/*

  * Entagged Audio Tag library

  * Copyright (c) 2004-2005 Christian Laireiter <liree@web.de>

  * 

  * 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 St, Fifth Floor, Boston, MA  02110-1301  USA

  */

 package org.jaudiotagger.audio.asf.io;

 import org.jaudiotagger.audio.asf.data.Chunk;

 import org.jaudiotagger.audio.asf.data.FileHeader;

 import org.jaudiotagger.audio.asf.data.GUID;

 import org.jaudiotagger.audio.asf.util.Utils;

 import java.io.IOException;

 import java.io.InputStream;

 import java.math.BigInteger;

 /**

  * Reads and interprets the data of the file header. <br>

  *

  * @author Christian Laireiter

  */

 public class FileHeaderReader implements ChunkReader

 {

     /**

      * Should not be used for now.

      */

     protected FileHeaderReader()

     {

         // NOTHING toDo

     }

     /**

      * {@inheritDoc}

      */

     public boolean canFail()

     {

         return false;

     }

     /**

      * {@inheritDoc}

      */

     public GUID getApplyingId()

     {

         return GUID.GUID_FILE;

     }

     /**

      * {@inheritDoc}

      */

     public Chunk read(final GUID guid, final InputStream stream, final long chunkStart) throws IOException

     {

         BigInteger chunkLen = Utils.readBig64(stream);

         // Skip client GUID.

         stream.skip(16);

         BigInteger fileSize = Utils.readBig64(stream);

         // fileTime in 100 ns since midnight of 1st january 1601 GMT

         BigInteger fileTime = Utils.readBig64(stream);

         BigInteger packageCount = Utils.readBig64(stream);

         BigInteger timeEndPos = Utils.readBig64(stream);

         BigInteger duration = Utils.readBig64(stream);

         BigInteger timeStartPos = Utils.readBig64(stream);

         long flags = Utils.readUINT32(stream);

         long minPkgSize = Utils.readUINT32(stream);

         long maxPkgSize = Utils.readUINT32(stream);

         long uncompressedFrameSize = Utils.readUINT32(stream);

         final FileHeader result = new FileHeader(chunkLen, fileSize, fileTime, packageCount, duration, timeStartPos, timeEndPos, flags, minPkgSize, maxPkgSize, uncompressedFrameSize);

         result.setPosition(chunkStart);

         return result;

     }

 }