/*
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF licenses this file
    *  to you under the Apache License, Version 2.0 (the
    *  "License"); you may not use this file except in compliance
    *  with the License.  You may obtain a copy of the License at
    * 
   *    http://www.apache.org/licenses/LICENSE-2.0
   * 
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License.
   * 
   */
  
  package org.apache.directory.server.dns.io.encoder;
  
  
  import java.io.IOException;
  
  import org.apache.directory.api.util.Strings;
  import org.apache.directory.server.dns.messages.RecordClass;
  import org.apache.directory.server.dns.messages.RecordType;
  import org.apache.directory.server.dns.messages.ResourceRecord;
  import org.apache.mina.core.buffer.IoBuffer;
  
  
  /**
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public abstract class ResourceRecordEncoder implements RecordEncoder
  {
      public void put( IoBuffer byteBuffer, ResourceRecord record ) throws IOException
      {
          putDomainName( byteBuffer, record.getDomainName() );
          putRecordType( byteBuffer, record.getRecordType() );
          putRecordClass( byteBuffer, record.getRecordClass() );
  
          byteBuffer.putInt( record.getTimeToLive() );
  
          putResourceRecord( byteBuffer, record );
      }
  
  
      protected abstract void putResourceRecordData( IoBuffer byteBuffer, ResourceRecord record );
  
  
      protected void putResourceRecord( IoBuffer byteBuffer, ResourceRecord record )
      {
          int startPosition = byteBuffer.position();
          byteBuffer.position( startPosition + 2 );
  
          putResourceRecordData( byteBuffer, record );
  
          putDataSize( byteBuffer, startPosition );
      }
  
  
      protected void putDataSize( IoBuffer byteBuffer, int startPosition )
      {
          int endPosition = byteBuffer.position();
          short length = ( short ) ( endPosition - startPosition - 2 );
  
          byteBuffer.position( startPosition );
          byteBuffer.putShort( length );
          byteBuffer.position( endPosition );
      }
  
  
      /**
       * &lt;domain-name&gt; is a domain name represented as a series of labels, and
       * terminated by a label with zero length.
       * 
       * @param byteBuffer the ByteBuffer to encode the domain name into
       * @param domainName the domain name to encode
       */
      protected void putDomainName( IoBuffer byteBuffer, String domainName )
      {
          if ( !Strings.isEmpty( domainName ) )
          {
              String[] labels = domainName.split( "\\." );
          
  
              for ( String label : labels )
              {
                  byteBuffer.put( ( byte ) label.length() );
      
                  char[] characters = label.toCharArray();
                  
                  for ( char c : characters )
                  {
                      byteBuffer.put( ( byte ) c );
                  }
              }
         }
 
         byteBuffer.put( ( byte ) 0x00 );
     }
 
 
     protected void putRecordType( IoBuffer byteBuffer, RecordType recordType )
     {
         byteBuffer.putShort( recordType.convert() );
     }
 
 
     protected void putRecordClass( IoBuffer byteBuffer, RecordClass recordClass )
     {
         byteBuffer.putShort( recordClass.convert() );
     }
 
 
     /**
      * &lt;character-string&gt; is a single length octet followed by that number
      * of characters.  &lt;character-string&gt; is treated as binary information,
      * and can be up to 256 characters in length (including the length octet).
      * 
      * @param byteBuffer The byte buffer to encode the character string into.
      * @param characterString the character string to encode
      */
     protected void putCharacterString( IoBuffer byteBuffer, String characterString )
     {
         byteBuffer.put( ( byte ) characterString.length() );
 
         char[] characters = characterString.toCharArray();
 
         for ( int ii = 0; ii < characters.length; ii++ )
         {
             byteBuffer.put( ( byte ) characters[ii] );
         }
     }
 }