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

/**** 
* Classes
****/ 
var Bomb = Container.expand(function () {
	var self = Container.call(this);
	var bombGraphics = self.attachAsset('bomb', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Bomb now uses dark colored shape asset instead of tint
	self.speed = 6;
	self.active = true;
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
	};
	return self;
});
var Cloud = Container.expand(function () {
	var self = Container.call(this);
	var cloudGraphics = self.attachAsset('cloud', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	cloudGraphics.alpha = 0.6;
	self.speed = Math.random() * 1 + 0.5; // Random speed between 0.5-1.5
	self.scaleX = self.scaleY = Math.random() * 0.8 + 0.6; // Random scale 0.6-1.4
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var EnemyAircraft = Container.expand(function (type) {
	var self = Container.call(this);
	var assetName = type || 'mig29';
	var aircraftGraphics = self.attachAsset(assetName, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.type = assetName;
	self.speed = 3;
	self.active = true;
	// Set point values based on aircraft type
	if (self.type === 'mig29') {
		self.points = 100;
		self.speed = 3;
	} else if (self.type === 'su27') {
		self.points = 150;
		self.speed = 2.5;
	} else if (self.type === 'tu95') {
		self.points = 200;
		self.speed = 2;
	} else if (self.type === 'su57') {
		self.points = 300;
		self.speed = 2.8;
		self.hp = 2; // Requires 2 hits to destroy
		self.maxHP = 2;
		self.stealthMode = false;
		self.stealthTimer = 0;
	}
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
		// SU-57 special abilities
		if (self.type === 'su57') {
			// Stealth mode toggle every 3 seconds
			self.stealthTimer++;
			if (self.stealthTimer >= 180) {
				// 3 seconds at 60fps
				self.stealthMode = !self.stealthMode;
				self.stealthTimer = 0;
				if (self.stealthMode) {
					tween(self, {
						alpha: 0.3
					}, {
						duration: 500,
						easing: tween.easeInOut
					});
				} else {
					tween(self, {
						alpha: 1.0
					}, {
						duration: 500,
						easing: tween.easeInOut
					});
				}
			}
			// Slight evasive maneuvers
			if (LK.ticks % 120 === 0) {
				// Every 2 seconds
				var evasiveMove = (Math.random() - 0.5) * 100; // Random movement -50 to +50
				self.x = Math.max(100, Math.min(1948, self.x + evasiveMove));
			}
		}
	};
	return self;
});
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('missile', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	bulletGraphics.tint = 0xFF4444; // Red tint for enemy bullets
	self.speed = 8;
	self.active = true;
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
	};
	return self;
});
var Explosion = Container.expand(function () {
	var self = Container.call(this);
	var explosionGraphics = self.attachAsset('explosion', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.lifetime = 20; // frames
	self.update = function () {
		self.lifetime--;
		self.alpha = self.lifetime / 20;
		self.scaleX = self.scaleY = (20 - self.lifetime) / 10;
	};
	return self;
});
var F18Hornet = Container.expand(function () {
	var self = Container.call(this);
	var hornetGraphics = self.attachAsset('gripen', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Distinctive blue tint for F-18 Hornet
	hornetGraphics.tint = 0x0066FF;
	// Scale to make it slightly larger than normal Gripen
	hornetGraphics.scaleX = 1.1;
	hornetGraphics.scaleY = 1.1;
	self.speed = 2.5; // Slightly faster than old friendly
	self.active = true;
	self.fireTimer = 0;
	self.burstCount = 0;
	self.burstTimer = 0;
	self.targetEnemy = null;
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
		// Advanced firing system - burst fire
		self.fireTimer++;
		self.burstTimer++;
		// Fire in bursts of 3 missiles every 60 ticks
		if (self.fireTimer >= 60 && enemies.length > 0 && self.burstCount < 3) {
			// Find closest enemy
			var closestEnemy = null;
			var closestDistance = 999999;
			for (var i = 0; i < enemies.length; i++) {
				var enemy = enemies[i];
				if (!enemy.active) continue;
				var distance = Math.abs(enemy.x - self.x) + Math.abs(enemy.y - self.y);
				if (distance < closestDistance) {
					closestDistance = distance;
					closestEnemy = enemy;
				}
			}
			if (closestEnemy && closestDistance < 900) {
				// Fire with slight spread for burst effect
				var missile = new Missile();
				missile.x = self.x + (self.burstCount - 1) * 20; // Slight horizontal spread
				missile.y = self.y - 50;
				missile.isFriendly = true;
				friendlyMissiles.push(missile);
				game.addChild(missile);
				LK.getSound('missile_fire').play();
				self.burstCount++;
			}
			self.fireTimer = 0;
		}
		// Reset burst after delay
		if (self.burstCount >= 3 && self.burstTimer >= 90) {
			self.burstCount = 0;
			self.burstTimer = 0;
		}
	};
	return self;
});
var GroundExplosion = Container.expand(function () {
	var self = Container.call(this);
	var explosionGraphics = self.attachAsset('groundExplosion', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	explosionGraphics.alpha = 1;
	explosionGraphics.scaleX = 0.2;
	explosionGraphics.scaleY = 0.2;
	self.active = true;
	// Start animation immediately
	tween(explosionGraphics, {
		scaleX: 2,
		scaleY: 2,
		alpha: 0
	}, {
		duration: 800,
		easing: tween.easeOut,
		onFinish: function onFinish() {
			self.active = false;
		}
	});
	return self;
});
var Missile = Container.expand(function () {
	var self = Container.call(this);
	var missileGraphics = self.attachAsset('missile', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -12;
	self.active = true;
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
	};
	return self;
});
var PlayerGripen = Container.expand(function () {
	var self = Container.call(this);
	var gripenGraphics = self.attachAsset('gripen', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.active = true;
	return self;
});
var Raindrop = Container.expand(function () {
	var self = Container.call(this);
	var dropGraphics = self.attachAsset('raindrop', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	dropGraphics.alpha = 0.6;
	self.speed = Math.random() * 8 + 12; // Random speed between 12-20
	self.active = true;
	self.update = function () {
		if (!self.active) return;
		self.y += self.speed;
	};
	return self;
});

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

/**** 
* Game Code
****/ 
// Sound effects
// Missiles
// Enemy aircraft types
// Player aircraft - JAS Gripen (distinctive delta wing design)
// Game variables
var player;
var missiles = [];
var enemies = [];
var enemyBullets = [];
var bombs = [];
var explosions = [];
var waveNumber = 1;
var enemiesSpawned = 0;
var enemiesInWave = 5;
var spawnTimer = 0;
var missileTimer = 0;
var enemyFireTimer = 0;
var waveTimer = 0;
var clouds = [];
var cloudSpawnTimer = 0;
var groundExplosions = [];
var raindrops = [];
var rainSpawnTimer = 0;
var weatherIntensity = 0.3; // 0 = no rain, 1 = heavy rain
// Friendly aircraft system
var friendlyAircraft = [];
var friendlyMissiles = [];
var friendlySpawnTimer = 0;
// Day/night cycle variables
var timeOfDay = 0; // 0 = night, 0.5 = dawn/dusk, 1 = day
var dayNightTimer = 0;
var dayNightCycleDuration = 1800; // 30 seconds for full cycle (60fps * 30)
var isTransitioning = false;
// Player health system
var playerHP = 3;
var maxHP = 3;
// UI elements
var scoreTxt = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0, 0);
scoreTxt.x = 120;
scoreTxt.y = 50;
LK.gui.topLeft.addChild(scoreTxt);
var hpTxt = new Text2('HP: 3/3', {
	size: 60,
	fill: 0xFF0000
});
hpTxt.anchor.set(0, 0);
hpTxt.x = 120;
hpTxt.y = 120;
LK.gui.topLeft.addChild(hpTxt);
var waveTxt = new Text2('Wave: 1', {
	size: 50,
	fill: 0xFFFFFF
});
waveTxt.anchor.set(1, 0);
waveTxt.y = 60; // Move wave text down to make room for pause button
LK.gui.topRight.addChild(waveTxt);
// Add pause button
var pauseTxt = new Text2('PAUSE', {
	size: 40,
	fill: 0xFFFFFF
});
pauseTxt.anchor.set(1, 0);
pauseTxt.x = -10;
pauseTxt.y = 10;
LK.gui.topRight.addChild(pauseTxt);
// Make pause text clickable
pauseTxt.down = function (x, y, obj) {
	LK.pauseGame(); // Trigger the built-in pause functionality
};
// Initialize player
player = new PlayerGripen();
player.x = 1024; // Center horizontally
player.y = 2500; // Near bottom of screen
game.addChild(player);
// Initialize HP display
updateHP();
// Touch/mouse controls for player movement
var isDragging = false;
game.down = function (x, y, obj) {
	isDragging = true;
	player.x = x;
};
game.move = function (x, y, obj) {
	if (isDragging && player.active) {
		player.x = Math.max(60, Math.min(1988, x)); // Keep player on screen
	}
};
game.up = function (x, y, obj) {
	isDragging = false;
};
// Spawn enemy function
function spawnEnemy() {
	var enemyTypes = ['mig29', 'su27', 'tu95'];
	// Add SU-57 from wave 3 onwards with lower spawn rate
	if (waveNumber >= 3 && Math.random() < 0.2) {
		enemyTypes.push('su57');
	}
	var randomType = enemyTypes[Math.floor(Math.random() * enemyTypes.length)];
	var enemy = new EnemyAircraft(randomType);
	enemy.x = Math.random() * 1800 + 124; // Random X position across screen
	enemy.y = -100; // Start above screen
	// Adjust speed based on wave
	enemy.speed += (waveNumber - 1) * 0.5;
	enemies.push(enemy);
	game.addChild(enemy);
	enemiesSpawned++;
}
// Fire missile function
function fireMissile() {
	if (!player.active) return;
	var missile = new Missile();
	missile.x = player.x;
	missile.y = player.y - 70;
	missiles.push(missile);
	game.addChild(missile);
	LK.getSound('missile_fire').play();
}
// Spawn friendly aircraft function
function spawnFriendlyAircraft() {
	var friendly = new F18Hornet();
	friendly.x = Math.random() * 1800 + 124; // Random X position
	friendly.y = 2800; // Start from bottom
	// Add entry animation
	tween(friendly, {
		scaleX: 1.1,
		scaleY: 1.1
	}, {
		duration: 500,
		easing: tween.easeOut
	});
	friendlyAircraft.push(friendly);
	game.addChild(friendly);
}
// Create explosion function
function createExplosion(x, y) {
	var explosion = new Explosion();
	explosion.x = x;
	explosion.y = y;
	explosions.push(explosion);
	game.addChild(explosion);
	LK.getSound('explosion').play();
}
// Create ground explosion function
function createGroundExplosion(x, y) {
	var groundExplosion = new GroundExplosion();
	groundExplosion.x = x;
	groundExplosion.y = y;
	groundExplosions.push(groundExplosion);
	game.addChild(groundExplosion);
	LK.getSound('explosion').play();
}
// Update score display
function updateScore() {
	scoreTxt.setText('Score: ' + LK.getScore());
}
// Update wave display
function updateWave() {
	waveTxt.setText('Wave: ' + waveNumber);
}
// Update HP display
function updateHP() {
	hpTxt.setText('HP: ' + playerHP + '/' + maxHP);
	if (playerHP <= 1) {
		hpTxt.fill = 0xFF0000; // Red when low HP
	} else if (playerHP <= 2) {
		hpTxt.fill = 0xFFFF00; // Yellow when medium HP
	} else {
		hpTxt.fill = 0x00FF00; // Green when full HP
	}
}
// Main game update loop
game.update = function () {
	if (!player.active) return;
	// Fire missiles automatically
	missileTimer++;
	if (missileTimer >= 20) {
		// Fire every 20 ticks (3 times per second)
		fireMissile();
		missileTimer = 0;
	}
	// Spawn enemies
	spawnTimer++;
	var spawnRate = Math.max(60 - waveNumber * 5, 30); // Faster spawning each wave
	if (spawnTimer >= spawnRate && enemiesSpawned < enemiesInWave) {
		spawnEnemy();
		spawnTimer = 0;
	}
	// Check for missile-enemy collisions
	for (var m = missiles.length - 1; m >= 0; m--) {
		var missile = missiles[m];
		if (!missile.active) continue;
		// Remove missiles that go off screen
		if (missile.y < -50) {
			missile.destroy();
			missiles.splice(m, 1);
			continue;
		}
		// Check collision with enemies
		for (var e = enemies.length - 1; e >= 0; e--) {
			var enemy = enemies[e];
			if (!enemy.active) continue;
			if (missile.intersects(enemy)) {
				// Handle SU-57 HP system
				if (enemy.type === 'su57' && enemy.hp > 1) {
					enemy.hp--;
					// Flash red when hit but not destroyed
					tween(enemy, {
						tint: 0xFF0000
					}, {
						duration: 200,
						easing: tween.easeOut,
						onFinish: function onFinish() {
							tween(enemy, {
								tint: 0xFFFFFF
							}, {
								duration: 200,
								easing: tween.easeOut
							});
						}
					});
					createExplosion(enemy.x, enemy.y);
					missile.active = false;
					missile.destroy();
					missiles.splice(m, 1);
					break;
				} else {
					// Create explosion
					createExplosion(enemy.x, enemy.y);
					// Award points
					LK.setScore(LK.getScore() + enemy.points);
					updateScore();
					// Remove missile and enemy
					missile.active = false;
					enemy.active = false;
					missile.destroy();
					enemy.destroy();
					missiles.splice(m, 1);
					enemies.splice(e, 1);
					LK.getSound('enemy_destroyed').play();
					break;
				}
			}
		}
	}
	// Update and check enemy collisions with player
	for (var e = enemies.length - 1; e >= 0; e--) {
		var enemy = enemies[e];
		if (!enemy.active) continue;
		// Remove enemies that go off screen
		if (enemy.y > 2800) {
			enemy.destroy();
			enemies.splice(e, 1);
			continue;
		}
		// Check collision with player
		if (enemy.intersects(player)) {
			// Take damage
			playerHP--;
			updateHP();
			createExplosion(enemy.x, enemy.y);
			enemy.active = false;
			enemy.destroy();
			enemies.splice(e, 1);
			// Check if player is dead
			if (playerHP <= 0) {
				createExplosion(player.x, player.y);
				player.active = false;
				LK.setTimeout(function () {
					LK.showGameOver();
				}, 1000);
				return;
			}
		}
	}
	// Enemy firing system
	enemyFireTimer++;
	if (enemyFireTimer >= 90) {
		// Fire every 1.5 seconds
		if (enemies.length > 0) {
			var randomEnemy = enemies[Math.floor(Math.random() * enemies.length)];
			if (randomEnemy.active && randomEnemy.y > 200 && randomEnemy.y < 2000) {
				if (randomEnemy.type === 'tu95') {
					// Tu-95 drops bombs
					var bomb = new Bomb();
					bomb.x = randomEnemy.x;
					bomb.y = randomEnemy.y + 50;
					bombs.push(bomb);
					game.addChild(bomb);
				} else if (randomEnemy.type === 'su57') {
					// SU-57 fires advanced missiles aimed at player
					var bullet = new EnemyBullet();
					bullet.x = randomEnemy.x;
					bullet.y = randomEnemy.y + 50;
					// Aim toward player position
					var dx = player.x - bullet.x;
					var distance = Math.abs(dx);
					if (distance > 50) {
						// Only adjust if player is not directly below
						bullet.x += dx * 0.3; // Adjust firing position toward player
					}
					bullet.speed = 10; // Faster than normal bullets
					enemyBullets.push(bullet);
					game.addChild(bullet);
				} else {
					// Other aircraft fire bullets
					var bullet = new EnemyBullet();
					bullet.x = randomEnemy.x;
					bullet.y = randomEnemy.y + 50;
					enemyBullets.push(bullet);
					game.addChild(bullet);
				}
			}
		}
		enemyFireTimer = 0;
	}
	// Update and check enemy bullets
	for (var eb = enemyBullets.length - 1; eb >= 0; eb--) {
		var bullet = enemyBullets[eb];
		if (!bullet.active) continue;
		// Remove bullets that go off screen
		if (bullet.y > 2800) {
			bullet.destroy();
			enemyBullets.splice(eb, 1);
			continue;
		}
		// Check collision with player
		if (bullet.intersects(player)) {
			// Take damage
			playerHP--;
			updateHP();
			createExplosion(bullet.x, bullet.y);
			bullet.destroy();
			enemyBullets.splice(eb, 1);
			// Check if player is dead
			if (playerHP <= 0) {
				createExplosion(player.x, player.y);
				player.active = false;
				LK.setTimeout(function () {
					LK.showGameOver();
				}, 1000);
				return;
			}
		}
	}
	// Update and check bombs
	for (var b = bombs.length - 1; b >= 0; b--) {
		var bomb = bombs[b];
		if (!bomb.active) continue;
		// Remove bombs that go off screen
		if (bomb.y > 2800) {
			// Bomb hits ground - create explosion
			createExplosion(bomb.x, bomb.y);
			createGroundExplosion(bomb.x, bomb.y);
			bomb.destroy();
			bombs.splice(b, 1);
			continue;
		}
		// Check collision with player
		if (bomb.intersects(player)) {
			// Take damage
			playerHP--;
			updateHP();
			createExplosion(bomb.x, bomb.y);
			bomb.destroy();
			bombs.splice(b, 1);
			// Check if player is dead
			if (playerHP <= 0) {
				createExplosion(player.x, player.y);
				player.active = false;
				LK.setTimeout(function () {
					LK.showGameOver();
				}, 1000);
				return;
			}
		}
	}
	// Update explosions
	for (var ex = explosions.length - 1; ex >= 0; ex--) {
		var explosion = explosions[ex];
		if (explosion.lifetime <= 0) {
			explosion.destroy();
			explosions.splice(ex, 1);
		}
	}
	// Check if wave is complete
	if (enemiesSpawned >= enemiesInWave && enemies.length === 0) {
		waveNumber++;
		enemiesSpawned = 0;
		enemiesInWave += 2; // More enemies each wave
		updateWave();
		// Brief pause between waves
		waveTimer = 120; // 2 second pause
	}
	// Handle wave timer
	if (waveTimer > 0) {
		waveTimer--;
	}
	// Spawn clouds for background atmosphere
	cloudSpawnTimer++;
	if (cloudSpawnTimer >= 180) {
		// Spawn cloud every 3 seconds
		var cloud = new Cloud();
		cloud.x = Math.random() * 2048; // Random X position across screen
		cloud.y = -100; // Start above screen
		clouds.push(cloud);
		game.addChild(cloud);
		cloudSpawnTimer = 0;
	}
	// Update and remove off-screen clouds
	for (var c = clouds.length - 1; c >= 0; c--) {
		var cloud = clouds[c];
		if (cloud.y > 2800) {
			// Remove when off screen
			cloud.destroy();
			clouds.splice(c, 1);
		}
	}
	// Update and remove finished ground explosions
	for (var ge = groundExplosions.length - 1; ge >= 0; ge--) {
		var groundExplosion = groundExplosions[ge];
		if (!groundExplosion.active) {
			groundExplosion.destroy();
			groundExplosions.splice(ge, 1);
		}
	}
	// Weather system - spawn raindrops
	rainSpawnTimer++;
	var rainSpawnRate = Math.max(5 - Math.floor(weatherIntensity * 4), 1); // More frequent with higher intensity
	if (rainSpawnTimer >= rainSpawnRate) {
		// Spawn multiple raindrops based on intensity
		var dropsToSpawn = Math.floor(weatherIntensity * 5) + 1;
		for (var rd = 0; rd < dropsToSpawn; rd++) {
			var raindrop = new Raindrop();
			raindrop.x = Math.random() * 2048; // Random X position across screen
			raindrop.y = -20; // Start above screen
			raindrops.push(raindrop);
			game.addChild(raindrop);
		}
		rainSpawnTimer = 0;
	}
	// Update and remove off-screen raindrops
	for (var rd = raindrops.length - 1; rd >= 0; rd--) {
		var raindrop = raindrops[rd];
		if (raindrop.y > 2800) {
			// Remove when off screen
			raindrop.destroy();
			raindrops.splice(rd, 1);
		}
	}
	// Day/night cycle system
	dayNightTimer++;
	if (dayNightTimer >= dayNightCycleDuration / 4) {
		// Update time every quarter cycle
		dayNightTimer = 0;
		var oldTimeOfDay = timeOfDay;
		// Cycle through time: 0 -> 0.25 -> 0.5 -> 0.75 -> 1 -> 0.75 -> 0.5 -> 0.25 -> 0
		if (timeOfDay >= 1) {
			timeOfDay = 0.75;
		} else if (timeOfDay >= 0.75) {
			timeOfDay = 0.5;
		} else if (timeOfDay >= 0.5) {
			timeOfDay = 0.25;
		} else if (timeOfDay >= 0.25) {
			timeOfDay = 0;
		} else {
			timeOfDay = 0.25;
		}
		// Only transition if time changed and not already transitioning
		if (oldTimeOfDay !== timeOfDay && !isTransitioning) {
			isTransitioning = true;
			var targetColor;
			var transitionDuration = 3000; // 3 seconds for smooth transition
			// Determine base color based on time of day
			if (timeOfDay === 0) {
				// Night - dark blue
				targetColor = 0x191970; // Midnight blue
			} else if (timeOfDay === 0.25) {
				// Dawn/Early morning - purple-pink
				targetColor = 0x4B0082; // Indigo
			} else if (timeOfDay === 0.5) {
				// Day - bright sky blue
				targetColor = 0x87CEEB; // Sky blue
			} else if (timeOfDay === 0.75) {
				// Dusk/Evening - orange-red
				targetColor = 0xFF4500; // Orange red
			}
			// Apply weather modifications to the base color
			if (weatherIntensity > 0.6) {
				// Heavy rain - make darker
				if (timeOfDay === 0) targetColor = 0x0F0F23; // Darker night
				else if (timeOfDay === 0.25) targetColor = 0x2F1B69; // Darker dawn
				else if (timeOfDay === 0.5) targetColor = 0x4682B4; // Darker day
				else if (timeOfDay === 0.75) targetColor = 0xB8460E; // Darker dusk
			} else if (weatherIntensity > 0.4) {
				// Medium rain - slightly darker
				if (timeOfDay === 0) targetColor = 0x151560; // Slightly darker night
				else if (timeOfDay === 0.25) targetColor = 0x3D2376; // Slightly darker dawn
				else if (timeOfDay === 0.5) targetColor = 0x6495ED; // Slightly darker day
				else if (timeOfDay === 0.75) targetColor = 0xD2691E; // Slightly darker dusk
			}
			// Smooth transition to new color
			tween(game, {
				backgroundColor: targetColor
			}, {
				duration: transitionDuration,
				easing: tween.easeInOut,
				onFinish: function onFinish() {
					isTransitioning = false;
				}
			});
		}
	}
	// Spawn friendly aircraft occasionally
	friendlySpawnTimer++;
	if (friendlySpawnTimer >= 1800 && friendlyAircraft.length < 2) {
		// Every 30 seconds, max 2 friendly
		spawnFriendlyAircraft();
		friendlySpawnTimer = 0;
	}
	// Update friendly aircraft
	for (var fa = friendlyAircraft.length - 1; fa >= 0; fa--) {
		var friendly = friendlyAircraft[fa];
		if (!friendly.active) continue;
		// Remove if goes off screen
		if (friendly.y < -100) {
			friendly.destroy();
			friendlyAircraft.splice(fa, 1);
			continue;
		}
	}
	// Update friendly missiles and check collisions with enemies
	for (var fm = friendlyMissiles.length - 1; fm >= 0; fm--) {
		var fMissile = friendlyMissiles[fm];
		if (!fMissile.active) continue;
		// Remove if off screen
		if (fMissile.y < -50) {
			fMissile.destroy();
			friendlyMissiles.splice(fm, 1);
			continue;
		}
		// Check collision with enemies
		for (var e = enemies.length - 1; e >= 0; e--) {
			var enemy = enemies[e];
			if (!enemy.active) continue;
			if (fMissile.intersects(enemy)) {
				// Handle SU-57 HP system
				if (enemy.type === 'su57' && enemy.hp > 1) {
					enemy.hp--;
					// Flash red when hit but not destroyed
					tween(enemy, {
						tint: 0xFF0000
					}, {
						duration: 200,
						easing: tween.easeOut,
						onFinish: function onFinish() {
							tween(enemy, {
								tint: 0xFFFFFF
							}, {
								duration: 200,
								easing: tween.easeOut
							});
						}
					});
					createExplosion(enemy.x, enemy.y);
					fMissile.active = false;
					fMissile.destroy();
					friendlyMissiles.splice(fm, 1);
					break;
				} else {
					// Create explosion
					createExplosion(enemy.x, enemy.y);
					// Award points (friendly assist gives half points)
					LK.setScore(LK.getScore() + Math.floor(enemy.points / 2));
					updateScore();
					// Remove missile and enemy
					fMissile.active = false;
					enemy.active = false;
					fMissile.destroy();
					enemy.destroy();
					friendlyMissiles.splice(fm, 1);
					enemies.splice(e, 1);
					LK.getSound('enemy_destroyed').play();
					break;
				}
			}
		}
	}
	// Change weather intensity over time (less frequent than before)
	if (LK.ticks % 900 === 0) {
		// Every 15 seconds
		weatherIntensity = Math.random() * 0.8 + 0.2; // Random intensity between 0.2-1.0
	}
};