import java.awt.Graphics;
import java.util.ArrayList;
import java.util.Random;

public class Boid extends PhysicsObject implements Drawable {
  private int group;

  public Boid(int width, int height, int group) {
    super(0, 0, 0, 0);
    Random r = new Random();
    this.x = r.nextInt(width);
    this.y = r.nextInt(height);
    this.apply_force(r.nextFloat() * 2 - 1, r.nextFloat() * 2 - 1, 1);
    this.group = group;
  }

  @Override
  public void draw(Graphics g) {
    g.fillOval((int) x, (int) y, 2, 2);
  }

  public void simulate(int group) {
    super.simulate();

    // Gruppen werden zeitversetzt aktualisiert um die Performance zu verbessern
    if (this.group != group)
      return;

    ArrayList<PhysicsObject> others = ChunkManager.get_objects((int) x, (int) y);

    int other_count = others.size();

    if (other_count == 0)
      return;

    for (int i = 0; i < other_count; i++) {
      // Überprüfung teilweise überspringen, wenn es zu viele objekte in der Nähe gibt
      if ((i + group) % Math.max(1, other_count / 16) != 1)
        continue;

      PhysicsObject o = others.get(i);
      double dist = this.get_sqr_distance(o);
      if (dist < 500 && dist > 20) {
        // Regel 1: Zu anderen hin bewegen
        this.apply_force(o.x - x, o.y - y, (float) Math.min(0.005 / dist, 1));
        // Regel 3: In die Richtung der anderen fliegen
        this.apply_force(o.v_x, o.v_y, 0.005f);
      } else if (dist < 20) {
        // Regel 2: Abstand halten
        this.apply_force(x - o.x, y - o.y, (float) Math.min(0.005 / dist, 1));
      }
    }

  }
}