var iam = [];
var dir = 0;
var kx = [1,0,-1,0];
var ky = [0,1,0,-1];
var lifeCounter = 0;
var apple;

function genApple() {
    apple.cursorX = Math.round(Math.random() * 15);
    apple.cursorY = Math.round(Math.random() * 15);
}

function createApple() {
    display.color(0xff);
    apple = display.print("@");
    genApple();
}

function createPlayer() {
    display.color(0);
    display.cursor(8, 8);
    iam = [display.print("*")];
}

function eat() {
    sound.play("mob.pig");
    display.color(0);
    display.cursor(apple.cursorX, apple.cursorY);
    iam.push(display.print("*"));
    genApple();
}

function init() {
    createPlayer();
    createApple();
}

function isEqual(o1, o2) {
    return o1.cursorX == o2.cursorX && o1.cursorY == o2.cursorY;
}

function selfCross() {
    for(var i = 1; i ‹ iam.length; i++) {
        if(isEqual(iam[0], iam[i])) {
            return true;
        }
    }
    return false;
}

function update(time) {
    lifeCounter++;
    if(lifeCounter == 10) {
        lifeCounter = 0;
        for(var i = iam.length-1; i › 0; i--) {
            iam[i].cursorX = iam[i-1].cursorX;
            iam[i].cursorY = iam[i-1].cursorY;
        }
        iam[0].cursorX += kx[dir];
        iam[0].cursorY += ky[dir];
        if(iam[0].cursorX ‹ 0) iam[0].cursorX += 16;
        if(iam[0].cursorY ‹ 0) iam[0].cursorY += 16;
        if(iam[0].cursorX › 15) iam[0].cursorX -= 16;
        if(iam[0].cursorY › 15) iam[0].cursorY -= 16;

        if(selfCross()) {
            sound.play("random.explode");
            display.clear();
            createPlayer();
            createApple();
        }
        else if(isEqual(iam[0], apple))
            eat();
    }
    
    if(key.press(200)) dir = 3;
    else if(key.press(208)) dir = 1;
    else if(key.press(203)) dir = 2;
    else if(key.press(205)) dir = 0;
}