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

/**** 
* Classes
****/ 
// Animal class
var Animal = Container.expand(function () {
	var self = Container.call(this);
	self.type = null;
	self.asset = null;
	self.setType = function (type) {
		self.type = type;
		if (self.asset) {
			self.removeChild(self.asset);
		}
		self.asset = self.attachAsset(type, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	return self;
});
// Snake Segment (body or head)
var SnakeSegment = Container.expand(function () {
	var self = Container.call(this);
	self.asset = null;
	self.setType = function (type) {
		if (self.asset) {
			self.removeChild(self.asset);
		}
		var assetId = type === 'head' ? 'snakeHead' : 'snakeBody';
		self.asset = self.attachAsset(assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	self.setType('body');
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222222
});

/**** 
* Game Code
****/ 
// Animal assets: pig, cat, bee, frog (box/ellipse with different colors)
// Game constants
var GAME_WIDTH = 2048;
var GAME_HEIGHT = 2732;
var SNAKE_START_LENGTH = 3;
var SNAKE_START_SPEED = 8; // pixels per tick
var SNAKE_SPEED_INCREMENT = 1.5; // speed up per sequence
var SNAKE_MAX_SPEED = 32;
var SEGMENT_SPACING = 90; // px between segments
var ANIMAL_TYPES = ['pig', 'cat', 'bee', 'frog'];
var ANIMAL_NAMES = {
	pig: "Pig",
	cat: "Cat",
	bee: "Bee",
	frog: "Frog"
};
// Game state
var snake = [];
var snakeDir = {
	x: 0,
	y: -1
}; // start moving up
var snakeNextDir = {
	x: 0,
	y: -1
};
var snakeSpeed = SNAKE_START_SPEED;
var snakePositions = []; // for body following
var animals = [];
var currentTargetIndex = 0; // which animal in sequence to eat next
var score = 0;
var sequenceCount = 0;
var isGameOver = false;
var moveCooldown = 0; // for swipe input
var dragStart = null;
// GUI
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
var orderTxt = new Text2('', {
	size: 70,
	fill: "#fff"
});
orderTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(orderTxt);
orderTxt.y = 130;
// Helper: get random position for animal, not too close to snake head
function getRandomAnimalPos() {
	var margin = 180;
	var tries = 0;
	while (tries < 20) {
		var x = margin + Math.random() * (GAME_WIDTH - 2 * margin);
		var y = margin + Math.random() * (GAME_HEIGHT - 2 * margin);
		// Avoid spawning too close to snake head
		var dx = x - snake[0].x;
		var dy = y - snake[0].y;
		if (dx * dx + dy * dy > 400 * 400) {
			return {
				x: x,
				y: y
			};
		}
		tries++;
	}
	// fallback
	return {
		x: margin + Math.random() * (GAME_WIDTH - 2 * margin),
		y: margin + Math.random() * (GAME_HEIGHT - 2 * margin)
	};
}
// Helper: update order text
function updateOrderText() {
	var s = '';
	for (var i = 0; i < ANIMAL_TYPES.length; i++) {
		if (i === currentTargetIndex) {
			s += '[b]' + ANIMAL_NAMES[ANIMAL_TYPES[i]] + '[/b] ';
		} else {
			s += ANIMAL_NAMES[ANIMAL_TYPES[i]] + ' ';
		}
	}
	orderTxt.setText(s.trim());
}
// Helper: spawn all animals
function spawnAnimals() {
	// Remove old
	for (var i = 0; i < animals.length; i++) {
		animals[i].destroy();
	}
	animals = [];
	for (var i = 0; i < ANIMAL_TYPES.length; i++) {
		var animal = new Animal();
		animal.setType(ANIMAL_TYPES[i]);
		var pos = getRandomAnimalPos();
		animal.x = pos.x;
		animal.y = pos.y;
		animals.push(animal);
		game.addChild(animal);
	}
}
// Helper: reset snake
function resetSnake() {
	for (var i = 0; i < snake.length; i++) {
		snake[i].destroy();
	}
	snake = [];
	snakePositions = [];
	var startX = GAME_WIDTH / 2;
	var startY = GAME_HEIGHT / 2 + 300;
	for (var i = 0; i < SNAKE_START_LENGTH; i++) {
		var seg = new SnakeSegment();
		seg.setType(i === 0 ? 'head' : 'body');
		seg.x = startX;
		seg.y = startY + i * SEGMENT_SPACING;
		snake.push(seg);
		game.addChild(seg);
		snakePositions.push({
			x: seg.x,
			y: seg.y
		});
	}
	snakeDir = {
		x: 0,
		y: -1
	};
	snakeNextDir = {
		x: 0,
		y: -1
	};
}
// Helper: grow snake
function growSnake() {
	var last = snake[snake.length - 1];
	var seg = new SnakeSegment();
	seg.setType('body');
	seg.x = last.x;
	seg.y = last.y;
	snake.push(seg);
	game.addChild(seg);
	snakePositions.push({
		x: seg.x,
		y: seg.y
	});
}
// Helper: check self collision
function checkSelfCollision() {
	var head = snake[0];
	for (var i = 2; i < snake.length; i++) {
		var seg = snake[i];
		var dx = head.x - seg.x;
		var dy = head.y - seg.y;
		if (dx * dx + dy * dy < 60 * 60) {
			return true;
		}
	}
	return false;
}
// Helper: check wall collision
function checkWallCollision() {
	var head = snake[0];
	var margin = 40;
	if (head.x < margin || head.x > GAME_WIDTH - margin || head.y < margin || head.y > GAME_HEIGHT - margin) {
		return true;
	}
	return false;
}
// Helper: check animal collision
function checkAnimalCollision() {
	var head = snake[0];
	for (var i = 0; i < animals.length; i++) {
		var animal = animals[i];
		var dx = head.x - animal.x;
		var dy = head.y - animal.y;
		if (dx * dx + dy * dy < 80 * 80) {
			return i;
		}
	}
	return -1;
}
// Helper: handle eating animal
function eatAnimal(idx) {
	var animal = animals[idx];
	if (animal.type === ANIMAL_TYPES[currentTargetIndex]) {
		// Correct animal
		growSnake();
		score++;
		scoreTxt.setText(score);
		// Remove and respawn this animal
		animal.destroy();
		animals.splice(idx, 1);
		// Next in sequence
		currentTargetIndex++;
		if (currentTargetIndex >= ANIMAL_TYPES.length) {
			// Sequence complete
			sequenceCount++;
			currentTargetIndex = 0;
			// Speed up
			snakeSpeed = Math.min(snakeSpeed + SNAKE_SPEED_INCREMENT, SNAKE_MAX_SPEED);
			// Respawn all animals
			spawnAnimals();
			// Flash green
			LK.effects.flashScreen(0x00ff00, 400);
		} else {
			// Only respawn this animal
			var newAnimal = new Animal();
			newAnimal.setType(animal.type);
			var pos = getRandomAnimalPos();
			newAnimal.x = pos.x;
			newAnimal.y = pos.y;
			animals.push(newAnimal);
			game.addChild(newAnimal);
		}
		updateOrderText();
	} else {
		// Wrong animal: game over
		LK.effects.flashScreen(0xff0000, 800);
		isGameOver = true;
		LK.showGameOver();
	}
}
// Helper: handle game over
function handleGameOver() {
	isGameOver = true;
	// LK.showGameOver() already called
}
// Input: swipe to change direction
function getSwipeDir(dx, dy) {
	if (Math.abs(dx) > Math.abs(dy)) {
		return {
			x: dx > 0 ? 1 : -1,
			y: 0
		};
	} else {
		return {
			x: 0,
			y: dy > 0 ? 1 : -1
		};
	}
}
// Input: touch/drag
game.down = function (x, y, obj) {
	dragStart = {
		x: x,
		y: y
	};
};
game.up = function (x, y, obj) {
	dragStart = null;
};
game.move = function (x, y, obj) {
	if (dragStart && !isGameOver) {
		var dx = x - dragStart.x;
		var dy = y - dragStart.y;
		if (dx * dx + dy * dy > 80 * 80) {
			var dir = getSwipeDir(dx, dy);
			// Prevent reversing
			if (!(dir.x === -snakeDir.x && dir.y === -snakeDir.y)) {
				snakeNextDir = dir;
			}
			dragStart = null;
		}
	}
};
// Main update loop
game.update = function () {
	if (isGameOver) return;
	// Move snake
	// Update direction
	if (snakeNextDir.x !== snakeDir.x || snakeNextDir.y !== snakeDir.y) {
		snakeDir = {
			x: snakeNextDir.x,
			y: snakeNextDir.y
		};
	}
	// Calculate new head position
	var head = snake[0];
	var newX = head.x + snakeDir.x * snakeSpeed;
	var newY = head.y + snakeDir.y * snakeSpeed;
	// Store previous positions
	snakePositions.unshift({
		x: newX,
		y: newY
	});
	if (snakePositions.length > snake.length * SEGMENT_SPACING / snakeSpeed + 2) {
		snakePositions.pop();
	}
	// Move segments
	for (var i = 0; i < snake.length; i++) {
		var posIdx = Math.min(i * Math.floor(SEGMENT_SPACING / snakeSpeed), snakePositions.length - 1);
		var pos = snakePositions[posIdx];
		snake[i].x = pos.x;
		snake[i].y = pos.y;
	}
	// Check wall collision
	if (checkWallCollision()) {
		LK.effects.flashScreen(0xff0000, 800);
		handleGameOver();
		LK.showGameOver();
		return;
	}
	// Check self collision
	if (checkSelfCollision()) {
		LK.effects.flashScreen(0xff0000, 800);
		handleGameOver();
		LK.showGameOver();
		return;
	}
	// Check animal collision
	var animalIdx = checkAnimalCollision();
	if (animalIdx !== -1) {
		eatAnimal(animalIdx);
	}
};
// Game start/reset
function startGame() {
	isGameOver = false;
	score = 0;
	sequenceCount = 0;
	snakeSpeed = SNAKE_START_SPEED;
	currentTargetIndex = 0;
	scoreTxt.setText(score);
	updateOrderText();
	resetSnake();
	spawnAnimals();
}
startGame();