/**
 * A Quitter keeps track of the number of times that this Quitter has been asked
 * to transform, and if that number is less than or equal to this Quitter's
 * quitting time, then the returned String is the given String with
 * "- I am on it" appended. After the quitting time, the returned String is the
 * given String, unchanged.
 * <p>
 * Each Quitter has its own quitting time; the default quitting time is 1.
 * 
 * @author David Mutchler. Created October 8, 2009.
 */
public class Quitter implements StringTransformable {
	private static String messageToApppend = " - I am on it!";
	private int quittingTime;
	private int numberOfTransformationsSoFar;

	/**
	 * Initializes the quitting time to 1 (so that the first transform returns
	 * the given String with the special message appended while subsequent
	 * transforms return the given String unchanged.
	 */
	public Quitter() {
		this(1);
	}

	/**
	 * Initializes the quitting time to the given value (so that transforms
	 * after the quitting time return the String unchanged, while transforms at
	 * or before the quitting time return the String with a message appended.
	 * 
	 * @param quittingTime
       *              Number of times to append the string before quitting.
	 */
	public Quitter(int quittingTime) {
		this.quittingTime = quittingTime;
		this.numberOfTransformationsSoFar = 0;
	}

	/**
	 * Keeps track of the number of times that this Quitter has been asked to
	 * transform, and if that number is less than or equal to this Quitter's
	 * quitting time, then the returned String is the given String with
	 * "- I am on it" appended. After the quitting time, the returned String is
	 * the given String, unchanged.
	 * 
	 * @param stringToTransform
       *              The String to transform.
	 * @return The transformed String.
	 */
	@Override
	public String transform(String stringToTransform) {
		++this.numberOfTransformationsSoFar;
		if (this.numberOfTransformationsSoFar <= this.quittingTime) {
			return stringToTransform + Quitter.messageToApppend;
		} else {
			return stringToTransform;
		}
	}
}