/*

  * 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 java.io.IOException;

 import java.io.InputStream;

 import java.math.BigInteger;

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

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

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

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

 /**

  * This class reads the chunk containing encoding data <br>

  * <b>Warning:<b><br>

  * Implementation is not completed. More analysis of this chunk is needed.

  * 

  * @author Christian Laireiter

  */

 class EncodingChunkReader implements ChunkReader

 {

         /**

          * Should not be used for now.

          */

         protected EncodingChunkReader() {

                 // NOTHING toDo

         }

         /**

      * {@inheritDoc}

      */

     public boolean canFail()

     {

         return false;

     }

         /**

          * {@inheritDoc}

          */

         public GUID getApplyingId() {

                 return GUID.GUID_ENCODING;

         }

     /**

          * {@inheritDoc}

          */

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

     {

                 BigInteger chunkLen = Utils.readBig64(stream);

                 EncodingChunk result = new EncodingChunk(chunkLen);

                 int readBytes = 24;

                 // Can't be interpreted

                 /*

                  * What do I think of this data, well it seems to be another GUID. Then

                  * followed by a UINT16 indicating a length of data following (by half).

                  * My test files just had the length of one and a two bytes zero.

                  */

                 stream.skip(20);

                 readBytes += 20;

                 /*

                  * Read the number of strings which will follow

                  */

                 int stringCount = Utils.readUINT16(stream);

                 readBytes += 2;

                 /*

                  * Now reading the specified amount of strings.

                  */

                 for (int i = 0; i < stringCount; i++) {

                         String curr = Utils.readCharacterSizedString(stream);

                         result.addString(curr);

                         readBytes += 4 + 2 * curr.length();

                 }

                 stream.skip(chunkLen.longValue() - readBytes);

                 result.setPosition(chunkStart);

                 return result;

         }

 }