Stage window;
Scene mainScene;

private final int WIDTH = 500;
private final int HEIGHT = 500;

Timeline timeline;

private Direction action = Direction.RIGHT;

private Rectangle snakeHead;
private final int speed = 3;
private int xSpeed = 3;
private int ySpeed = 3;

private int snakeW = 20;
private int snakeH = 20;
private BoundingBox snakeBox;

private BoundingBox foodBox;

private ImageView food;
private Random rand = new Random();

private double foodX;
private double foodY;

enum Direction {
    LEFT,RIGHT,UP,DOWN;
}

private Parent createContent(){
    Pane root = new Pane();

    //food = new Food();
    food = new ImageView(new Image("resources/apple.png"));
    food.setFitHeight(25);
    food.setFitWidth(25);
    food.setPreserveRatio(true);
    newFood();
    foodBox = new BoundingBox(foodX,foodY,20,20);


    snakeHead = new Rectangle(snakeW,snakeH);
    snakeHead.setTranslateX(200);
    snakeHead.setTranslateY(200);

    snakeBox = new BoundingBox(snakeHead.getTranslateX(),snakeHead.getTranslateY(),snakeW,snakeH);

    timeline = new Timeline(new KeyFrame(Duration.millis(16), e-> {
        //Snake movement
        if(action == Direction.LEFT) {snakeHead.setTranslateX(snakeHead.getTranslateX() - xSpeed);}
        if(action == Direction.RIGHT) {snakeHead.setTranslateX(snakeHead.getTranslateX() + xSpeed);}
        if(action == Direction.UP) {snakeHead.setTranslateY(snakeHead.getTranslateY() - ySpeed);}
        if(action == Direction.DOWN) {snakeHead.setTranslateY(snakeHead.getTranslateY() + ySpeed);}

        //Stops snake at edges of screen
        if(snakeHead.getTranslateX() <= 0){
            xSpeed = 0;
            if(action == Direction.RIGHT){xSpeed = speed;}
        }
        if(snakeHead.getTranslateX() >= WIDTH - snakeW){
            xSpeed = 0;
            if(action == Direction.LEFT){xSpeed = speed;}
        }
        if(snakeHead.getTranslateY() <= 0){
            ySpeed = 0;
            if(action == Direction.DOWN){ySpeed = speed;}
        }
        if(snakeHead.getTranslateY() >= HEIGHT - snakeH){
            ySpeed = 0;
            if(action == Direction.UP){ySpeed = speed;}
        }

        //TODO: Detect Collisions
                 if(foodBox.intersects(snakeHead.getTranslateX(),snakeHead.getTranslateY (),snakeW,snakeH)){
            newFood();
            System.out.println("Collision");
        }

    }));



    timeline.setCycleCount(Timeline.INDEFINITE);

    root.getChildren().addAll(snakeHead,food);

    return root;
}

private void newFood() {
    foodX = rand.nextInt(500);
    foodY = rand.nextInt(500);

    food.setTranslateX(foodX);
    food.setTranslateY(foodY);

    System.out.println("X " + foodX);
    System.out.println("Y " + foodY);
}

private void startGame() {
    timeline.play();
}

private void stopGame() {
    timeline.stop();
}


@Override
public void start(Stage primaryStage) throws Exception{
    window = primaryStage;
    mainScene = new Scene(createContent(),WIDTH,HEIGHT);

    mainScene.setOnKeyPressed(e-> {
        switch(e.getCode()) {
            case UP: action = Direction.UP; break;
            case DOWN: action = Direction.DOWN; break;
            case LEFT: action = Direction.LEFT; break;
            case RIGHT: action = Direction.RIGHT; break;
        }
    });

    window.setTitle("Snake");
    window.setResizable(false);
    window.setScene(mainScene);
    window.show();

    startGame();
}


public static void main(String[] args) {
    launch(args);
}