/**
 * A point has an x- and y-coordinate.
 *
 * @author Franck van Breugel
 */
public class Point implements Comparable<Point>
{
    private int x;
    private int y;

    /**
     * Initializes this point with the given x- and y-coordinate.
     *
     * @param x the x-coordinate of this point.
     * @param y the y-coordinate of this point.
     */
    public Point(int x, int y)
    {
	this.setX(x);
	this.setY(y);
    }

    /**
     * Returns the x-coordinate of this point.
     *
     * @return the x-coordinate of this point.
     */
    public int getX()
    {
	return this.x;
    }

    /**
     * Sets the x-coordinate of this point to the given x-coordinate.
     * 
     * @param x the new x-coordinate of this point.
     */
    private void setX(int x)
    {
	this.x = x;
    }

    /**
     * Returns the y-coordinate of this point.
     *
     * @return the y-coordinate of this point.
     */
    public int getY()
    {
	return this.y;
    }

    /**
     * Sets the y-coordinate of this point to the given y-coordinate.
     * 
     * @param y the new y-coordinate of this point.
     */
    private void setY(int y)
    {
	this.y = y;
    }

    /**
     * Returns the hash code of this point.
     * 
     * @return the hash code of this point.
     */
    public int hashCode()
    {
	return this.getX() * this.getY();
    }

    /**
     * Tests whether this point is the same as the given object.
     * Two points are the same if they have the same x- and 
     * y-coordinates.
     * 
     * @param object an object
     * @return true if this point is the same as the given object,
     * false otherwise.
     */
    public boolean equals(Object object)
    {
	boolean equal;
	if (object != null && this.getClass() == object.getClass())
	{
	    Point other = (Point) object;
	    equal = this.getX() == other.getX() &&
		this.getY() == other.getY();
	}
	else
	{
	    equal = false;
	}
	return equal;
    }
    
    /**
     * Compares this point to the other given point.
     * Returns a negative integer/zero/positive integer
     * if this point is smaller than/the same/greater than
     * the other point in the lexicographic order.
     * 
     * @param other another point.
     * @return a negative integer/zero/positive integer
     * if this point is smaller than/the same/greater than
     * the other point in the lexicographic order.
     */
    public int compareTo(Point other)
    {
	int difference;
	if (this.getX() == other.getX())
	{
	    difference = this.getY() - other.getY();
	}
	else
	{
	    difference = this.getX() - other.getX();
	}
	return difference;
    }

    /**
     * Returns a string representation of this point.
     * The representation is of the form (x, y), where
     * x and y are the x- and y-coordinates of this point.
     * 
     * @return a string representation of this point.
     */
    public String toString()
    {
	return String.format("(%d, %d)", this.getX(), this.getY());
    }
}