/*
 * $Id$
 *
 * Copyright (C) 2003-2015 JNode.org
 *
 * 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., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
package org.jnode.fs.ext2;

import java.io.IOException;
import java.nio.ByteBuffer;
import org.jnode.driver.Device;
import org.jnode.driver.block.FSBlockDeviceAPI;
import org.jnode.fs.BlockDeviceFileSystemType;
import org.jnode.fs.FileSystemException;
import org.jnode.partitions.PartitionTableEntry;
import org.jnode.util.LittleEndian;

/**
 * @author Andras Nagy
 */
public class Ext2FileSystemType implements BlockDeviceFileSystemType<Ext2FileSystem> {
    public static final Class<Ext2FileSystemType> ID = Ext2FileSystemType.class;

    /**
     * @see org.jnode.fs.FileSystemType#create(Device, boolean)
     */
    public Ext2FileSystem create(Device device, boolean readOnly) throws FileSystemException {
        Ext2FileSystem fs = new Ext2FileSystem(device, readOnly, this);
        fs.read();
        return fs;
    }

    /**
     * @see org.jnode.fs.FileSystemType#getName()
     */
    public String getName() {
        return "EXT2";
    }

    /**
     * @see org.jnode.fs.BlockDeviceFileSystemType#supports(PartitionTableEntry, byte[], FSBlockDeviceAPI)
     */
    public boolean supports(PartitionTableEntry pte, byte[] firstSector, FSBlockDeviceAPI devApi) {
/*
        if (pte != null) {
            if (pte instanceof IBMPartitionTableEntry) {
                if (((IBMPartitionTableEntry) pte).getSystemIndicator() != IBMPartitionTypes.PARTTYPE_LINUXNATIVE) {
                    return false;
                }
            }
        }
*/

        //need to check the magic
        ByteBuffer magic = ByteBuffer.allocate(2);
        ByteBuffer revLevel = ByteBuffer.allocate(4);
        try {
            devApi.read(1024 + 56, magic);
            devApi.read(1024 + 78, revLevel);
        } catch (IOException e) {
            return false;
        }
        return
            (LittleEndian.getUInt16(magic.array(), 0) == 0xEF53) &&
            (LittleEndian.getUInt32(revLevel.array(), 0) == 0 || LittleEndian.getUInt32(revLevel.array(), 0) == 1);
    }
}