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

/**** 
* Classes
****/ 
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdGraphics = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.velocityY = 0;
	self.gravity = 0.6;
	self.flapPower = -16;
	self.maxFallSpeed = 12;
	self.flap = function () {
		self.velocityY = self.flapPower;
		LK.getSound('flap').play();
		// Rotate bird upward when flapping
		tween(birdGraphics, {
			rotation: -0.3
		}, {
			duration: 150
		});
	};
	self.update = function () {
		// Apply gravity
		self.velocityY += self.gravity;
		if (self.velocityY > self.maxFallSpeed) {
			self.velocityY = self.maxFallSpeed;
		}
		// Move bird
		self.y += self.velocityY;
		// Rotate bird based on velocity
		if (self.velocityY > 0) {
			var targetRotation = Math.min(self.velocityY * 0.08, 1.5);
			tween(birdGraphics, {
				rotation: targetRotation
			}, {
				duration: 200
			});
		}
	};
	return self;
});
var Pipe = Container.expand(function () {
	var self = Container.call(this);
	self.topPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 1
	});
	self.bottomPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 0
	});
	self.gapSize = 400;
	self.speed = -4;
	self.scored = false;
	self.setup = function (gapY) {
		// Ensure gap is properly centered and pipes are aligned
		var halfGap = self.gapSize / 2;
		// Position pipes to create a clear, passable gap
		// Top pipe extends from screen top to gap start
		self.topPipe.y = gapY - halfGap;
		// Bottom pipe extends from gap end to screen bottom  
		self.bottomPipe.y = gapY + halfGap;
		// Ensure pipes are perfectly aligned horizontally
		self.topPipe.x = 0;
		self.bottomPipe.x = 0;
		// Ensure the gap is visually clear and bird-sized
		self.topPipe.height = Math.max(0, gapY - halfGap);
		self.bottomPipe.height = Math.max(0, 2732 - (gapY + halfGap));
	};
	self.update = function () {
		self.x += self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87CEEB
});

/**** 
* Game Code
****/ 
var bird;
var pipes = [];
var ground;
var gameStarted = false;
var gameOver = false;
var pipeSpawnTimer = 0;
var pipeSpawnInterval = 240; // frames between pipe spawns
// Create score display
var scoreTxt = new Text2('0', {
	size: 100,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Create tap to start instruction
var instructionTxt = new Text2('TAP TO START', {
	size: 80,
	fill: 0xFFFFFF
});
instructionTxt.anchor.set(0.5, 0.5);
instructionTxt.x = 2048 / 2;
instructionTxt.y = 2732 / 2 - 200;
game.addChild(instructionTxt);
// Initialize bird
bird = game.addChild(new Bird());
bird.x = 2048 / 4;
bird.y = 2732 / 2;
// Create ground
ground = game.addChild(LK.getAsset('ground', {
	anchorX: 0,
	anchorY: 1
}));
ground.x = 0;
ground.y = 2732;
function startGame() {
	gameStarted = true;
	if (instructionTxt.parent) {
		instructionTxt.parent.removeChild(instructionTxt);
	}
	bird.flap();
}
function spawnPipe() {
	var pipe = new Pipe();
	// Calculate safe boundaries for gap placement
	var safeTop = 250; // Increased distance from top for easier passage
	var safeBottom = ground.y - 250; // Increased distance from ground for easier passage
	var availableHeight = safeBottom - safeTop;
	// Create more predictable, bird-friendly gap positioning
	// Focus gaps in the middle 60% of the safe area for better playability
	var gapY = safeTop + availableHeight * 0.2 + Math.random() * (availableHeight * 0.6);
	// Ensure gap is always within safe bounds with proper clearance
	var minGapY = safeTop + pipe.gapSize / 2;
	var maxGapY = safeBottom - pipe.gapSize / 2;
	gapY = Math.max(minGapY, Math.min(maxGapY, gapY));
	// Apply additional smoothing to prevent extreme positions
	var screenCenter = 2732 / 2;
	gapY = gapY * 0.7 + screenCenter * 0.3; // Bias toward screen center
	pipe.setup(gapY);
	pipe.x = 2048 + 60; // Start position for smooth entry
	pipes.push(pipe);
	game.addChild(pipe);
}
function checkCollisions() {
	// Check ground collision
	if (bird.y + 30 >= ground.y) {
		return true;
	}
	// Check ceiling collision
	if (bird.y - 30 <= 0) {
		return true;
	}
	// Check pipe collisions
	for (var i = 0; i < pipes.length; i++) {
		var pipe = pipes[i];
		var birdLeft = bird.x - 40;
		var birdRight = bird.x + 40;
		var birdTop = bird.y - 30;
		var birdBottom = bird.y + 30;
		var pipeLeft = pipe.x - 150;
		var pipeRight = pipe.x + 150;
		// Check if bird is in pipe's x range
		if (birdRight > pipeLeft && birdLeft < pipeRight) {
			// Check collision with top pipe (more precise alignment)
			if (birdTop <= pipe.topPipe.y) {
				return true;
			}
			// Check collision with bottom pipe (more precise alignment)
			if (birdBottom >= pipe.bottomPipe.y) {
				return true;
			}
		}
	}
	return false;
}
function updateScore() {
	for (var i = 0; i < pipes.length; i++) {
		var pipe = pipes[i];
		if (!pipe.scored && bird.x > pipe.x + 150) {
			pipe.scored = true;
			LK.setScore(LK.getScore() + 1);
			scoreTxt.setText(LK.getScore());
			LK.getSound('score').play();
			// Increase difficulty slightly
			if (LK.getScore() % 5 === 0 && pipeSpawnInterval > 60) {
				pipeSpawnInterval -= 2;
			}
			break;
		}
	}
}
function cleanupPipes() {
	for (var i = pipes.length - 1; i >= 0; i--) {
		var pipe = pipes[i];
		if (pipe.x < -200) {
			pipe.destroy();
			pipes.splice(i, 1);
		}
	}
}
game.down = function (x, y, obj) {
	if (gameOver) {
		return;
	}
	if (!gameStarted) {
		startGame();
	} else {
		bird.flap();
	}
};
game.update = function () {
	if (gameOver) {
		return;
	}
	if (gameStarted) {
		// Check for collisions
		if (checkCollisions()) {
			gameOver = true;
			LK.showGameOver();
			return;
		}
		// Spawn pipes
		pipeSpawnTimer++;
		if (pipeSpawnTimer >= pipeSpawnInterval) {
			spawnPipe();
			pipeSpawnTimer = 0;
		}
		// Update score
		updateScore();
		// Cleanup off-screen pipes
		cleanupPipes();
	} else {
		// Gentle floating animation when waiting to start
		bird.y += Math.sin(LK.ticks * 0.1) * 0.5;
	}
};