/**
 * This Intersection class represents a single intersection point where two streets laid out 
 * on a grid plan cross at specified x and y coordinate positions
 */
public class Intersection {

  private final int x; // X-axis coordinate of this intersection
  private final int y; // Y-axis coordinate of this intersection

  /**
   * Initializes this intersection with the given coordinates
   * 
   * @param x Horizontal position of this Intersection
   * @param y Vertical position of this Intersection
   */
  public Intersection(int x, int y) {
    this.x = x;
    this.y = y;
  }

  /**
   * Returns the horizontal position of this Intersection
   * 
   * @return the horizontal position of this Intersection
   */
  public int getX() {
    return x;
  }
  
  /**
   * Returns the vertical position of this Intersection
   * 
   * @return the vertical position of this Intersection
   */
  public int getY() {
    return y;
  }

  /**
   * Returns a coordinate-pair representation of this Intersection in the form "(x,y)"
   * 
   * @return a coordinate-pair representation of this Intersection
   */
  @Override
  public String toString() {
    return "(" + this.x + "," + this.y + ")";
  }

  /**
   * Returns true if the given Object is identical to this Intersection
   * 
   * @param o - object to compare for equality
   * @return true if the given Object is an Intersection object which has the same x and y coordinates as this Intersection
   */
  @Override
  public boolean equals(Object o) {
    Intersection i;
    if (o instanceof Intersection) {
      i = (Intersection) o;
      if (i.getX() == this.x && i.getY() == this.y) {
        return true;
      }
    }
    return false;
  }

  /**
   * Creates a new Intersection instance which is one step directly above this Intersection. 
   * Should not modify the original Intersection object.
   * 
   * @return a new Intersection instance which is one step directly above this Intersection
   */
  public Intersection goNorth() {
    Intersection north = new Intersection(this.x, this.y + 1);
    return north;
  }

  /**
   * Creates a new Intersection instance which is one step directly below this Intersection. 
   * Should not modify the original Intersection object.
   * 
   * @return a new Intersection instance which is one step directly below this Intersection
   */
  public Intersection goSouth() {
    Intersection south = new Intersection(this.x, this.y - 1);
    return south;
  }

  /**
   * Creates a new Intersection instance which is one step directly to the right of this Intersection object. 
   * Should not modify the original Intersection object.
   * 
   * @return a new Intersection instance which is one step directly to the right of this Intersection
   */
  public Intersection goEast() {
    Intersection east = new Intersection(this.x + 1, this.y);
    return east;
  }
  
  /**
   * Creates a new Intersection instance which is one step directly to the left of this Intersection. 
   * Should not modify the original Intersection object.
   * 
   * @return a new Intersection instance which is one step directly to the left of this Intersection
   */
  public Intersection goWest() {
    Intersection west = new Intersection(this.x - 1, this.y);
    return west;
  }

}