/**** 
* Plugins
****/ 
var storage = LK.import("@upit/storage.v1");

/**** 
* Classes
****/ 
var Food = Container.expand(function () {
	var self = Container.call(this);
	var foodGraphics = self.attachAsset('food', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	return self;
});
var SnakeSegment = Container.expand(function () {
	var self = Container.call(this);
	var segmentGraphics = self.attachAsset('snakeSegment', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x1a1a1a
});

/**** 
* Game Code
****/ 
var GRID_SIZE = 40;
var GRID_WIDTH = Math.floor(2048 / GRID_SIZE);
var GRID_HEIGHT = Math.floor(2732 / GRID_SIZE);
var INITIAL_SPEED = 8;
var MAX_SPEED = 15;
var snake = [];
var snakeDirection = {
	x: 1,
	y: 0
};
var nextDirection = {
	x: 1,
	y: 0
};
var food = null;
var score = 0;
var moveCounter = 0;
var currentSpeed = INITIAL_SPEED;
var gameActive = true;
var lastTouchX = null;
var lastTouchY = null;
// Initialize score display
var scoreTxt = new Text2('Score: 0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Initialize snake with 3 segments
function initializeSnake() {
	snake = [];
	var startX = Math.floor(GRID_WIDTH / 2);
	var startY = Math.floor(GRID_HEIGHT / 2);
	for (var i = 0; i < 3; i++) {
		var segment = game.addChild(new SnakeSegment());
		segment.gridX = startX - i;
		segment.gridY = startY;
		segment.x = segment.gridX * GRID_SIZE + GRID_SIZE / 2;
		segment.y = segment.gridY * GRID_SIZE + GRID_SIZE / 2;
		snake.push(segment);
	}
}
// Spawn food at random location
function spawnFood() {
	if (food) {
		food.destroy();
	}
	var foodGridX, foodGridY, isValid;
	do {
		isValid = true;
		foodGridX = Math.floor(Math.random() * GRID_WIDTH);
		foodGridY = Math.floor(Math.random() * GRID_HEIGHT);
		// Check if food spawns on snake
		for (var i = 0; i < snake.length; i++) {
			if (snake[i].gridX === foodGridX && snake[i].gridY === foodGridY) {
				isValid = false;
				break;
			}
		}
	} while (!isValid);
	food = game.addChild(new Food());
	food.gridX = foodGridX;
	food.gridY = foodGridY;
	food.x = food.gridX * GRID_SIZE + GRID_SIZE / 2;
	food.y = food.gridY * GRID_SIZE + GRID_SIZE / 2;
}
// Update score display
function updateScoreDisplay() {
	scoreTxt.setText('Score: ' + score);
}
// Increase difficulty based on snake length
function updateDifficulty() {
	currentSpeed = INITIAL_SPEED + Math.floor(snake.length / 5);
	if (currentSpeed > MAX_SPEED) {
		currentSpeed = MAX_SPEED;
	}
}
// Handle swipe direction changes
game.down = function (x, y, obj) {
	lastTouchX = x;
	lastTouchY = y;
};
game.up = function (x, y, obj) {
	if (lastTouchX === null || lastTouchY === null) {
		return;
	}
	var deltaX = x - lastTouchX;
	var deltaY = y - lastTouchY;
	var absDeltaX = Math.abs(deltaX);
	var absDeltaY = Math.abs(deltaY);
	// Require minimum swipe distance
	if (absDeltaX < 50 && absDeltaY < 50) {
		lastTouchX = null;
		lastTouchY = null;
		return;
	}
	// Determine swipe direction
	if (absDeltaX > absDeltaY) {
		// Horizontal swipe
		if (deltaX > 0 && snakeDirection.x !== -1) {
			nextDirection = {
				x: 1,
				y: 0
			};
		} else if (deltaX < 0 && snakeDirection.x !== 1) {
			nextDirection = {
				x: -1,
				y: 0
			};
		}
	} else {
		// Vertical swipe
		if (deltaY > 0 && snakeDirection.y !== -1) {
			nextDirection = {
				x: 0,
				y: 1
			};
		} else if (deltaY < 0 && snakeDirection.y !== 1) {
			nextDirection = {
				x: 0,
				y: -1
			};
		}
	}
	lastTouchX = null;
	lastTouchY = null;
};
// Main game update loop
game.update = function () {
	if (!gameActive) {
		return;
	}
	moveCounter++;
	// Move snake at current speed
	if (moveCounter >= 60 / currentSpeed) {
		moveCounter = 0;
		// Update direction
		snakeDirection = nextDirection;
		// Calculate new head position
		var headGridX = snake[0].gridX + snakeDirection.x;
		var headGridY = snake[0].gridY + snakeDirection.y;
		// Check wall collision
		if (headGridX < 0 || headGridX >= GRID_WIDTH || headGridY < 0 || headGridY >= GRID_HEIGHT) {
			LK.getSound('crash').play();
			gameActive = false;
			LK.showGameOver();
			return;
		}
		// Check self collision
		for (var i = 0; i < snake.length; i++) {
			if (snake[i].gridX === headGridX && snake[i].gridY === headGridY) {
				LK.getSound('crash').play();
				gameActive = false;
				LK.showGameOver();
				return;
			}
		}
		// Create new head segment
		var newHead = game.addChild(new SnakeSegment());
		newHead.gridX = headGridX;
		newHead.gridY = headGridY;
		newHead.x = newHead.gridX * GRID_SIZE + GRID_SIZE / 2;
		newHead.y = newHead.gridY * GRID_SIZE + GRID_SIZE / 2;
		snake.unshift(newHead);
		// Check food collision
		if (food && food.gridX === headGridX && food.gridY === headGridY) {
			LK.getSound('eat').play();
			score += 10;
			LK.setScore(score);
			updateScoreDisplay();
			updateDifficulty();
			spawnFood();
		} else {
			// Remove tail if not eating
			var tail = snake.pop();
			tail.destroy();
		}
	}
};
// Initialize game
initializeSnake();
spawnFood();
updateScoreDisplay();