/*
 * Copyright 2007 (C) Tom Parker <thpr@users.sourceforge.net>
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package pcgen.cdom.processor;

import pcgen.cdom.content.HitDie;
import pcgen.cdom.content.Processor;

/**
 * A HitDieLock represents a constrained HitDie that does not change. Since this
 * acts as a Processor, the effect of the application of this Processor is
 * unconditional return of the HitDie object provided at construction of the
 * HitDieLock object.
 */
public class HitDieLock implements Processor<HitDie>
{

	/**
	 * The HitDie to which this HitDieLock is "locked"
	 */
	private final HitDie hitDie;

	/**
	 * Constructs a new HitDieLock which will unconditionally return the given
	 * HitDie object.
	 * 
	 * @param die
	 *            The HitDie for this HitDieLock
	 * @throws IllegalArgumentException
	 *             if the given HitDie is null
	 */
	public HitDieLock(HitDie die)
	{
		super();
		if (die == null)
		{
			throw new IllegalArgumentException(
					"Die for HitDieLock cannot be null");
		}
		hitDie = die;
	}

	/**
	 * Applies this Processor by returning the HitDie to which this HitDieLock is
	 * set.
	 * 
	 * Since HitDieLock is universal, the given context is ignored.
	 * 
	 * @param origHD
	 *            The input HitDie this Processor will act upon
	 * @param context
	 *            The context of this Processor, ignored by HitDieLock.
	 * @return The modified object, of the same class as the input object.
	 */
	@Override
	public HitDie applyProcessor(HitDie origHD, Object context)
	{
		return hitDie;
	}

	/**
	 * Returns a representation of this HitDieLock, suitable for storing in an
	 * LST file.
	 * 
	 * @return A representation of this HitDieLock, suitable for storing in an
	 *         LST file.
	 */
	@Override
	public String getLSTformat()
	{
		return Integer.toString(hitDie.getDie());
	}

	/**
	 * The class of object this Processor acts upon (HitDie).
	 * 
	 * @return The class of object this Processor acts upon (HitDie.class)
	 */
	@Override
	public Class<HitDie> getModifiedClass()
	{
		return HitDie.class;
	}

	/**
	 * Returns the consistent-with-equals hashCode for this HitDieLock
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode()
	{
		return hitDie.hashCode();
	}

	/**
	 * Returns true if this HitDieLock is equal to the given Object. Equality is
	 * defined as being another HitDieLock object with HitDie to which it is
	 * "locked".
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj)
	{
		return obj instanceof HitDieLock
				&& ((HitDieLock) obj).hitDie.equals(hitDie);
	}

}