/*
 * 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.base;

import java.util.Collection;
import java.util.Collections;

import pcgen.cdom.enumeration.GroupingState;
import pcgen.core.PlayerCharacter;

/**
 * A PrimitiveChoiceSet contains references to Objects. Often these are
 * CDOMObjects, but that is not strictly required.
 * 
 * The intent is for a PrimitiveChoiceSet to be created and populated with a set
 * of CDOMObjects. It is possible that the contents of the PrimitiveChoiceSet
 * will be dynamic based on the PlayerCharacter used to resolve the contents of
 * the PrimitiveChoiceSet.
 * 
 * @param <T>
 *            The class of object this PrimitiveChoiceSet contains.
 */
public interface PrimitiveChoiceSet<T>
{
	PrimitiveChoiceSet INVALID = new PrimitiveChoiceSet(){

		@Override
		public Class getChoiceClass()
		{
			return Object.class;
		}

		@Override
		public GroupingState getGroupingState()
		{
			return GroupingState.INVALID;
		}

		@Override
		public String getLSTformat(boolean useAny)
		{
			return "ERROR";
		}

		@Override
		public Collection getSet(PlayerCharacter pc)
		{
			return Collections.emptyList();
		}};

	/**
	 * Returns a Set containing the Objects which this PrimitiveChoiceSet
	 * contains.
	 * 
	 * It is intended that classes which implement PrimitiveChoiceSet will make
	 * this method value-semantic, meaning that ownership of the Set returned by
	 * this method will be transferred to the calling object. Modification of
	 * the returned Set should not result in modifying the PrimitiveChoiceSet,
	 * and modifying the PrimitiveChoiceSet after the Set is returned should not
	 * modify the Set.
	 * 
	 * @param pc
	 *            The PlayerCharacter for which the choices in this
	 *            PrimitiveChoiceSet should be returned.
	 * @return A Set containing the Objects which this PrimitiveChoiceSet
	 *         contains.
	 */
	public Collection<? extends T> getSet(PlayerCharacter pc);

	/**
	 * The class of object this PrimitiveChoiceSet contains.
	 * 
	 * @return The class of object this PrimitiveChoiceSet contains.
	 */
	public Class<? super T> getChoiceClass();

	/**
	 * Returns a representation of this PrimitiveChoiceSet, suitable for storing
	 * in an LST file.
	 * 
	 * @param useAny
	 *            use "ANY" for the global "ALL" reference when creating the LST
	 *            format
	 * @return A representation of this PrimitiveChoiceSet, suitable for storing
	 *         in an LST file.
	 */
	public String getLSTformat(boolean useAny);

	/**
	 * Returns the GroupingState for this PrimitiveChoiceSet. The GroupingState
	 * indicates how this PrimitiveChoiceSet can be combined with other
	 * PrimitiveChoiceSets.
	 * 
	 * @return The GroupingState for this PrimitiveChoiceSet.
	 */
	public GroupingState getGroupingState();
}