/*
 * Copyright (c) Thomas Parker, 2010.
 * 
 * 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.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import pcgen.cdom.enumeration.CharID;
import pcgen.cdom.facet.event.DataFacetChangeEvent;
import pcgen.cdom.facet.event.DataFacetChangeListener;
import pcgen.cdom.helper.CNAbilitySelection;
import pcgen.cdom.helper.CNAbilitySelectionUtilities;

public class AbstractCNASEnforcingFacet extends
		AbstractDataFacet<CharID, CNAbilitySelection> implements
		DataFacetChangeListener<CharID, CNAbilitySelection>
{
	public boolean isEmpty(CharID id)
	{
		List<List<SourcedCNAS>> list = getList(id);
		return (list == null) || list.isEmpty();
	}

	public boolean add(CharID id, CNAbilitySelection cnas, Object source)
	{
		if (cnas == null)
		{
			throw new IllegalArgumentException("Attempt to add null to list");
		}
		if (source == null)
		{
			throw new IllegalArgumentException(
				"Attempt to add object with null source to list");
		}
		List<List<SourcedCNAS>> list = getConstructingList(id);
		for (List<SourcedCNAS> slist : list)
		{
			CNAbilitySelection main = slist.get(0).cnas;
			if (!CNAbilitySelectionUtilities.canCoExist(main, cnas))
			{
				slist.add(new SourcedCNAS(cnas, source));
				return false;
			}
		}
		List<SourcedCNAS> newList = new ArrayList<>(1);
		newList.add(new SourcedCNAS(cnas, source));
		list.add(newList);
		fireDataFacetChangeEvent(id, cnas, DataFacetChangeEvent.DATA_ADDED);
		return true;
	}

	public boolean remove(CharID id, CNAbilitySelection cnas, Object source)
	{
		if (cnas == null)
		{
			throw new IllegalArgumentException(
				"Attempt to remove null from list");
		}
		if (source == null)
		{
			throw new IllegalArgumentException(
				"Attempt to remove object with null source from list");
		}
		List<List<SourcedCNAS>> list = getList(id);
		if (list == null)
		{
			return false;
		}
		for (Iterator<List<SourcedCNAS>> listIT = list.iterator(); listIT.hasNext();)
		{
			List<SourcedCNAS> array = listIT.next();
			int length = array.size();
			//Iterate backwards, so that we remove harmless items first
			for (int j = length - 1; j >= 0; j--)
			{
				SourcedCNAS sc = array.get(j);
				if (cnas.equals(sc.cnas) && source.equals(sc.source))
				{
					//fix the array here
					if ((j == 0) && (length == 1))
					{
						//There is no alternative, remove the array from the list;
						listIT.remove();
						fireDataFacetChangeEvent(id, cnas, DataFacetChangeEvent.DATA_REMOVED);
						return true;
					}
					else
					{
						array.remove(j);
						CNAbilitySelection newPrimary = array.get(0).cnas;
						//Only fire if the CNAS differs to avoid churn
						if (!cnas.equals(newPrimary) && (j == 0))
						{
							fireDataFacetChangeEvent(id, cnas,
								DataFacetChangeEvent.DATA_REMOVED);
							fireDataFacetChangeEvent(id, newPrimary,
								DataFacetChangeEvent.DATA_ADDED);
							return true;
						}
						return false;
					}
				}
			}
		}
		return false;
	}

	public Collection<CNAbilitySelection> getSet(CharID id)
	{
		List<List<SourcedCNAS>> list = getList(id);
		if (list == null)
		{
			return Collections.emptyList();
		}
		List<CNAbilitySelection> returnList = new ArrayList<>();
		for (List<SourcedCNAS> array : list)
		{
			returnList.add(array.get(0).cnas);
		}
		return returnList;
	}

	protected List<List<SourcedCNAS>> getList(CharID id)
	{
		return (List<List<SourcedCNAS>>) this.getCache(id);
	}

	private List<List<SourcedCNAS>> getConstructingList(CharID id)
	{
		List<List<SourcedCNAS>> list = getList(id);
		if (list == null)
		{
			list = new ArrayList<>();
			setCache(id, list);
		}
		return list;
	}

	@Override
	public void copyContents(CharID source, CharID copy)
	{
		List<List<SourcedCNAS>> list = getList(source);
		if (list != null)
		{
			List<List<SourcedCNAS>> constructingList = getConstructingList(copy);
			for (List<SourcedCNAS> orig : list)
			{
				List<SourcedCNAS> newCnasList =
                        new ArrayList<>(
                                orig);
				constructingList.add(newCnasList);
			}
		}
	}

	public int getCount(CharID id)
	{
		List<List<SourcedCNAS>> list = getList(id);
		return (list == null) ? 0 : list.size();
	}

	@Override
	public void dataAdded(DataFacetChangeEvent<CharID, CNAbilitySelection> dfce)
	{
		add(dfce.getCharID(), dfce.getCDOMObject(), dfce.getSource());
	}

	@Override
	public void dataRemoved(
		DataFacetChangeEvent<CharID, CNAbilitySelection> dfce)
	{
		remove(dfce.getCharID(), dfce.getCDOMObject(), dfce.getSource());
	}

	protected static class SourcedCNAS
	{
		public final CNAbilitySelection cnas;
		public final Object source;

		public SourcedCNAS(CNAbilitySelection cnas, Object source)
		{
			this.cnas = cnas;
			this.source = source;
		}

		@Override
		public String toString()
		{
			return cnas + " (src: " + source + ")";
		}
		
		@Override
		public int hashCode()
		{
			return source.hashCode() ^ cnas.hashCode();
		}
		
		@Override
		public boolean equals(Object o)
		{
			if (o == this)
			{
				return true;
			}
			if (o instanceof SourcedCNAS)
			{
				SourcedCNAS other = (SourcedCNAS) o;
				return cnas.equals(other.cnas) && source.equals(other.source);
			}
			return false;
		}

	}
}