/**

  *  @author : Paul Taylor

  *  @author : Eric Farng

  *

  *  Version @version:$Id: AbstractLyrics3v2FieldFrameBody.java,v 1.11 2008/07/21 10:45:49 paultaylor Exp $

  *

  *  MusicTag Copyright (C)2003,2004

  *

  *  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,

  *  you can get a copy from http://www.opensource.org/licenses/lgpl-license.php or write to the Free Software

  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

  *

  * Description:

  */

 package org.jaudiotagger.tag.lyrics3;

 import org.jaudiotagger.tag.InvalidTagException;

 import org.jaudiotagger.tag.TagOptionSingleton;

 import org.jaudiotagger.tag.datatype.AbstractDataType;

 import org.jaudiotagger.tag.id3.AbstractTagFrameBody;

 import java.io.IOException;

 import java.io.RandomAccessFile;

 import java.nio.ByteBuffer;

 import java.util.Iterator;

 public abstract class AbstractLyrics3v2FieldFrameBody extends AbstractTagFrameBody

 {

     public AbstractLyrics3v2FieldFrameBody()

     {

     }

     public AbstractLyrics3v2FieldFrameBody(AbstractLyrics3v2FieldFrameBody copyObject)

     {

         super(copyObject);

     }

     /**

      * This is called by superclass when attempt to read data from file.

      *

      * @param file

      * @return

      * @throws InvalidTagException

      * @throws IOException

      */

     protected int readHeader(RandomAccessFile file) throws InvalidTagException, IOException

     {

         int size;

         byte[] buffer = new byte[5];

         // read the 5 character size

         file.read(buffer, 0, 5);

         size = Integer.parseInt(new String(buffer, 0, 5));

         if ((size == 0) && (TagOptionSingleton.getInstance().isLyrics3KeepEmptyFieldIfRead() == false))

         {

             throw new InvalidTagException("Lyircs3v2 Field has size of zero.");

         }

         return size;

     }

     /**

      * This is called by superclass when attempt to write data from file.

      *

      * @param file

      * @param size

      * @throws IOException

      */

     protected void writeHeader(RandomAccessFile file, int size) throws IOException

     {

         String str;

         int offset = 0;

         byte[] buffer = new byte[5];

         /**

          * @todo change this to use pad String

          */

         str = Integer.toString(getSize());

         for (int i = 0; i < (5 - str.length()); i++)

         {

             buffer[i] = (byte) '0';

         }

         offset += (5 - str.length());

         for (int i = 0; i < str.length(); i++)

         {

             buffer[i + offset] = (byte) str.charAt(i);

         }

         file.write(buffer);

     }

     /**

      * This reads a frame body from its file into the appropriate FrameBody class

      * Read the data from the given file into this datatype. The file needs to

      * have its file pointer in the correct location. The size as indicated in the

      * header is passed to the frame constructor when reading from file.

      *

      * @param byteBuffer file to read

      * @throws IOException         on any I/O error

      * @throws InvalidTagException if there is any error in the data format.

      */

     public void read(ByteBuffer byteBuffer) throws InvalidTagException

     {

         int size = getSize();

         //Allocate a buffer to the size of the Frame Body and read from file

         byte[] buffer = new byte[size];

         byteBuffer.get(buffer);

         //Offset into buffer, incremented by length of previous MP3Object

         int offset = 0;

         //Go through the ObjectList of the Frame reading the data into the

         //correct datatype.

         AbstractDataType object;

         Iterator<AbstractDataType> iterator = objectList.listIterator();

         while (iterator.hasNext())

         {

             //The read has extended further than the defined frame size

             if (offset > (size - 1))

             {

                 throw new InvalidTagException("Invalid size for Frame Body");

             }

             //Get next Object and load it with data from the Buffer

             object = iterator.next();

             object.readByteArray(buffer, offset);

             //Increment Offset to start of next datatype.

             offset += object.getSize();

         }

     }

     /**

      * Write the contents of this datatype to the file at the position it is

      * currently at.

      *

      * @param file destination file

      * @throws IOException on any I/O error

      */

     public void write(RandomAccessFile file) throws IOException

     {

         //Write the various fields to file in order

         byte[] buffer;

         AbstractDataType object;

         Iterator<AbstractDataType> iterator = objectList.listIterator();

         while (iterator.hasNext())

         {

             object = iterator.next();

             buffer = object.writeByteArray();

             file.write(buffer);

         }

     }

 }