/*
 * 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.system;

import java.io.File;
import java.net.URI;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import pcgen.facade.util.AbstractListFacade;

import org.apache.commons.lang3.ArrayUtils;

class RecentFileList extends AbstractListFacade<File>
{

	private static final int MAX_RECENT_FILES = 8;
	private final LinkedList<File> fileList = new LinkedList<>();
	private final String contextProp;

	RecentFileList(String contextProp)
	{
		this.contextProp = contextProp;
		String[] recentFiles = PCGenSettings.getInstance().getStringArray(contextProp);
		if (!ArrayUtils.isEmpty(recentFiles))
		{
			URI userdir = new File(ConfigurationSettings.getUserDir()).toURI();
			for (int i = recentFiles.length-1; i >= 0; i--)
			{
				addRecentFile(new File(userdir.resolve(recentFiles[i])));
			}
		}
	}

	private void updateRecentFileProp()
	{
		URI userdir = new File(ConfigurationSettings.getUserDir()).toURI();

		List<String> uris = new ArrayList<>(fileList.size());
		for (final File file : fileList)
		{
			URI uri = userdir.relativize(file.toURI());
			uris.add(uri.toString());
		}
		PCGenSettings.getInstance().setStringArray(contextProp, uris);
	}

	void addRecentFile(File file)
	{
		if ((file == null) || !file.isFile())
		{
			return;
		}
		//Remove the file if it already exists, that way it gets moved to the top
		int index = indexOf(file);
		if (index != -1)
		{
			File oldFile = fileList.remove(index);
			fireElementRemoved(this, oldFile, index);
		}
		//add it to the front
		fileList.addFirst(file);
		fireElementAdded(this, file, 0);
		//then remove any overflowing files
		if (fileList.size() > MAX_RECENT_FILES)
		{
			File oldFile = fileList.removeLast();
			fireElementRemoved(this, oldFile, MAX_RECENT_FILES);
		}
		updateRecentFileProp();
	}

    @Override
	public File getElementAt(int index)
	{
		return fileList.get(index);
	}

    @Override
	public int getSize()
	{
		return fileList.size();
	}

	@Override
	public boolean containsElement(File element)
	{
		return indexOf(element) != -1;
	}

	private int indexOf(File element)
	{
		if (element != null)
		{
			for (int i = 0; i < fileList.size(); i++)
			{
				if (fileList.get(i).getAbsolutePath().equals(element.getAbsolutePath()))
				{
					return i;
				}
			}
		}
		return -1;
	}

}