static final int windowScale = 2;
    public static final int imageWidth = windowWidth * 4;
    public static final int imageHeight = windowHeight * 4;

    public static final int TILE_SIZE = 128;
    public static final int BIT_TILE_SIZE_MASK = 7; // 2^7 = 128

    private BufferedImage image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);

    private int[] pixels = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();

    private boolean running = false;

    public Game() {
	frame = new JFrame();
	key = new KeyHandel();
	screen = new Screen(imageWidth, imageHeight);
	level = new Map_One("/maps/map_one.png");
	player = new EntityPlayer(Sprite.player, key).setX(700).setY(500);
	level.addEntity(player);

	init();
    }

    private void init() {
	Dimension size = new Dimension(windowWidth * windowScale, windowHeight * windowScale);
	setPreferredSize(size);
	addKeyListener(key);
	}

    public static void main(String[] args) {
	Game game = new Game();
	game.frame.setResizable(false);
	game.frame.setTitle(gameTitle);

	game.frame.add(game);
	game.frame.pack();
	game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	game.frame.setLocationRelativeTo(null);
	game.frame.setVisible(true);
	game.requestFocus();

	game.start();
    }

    private void start() {
	running = true;
	new Thread(this, gameThreadName).start();
    }

    private void stop() {
	running = false;
    }

    @Override
    public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1_000_000_000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;

	while (running) {
	    long now = System.nanoTime();
	    delta += (now - lastTime) / ns;
	    lastTime = now;
	    while (delta >= 1) {
		tick();
		updates++;
		delta--;
	    }

	    render();
	    frames++;

	    if (System.currentTimeMillis() - timer >= 1000) {
		timer += 1000;
		frame.setTitle(gameTitle + "  |  " + updates + " ups, " + frames + " fps");
		frames = 0;
		updates = 0;
	    }
	}
	stop();
    }

    private void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
	    createBufferStrategy(3);
	    return;
	}

	int xOffset = player.getX() - screen.getWidth() / 2;
	int yOffset = player.getY() - screen.getHeight() / 2;

	level.render(xOffset, yOffset, screen); // renders the level

	for (int i = 0; i < pixels.length; i++) {
	    pixels[i] = screen.getPixelAt(i); // saves the pixels of the screen in the image pixels array
	}

	Graphics g = bs.getDrawGraphics();

	g.drawImage(image, 0, 0, getWidth(), getHeight(), null); // stretchs the image to the screen (the actual image is bigger than the window so it fits more tiles on the screen)

	g.dispose();
	bs.show();
    }

    private void tick() {

	key.update();
	level.update(); //updates the level ( updates entities positions)
    }
}