/******************************** FILE HEADER **********************************
Main Class File:	Main.java
File:			Point.java

Author:                 Michael Schultz
CS Login:               mschultz
Collaborators:

Completion Date:	9/24/02

Course:                 CS 302
TA:                     Mr. Schultz

Compiler:               Code Warrior IDE 5.0
Platform:               Windows 2000
*******************************************************************************/

/**
 * The Point class is used to represent a point in some two-dimenstion space, 
 * the axes of which are labeled here as x and y. Each point also has a
 * constant name, so that the points may be reassigned x / y values.<br><br>
 * There is a class method called distance, which computes the euclidean
 * distance between two Point instances, using the java.lang.Math class.
 *
Bugs: none known
 *
 * @author	Michael Schultz
 * @version	1.0
 * @see also	Main.java
 */

public class Point {

    /** The name of the Point instance */
    private final String name;

    /** The value of the x-coordiante */
    private int x;

    /** The value of the y-coordinate */
    private int y;

    /**
     * A constructor in which to specify just the name. The other values are
     * given their default values according to their primitive types.
     *
     * @param name The name of the point
     */
    public Point(String name) {
        this.name = name;
        System.out.println("A new Point object, \"" + getName() + "\", has " +
                           "been created with the default int values for x" +
                           " and y.\n");
    }

    /**
     * A constructor in which to specify all three data members at once. Uses
     * the "this" reference to call the first constructor.
     *
     * @param name The name of the point, gets passed to the first constructor
     * @param startX The initial x-coordinate of the point
     * @param startY The initial y-coordinate of the point
     */
    public Point(String name, int startX, int startY) {
        this(name);
        setX(startX);
        setY(startY);
        System.out.println("A new Point object, \"" + getName() + "\", has " +
                           "been created at (" + getX() + "," + getY() +
                           ").\n");
    }

    /**
     * A copy constructor, in which to specify the name of the new point, and
     * a point whose coordinates to copy into this
     *
     * @param name The name of the point
     * @param source The source Point whose coordinates to copy
     */
    public Point(String name, Point source) {
        this.name = name;
        setX(source.getX());
        setY(source.getY());
        System.out.println("A new Point object, \"" + getName() + "\", has " +
                           "been created copying Point " + source.getName() +
                           " at (" + getX() + "," + getY() + ").\n");
    }

    /**
     * An accessor for the data name
     *
     *@return The name of the point
     */
    public String getName() {
        return name;
    }

    /**
     * An accessor for the x-coordiante
     *
     * @return The value of the x-coordinate
     */
    public int getX() {
        return x;
    }

    /**
     * An accessor for the y-coordinate
     *
     * @return The value of the y-coordinate
     */
    public int getY() {
        return y;
    }

    /**
     * A mutator for the x-coordiante
     *
     * @param newX The new value for the x-coordinate
     */
    public void setX(int newX) {
        x = newX;
    }

    /**
     * A mutator for the y-coordiante
     *
     * @param newY The new value for the y-coordinate
     */
    public void setY(int newY) {
        y = newY;
    }

    /**
     * A public class method that returns the euclidean distance between two
     * point instances. The euclidean distance metric is order-independent.
     * Also note that while the method take in intergral point values, the
     * return is necessarily a decimal.
     *
     * @param a One of the Points for the calculation
     * @param b One of the Points for the calculation
     *
     * @return The decimal euclidean distance metric
     */
    public static double distance(Point a, Point b) {
        int xDistance = distance(a.getX(),b.getX());
        int yDistance = distance(a.getY(),b.getY());
        double xDistanceSquared = Math.pow(xDistance,2);
        double yDistanceSquared = Math.pow(yDistance,2);
        return Math.sqrt(xDistanceSquared + yDistanceSquared);
    }

    /**
     * A private class helper method which returns the linear distance
     * between two integer numbers. This is order independent.
     *
     * @param coordinate1 The first integer value
     * @param coordinate2 The second integer value
     *
     * @return The linear distance (absolute value of the difference) between
     * the two values
     */
    private static int distance(int coordinate1, int coordinate2) {
        return Math.abs(coordinate1 - coordinate2);
    }

    /**
     * The method inherited from Object and overriden here to give an
     * informative String about the instance at hand
     *
     * @return An informative String about "this" instance
     */
    public String toString() {
        return "Point " + getName() + " is located at (" + getX() +"," +
                getY() + ").\n";
    }

}