/*
 * Copyright 2007, 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.formula;

import pcgen.base.formula.Formula;
import pcgen.cdom.enumeration.IntegerKey;
import pcgen.cdom.reference.CDOMSingleRef;
import pcgen.core.Equipment;
import pcgen.core.PlayerCharacter;
import pcgen.core.SizeAdjustment;

/**
 * A FixedSizeFormula is a Formula that returns a deterministic value, used to
 * uniquely identify a SizeAdjustment. The SizeAdjustment for which this Formula
 * will return the value must be defined during construction of the
 * FixedSizeFormula.
 */
public class FixedSizeFormula implements Formula
{

	/**
	 * The underlying SizeAdjustment for which this Formula will return the
	 * identifying value.
	 */
	private final CDOMSingleRef<SizeAdjustment> size;

	/**
	 * Creates a new FixedSizeFormula for the given SizeAdjustment.
	 * 
	 * @param sAdj
	 *            The SizeAdjustment for which this Formula will return the
	 *            identifying value.
	 * @throws IllegalArgumentException
	 *             if the given SizeAdjustment is null
	 */
	public FixedSizeFormula(CDOMSingleRef<SizeAdjustment> sAdj)
	{
		if (sAdj == null)
		{
			throw new IllegalArgumentException(
					"Size Adjustment for FixedSizeFormula cannot be null");
		}
		size = sAdj;
	}

	/**
	 * Returns a String representation of this FixedSizeFormula, primarily for
	 * purposes of debugging. It is strongly advised that no dependency on this
	 * method be created, as the return value may be changed without warning.
	 */
	@Override
	public String toString()
	{
		return size.getLSTformat(false);
	}

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

	/**
	 * Returns true if this FixedSizeFormula is equal to the given Object.
	 * Equality is defined as being another FixedSizeFormula object with equal
	 * underlying SizeAdjustment
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj)
	{
		return obj instanceof FixedSizeFormula
				&& size.equals(((FixedSizeFormula) obj).size);
	}

	/**
	 * Resolves to the identifying value of the SizeAdjustment provided during
	 * construction of the FixedSizeFormula. The given PlayerCharacter and
	 * source are ignored.
	 * 
	 * @param pc
	 *            The PlayerCharacter relative to which the FixedSizeFormula
	 *            should be resolved (ignored)
	 * @param source
	 *            The source object of the FixedSizeFormula, for purposes of
	 *            resolution (ignored)
	 * @return The identifying value of the SizeAdjustment this FixedSizeFormula
	 *         represents.
	 */
	@Override
	public Integer resolve(PlayerCharacter pc, String source)
	{
		return resolveStatic();
	}

	/**
	 * Resolves to the identifying value of the SizeAdjustment provided during
	 * construction of the FixedSizeFormula. The given arguments are ignored as
	 * no source or context is requried to resolve a FixedSizeFormula.
	 * 
	 * @param equipment
	 *            The Equipment relative to which the FixedSizeFormula should be
	 *            resolved (ignored)
	 * @param primary
	 *            True if the primary head of the given Equipment should be used
	 *            for resolution, false if the secondary head should be used for
	 *            resolution (ignored)
	 * @param apc
	 *            The PlayerCharacter relative to which the FixedSizeFormula
	 *            should be resolved (ignored)
	 * @param source
	 *            The source object of the FixedSizeFormula, for purposes of
	 *            resolution (ignored)
	 * @return The identifying value of the SizeAdjustment this FixedSizeFormula
	 *         represents.
	 */
	@Override
	public Number resolve(Equipment equipment, boolean primary,
			PlayerCharacter apc, String source)
	{
		return resolveStatic();
	}

	/**
	 * Returns true if this Formula is static (will always return the same
	 * value). As a FixedSizeFormula will always return the same value except in
	 * circumvention of a key assumption (a consistent, ordered set of
	 * SizeAdjustment objects in a given GameMode), this will return true.
	 * 
	 * @return true
	 */
	@Override
	public boolean isStatic()
	{
		return true;
	}

	@Override
	public boolean isValid()
	{
		return true;
	}

	/**
	 * Resolves to the identifying value of the SizeAdjustment provided during
	 * construction of the FixedSizeFormula.
	 * 
	 * @return The identifying value of the SizeAdjustment this FixedSizeFormula
	 *         represents.
	 */
	@Override
	public Integer resolveStatic()
	{
		return size.get().get(IntegerKey.SIZEORDER);
	}
}