/*
 * Copyright 2014 (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.content.fact;

import pcgen.cdom.base.CDOMObject;
import pcgen.cdom.enumeration.FactKey;
import pcgen.persistence.lst.LstToken;
import pcgen.rules.context.LoadContext;
import pcgen.rules.persistence.token.DeferredToken;
import pcgen.util.Logging;

/**
 * A FactDefinitionEnforcer is a dynamically built DeferredToken used when a
 * FACT: is defined as REQUIRED:YES
 * 
 * This will thus enforce that every object of that type has the required FACT
 * present on the object.
 * 
 * @param <T>
 *            The type of of object upon which the FactDefinitionEnforcer will
 *            be used
 * @param <F>
 *            The format of the data stored in the Fact
 */
public class FactDefinitionEnforcer<T extends CDOMObject, F> implements
		DeferredToken<T>, LstToken
{

	/**
	 * The FactInfo that this FactDefinitionEnforcer is ensuring is present in
	 * the data
	 */
	private final FactInfo<T, F> def;

	/**
	 * Constructs a new FactDefintionEnforcer to enforce that the given FactInfo
	 * is required in the data.
	 * 
	 * @param fi
	 *            The FactInfo that will be enforced to ensure it exists in the
	 *            data
	 */
	public FactDefinitionEnforcer(FactInfo<T, F> fi)
	{
		if (fi == null)
		{
			throw new IllegalArgumentException("Fact Info cannot be null");
		}
		def = fi;
	}

	/**
	 * @see pcgen.rules.persistence.token.DeferredToken#process(pcgen.rules.context.LoadContext,
	 *      pcgen.cdom.base.Loadable)
	 */
	@Override
	public boolean process(LoadContext context, T obj)
	{
		FactKey<F> fk = def.getFactKey();
		if (context.getObjectContext().getFact(obj, fk) != null)
		{
			return true;
		}
		Logging.errorPrint("FACT " + def.getFactName()
			+ " was required but not set in " + obj.getClass().getSimpleName()
			+ " " + obj.getKeyName());
		return false;
	}

	/**
	 * @see pcgen.rules.persistence.token.DeferredToken#getDeferredTokenClass()
	 */
	@Override
	public Class<T> getDeferredTokenClass()
	{
		return def.getUsableLocation();
	}

	/**
	 * @see pcgen.persistence.lst.LstToken#getTokenName()
	 */
	@Override
	public String getTokenName()
	{
		return "FACTENFORCE";
	}

}