/* Copyright (c) 2002-2011 by XMLVM.org
 *
 * Project Info:  http://www.xmlvm.org
 *
 * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 */

package org.xmlvm.proc.in;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.xmlvm.Log;
import org.xmlvm.util.universalfile.UniversalFile;
import org.xmlvm.util.universalfile.UniversalFileCreator;

/**
 * This class contains methods for creating {@link InputProcess} instances from
 * ZIP and JAR archives.
 */
public class ZipArchiveExtractor
{
	private static final String TAG= "ZipInputProcessFactory";

	private static final String[] SUPPORTED_TYPES= { "zip", "jar" };

	/**
	 * Returns whether the file is an archive that this class can handle.
	 * 
	 * @param filename
	 *            the name of the file
	 * @return Whether the file is a ZIP/JAR archive.
	 */
	public static boolean isZipArchive(String filename)
	{
		for (String supportedType : SUPPORTED_TYPES)
		{
			if (filename.toLowerCase().endsWith("." + supportedType))
			{
				return true;
			}
		}
		return false;
	}

	/**
	 * Creates a list of {@link UniversalFile} instances based on the given
	 * ZIP/Archive.
	 */
	public static List<UniversalFile> createFilesForArchive(String location)
	{
		Log.debug(TAG, "Creating input processes for archive: " + location);
		List<UniversalFile> result= new ArrayList<UniversalFile>();
		File archiveFile= new File(location);

		// Sanity checks.
		if (!archiveFile.exists() || !archiveFile.isFile())
		{
			Log.error(TAG, "Could not find archive file: " + location);
			return result;
		}

		ZipInputStream zipStream;
		try
		{
			zipStream= new ZipInputStream(new FileInputStream(archiveFile));

			byte data[]= new byte[4096];
			ZipEntry entry;
			while ((entry= zipStream.getNextEntry()) != null)
			{
				// We are only interested in file entries.
				if (entry.isDirectory())
				{
					continue;
				}

				ByteArrayOutputStream outputStream= new ByteArrayOutputStream();
				int len= 0;
				while ((len= zipStream.read(data)) != -1)
				{
					outputStream.write(data, 0, len);
				}
				String name= archiveFile.getAbsolutePath() + File.separator + entry.getName();
				result.add(UniversalFileCreator.createFile(name, new ByteArrayInputStream(outputStream.toByteArray()), entry.getTime()));
			}
		}
		catch (FileNotFoundException e)
		{
			e.printStackTrace();
			Log.error(TAG, "Could not find archive: " + location);
		}
		catch (IOException e)
		{
			e.printStackTrace();
			Log.error(TAG, "Error reading archive: " + location);
		}
		return result;
	}
}