/**** 
* Classes
****/
var HomingProjectile = Container.expand(function (target) {
	var self = Container.call(this);
	var projectileGraphic = self.createAsset('projectile', 'Homing Projectile', 0.5, 0.5);
	projectileGraphic.scale.set(0.5);
	self.speed = 5;
	self.target = target;
	self.move = function () {
		var directionX = self.target.x - self.x;
		var directionY = self.target.y - self.y;
		var magnitude = Math.sqrt(directionX * directionX + directionY * directionY);
		var homingFactor = 0.5;
		self.x += directionX / magnitude * self.speed * homingFactor;
		self.y += directionY / magnitude * self.speed * homingFactor;
	};
});
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.projectiles = [];
	self.shoot = function (targetX, targetY) {
		var projectile = new HomingProjectile(snake[0]);
		projectile.x = self.x;
		projectile.y = self.y;
		self.projectiles.push(projectile);
		game.addChild(projectile);
		LK.setTimeout(function () {
			projectile.destroy();
			var index = self.projectiles.indexOf(projectile);
			if (index > -1) {
				self.projectiles.splice(index, 1);
			}
		}, 2500);
	};
	self.place = function (x, y) {
		self.x = x;
		self.y = y;
	};
	self.moveProjectiles = function () {
		for (var i = self.projectiles.length - 1; i >= 0; i--) {
			self.projectiles[i].move();
			if (self.projectiles[i].x < 0 || self.projectiles[i].x > 2048 || self.projectiles[i].y < 0 || self.projectiles[i].y > 2732) {
				self.projectiles[i].destroy();
				self.projectiles.splice(i, 1);
			}
		}
	};
});
var Projectile = Container.expand(function () {
	var self = Container.call(this);
	var projectileGraphic = self.createAsset('projectile', 'Lethal Projectile', 0.5, 0.5);
	projectileGraphic.scale.set(0.5);
	self.speed = 4;
	self.direction = {
		x: 0,
		y: 1
	};
	self.move = function () {
		self.x += self.direction.x * self.speed;
		self.y += self.direction.y * self.speed;
	};
	self.setDirection = function (x, y) {
		self.direction.x = x;
		self.direction.y = y;
	};
});

/**** 
* Initialize Game
****/
var game = new LK.Game({
	backgroundColor: 0x1F7A1F //Change background color to green for pool table
});

/**** 
* Game Code
****/
var snake = [];
var food;
var direction = {
	x: 0,
	y: 0
};
var nextDirection = {
	x: 0,
	y: 0
};
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 * 2) / gridSize)) * gridSize + gridSize * 1.5;
	var foodY = Math.floor(Math.random() * ((2732 - gridSize * 2) / gridSize)) * gridSize + gridSize * 1.5;
	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];
	var deltaX = touchPos.x - head.x;
	var deltaY = touchPos.y - head.y;
	var magnitude = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
	nextDirection = {
		x: deltaX / magnitude * gridSize,
		y: deltaY / magnitude * 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 * 0.2;
	var newY = snake[0].y + direction.y * 0.2;
	// 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 tail = snake[snake.length - 1];
		var newSegment1 = new SnakeSegment();
		var newSegment2 = new SnakeSegment();
		var newSegmentX1 = tail.x - direction.x;
		var newSegmentY1 = tail.y - direction.y;
		var newSegmentX2 = newSegmentX1 - direction.x;
		var newSegmentY2 = newSegmentY1 - direction.y;
		newSegment1.move(newSegmentX1, newSegmentY1);
		newSegment2.move(newSegmentX2, newSegmentY2);
		snake.push(newSegment1);
		snake.push(newSegment2);
		game.addChild(newSegment1);
		game.addChild(newSegment2);
		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);
	// Food shoots projectiles randomly
	if (Math.random() < 0.005) {
		// 0.5% chance each tick
		food.shoot(snake[0].x, snake[0].y);
	}
	// Move projectiles
	food.moveProjectiles();
	// Check for collisions with projectiles
	for (var i = 0; i < food.projectiles.length; i++) {
		if (snake[0].intersects(food.projectiles[i])) {
			gameOver();
			return;
		}
	}
});
// Start the game
initGame();