/*
    * 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 entagged.audioformats.asf.data;
  
  import java.io.ByteArrayOutputStream;
  import java.math.BigInteger;
  
  import entagged.audioformats.asf.util.Utils;
  
  /***
   * This class represents the data of a chunk which contains title, author,
   * copyright, description and the rating of the file. <br>
   * It is optional whithin asf files. But if exists only once.
   * 
   * @author Christian Laireiter
   */
  public class ContentDescription extends Chunk {
  
      /***
       * File artist.
       */
      private String author = null;
  
      /***
       * File copyright.
       */
      private String copyRight = null;
  
      /***
       * File comment.
       */
      private String description = null;
  
      /***
       * File rating.
       */
      private String rating = null;
  
      /***
       * File title.
       */
      private String title = null;
  
      /***
       * Creates an instance. <br>
       */
      public ContentDescription() {
          this(0, BigInteger.valueOf(0));
      }
  
      /***
       * Creates an instance.
       * 
       * @param pos
       *                   Position of content description within file or stream
       * @param chunkLen
       *                   Length of content description.
       */
      public ContentDescription(long pos, BigInteger chunkLen) {
          super(GUID.GUID_CONTENTDESCRIPTION, pos, chunkLen);
      }
  
      /***
       * @return Returns the author.
       */
      public String getAuthor() {
          if (author == null)
              return "";
          return author;
      }
  
      /***
       * This method creates a byte array that could directly be written to an asf
       * file. <br>
       * 
       * @return The asf chunk representation of a content description with the
       *               values of the current object.
       */
      public byte[] getBytes() {
          ByteArrayOutputStream result = new ByteArrayOutputStream();
          try {
              ByteArrayOutputStream tags = new ByteArrayOutputStream();
              String[] toWrite = new String[] { getTitle(), getAuthor(),
                     getCopyRight(), getComment(), getRating() };
             byte[][] stringRepresentations = new byte[toWrite.length][];
             // Create byte[] of UTF-16LE encodings
             for (int i = 0; i < toWrite.length; i++) {
                 stringRepresentations[i] = toWrite[i].getBytes("UTF-16LE");
             }
             // Write the amount of bytes needed to store the values.
             for (int i = 0; i < stringRepresentations.length; i++) {
                 tags.write(Utils.getBytes(stringRepresentations[i].length + 2,
                         2));
             }
             // Write the values themselves.
             for (int i = 0; i < toWrite.length; i++) {
                 tags.write(stringRepresentations[i]);
                 // Zero term character.
                 tags.write(Utils.getBytes(0, 2));
             }
             // Now tags has got the values. The result just needs
             // The GUID, length of the chunk and the tags.
             byte[] tagContent = tags.toByteArray();
             // The guid of the chunk
             result.write(GUID.GUID_CONTENTDESCRIPTION.getBytes());
             /*
              * The length of the chunk. 16 Bytes guid 8 Bytes the length
              * tagContent.length bytes.
              */
             result.write(Utils.getBytes(tagContent.length + 24, 8));
             // The tags.
             result.write(tagContent);
         } catch (Exception e) {
             e.printStackTrace();
         }
         return result.toByteArray();
     }
 
     /***
      * @return Returns the comment.
      */
     public String getComment() {
         if (description == null)
             return "";
         return description;
     }
 
     /***
      * @return Returns the copyRight.
      */
     public String getCopyRight() {
         if (copyRight == null)
             return "";
         return copyRight;
     }
 
     /***
      * @return returns the rating.
      */
     public String getRating() {
         if (rating == null)
             return "";
         return rating;
     }
 
     /***
      * @return Returns the title.
      */
     public String getTitle() {
         if (title == null)
             return "";
         return title;
     }
 
     /***
      * (overridden)
      * 
      * @see entagged.audioformats.asf.data.Chunk#prettyPrint()
      */
     public String prettyPrint() {
         StringBuffer result = new StringBuffer(super.prettyPrint());
         result.insert(0, Utils.LINE_SEPARATOR + "Content Description:"
                 + Utils.LINE_SEPARATOR);
         result.append("   Title      : " + getTitle() + Utils.LINE_SEPARATOR);
         result.append("   Author     : " + getAuthor() + Utils.LINE_SEPARATOR);
         result.append("   Copyright  : " + getCopyRight()
                 + Utils.LINE_SEPARATOR);
         result.append("   Description: " + getComment() + Utils.LINE_SEPARATOR);
         result.append("   Rating     :" + getRating() + Utils.LINE_SEPARATOR);
         return result.toString();
     }
 
     /***
      * @param fileAuthor
      *                   The author to set.
      * @throws IllegalArgumentException
      *                    If "UTF-16LE"-byte-representation would take more than 65535
      *                    bytes.
      */
     public void setAuthor(String fileAuthor) throws IllegalArgumentException {
         Utils.checkStringLengthNullSafe(fileAuthor);
         this.author = fileAuthor;
     }
 
     /***
      * @param tagComment
      *                   The comment to set.
      * @throws IllegalArgumentException
      *                    If "UTF-16LE"-byte-representation would take more than 65535
      *                    bytes.
      */
     public void setComment(String tagComment) throws IllegalArgumentException {
         Utils.checkStringLengthNullSafe(tagComment);
         this.description = tagComment;
     }
 
     /***
      * @param cpright
      *                   The copyRight to set.
      * @throws IllegalArgumentException
      *                    If "UTF-16LE"-byte-representation would take more than 65535
      *                    bytes.
      */
     public void setCopyRight(String cpright) throws IllegalArgumentException {
         Utils.checkStringLengthNullSafe(cpright);
         this.copyRight = cpright;
     }
 
     /***
      * @param ratingText
      *                   The rating to be set.
      * @throws IllegalArgumentException
      *                    If "UTF-16LE"-byte-representation would take more than 65535
      *                    bytes.
      */
     public void setRating(String ratingText) throws IllegalArgumentException {
         Utils.checkStringLengthNullSafe(ratingText);
         this.rating = ratingText;
     }
 
     /***
      * @param songTitle
      *                   The title to set.
      * @throws IllegalArgumentException
      *                    If "UTF-16LE"-byte-representation would take more than 65535
      *                    bytes.
      */
     public void setTitle(String songTitle) throws IllegalArgumentException {
         Utils.checkStringLengthNullSafe(songTitle);
         this.title = songTitle;
     }
 }