/****
* Classes
****/
var SnakeSegment = Container.expand(function () {
  var self = Container.call(this);
  var segmentGraphic = self.createAsset('snakeSegment', 'Snake Segment', 0.5, 0.5);
  self.move = function (x, y) {
    self.x = x;
    self.y = y;
  };
});
var Food = Container.expand(function () {
  var self = Container.call(this);
  var foodGraphic = self.createAsset('food', 'Food', 0.5, 0.5);
  self.place = function (x, y) {
    self.x = x;
    self.y = y;
  };
});

/****
* Initialize Game
****/
var game = new LK.Game({
  backgroundColor: 0x000000 //Init game with black background 
});

/****
* Game Code
****/
var snake = [];
var food;
var direction = {
  x: 0,
  y: 0
};
var nextDirection = {
  x: 0,
  y: 0
};
var snakeSpeed = 5;
var gridSize = 64;
var score = 0;
var scoreTxt;
var isGameOver = false;
function initGame() {
  // Initialize the snake in the center of the screen
  var initialX = 2048 / 2;
  var initialY = 2732 / 2;
  var snakeHead = new SnakeSegment();
  snakeHead.move(initialX, initialY);
  snake.push(snakeHead);
  game.addChild(snakeHead);
  // Initialize the food at a random position
  placeFood();
  // Initialize score display
  scoreTxt = new Text2(score.toString(), {
    size: 150,
    fill: "#ffffff"
  });
  scoreTxt.anchor.set(0.5, 0);
  LK.gui.top.addChild(scoreTxt);
  // Set initial direction
  direction = {
    x: gridSize,
    y: 0
  };
}
function placeFood() {
  var foodX = Math.floor(Math.random() * (2048 / gridSize)) * gridSize + gridSize / 2;
  var foodY = Math.floor(Math.random() * (2732 / gridSize)) * gridSize + gridSize / 2;
  if (!food) {
    food = new Food();
    game.addChild(food);
  }
  food.place(foodX, foodY);
}
function updateScore() {
  score += 1;
  scoreTxt.setText(score.toString());
}
function gameOver() {
  isGameOver = true;
  LK.effects.flashScreen(0xff0000, 1000);
  LK.showGameOver();
}
function handleInput(obj) {
  var touchPos = obj.event.getLocalPosition(game);
  var head = snake[0];
  if (Math.abs(touchPos.x - head.x) > Math.abs(touchPos.y - head.y)) {
    if (touchPos.x > head.x && direction.x === 0) {
      nextDirection = {
        x: gridSize,
        y: 0
      };
    } else if (touchPos.x < head.x && direction.x === 0) {
      nextDirection = {
        x: -gridSize,
        y: 0
      };
    }
  } else {
    if (touchPos.y > head.y && direction.y === 0) {
      nextDirection = {
        x: 0,
        y: gridSize
      };
    } else if (touchPos.y < head.y && direction.y === 0) {
      nextDirection = {
        x: 0,
        y: -gridSize
      };
    }
  }
}
game.on('down', handleInput);
LK.on('tick', function () {
  if (isGameOver) return;
  // Update direction
  direction = nextDirection;
  // Move snake
  var newX = snake[0].x + direction.x;
  var newY = snake[0].y + direction.y;
  // Check for collisions with walls
  if (newX < 0 || newX > 2048 || newY < 0 || newY > 2732) {
    gameOver();
    return;
  }
  // Check for collisions with self
  for (var i = 1; i < snake.length; i++) {
    if (snake[i].x === newX && snake[i].y === newY) {
      gameOver();
      return;
    }
  }
  // Check for food collision
  if (snake[0].intersects(food)) {
    var newSegment = new SnakeSegment();
    newSegment.move(snake[snake.length - 1].x, snake[snake.length - 1].y);
    snake.push(newSegment);
    game.addChild(newSegment);
    updateScore();
    placeFood();
  }
  // Move snake segments
  for (var i = snake.length - 1; i > 0; i--) {
    snake[i].move(snake[i - 1].x, snake[i - 1].y);
  }
  // Move head last
  snake[0].move(newX, newY);
});
// Start the game
initGame();