/*
 This file is part of the OdinMS Maple Story Server
 Copyright (C) 2008 ~ 2010 Patrick Huy <patrick.huy@frz.cc> 
 Matthias Butz <matze@odinms.de>
 Jan Christian Meyer <vimes@odinms.de>

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License version 3
 as published by the Free Software Foundation. You may not use, modify
 or distribute this program under any other version of the
 GNU Affero General Public License.

 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 Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package tools.data.input;

import java.io.IOException;

/**
 * Provides an abstract accessor to a generic Little Endian byte stream. This
 * accessor is seekable.
 *
 * @author Frz
 * @version 1.0
 * @since Revision 323
 * @see GenericLittleEndianAccessor
 */
public class GenericSeekableLittleEndianAccessor extends GenericLittleEndianAccessor implements SeekableLittleEndianAccessor {

    private final SeekableInputStreamBytestream bs;

    /**
     * Class constructor Provide a seekable input stream to wrap this object
     * around.
     *
     * @param bs The byte stream to wrap this around.
     */
    public GenericSeekableLittleEndianAccessor(final SeekableInputStreamBytestream bs) {
        super(bs);
        this.bs = bs;
    }

    /**
     * Seek the pointer to <code>offset</code>
     *
     * @param offset The offset to seek to.
     * @see SeekableInputStreamBytestream#seek
     */
    @Override
    public final void seek(final long offset) {
        try {
            bs.seek(offset);
        } catch (IOException e) {
            System.err.println("Seek failed" + e);
        }
    }

    /**
     * Get the current position of the pointer.
     *
     * @return The current position of the pointer as a long integer.
     * @see SeekableInputStreamBytestream#getPosition
     */
    @Override
    public final long getPosition() {
        try {
            return bs.getPosition();
        } catch (IOException e) {
            System.err.println("getPosition failed" + e);
            return -1;
        }
    }

    /**
     * Skip <code>num</code> number of bytes in the stream.
     *
     * @param num The number of bytes to skip.
     */
    @Override
    public final void skip(final int num) {
        seek(getPosition() + num);
    }
}