/*

  * Entagged Audio Tag library

  * Copyright (c) 2003-2005 Raphaël Slinckx <raphael@slinckx.net>

  * 

  * 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.flac;

 import org.jaudiotagger.audio.flac.metadatablock.BlockType;

 import org.jaudiotagger.audio.flac.metadatablock.MetadataBlockDataPadding;

 import org.jaudiotagger.audio.flac.metadatablock.MetadataBlockDataPicture;

 import org.jaudiotagger.audio.flac.metadatablock.MetadataBlockHeader;

 import org.jaudiotagger.audio.generic.AbstractTagCreator;

 import org.jaudiotagger.tag.Tag;

 import org.jaudiotagger.tag.flac.FlacTag;

 import org.jaudiotagger.tag.vorbiscomment.VorbisCommentCreator;

 import java.io.UnsupportedEncodingException;

 import java.nio.ByteBuffer;

 import java.util.ListIterator;

 import java.util.logging.Logger;

 /**

  * Create the tag data ready for writing to flac file

  */

 public class FlacTagCreator extends AbstractTagCreator

 {

     // Logger Object

     public static Logger logger = Logger.getLogger("org.jaudiotagger.audio.flac");

     public static final int DEFAULT_PADDING = 4000;

     private static final VorbisCommentCreator creator = new VorbisCommentCreator();

     /**

      * @param tag

      * @param paddingSize extra padding to be added

      * @return

      * @throws UnsupportedEncodingException

      */

     public ByteBuffer convert(Tag tag, int paddingSize) throws UnsupportedEncodingException

     {

         logger.info("Convert flac tag:padding:" + paddingSize);

         FlacTag flacTag = (FlacTag) tag;

         int tagLength = 0;

         ByteBuffer vorbiscomment = null;

         if (flacTag.getVorbisCommentTag() != null)

         {

             vorbiscomment = creator.convert(flacTag.getVorbisCommentTag());

             tagLength = vorbiscomment.capacity() + MetadataBlockHeader.HEADER_LENGTH;

         }

         for (MetadataBlockDataPicture image : flacTag.getImages())

         {

             tagLength += image.getBytes().length + MetadataBlockHeader.HEADER_LENGTH;

         }

         logger.info("Convert flac tag:taglength:" + tagLength);

         ByteBuffer buf = ByteBuffer.allocate(tagLength + paddingSize);

         MetadataBlockHeader vorbisHeader;

         //If there are other metadata blocks

         if (flacTag.getVorbisCommentTag() != null)

         {

             if ((paddingSize > 0) || (flacTag.getImages().size() > 0))

             {

                 vorbisHeader = new MetadataBlockHeader(false, BlockType.VORBIS_COMMENT, vorbiscomment.capacity());

             }

             else

             {

                 vorbisHeader = new MetadataBlockHeader(true, BlockType.VORBIS_COMMENT, vorbiscomment.capacity());

             }

             buf.put(vorbisHeader.getBytes());

             buf.put(vorbiscomment);

         }

         //Images

         ListIterator<MetadataBlockDataPicture> li = flacTag.getImages().listIterator();

         while (li.hasNext())

         {

             MetadataBlockDataPicture imageField = li.next();

             MetadataBlockHeader imageHeader;

             if (paddingSize > 0 || li.hasNext())

             {

                 imageHeader = new MetadataBlockHeader(false, BlockType.PICTURE, imageField.getLength());

             }

             else

             {

                 imageHeader = new MetadataBlockHeader(true, BlockType.PICTURE, imageField.getLength());

             }

             buf.put(imageHeader.getBytes());

             buf.put(imageField.getBytes());

         }

         //Padding

         logger.info("Convert flac tag at" + buf.position());

         if (paddingSize > 0)

         {

             int paddingDataSize = paddingSize - MetadataBlockHeader.HEADER_LENGTH;

             MetadataBlockHeader paddingHeader = new MetadataBlockHeader(true, BlockType.PADDING, paddingDataSize);

             MetadataBlockDataPadding padding = new MetadataBlockDataPadding(paddingDataSize);

             buf.put(paddingHeader.getBytes());

             buf.put(padding.getBytes());

         }

         buf.rewind();

         return buf;

     }

 }