/****
* Classes
****/
// Enemy class
var Enemy = Container.expand(function () {
  var self = Container.call(this);
  var enemyGraphics = self.attachAsset('enemy', {
    anchorX: 0.5,
    anchorY: 0.5
  });
  self.update = function () {
    // Enemy behavior can be added here
  };
});
//<Assets used in the game will automatically appear here>
// Explosion class
var Explosion = Container.expand(function () {
  var self = Container.call(this);
  var explosionGraphics = self.attachAsset('explosion', {
    anchorX: 0.5,
    anchorY: 0.5
  });
  self.radius = 50;
  self.expandRate = 5;
  self.update = function () {
    self.radius += self.expandRate;
    explosionGraphics.width = self.radius * 2;
    explosionGraphics.height = self.radius * 2;
    if (self.radius > 200) {
      self.destroy();
    }
  };
});

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

/****
* Game Code
****/
// Initialize arrays and variables
var explosions = [];
var enemies = [];
// Function to create an explosion
function createExplosion(x, y) {
  var explosion = new Explosion();
  explosion.x = x;
  explosion.y = y;
  explosions.push(explosion);
  game.addChild(explosion);
}
// Function to create an enemy
function createEnemy(x, y) {
  var enemy = new Enemy();
  enemy.x = x;
  enemy.y = y;
  enemies.push(enemy);
  game.addChild(enemy);
}
// Handle screen press to create an explosion
game.down = function (x, y, obj) {
  createExplosion(x, y);
};
// Update function called every game tick
game.update = function () {
  // Update explosions
  for (var i = explosions.length - 1; i >= 0; i--) {
    explosions[i].update();
    if (explosions[i].radius > 200) {
      explosions.splice(i, 1);
    }
  }
  // Check for collisions between explosions and enemies
  for (var j = enemies.length - 1; j >= 0; j--) {
    for (var k = 0; k < explosions.length; k++) {
      if (enemies[j].intersects(explosions[k])) {
        createExplosion(enemies[j].x, enemies[j].y);
        enemies[j].destroy();
        enemies.splice(j, 1);
        break;
      }
    }
  }
};
// Create initial enemies
createEnemy(500, 500);
createEnemy(1000, 1000);
createEnemy(1500, 1500);