/**
 * This class represents a circle.  It offers all the operations mandated by the
 * Shape interface.
 */
public class Circle extends AbstractShape {
  private double radius;

  /**
   * Construct a circle object using the given center and radius
   *
   * @param x      x coordinate of the center of this circle
   * @param y      y coordinate of the center of this circle
   * @param radius the radius of this circle
   */
  public Circle(double x, double y, double radius) {
    super(new Point2D(x, y));
    this.radius = radius;
  }

  /**
   * Construct a circle object with the given radius. It is centered at (0,0)
   *
   * @param radius the radius of this circle
   */
  public Circle(double radius) {
    super(new Point2D(0, 0));
    this.radius = radius;
  }

  @Override
  public double area() {
    return Math.PI * radius * radius;
  }

  @Override
  public double perimeter() {
    return 2 * Math.PI * radius;
  }

  @Override
  public Shape resize(double factor) {
    return new Circle(reference.getX(), reference.getY(), Math.sqrt(factor) *
                                                          radius);
  }


  public String toString() {
    return String.format("Circle: center (%.3f,%.3f) radius %.3f",
            this.reference.getX(), this.reference.getY(), this.radius);
  }

  @Override
  protected boolean equalsCircle(Circle other) {
    return Math.abs(this.reference.dist(other.reference)) < 0.001 && Math.abs
            (this.radius - other.radius) < 0.001;
  }

  public boolean equals(Object other) {
    if (other instanceof AbstractShape) {
      AbstractShape ashape = (AbstractShape) other;
      //we know that this is a rectangle, so we check rectangle equality
      return ashape.equalsCircle(this);
    }
    return false; //since it is not AbstractShape it is not a circle either, so return false
  }
}