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

/**** 
* Classes
****/ 
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 6;
	self.targetX = 0;
	self.targetY = 0;
	self.setTarget = function (x, y) {
		self.targetX = x;
		self.targetY = y;
	};
	self.update = function () {
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		if (distance > 0) {
			self.x += dx / distance * self.speed;
			self.y += dy / distance * self.speed;
		}
	};
	return self;
});
var PlayerBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('playerBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 12;
	self.update = function () {
		self.y -= self.speed;
	};
	return self;
});
var PlayerTank = Container.expand(function () {
	var self = Container.call(this);
	var tankGraphics = self.attachAsset('playerTank', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.fireRate = 15;
	self.fireTimer = 0;
	self.update = function () {
		if (self.fireTimer > 0) {
			self.fireTimer--;
		}
	};
	self.canFire = function () {
		return self.fireTimer <= 0;
	};
	self.fire = function () {
		if (self.canFire()) {
			self.fireTimer = self.fireRate;
			return true;
		}
		return false;
	};
	return self;
});
var Spaceship = Container.expand(function () {
	var self = Container.call(this);
	var spaceshipGraphics = self.attachAsset('spaceship', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.direction = 1;
	self.deployTimer = 0;
	self.deployRate = 180;
	self.movePattern = Math.random() < 0.5 ? 'horizontal' : 'diagonal';
	self.update = function () {
		if (self.movePattern === 'horizontal') {
			self.x += self.speed * self.direction;
			if (self.x > 1900 || self.x < 148) {
				self.direction *= -1;
			}
		} else {
			self.x += self.speed * self.direction;
			self.y += self.speed * 0.5;
			if (self.x > 1900 || self.x < 148) {
				self.direction *= -1;
			}
		}
		self.deployTimer++;
		if (self.deployTimer >= self.deployRate) {
			self.deployTimer = 0;
			return true;
		}
		return false;
	};
	return self;
});
var UAV = Container.expand(function () {
	var self = Container.call(this);
	var uavGraphics = self.attachAsset('uav', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 4;
	self.targetX = 0;
	self.targetY = 0;
	self.setTarget = function (x, y) {
		self.targetX = x;
		self.targetY = y;
	};
	self.update = function () {
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		if (distance > 0) {
			self.x += dx / distance * self.speed;
			self.y += dy / distance * self.speed;
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000033
});

/**** 
* Game Code
****/ 
var player = new PlayerTank();
player.x = 1024;
player.y = 2600;
game.addChild(player);
var playerBullets = [];
var spaceships = [];
var uavs = [];
var enemyBullets = [];
var spawnTimer = 0;
var spawnRate = 120;
var difficultyTimer = 0;
var enemyFireTimer = 0;
var enemyFireRate = 90;
var scoreTxt = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
var dragActive = false;
function updateScore() {
	scoreTxt.setText('Score: ' + LK.getScore());
}
function spawnSpaceship() {
	var spaceship = new Spaceship();
	spaceship.x = Math.random() * 1800 + 124;
	spaceship.y = -50;
	spaceships.push(spaceship);
	game.addChild(spaceship);
}
function deployUAV(fromX, fromY) {
	var uav = new UAV();
	uav.x = fromX;
	uav.y = fromY;
	uav.setTarget(player.x, player.y);
	uavs.push(uav);
	game.addChild(uav);
	LK.getSound('uavDeploy').play();
}
function fireEnemyBullet(fromX, fromY) {
	var bullet = new EnemyBullet();
	bullet.x = fromX;
	bullet.y = fromY;
	bullet.setTarget(player.x, player.y);
	enemyBullets.push(bullet);
	game.addChild(bullet);
}
game.down = function (x, y, obj) {
	dragActive = true;
	player.x = x;
	if (player.x < 60) player.x = 60;
	if (player.x > 1988) player.x = 1988;
	// Fire bullet when touching screen
	if (player.fire()) {
		var bullet = new PlayerBullet();
		bullet.x = player.x;
		bullet.y = player.y - 40;
		playerBullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('playerShoot').play();
	}
};
game.move = function (x, y, obj) {
	if (dragActive) {
		player.x = x;
		if (player.x < 60) player.x = 60;
		if (player.x > 1988) player.x = 1988;
	}
};
game.up = function (x, y, obj) {
	dragActive = false;
};
game.update = function () {
	// Spawn spaceships
	spawnTimer++;
	if (spawnTimer >= spawnRate) {
		spawnTimer = 0;
		spawnSpaceship();
	}
	// Increase difficulty over time
	difficultyTimer++;
	if (difficultyTimer >= 1800) {
		// Every 30 seconds
		difficultyTimer = 0;
		if (spawnRate > 60) {
			spawnRate -= 10;
		}
		if (enemyFireRate > 45) {
			enemyFireRate -= 5;
		}
	}
	// Player auto-fire
	if (player.fire()) {
		var bullet = new PlayerBullet();
		bullet.x = player.x;
		bullet.y = player.y - 40;
		playerBullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('playerShoot').play();
	}
	// Enemy firing
	enemyFireTimer++;
	if (enemyFireTimer >= enemyFireRate) {
		enemyFireTimer = 0;
		if (spaceships.length > 0) {
			var randomSpaceship = spaceships[Math.floor(Math.random() * spaceships.length)];
			fireEnemyBullet(randomSpaceship.x, randomSpaceship.y);
		}
	}
	// Update player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var bullet = playerBullets[i];
		if (bullet.lastY === undefined) bullet.lastY = bullet.y;
		if (bullet.lastY >= -20 && bullet.y < -20) {
			bullet.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		bullet.lastY = bullet.y;
	}
	// Update spaceships
	for (var j = spaceships.length - 1; j >= 0; j--) {
		var spaceship = spaceships[j];
		if (spaceship.lastY === undefined) spaceship.lastY = spaceship.y;
		var shouldDeploy = spaceship.update();
		if (shouldDeploy) {
			deployUAV(spaceship.x, spaceship.y);
		}
		if (spaceship.lastY < 2732 && spaceship.y >= 2732) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
		spaceship.lastY = spaceship.y;
	}
	// Update UAVs
	for (var k = uavs.length - 1; k >= 0; k--) {
		var uav = uavs[k];
		if (uav.lastY === undefined) uav.lastY = uav.y;
		if (uav.lastY < 2732 && uav.y >= 2732) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
		uav.lastY = uav.y;
	}
	// Update enemy bullets
	for (var l = enemyBullets.length - 1; l >= 0; l--) {
		var enemyBullet = enemyBullets[l];
		if (enemyBullet.lastY === undefined) enemyBullet.lastY = enemyBullet.y;
		if (enemyBullet.lastX === undefined) enemyBullet.lastX = enemyBullet.x;
		// Destroy bullet if it goes off-screen (bottom, left, or right)
		if (enemyBullet.lastY < 2732 && enemyBullet.y >= 2732) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		// Destroy bullet if it goes off-screen (left side)
		if (enemyBullet.lastX >= 0 && enemyBullet.x < 0) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		// Destroy bullet if it goes off-screen (right side)
		if (enemyBullet.lastX <= 2048 && enemyBullet.x > 2048) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		enemyBullet.lastY = enemyBullet.y;
		enemyBullet.lastX = enemyBullet.x;
	}
	// Collision detection - Player bullets vs Spaceships
	for (var m = playerBullets.length - 1; m >= 0; m--) {
		var pBullet = playerBullets[m];
		for (var n = spaceships.length - 1; n >= 0; n--) {
			var ship = spaceships[n];
			if (pBullet.intersects(ship)) {
				// Fire multiple bullets when spaceship is destroyed
				for (var fireCount = 0; fireCount < 3; fireCount++) {
					fireEnemyBullet(ship.x + (fireCount - 1) * 20, ship.y);
				}
				LK.setScore(LK.getScore() + 100);
				updateScore();
				LK.getSound('enemyDestroy').play();
				LK.effects.flashObject(ship, 0xffff00, 200);
				pBullet.destroy();
				playerBullets.splice(m, 1);
				ship.destroy();
				spaceships.splice(n, 1);
				break;
			}
		}
	}
	// Collision detection - Player bullets vs UAVs
	for (var o = playerBullets.length - 1; o >= 0; o--) {
		var pBullet2 = playerBullets[o];
		for (var p = uavs.length - 1; p >= 0; p--) {
			var uav2 = uavs[p];
			if (pBullet2.intersects(uav2)) {
				// Fire a bullet when UAV is destroyed
				fireEnemyBullet(uav2.x, uav2.y);
				LK.setScore(LK.getScore() + 50);
				updateScore();
				LK.getSound('enemyDestroy').play();
				LK.effects.flashObject(uav2, 0xffff00, 200);
				pBullet2.destroy();
				playerBullets.splice(o, 1);
				uav2.destroy();
				uavs.splice(p, 1);
				break;
			}
		}
	}
	// Collision detection - Enemy bullets vs Player
	for (var q = enemyBullets.length - 1; q >= 0; q--) {
		var eBullet = enemyBullets[q];
		if (eBullet.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
	}
	// Collision detection - UAVs vs Player
	for (var r = uavs.length - 1; r >= 0; r--) {
		var uav3 = uavs[r];
		if (uav3.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
	}
	// Collision detection - Spaceships vs Player
	for (var s = spaceships.length - 1; s >= 0; s--) {
		var ship2 = spaceships[s];
		if (ship2.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
	}
};
LK.playMusic('battleMusic');

===================================================================
--- original.js
+++ change.js
@@ -187,8 +187,17 @@
 	dragActive = true;
 	player.x = x;
 	if (player.x < 60) player.x = 60;
 	if (player.x > 1988) player.x = 1988;
+	// Fire bullet when touching screen
+	if (player.fire()) {
+		var bullet = new PlayerBullet();
+		bullet.x = player.x;
+		bullet.y = player.y - 40;
+		playerBullets.push(bullet);
+		game.addChild(bullet);
+		LK.getSound('playerShoot').play();
+	}
 };
 game.move = function (x, y, obj) {
 	if (dragActive) {
 		player.x = x;