/****
* Classes
****/
// Alien class representing the enemies
var Alien = Container.expand(function () {
  var self = Container.call(this);
  var alienGraphics = self.attachAsset('alien', {
    anchorX: 0.5,
    anchorY: 0.5
  });
  self.speed = 5;
  self.update = function () {
    self.y += self.speed;
    if (self.y > 2732) {
      self.destroy();
    }
  };
});
// Bullet class for player's bullets
var Bullet = Container.expand(function () {
  var self = Container.call(this);
  var bulletGraphics = self.attachAsset('bullet', {
    anchorX: 0.5,
    anchorY: 0.5
  });
  self.speed = -15;
  self.update = function () {
    self.y += self.speed;
    if (self.y < 0) {
      self.destroy();
    }
  };
});
//<Assets used in the game will automatically appear here>
// Player class representing the elite operative
var Player = Container.expand(function () {
  var self = Container.call(this);
  var playerGraphics = self.attachAsset('player', {
    anchorX: 0.5,
    anchorY: 0.5
  });
  self.speed = 10;
  self.update = function () {
    // Player update logic
  };
});

/****
* Initialize Game
****/
var game = new LK.Game({
  backgroundColor: 0x000000 //Init game with black background 
});

/****
* Game Code
****/
// Initialize player
var player = game.addChild(new Player());
player.x = 2048 / 2;
player.y = 2500;
// Array to hold bullets
var bullets = [];
// Array to hold aliens
var aliens = [];
// Function to spawn aliens
function spawnAlien() {
  var alien = new Alien();
  alien.x = Math.random() * 2048;
  alien.y = 0;
  aliens.push(alien);
  game.addChild(alien);
}
// Function to handle shooting
function shoot() {
  var bullet = new Bullet();
  bullet.x = player.x;
  bullet.y = player.y;
  bullets.push(bullet);
  game.addChild(bullet);
}
// Game update loop
game.update = function () {
  // Update player
  player.update();
  // Update bullets
  for (var i = bullets.length - 1; i >= 0; i--) {
    bullets[i].update();
    if (bullets[i].destroyed) {
      bullets.splice(i, 1);
    }
  }
  // Update aliens
  for (var j = aliens.length - 1; j >= 0; j--) {
    aliens[j].update();
    if (aliens[j].destroyed) {
      aliens.splice(j, 1);
    }
  }
  // Check for collisions
  for (var k = bullets.length - 1; k >= 0; k--) {
    for (var l = aliens.length - 1; l >= 0; l--) {
      if (bullets[k].intersects(aliens[l])) {
        bullets[k].destroy();
        aliens[l].destroy();
        bullets.splice(k, 1);
        aliens.splice(l, 1);
        break;
      }
    }
  }
  // Spawn aliens periodically
  if (LK.ticks % 60 == 0) {
    spawnAlien();
  }
};
// Handle player movement
game.move = function (x, y, obj) {
  player.x = x;
  player.y = y;
};
// Handle shooting
game.down = function (x, y, obj) {
  shoot();
};