/*

  * 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 {

     /**

      * The GUID this reader {@linkplain #getApplyingIds() applies to}

      */

     private final static GUID[] APPLYING = { GUID.GUID_FILE };

     /**

      * Should not be used for now.

      */

     protected FileHeaderReader() {

         // NOTHING toDo

     }

     /**

      * {@inheritDoc}

      */

     public boolean canFail() {

         return false;

     }

     /**

      * {@inheritDoc}

      */

     public GUID[] getApplyingIds() {

         return APPLYING.clone();

     }

     /**

      * {@inheritDoc}

      */

     public Chunk read(final GUID guid, final InputStream stream,

             final long chunkStart) throws IOException {

         final BigInteger chunkLen = Utils.readBig64(stream);

         // Skip client GUID.

         stream.skip(16);

         final BigInteger fileSize = Utils.readBig64(stream);

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

         final BigInteger fileTime = Utils.readBig64(stream);

         final BigInteger packageCount = Utils.readBig64(stream);

         final BigInteger timeEndPos = Utils.readBig64(stream);

         final BigInteger duration = Utils.readBig64(stream);

         final BigInteger timeStartPos = Utils.readBig64(stream);

         final long flags = Utils.readUINT32(stream);

         final long minPkgSize = Utils.readUINT32(stream);

         final long maxPkgSize = Utils.readUINT32(stream);

         final 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;

     }

 }