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

/**** 
* Classes
****/ 
// Enemy base class
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	self.type = 'base';
	self.speed = 4;
	self.health = 3;
	self.isFlashing = false;
	self.flashTimeout = null;
	self.update = function () {};
	self.takeDamage = function () {
		if (self.isFlashing) return;
		self.health--;
		self.isFlashing = true;
		// Flash red for 200ms
		LK.effects.flashObject(self, 0xff0000, 200);
		if (self.flashTimeout) LK.clearTimeout(self.flashTimeout);
		self.flashTimeout = LK.setTimeout(function () {
			self.isFlashing = false;
		}, 200);
	};
	return self;
});
// Enemy: Spinner (orbits the central target)
var EnemySpinner = Enemy.expand(function () {
	var self = Enemy.call(this);
	var asset = self.attachAsset('enemySpinner', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.type = 'spinner';
	self.radius = 400 + Math.random() * 200;
	self.angle = Math.random() * Math.PI * 2;
	self.speed = 0.012 + Math.random() * 0.005;
	self.update = function () {
		self.angle += self.speed;
		self.x = centralTarget.x + Math.cos(self.angle) * self.radius;
		self.y = centralTarget.y + Math.sin(self.angle) * self.radius;
	};
	return self;
});
// Enemy: Seeker (moves toward player)
var EnemySeeker = Enemy.expand(function () {
	var self = Enemy.call(this);
	var asset = self.attachAsset('enemySeeker', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.type = 'seeker';
	self.speed = 3;
	self.update = function () {
		// Move toward player
		if (!player) return;
		var dx = player.x - self.x;
		var dy = player.y - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist > 0) {
			self.x += dx / dist * self.speed;
			self.y += dy / dist * self.speed;
		}
	};
	return self;
});
// Enemy: Dasher (dashes horizontally or vertically)
var EnemyDasher = Enemy.expand(function () {
	var self = Enemy.call(this);
	var asset = self.attachAsset('enemyDasher', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.type = 'dasher';
	self.axis = Math.random() < 0.5 ? 'x' : 'y';
	self.speed = 9 + Math.random() * 3;
	self.direction = Math.random() < 0.5 ? 1 : -1;
	self.update = function () {
		if (self.axis === 'x') {
			self.x += self.speed * self.direction;
		} else {
			self.y += self.speed * self.direction;
		}
	};
	return self;
});
// Health Pickup
var HealthPickup = Container.expand(function () {
	var self = Container.call(this);
	var asset = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 0.5,
		scaleY: 0.5,
		tint: 0x2ecc71 // green tint for health
	});
	self.type = 'health';
	self.update = function () {};
	return self;
});
// Player class
var Player = Container.expand(function () {
	var self = Container.call(this);
	var asset = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = 700;
	self.angle = -Math.PI / 2;
	self.x = 0;
	self.y = 0;
	self.updatePosition = function () {
		self.x = centralTarget.x + Math.cos(self.angle) * self.radius;
		self.y = centralTarget.y + Math.sin(self.angle) * self.radius;
	};
	self.updatePosition();
	return self;
});
// Player bullet
var PlayerBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletAsset = self.attachAsset('playerBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// vx, vy will be set on creation
	self.vx = 0;
	self.vy = -32;
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
	};
	return self;
});
// Shield Pickup
var ShieldPickup = Container.expand(function () {
	var self = Container.call(this);
	var asset = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 0.5,
		scaleY: 0.5,
		tint: 0xf1c40f // yellow tint for shield
	});
	self.type = 'shield';
	self.update = function () {};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x181c20
});

/**** 
* Game Code
****/ 
// Central target
// Player character
// Player bullet
// Central target
// Enemy type 1: Seeker
// Enemy type 2: Spinner
// Enemy type 3: Dasher
// Sound for shooting
// Sound for enemy destroyed
// Sound for hit target
// Music
var centralTarget = LK.getAsset('centralTarget', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 2048 / 2,
	y: 2732 / 2
});
game.addChild(centralTarget);
// Player
var player = new Player();
player.updatePosition();
game.addChild(player);
// Player health (3 hits to die)
var playerHealth = 3;
// Shield state
var playerShieldActive = false;
var playerShieldTimer = 0;
// Bullets and enemies arrays
var playerBullets = [];
var enemies = [];
// Score
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Track background state for multi-background progression
game.backgroundChanged = 0;
// Timer text (minutes:seconds)
var timerTxt = new Text2('0:00', {
	size: 90,
	fill: 0xFFFFFF
});
timerTxt.anchor.set(0.5, 0);
timerTxt.y = 110; // Place below score, avoid top 100px
LK.gui.top.addChild(timerTxt);
// Track elapsed time in frames
var elapsedFrames = 0;
// Difficulty and spawn control
var spawnTimer = 0;
var spawnInterval = 90; // frames
var enemyTypes = ['seeker'];
var difficultyTimer = 0;
// Stage control
var stage = 1;
var fireTimer = 0;
var fireInterval = 18; // frames between shots, default for stage 1
// Drag control
var dragging = false;
var dragStartAngle = 0;
var dragStartX = 0;
var dragStartY = 0;
// Helper: get angle from center to (x, y)
function getAngleToCenter(x, y) {
	var dx = x - centralTarget.x;
	var dy = y - centralTarget.y;
	return Math.atan2(dy, dx);
}
// Move handler: drag around the central target
function handleMove(x, y, obj) {
	if (!dragging) return;
	var angle = getAngleToCenter(x, y);
	player.angle = angle;
	player.updatePosition();
}
game.move = handleMove;
game.down = function (x, y, obj) {
	// Only start drag if not on top left 100x100
	if (x < 100 && y < 100) return;
	dragging = true;
	handleMove(x, y, obj);
};
game.up = function (x, y, obj) {
	dragging = false;
};
// Shoot on tap anywhere (except top left)
game.down = function (x, y, obj) {
	if (x < 100 && y < 100) return;
	// Fire bullet toward tap/click
	var bullet = new PlayerBullet();
	bullet.x = player.x;
	bullet.y = player.y;
	bullet.lastY = bullet.y;
	bullet.lastIntersecting = false;
	// Calculate direction from player to tap/click
	var dx = x - player.x;
	var dy = y - player.y;
	var dist = Math.sqrt(dx * dx + dy * dy);
	if (dist > 0) {
		var speed = 32;
		bullet.vx = dx / dist * speed;
		bullet.vy = dy / dist * speed;
		// Rotate player to face shooting direction
		player.angle = Math.atan2(dy, dx);
		player.updatePosition();
	} else {
		bullet.vx = 0;
		bullet.vy = -32;
	}
	playerBullets.push(bullet);
	game.addChild(bullet);
	LK.getSound('shoot').play();
	// Also allow drag
	dragging = true;
	handleMove(x, y, obj);
};
game.up = function (x, y, obj) {
	dragging = false;
};
// Enemy spawn logic
function spawnEnemy() {
	var type = enemyTypes[Math.floor(Math.random() * enemyTypes.length)];
	var enemy;
	if (type === 'seeker') {
		enemy = new EnemySeeker();
		// Spawn at random edge
		var edge = Math.floor(Math.random() * 4);
		if (edge === 0) {
			// top
			enemy.x = Math.random() * 2048;
			enemy.y = -100;
		} else if (edge === 1) {
			// right
			enemy.x = 2048 + 100;
			enemy.y = Math.random() * 2732;
		} else if (edge === 2) {
			// bottom
			enemy.x = Math.random() * 2048;
			enemy.y = 2732 + 100;
		} else {
			// left
			enemy.x = -100;
			enemy.y = Math.random() * 2732;
		}
	} else if (type === 'spinner') {
		enemy = new EnemySpinner();
		// Place at random angle
		enemy.angle = Math.random() * Math.PI * 2;
		enemy.radius = 400 + Math.random() * 400;
		enemy.x = centralTarget.x + Math.cos(enemy.angle) * enemy.radius;
		enemy.y = centralTarget.y + Math.sin(enemy.angle) * enemy.radius;
	} else if (type === 'dasher') {
		enemy = new EnemyDasher();
		// Start at random edge
		if (enemy.axis === 'x') {
			enemy.x = enemy.direction > 0 ? -100 : 2048 + 100;
			enemy.y = Math.random() * 2732;
		} else {
			enemy.x = Math.random() * 2048;
			enemy.y = enemy.direction > 0 ? -100 : 2732 + 100;
		}
	}
	if (enemy) {
		enemy.lastIntersectingPlayer = false;
		enemy.lastIntersectingTarget = false;
		enemies.push(enemy);
		game.addChild(enemy);
	}
}
// Main update loop
game.update = function () {
	// Update timer
	elapsedFrames++;
	var totalSeconds = Math.floor(elapsedFrames / 60);
	var minutes = Math.floor(totalSeconds / 60);
	var seconds = totalSeconds % 60;
	var secondsStr = seconds < 10 ? '0' + seconds : '' + seconds;
	timerTxt.setText(minutes + ':' + secondsStr);
	// Difficulty scaling
	difficultyTimer++;
	if (difficultyTimer % 600 === 0 && enemyTypes.length < 3) {
		if (enemyTypes.length === 1) {
			enemyTypes.push('spinner');
		} else if (enemyTypes.length === 2) {
			enemyTypes.push('dasher');
		}
		if (spawnInterval > 40) spawnInterval -= 10;
	}
	// Stage progression: switch to stage 2 at score 30, and to stage 3 at score 70
	if (stage === 1 && LK.getScore() >= 30) {
		stage = 2;
		spawnInterval = 90; // slower spawn for stage 2
		fireInterval = 7; // faster fire rate
	}
	if (stage === 2 && LK.getScore() >= 70) {
		stage = 3;
		spawnInterval = 30; // much faster enemy spawn in stage 3
		fireInterval = 4; // even faster fire rate
		// Activate shield for 3 seconds (180 frames)
		if (!playerShieldActive) {
			playerShieldActive = true;
			playerShieldTimer = 180;
			// Optional: flash player or add effect
			LK.effects.flashObject(player, 0xf1c40f, 3000);
		}
	}
	// Handle shield timer
	if (playerShieldActive) {
		playerShieldTimer--;
		if (playerShieldTimer <= 0) {
			playerShieldActive = false;
			playerShieldTimer = 0;
		}
	}
	// Spawn enemies
	spawnTimer++;
	if (spawnTimer >= spawnInterval) {
		// In stage 1, spawn 1 enemy per interval
		if (stage === 1) {
			spawnEnemy();
		} else if (stage === 2) {
			// In stage 2, spawn 1 enemy per interval (less than before)
			spawnEnemy();
		} else if (stage === 3) {
			// In stage 3, spawn 4 enemies per interval (increase)
			spawnEnemy();
			spawnEnemy();
			spawnEnemy();
			spawnEnemy();
		}
		spawnTimer = 0;
	}
	// Automatic fire logic (increased fire rate in stage 2 and 3)
	fireTimer++;
	if (fireTimer >= fireInterval && dragging) {
		// Fire bullet toward current player angle (in direction player is facing)
		var bullet = new PlayerBullet();
		bullet.x = player.x;
		bullet.y = player.y;
		bullet.lastY = bullet.y;
		bullet.lastIntersecting = false;
		// Fire toward central target
		var dx = centralTarget.x - player.x;
		var dy = centralTarget.y - player.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist > 0) {
			var speed = 32;
			bullet.vx = dx / dist * speed;
			bullet.vy = dy / dist * speed;
		} else {
			bullet.vx = 0;
			bullet.vy = -32;
		}
		playerBullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('shoot').play();
		fireTimer = 0;
	}
	// Update player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var bullet = playerBullets[i];
		bullet.update();
		// Remove if off screen
		if (bullet.y < -60 || bullet.y > 2732 + 60 || bullet.x < -60 || bullet.x > 2048 + 60) {
			bullet.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		// Check hit on central target
		var hitTarget = bullet.intersects(centralTarget);
		if (!bullet.lastIntersecting && hitTarget) {
			LK.setScore(LK.getScore() + 1);
			scoreTxt.setText(LK.getScore());
			LK.getSound('targetHit').play();
			bullet.destroy();
			playerBullets.splice(i, 1);
			// Win condition: Instead of ending, change background and continue
			if (LK.getScore() >= 100) {
				if (!game.backgroundChanged) {
					// First background change (after 100 points)
					game.setBackgroundColor(0x1a1a40); // 2nd background color
					game.backgroundChanged = 1;
					// Remove all enemies from the game
					for (var ei = enemies.length - 1; ei >= 0; ei--) {
						enemies[ei].destroy();
					}
					enemies = [];
					// Reset score, stage, and timer
					LK.setScore(0);
					scoreTxt.setText('0');
					stage = 1;
					spawnInterval = 90;
					fireInterval = 18;
					elapsedFrames = 0;
					difficultyTimer = 0;
					// Set new enemy types for 2nd background
					enemyTypes = ['spinner', 'dasher'];
					// Optionally, you could add a visual effect or message here
				} else if (game.backgroundChanged === 1 && LK.getScore() >= 100) {
					// Second background change (after 2nd 100 points)
					game.setBackgroundColor(0x1a4020); // 3rd background color
					game.backgroundChanged = 2;
					for (var ei = enemies.length - 1; ei >= 0; ei--) {
						enemies[ei].destroy();
					}
					enemies = [];
					LK.setScore(0);
					scoreTxt.setText('0');
					stage = 1;
					spawnInterval = 90;
					fireInterval = 18;
					elapsedFrames = 0;
					difficultyTimer = 0;
					// Set new enemy types for 3rd background
					enemyTypes = ['seeker', 'dasher'];
				} else if (game.backgroundChanged === 2 && LK.getScore() >= 100) {
					// Third background change (after 3rd 100 points)
					game.setBackgroundColor(0x40201a); // 4th background color
					game.backgroundChanged = 3;
					for (var ei = enemies.length - 1; ei >= 0; ei--) {
						enemies[ei].destroy();
					}
					enemies = [];
					LK.setScore(0);
					scoreTxt.setText('0');
					stage = 1;
					spawnInterval = 90;
					fireInterval = 18;
					elapsedFrames = 0;
					difficultyTimer = 0;
					// Set new enemy types for 4th background
					enemyTypes = ['seeker', 'spinner'];
				} else if (game.backgroundChanged === 3 && LK.getScore() >= 100) {
					// Fourth background change (after 4th 100 points)
					game.setBackgroundColor(0x204040); // 5th background color
					game.backgroundChanged = 4;
					for (var ei = enemies.length - 1; ei >= 0; ei--) {
						enemies[ei].destroy();
					}
					enemies = [];
					LK.setScore(0);
					scoreTxt.setText('0');
					stage = 1;
					spawnInterval = 90;
					fireInterval = 18;
					elapsedFrames = 0;
					difficultyTimer = 0;
					// Set new enemy types for 5th background
					enemyTypes = ['dasher', 'spinner'];
				}
			}
			continue;
		}
		bullet.lastIntersecting = hitTarget;
		// Check hit on enemies
		for (var j = enemies.length - 1; j >= 0; j--) {
			var enemy = enemies[j];
			if (bullet.intersects(enemy)) {
				LK.getSound('enemyDown').play();
				bullet.destroy();
				playerBullets.splice(i, 1);
				enemy.takeDamage();
				if (enemy.health <= 0) {
					enemy.destroy();
					enemies.splice(j, 1);
				}
				break;
			}
		}
	}
	// Update enemies
	for (var i = enemies.length - 1; i >= 0; i--) {
		var enemy = enemies[i];
		enemy.update();
		// Remove if off screen (for dashers)
		if (enemy.x < -200 || enemy.x > 2048 + 200 || enemy.y < -200 || enemy.y > 2732 + 200) {
			enemy.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Check collision with player
		var hitPlayer = enemy.intersects(player);
		if (!enemy.lastIntersectingPlayer && hitPlayer) {
			if (!playerShieldActive) {
				playerHealth--;
				LK.effects.flashScreen(0xff0000, 800);
				if (playerHealth <= 0) {
					LK.showGameOver();
					return;
				}
			}
		}
		enemy.lastIntersectingPlayer = hitPlayer;
		// Check collision with central target (optional: could penalize or just remove)
		var hitTarget = enemy.intersects(centralTarget);
		if (!enemy.lastIntersectingTarget && hitTarget) {
			// Remove enemy
			enemy.destroy();
			enemies.splice(i, 1);
			continue;
		}
		enemy.lastIntersectingTarget = hitTarget;
	}
};
// Play background music
LK.playMusic('bgmusic', {
	fade: {
		start: 0,
		end: 1,
		duration: 1200
	}
});

===================================================================
--- original.js
+++ change.js
@@ -184,8 +184,11 @@
 player.updatePosition();
 game.addChild(player);
 // Player health (3 hits to die)
 var playerHealth = 3;
+// Shield state
+var playerShieldActive = false;
+var playerShieldTimer = 0;
 // Bullets and enemies arrays
 var playerBullets = [];
 var enemies = [];
 // Score
@@ -356,9 +359,24 @@
 	if (stage === 2 && LK.getScore() >= 70) {
 		stage = 3;
 		spawnInterval = 30; // much faster enemy spawn in stage 3
 		fireInterval = 4; // even faster fire rate
+		// Activate shield for 3 seconds (180 frames)
+		if (!playerShieldActive) {
+			playerShieldActive = true;
+			playerShieldTimer = 180;
+			// Optional: flash player or add effect
+			LK.effects.flashObject(player, 0xf1c40f, 3000);
+		}
 	}
+	// Handle shield timer
+	if (playerShieldActive) {
+		playerShieldTimer--;
+		if (playerShieldTimer <= 0) {
+			playerShieldActive = false;
+			playerShieldTimer = 0;
+		}
+	}
 	// Spawn enemies
 	spawnTimer++;
 	if (spawnTimer >= spawnInterval) {
 		// In stage 1, spawn 1 enemy per interval
@@ -526,13 +544,15 @@
 		}
 		// Check collision with player
 		var hitPlayer = enemy.intersects(player);
 		if (!enemy.lastIntersectingPlayer && hitPlayer) {
-			playerHealth--;
-			LK.effects.flashScreen(0xff0000, 800);
-			if (playerHealth <= 0) {
-				LK.showGameOver();
-				return;
+			if (!playerShieldActive) {
+				playerHealth--;
+				LK.effects.flashScreen(0xff0000, 800);
+				if (playerHealth <= 0) {
+					LK.showGameOver();
+					return;
+				}
 			}
 		}
 		enemy.lastIntersectingPlayer = hitPlayer;
 		// Check collision with central target (optional: could penalize or just remove)