/*
 * PrerequisiteWriter.java
 *
 * Copyright 2004 (C) Frugal <frugal@purplewombat.co.uk>
 *
 * 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
 *
 * Created on 18-Dec-2003
 *
 * Current Ver: $Revision$
 *
 *
 *
 */
package pcgen.persistence.lst.output.prereq;

import java.io.StringWriter;
import java.io.Writer;
import java.util.Collection;
import java.util.TreeSet;

import pcgen.base.lang.StringUtil;
import pcgen.cdom.base.Constants;
import pcgen.cdom.base.PrereqObject;
import pcgen.core.prereq.Prerequisite;
import pcgen.persistence.PersistenceLayerException;
import pcgen.util.Logging;

public class PrerequisiteWriter
{
	public void write(Writer stringWriter, Prerequisite prereq)
			throws PersistenceLayerException
	{
		PrerequisiteWriterFactory factory = PrerequisiteWriterFactory
				.getInstance();
		PrerequisiteWriterInterface writer = factory
				.getWriter(prereq.getKind());
		if (writer == null)
		{
			throw new PersistenceLayerException(
					"Can not find a Writer for prerequisites fo kind: "
							+ prereq.getKind());
		}
		writer.write(stringWriter, prereq);
	}

	/**
	 * Convert the prerequisites of a PObject to a String in .lst-compatible
	 * form
	 * 
	 * @param pObj
	 *            A PObject object.
	 * @return The .lst-compatible string representation of the prerequisite
	 *         list.
	 */
	static public String prereqsToString(final PrereqObject pObj)
	{
		if (pObj.hasPrerequisites())
		{
			final PrerequisiteWriter prereqWriter = new PrerequisiteWriter();
			return prereqWriter.getPrerequisiteString(pObj.getPrerequisiteList(), Constants.TAB);
		}
		return "";
	}

	public String getPrerequisiteString(Collection<Prerequisite> prereqs)
			throws PersistenceLayerException
	{
		return getPrereqString(prereqs, Constants.PIPE);
	}

	private String getPrereqString(Collection<Prerequisite> prereqs, String separator)
			throws PersistenceLayerException
	{
		String prereqString = null;
		if (prereqs != null && !prereqs.isEmpty())
		{
			TreeSet<String> list = new TreeSet<>();
			for (Prerequisite p : prereqs)
			{
				StringWriter swriter = new StringWriter();
				write(swriter, p);
				list.add(swriter.toString());
			}
			prereqString = StringUtil.join(list, separator);
		}
		return prereqString;
	}

	public String getPrerequisiteString(Collection<Prerequisite> prereqs, String separator)
	{
		try
		{
			return getPrereqString(prereqs, separator);
		}
		catch (PersistenceLayerException e)
		{
			Logging.errorPrint("Error writing Prerequisites: " + prereqs);
		}
		return "";
	}

}