/*
 * Copyright 2008 (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.helper;

import pcgen.base.formula.Formula;
import pcgen.cdom.list.CompanionList;
import pcgen.cdom.reference.CDOMSingleRef;

/**
 * A FollowerLimit represents an upper bound (stored as a Formula) on the number
 * of Companions a PlayerCharacter may have for a specific CompanionList.
 */
public class FollowerLimit
{

	/**
	 * A reference to the CompanionList to which this FollowerLimit applies
	 */
	private final CDOMSingleRef<CompanionList> ref;

	/**
	 * The Formula that represents the upper bound on the number of Companions a
	 * PlayerCharacter may have for the CompanionList.
	 */
	private final Formula formula;

	/**
	 * Creates a new FollowerLimit for the given CompanionList (provided by
	 * reference), which is limited by the given Formula.
	 * 
	 * @param clRef
	 *            A reference to the CompanionList to which this FollowerLimit
	 *            applies
	 * @param limit
	 *            The Formula that represents the upper bound on the number of
	 *            Companions a PlayerCharacter may have for the CompanionList.
	 */
	public FollowerLimit(CDOMSingleRef<CompanionList> clRef, Formula limit)
	{
		if (clRef == null)
		{
			throw new IllegalArgumentException(
					"Reference for FollowerLimit cannot be null");
		}
		if (limit == null)
		{
			throw new IllegalArgumentException(
					"Formula for FollowerLimit cannot be null");
		}
		ref = clRef;
		formula = limit;
	}

	/**
	 * Returns a reference to the CompanionList to which this FollowerLimit
	 * applies
	 * 
	 * @return A reference to the CompanionList to which this FollowerLimit
	 *         applies
	 */
	public CDOMSingleRef<CompanionList> getCompanionList()
	{
		return ref;
	}

	/**
	 * Returns the Formula that represents the upper bound on the number of
	 * Companions a PlayerCharacter may have for the CompanionList.
	 * 
	 * @return The Formula that represents the upper bound on the number of
	 *         Companions a PlayerCharacter may have for the CompanionList.
	 */
	public Formula getValue()
	{
		return formula;
	}

	/**
	 * Returns a consistent-with-equals hashCode for this FollowerLimit
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode()
	{
		return ref.hashCode() * 31 + formula.hashCode();
	}

	/**
	 * Returns true if the given object is a FollowerLimit with identical
	 * underlying CompanionList reference and limit Formula.
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object o)
	{
		if (o instanceof FollowerLimit)
		{
			FollowerLimit other = (FollowerLimit) o;
			return ref.equals(other.ref) && formula.equals(other.formula);
		}
		return false;
	}

}