/**** 
* 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.velocityX = 0;
	self.velocityY = 0;
	self.isLaunched = false;
	self.isActive = true;
	self.gravity = 0.5;
	self.hasUsedAbility = false;
	self.update = function () {
		if (self.isLaunched && self.isActive) {
			self.velocityY += self.gravity;
			self.x += self.velocityX;
			self.y += self.velocityY;
			// Check ground collision
			if (self.y >= groundY - 30) {
				self.y = groundY - 30;
				self.velocityX *= 0.5;
				self.velocityY = -self.velocityY * 0.6; // Bounce with 60% of velocity
				if (Math.abs(self.velocityX) < 0.5 && Math.abs(self.velocityY) < 0.5) {
					self.isActive = false;
					checkLevelComplete();
				}
			}
			// Check screen boundaries
			if (self.x > 2048 + 100) {
				self.isActive = false;
				checkLevelComplete();
			}
		}
	};
	self.launch = function (velX, velY) {
		self.velocityX = velX;
		self.velocityY = velY;
		self.isLaunched = true;
		LK.getSound('launch').play();
	};
	self.useAbility = function () {
		if (!self.hasUsedAbility && self.isLaunched) {
			self.hasUsedAbility = true;
			// Simple ability: speed boost
			self.velocityX *= 2.5;
			self.velocityY *= 2.5;
		}
	};
	return self;
});
var Block = Container.expand(function (type) {
	var self = Container.call(this);
	var blockGraphics = self.attachAsset(type === 'wood' ? 'woodBlock' : 'stoneBlock', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.type = type;
	self.health = type === 'wood' ? 1 : 2;
	self.velocityX = 0;
	self.velocityY = 0;
	self.isActive = false;
	self.gravity = 0.3;
	self.update = function () {
		if (self.isActive) {
			self.velocityY += self.gravity;
			self.x += self.velocityX;
			self.y += self.velocityY;
			// Ground collision
			if (self.y >= groundY - 50) {
				self.y = groundY - 50;
				self.velocityX *= 0.3;
				self.velocityY = 0;
				if (Math.abs(self.velocityX) < 0.2) {
					self.isActive = false;
				}
			}
		}
	};
	self.takeDamage = function (damage, impactX, impactY) {
		self.health -= damage * 2;
		LK.getSound('hit').play();
		if (self.health <= 0) {
			self.destroy();
		} else {
			// Add some physics impact
			self.velocityX = (impactX - self.x) * 0.15;
			self.velocityY = (impactY - self.y) * 0.15;
			self.isActive = true;
		}
	};
	self.destroy = function () {
		LK.effects.flashObject(self, 0xffff00, 300);
		tween(self, {
			alpha: 0,
			rotation: Math.PI
		}, {
			duration: 1000,
			onFinish: function onFinish() {
				if (self.parent) {
					self.parent.removeChild(self);
				}
				var blockIndex = blocks.indexOf(self);
				if (blockIndex !== -1) {
					blocks.splice(blockIndex, 1);
				}
			}
		});
	};
	return self;
});
var Pig = Container.expand(function () {
	var self = Container.call(this);
	var pigGraphics = self.attachAsset('pig', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.isDestroyed = false;
	self.health = 1;
	self.takeDamage = function (damage) {
		self.health -= damage;
		if (self.health <= 0) {
			self.destroy();
		}
	};
	self.destroy = function () {
		if (!self.isDestroyed) {
			self.isDestroyed = true;
			LK.effects.flashObject(self, 0xff0000, 500);
			LK.getSound('destroy').play();
			tween(self, {
				alpha: 0,
				scaleX: 0.1,
				scaleY: 0.1
			}, {
				duration: 500,
				onFinish: function onFinish() {
					if (self.parent) {
						self.parent.removeChild(self);
					}
					var pigIndex = pigs.indexOf(self);
					if (pigIndex !== -1) {
						pigs.splice(pigIndex, 1);
					}
					checkLevelComplete();
				}
			});
		}
	};
	return self;
});

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

/**** 
* Game Code
****/ 
var groundY = 2732 - 100;
var slingshotX = 400;
var slingshotY = groundY - 150;
var birds = [];
var pigs = [];
var blocks = [];
var currentBird = null;
var trajectoryDots = [];
var isDragging = false;
var dragStartX = 0;
var dragStartY = 0;
var gameState = 'aiming'; // 'aiming', 'flying', 'waiting'
var levelComplete = false;
// Create ground
var ground = game.addChild(LK.getAsset('ground', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: groundY
}));
// Create slingshot
var slingshot = game.addChild(LK.getAsset('slingshot', {
	anchorX: 0.5,
	anchorY: 1,
	x: slingshotX,
	y: slingshotY
}));
// Create trajectory dots
for (var i = 0; i < 20; i++) {
	var dot = game.addChild(LK.getAsset('trajectory', {
		anchorX: 0.5,
		anchorY: 0.5,
		alpha: 0
	}));
	trajectoryDots.push(dot);
}
// Create level structure
function createLevel() {
	// Clear existing level
	while (birds.length > 0) {
		birds[0].parent.removeChild(birds[0]);
		birds.splice(0, 1);
	}
	while (pigs.length > 0) {
		pigs[0].parent.removeChild(pigs[0]);
		pigs.splice(0, 1);
	}
	while (blocks.length > 0) {
		blocks[0].parent.removeChild(blocks[0]);
		blocks.splice(0, 1);
	}
	// Create birds
	for (var i = 0; i < 3; i++) {
		var bird = new Bird();
		bird.x = slingshotX - 100 - i * 80;
		bird.y = slingshotY - 30;
		birds.push(bird);
		game.addChild(bird);
	}
	// Create structure with blocks and pigs
	var structureX = 1600;
	var structureY = groundY;
	// Create blocks
	for (var i = 0; i < 3; i++) {
		var block = new Block('wood');
		block.x = structureX + i * 60;
		block.y = structureY - 50;
		blocks.push(block);
		game.addChild(block);
	}
	// Create upper level blocks
	for (var i = 0; i < 2; i++) {
		var block = new Block('wood');
		block.x = structureX + 30 + i * 60;
		block.y = structureY - 150;
		blocks.push(block);
		game.addChild(block);
	}
	// Create pigs
	var pig1 = new Pig();
	pig1.x = structureX + 30;
	pig1.y = structureY - 100;
	pigs.push(pig1);
	game.addChild(pig1);
	var pig2 = new Pig();
	pig2.x = structureX + 90;
	pig2.y = structureY - 100;
	pigs.push(pig2);
	game.addChild(pig2);
	// Set current bird
	currentBird = birds[0];
	currentBird.x = slingshotX;
	currentBird.y = slingshotY - 30;
	gameState = 'aiming';
	levelComplete = false;
}
function updateTrajectory(mouseX, mouseY) {
	var deltaX = mouseX - slingshotX;
	var deltaY = mouseY - slingshotY;
	var distance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
	if (distance > 150) {
		deltaX = deltaX / distance * 150;
		deltaY = deltaY / distance * 150;
	}
	var velocityX = -deltaX * 0.2;
	var velocityY = -deltaY * 0.2;
	for (var i = 0; i < trajectoryDots.length; i++) {
		var t = i * 3;
		var x = slingshotX + velocityX * t;
		var y = slingshotY - 30 + velocityY * t + 0.5 * 0.5 * t * t;
		trajectoryDots[i].x = x;
		trajectoryDots[i].y = y;
		trajectoryDots[i].alpha = Math.max(0, 1 - i * 0.05);
	}
}
function hideTrajectory() {
	for (var i = 0; i < trajectoryDots.length; i++) {
		trajectoryDots[i].alpha = 0;
	}
}
function checkCollisions() {
	if (!currentBird || !currentBird.isLaunched) return;
	// Check bird-pig collisions
	for (var i = 0; i < pigs.length; i++) {
		var pig = pigs[i];
		if (!pig.isDestroyed && currentBird.intersects(pig)) {
			pig.takeDamage(1);
			currentBird.isActive = false;
			checkLevelComplete();
			return;
		}
	}
	// Check bird-block collisions
	for (var i = 0; i < blocks.length; i++) {
		var block = blocks[i];
		if (currentBird.intersects(block)) {
			block.takeDamage(1, currentBird.x, currentBird.y);
			currentBird.isActive = false;
			checkLevelComplete();
			return;
		}
	}
}
function checkLevelComplete() {
	if (levelComplete) return;
	// Check if all blocks are destroyed
	var activeBlocks = 0;
	for (var i = 0; i < blocks.length; i++) {
		activeBlocks++;
	}
	if (activeBlocks === 0) {
		levelComplete = true;
		LK.setTimeout(function () {
			LK.showYouWin();
		}, 1000);
		return;
	}
	// Check if current bird is inactive and we need next bird
	if (currentBird && !currentBird.isActive && gameState === 'flying') {
		gameState = 'waiting';
		hideTrajectory();
		LK.setTimeout(function () {
			// Find next bird
			var nextBirdIndex = birds.indexOf(currentBird) + 1;
			if (nextBirdIndex < birds.length) {
				currentBird = birds[nextBirdIndex];
				currentBird.x = slingshotX;
				currentBird.y = slingshotY - 30;
				gameState = 'aiming';
			} else {
				// No more birds, game over
				LK.showGameOver();
			}
		}, 1000);
	}
}
// Game event handlers
game.down = function (x, y, obj) {
	if (gameState === 'aiming' && currentBird) {
		isDragging = true;
		dragStartX = x;
		dragStartY = y;
		updateTrajectory(x, y);
	}
};
game.move = function (x, y, obj) {
	if (isDragging && gameState === 'aiming' && currentBird) {
		var deltaX = x - slingshotX;
		var deltaY = y - slingshotY;
		var distance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
		if (distance > 150) {
			deltaX = deltaX / distance * 150;
			deltaY = deltaY / distance * 150;
		}
		currentBird.x = slingshotX + deltaX;
		currentBird.y = slingshotY - 30 + deltaY;
		updateTrajectory(x, y);
	}
};
game.up = function (x, y, obj) {
	if (isDragging && gameState === 'aiming' && currentBird) {
		isDragging = false;
		var deltaX = currentBird.x - slingshotX;
		var deltaY = currentBird.y - (slingshotY - 30);
		var velocityX = -deltaX * 0.2;
		var velocityY = -deltaY * 0.2;
		if (Math.abs(velocityX) > 1 || Math.abs(velocityY) > 1) {
			currentBird.launch(velocityX, velocityY);
			gameState = 'flying';
			hideTrajectory();
		} else {
			currentBird.x = slingshotX;
			currentBird.y = slingshotY - 30;
			hideTrajectory();
		}
	} else if (gameState === 'flying' && currentBird) {
		// Use bird ability
		currentBird.useAbility();
	}
};
game.update = function () {
	checkCollisions();
	// Update blocks physics
	for (var i = 0; i < blocks.length; i++) {
		var block = blocks[i];
		// Check block-pig collisions
		for (var j = 0; j < pigs.length; j++) {
			var pig = pigs[j];
			if (!pig.isDestroyed && block.intersects(pig)) {
				pig.takeDamage(1);
			}
		}
	}
};
// Initialize level
createLevel();

===================================================================
--- original.js
+++ change.js
@@ -103,10 +103,15 @@
 			rotation: Math.PI
 		}, {
 			duration: 1000,
 			onFinish: function onFinish() {
-				self.parent.removeChild(self);
-				blocks.splice(blocks.indexOf(self), 1);
+				if (self.parent) {
+					self.parent.removeChild(self);
+				}
+				var blockIndex = blocks.indexOf(self);
+				if (blockIndex !== -1) {
+					blocks.splice(blockIndex, 1);
+				}
 			}
 		});
 	};
 	return self;
@@ -136,10 +141,15 @@
 				scaleY: 0.1
 			}, {
 				duration: 500,
 				onFinish: function onFinish() {
-					self.parent.removeChild(self);
-					pigs.splice(pigs.indexOf(self), 1);
+					if (self.parent) {
+						self.parent.removeChild(self);
+					}
+					var pigIndex = pigs.indexOf(self);
+					if (pigIndex !== -1) {
+						pigs.splice(pigIndex, 1);
+					}
 					checkLevelComplete();
 				}
 			});
 		}