function randInt(min, max) {
    return Math.floor(Math.random() * max) + min;
}

let snake = {
    x: 0,
    y: 0,
    dir: 1,
    score: 0,
    tail: []
};

let apple = {
    x: randInt(0, 14),
    y: randInt(0, 14),
    reset: () => {
        apple.x = randInt(0, 14);
        apple.y = randInt(0, 14);
    }
};
//   4
// 3 - 1
//   2

function setup(){
    createCanvas(700, 700);
    game();
}

function game(){
    let game = setInterval(() => {
        background(240);
        snake.tail.push([snake.x, snake.y]);

        if(snake.dir == 1) snake.x++;
        else if(snake.dir == 2) snake.y++;
        else if(snake.dir == 3) snake.x--;
        else if(snake.dir == 4) snake.y--;

        if(snake.x == apple.x && snake.y == apple.y){
            snake.score++;
            document.getElementById("score").innerText = snake.score;
            apple.reset();
        }
        else snake.tail.shift();

        fill(51,203,41);
        rect(snake.x*50,snake.y*50,50);

        let end = false;
        snake.tail.forEach(tail => {
            fill(169,246,164);
            rect(tail[0]*50,tail[1]*50,50);
            if(tail[0] == snake.x && tail[1] == snake.y) end = !end;
        })

        fill(240,55,55);
        rect(apple.x*50,apple.y*50,50);

        if(snake.x >= 14 ||snake.y >= 14 || snake.x < 0 ||snake.y < 0 || end){
            background(0);
            document.getElementById("loose").style.display="block";
            clearInterval(game);
        }
    }, 200)
}

function keyPressed(){
    if(keyCode === RIGHT_ARROW && snake.dir != 3){
        snake.dir = 1;
    }
    else if(keyCode === DOWN_ARROW && snake.dir != 4){
        snake.dir = 2;
    }
    else if(keyCode === LEFT_ARROW && snake.dir != 1){
        snake.dir = 3;
    }
    else if(keyCode === UP_ARROW && snake.dir != 2){
        snake.dir = 4;
    }
}

function restart(){
    document.getElementById("loose").style.display = "none";
    game();
    snake = {
        x: 0,
        y: 0,
        dir: 1,
        score: 0,
        tail: []
    };
    apple.reset();
}

window.addEventListener("keydown", function(e) {
    if(["Space","ArrowUp","ArrowDown","ArrowLeft","ArrowRight"].indexOf(e.code) > -1) {
        e.preventDefault();
    }
}, false);