/*
 * Copyright (c) Thomas Parker, 2012.
 * 
 * This program 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 program 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
package pcgen.cdom.facet.base;

import java.util.Collection;
import java.util.Collections;
import java.util.IdentityHashMap;
import java.util.Map;

import pcgen.base.util.WrappedMapSet;
import pcgen.cdom.base.PCGenIdentifier;

public abstract class AbstractSubAssociationFacet<IDT extends PCGenIdentifier, S1, S2, A>
		extends AbstractStorageFacet<IDT>
{

	public A get(IDT id, S1 obj1, S2 obj2)
	{
		if (obj1 == null)
		{
			throw new IllegalArgumentException(
				"Object for getting association may not be null");
		}
		if (obj2 == null)
		{
			throw new IllegalArgumentException(
				"Object for getting association may not be null");
		}
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		if (map == null)
		{
			return null;
		}
		Map<S2, A> subMap = map.get(obj1);
		if (subMap == null)
		{
			return null;
		}
		return subMap.get(obj2);
	}

	public boolean set(IDT id, S1 obj1, S2 obj2, A association)
	{
		if (obj1 == null)
		{
			throw new IllegalArgumentException("Object to add may not be null");
		}
		if (obj2 == null)
		{
			throw new IllegalArgumentException("Object to add may not be null");
		}
		if (association == null)
		{
			throw new IllegalArgumentException("Association may not be null");
		}
		Map<S2, A> map = getConstructingCachedMap(id, obj1);
		A old = map.put(obj2, association);
		return old == null;
	}

	public void remove(IDT id, S1 obj1, S2 obj2)
	{
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		if (map != null)
		{
			Map<S2, A> subMap = map.get(obj1);
			if (subMap != null)
			{
				map.remove(obj2);
				if (subMap.isEmpty())
				{
					map.remove(obj1);
				}
			}
		}
	}

	public Map<S1, Map<S2, A>> removeAll(IDT id)
	{
		Map<S1, Map<S2, A>> componentMap =
				(Map<S1, Map<S2, A>>) removeCache(id);
		if (componentMap == null)
		{
			return Collections.emptyMap();
		}
		return componentMap;
	}

	public boolean isEmpty(IDT id)
	{
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		return map == null || map.isEmpty();
	}

	protected Map<S1, Map<S2, A>> getCachedMap(IDT id)
	{
		return (Map<S1, Map<S2, A>>) getCache(id);
	}

	private Map<S2, A> getConstructingCachedMap(IDT id, S1 obj1)
	{
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		if (map == null)
		{
			map = getComponentMap();
			setCache(id, map);
		}
		Map<S2, A> subMap = map.get(obj1);
		if (subMap == null)
		{
			subMap = getSubComponentMap();
			map.put(obj1, subMap);
		}
		return subMap;
	}

	protected Map<S1, Map<S2, A>> getComponentMap()
	{
		return new IdentityHashMap<>();
	}

	protected Map<S2, A> getSubComponentMap()
	{
		return new IdentityHashMap<>();
	}

	@Override
	public void copyContents(IDT source, IDT destination)
	{
		Map<S1, Map<S2, A>> sourceMap = getCachedMap(source);
		if (sourceMap != null)
		{
			for (Map.Entry<S1, Map<S2, A>> me : sourceMap.entrySet())
			{
				getConstructingCachedMap(destination, me.getKey()).putAll(
					me.getValue());
			}
		}
	}
	
	public Collection<S1> getObjects(IDT id)
	{
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		if (map == null)
		{
			return Collections.emptyList();
		}
		WrappedMapSet<S1> set =
                new WrappedMapSet<>(getComponentMap().getClass());
		set.addAll(map.keySet());
		return set;
	}

	public Collection<S2> getSubObjects(IDT id, S1 obj1)
	{
		Map<S1, Map<S2, A>> map = getCachedMap(id);
		if (map == null)
		{
			return Collections.emptyList();
		}
		Map<S2, A> subMap = map.get(obj1);
		if (subMap == null)
		{
			return Collections.emptyList();
		}
		WrappedMapSet<S2> set =
                new WrappedMapSet<>(getSubComponentMap().getClass());
		set.addAll(subMap.keySet());
		return set;
	}

}