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

/**** 
* Classes
****/ 
// Bird class
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdSprite = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.vy = 0; // vertical velocity
	// Bird physics constants
	self.gravity = 0.8; // px per frame^2 (further reduced for even slower fall)
	self.flapStrength = -24; // px per frame (reduced for less ascent)
	// Flap method
	self.flap = function () {
		self.vy = self.flapStrength;
		// Animate a quick scale for feedback
		tween(birdSprite, {
			scaleY: 0.7
		}, {
			duration: 60,
			easing: tween.cubicOut,
			onFinish: function onFinish() {
				tween(birdSprite, {
					scaleY: 1
				}, {
					duration: 120,
					easing: tween.cubicOut
				});
			}
		});
	};
	// Update method
	self.update = function () {
		self.vy += self.gravity;
		self.y += self.vy;
		// Clamp rotation for visual feedback
		var maxAngle = Math.PI / 4;
		var minAngle = -Math.PI / 6;
		var angle = self.vy / 40 * maxAngle;
		if (angle > maxAngle) angle = maxAngle;
		if (angle < minAngle) angle = minAngle;
		birdSprite.rotation = angle;
	};
	return self;
});
// PipePair class (top and bottom pipes)
var PipePair = Container.expand(function () {
	var self = Container.call(this);
	// Pipe gap size and min/max Y for gap center
	self.gap = 600; // Increased gap size for easier play
	self.pipeWidth = 200;
	self.pipeHeight = 900;
	// Top pipe
	self.topPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 1,
		width: self.pipeWidth,
		height: self.pipeHeight
	});
	// Bottom pipe
	self.bottomPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 0,
		width: self.pipeWidth,
		height: self.pipeHeight
	});
	// Set pipes' positions based on gapY
	self.setGapY = function (gapY) {
		// Top pipe: bottom at gapY - gap/2, top at y=0
		self.topPipe.y = gapY - self.gap / 2;
		self.topPipe.height = self.topPipe.y; // height from top to bottom of top pipe
		// Bottom pipe: top at gapY + gap/2, bottom at ground
		var groundY = 2732 - 60; // GROUND_Y
		self.bottomPipe.y = gapY + self.gap / 2;
		self.bottomPipe.height = groundY - self.bottomPipe.y; // height from top of bottom pipe to ground
	};
	// For scoring
	self.passed = false;
	// Update method
	self.update = function () {
		self.x -= pipeSpeed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87ceeb // Sky blue
});

/**** 
* Game Code
****/ 
// Game constants
// Bird: yellow ellipse
// Pipe: green box
// Ground: brown box
var BIRD_START_X = 600;
var BIRD_START_Y = 1200;
var GROUND_Y = 2732 - 60; // ground height is 120, anchorY=0
var PIPE_INTERVAL = 105; // frames between pipes (~1.75s at 60fps)
var PIPE_MIN_Y = 500;
var PIPE_MAX_Y = 2732 - 500 - 420; // leave space for gap and ground
var pipeSpeed = 16; // px per frame, increases with score
// Game state
var bird;
var pipes = [];
var ground;
var score = 0;
var scoreTxt;
var lastPipeTick = 0;
var gameStarted = false;
var gameOver = false;
// Add ground
ground = LK.getAsset('ground', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: GROUND_Y
});
game.addChild(ground);
// Add score text to GUI
scoreTxt = new Text2('0', {
	size: 160,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Add bird
bird = new Bird();
bird.x = BIRD_START_X;
bird.y = BIRD_START_Y;
game.addChild(bird);
// Start game on first tap
function startGame() {
	if (!gameStarted) {
		gameStarted = true;
		score = 0;
		LK.setScore(0);
		scoreTxt.setText('0');
		// Remove old pipes
		for (var i = 0; i < pipes.length; i++) {
			pipes[i].destroy();
		}
		pipes = [];
		// Reset bird
		bird.x = BIRD_START_X;
		bird.y = BIRD_START_Y;
		bird.vy = 0;
		pipeSpeed = 16;
		lastPipeTick = LK.ticks;
		gameOver = false;
	}
}
// Flap on tap
game.down = function (x, y, obj) {
	if (gameOver) return;
	if (!gameStarted) {
		startGame();
	}
	bird.flap();
};
// Main update loop
game.update = function () {
	if (!gameStarted || gameOver) return;
	// Bird physics
	bird.update();
	// Clamp bird to top of screen
	if (bird.y < 0) bird.y = 0;
	// Pipes
	for (var i = pipes.length - 1; i >= 0; i--) {
		var pipePair = pipes[i];
		pipePair.update();
		// Remove pipes off screen
		if (pipePair.x < -pipePair.pipeWidth) {
			pipePair.destroy();
			pipes.splice(i, 1);
			continue;
		}
		// Scoring: passed center of pipes
		if (!pipePair.passed && bird.x > pipePair.x + pipePair.pipeWidth / 2) {
			pipePair.passed = true;
			score += 1;
			LK.setScore(score);
			scoreTxt.setText(score + '');
			// Increase speed every 10 points
			if (score % 10 === 0) {
				pipeSpeed += 2;
			}
		}
		// Collision detection
		// Top pipe
		if (bird.intersects(pipePair.topPipe) || bird.intersects(pipePair.bottomPipe)) {
			endGame();
			return;
		}
	}
	// Add new pipes
	if (LK.ticks - lastPipeTick > PIPE_INTERVAL) {
		var gapY = PIPE_MIN_Y + Math.floor(Math.random() * (PIPE_MAX_Y - PIPE_MIN_Y));
		var pipePair = new PipePair();
		pipePair.x = 2048 + 200; // start just off right edge
		pipePair.setGapY(gapY);
		pipes.push(pipePair);
		game.addChild(pipePair);
		lastPipeTick = LK.ticks;
	}
	// Ground collision
	if (bird.y + bird.height / 2 > GROUND_Y) {
		bird.y = GROUND_Y - bird.height / 2;
		endGame();
		return;
	}
};
// End game
function endGame() {
	if (gameOver) return;
	gameOver = true;
	// Flash red
	LK.effects.flashScreen(0xff0000, 600);
	// Show game over popup (handled by LK)
	LK.showGameOver();
}
// Reset on game over (handled by LK engine, but for safety)
game.onGameOver = function () {
	gameStarted = false;
	gameOver = false;
	score = 0;
	LK.setScore(0);
	scoreTxt.setText('0');
	// Remove pipes
	for (var i = 0; i < pipes.length; i++) {
		pipes[i].destroy();
	}
	pipes = [];
	// Reset bird
	bird.x = BIRD_START_X;
	bird.y = BIRD_START_Y;
	bird.vy = 0;
	pipeSpeed = 16;
	lastPipeTick = LK.ticks;
};