/*
    *  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.core.partition.impl.btree.mavibot;
  
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutput;
  import java.io.ObjectOutputStream;
  import java.nio.ByteBuffer;
  import java.util.Comparator;
  
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.ldap.model.schema.comparators.DnComparator;
  import org.apache.directory.mavibot.btree.serializer.AbstractElementSerializer;
  import org.apache.directory.mavibot.btree.serializer.BufferHandler;
  import org.apache.directory.server.i18n.I18n;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * Serialize and deserialize a Dn.
   * <br><br>
   * <b>This class must *not* be used outside of the server.</b>
   *  
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class DnSerializer extends AbstractElementSerializer<Dn>
  {
      /** The serialVersionUID */
      private static final long serialVersionUID = 1L;
  
      /** the logger for this class */
      private static final Logger LOG = LoggerFactory.getLogger( DnSerializer.class );
  
      /**
       * Speedup for logs
       */
      private static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      private static Comparator<Dn> comp = new Comparator<Dn>()
      {
          DnComparator comparator = new DnComparator( null );
          
          @Override
          public int compare( Dn dn1, Dn dn2 )
          {
              return comparator.compare( dn1,  dn2 );
          }
      };
  
  
      /**
       * Creates a new instance of DnSerializer.
       */
      public DnSerializer()
      {
          super( comp );
      }
  
  
      /**
       * This is the place where we serialize Dn
       * 
       * @param dn The Dn to serialize
       * @return The byte[] containing the serialized Dn
       */
      public byte[] serialize( Dn dn )
      {
          try
          {
              ByteArrayOutputStream baos = new ByteArrayOutputStream();
              ObjectOutput out = new ObjectOutputStream( baos );
  
              // First, the Dn
              dn.writeExternal( out );
  
              out.flush();
  
             if ( IS_DEBUG )
             {
                 LOG.debug( ">------------------------------------------------" );
                 LOG.debug( "Serialized {}", dn );
             }
 
             return baos.toByteArray();
         }
         catch ( IOException e )
         {
             throw new RuntimeException( e );
         }
     }
 
 
     /**
      *  Deserialize a Dn.
      *  
      *  @param buffer the buffer containing the serialized Dn
      *  @return An instance of a Dn object 
      *  @throws IOException if we can't deserialize the Dn
      */
     @Override
     public Dn deserialize( ByteBuffer buffer ) throws IOException
     {
         return deserialize( new BufferHandler( buffer.array() ) );
     }
 
 
     @Override
     public Dn deserialize( BufferHandler bufferHandler ) throws IOException
     {
         ObjectInputStream in = new ObjectInputStream( new ByteArrayInputStream( bufferHandler.getBuffer() ) );
 
         try
         {
             Dn dn = new Dn();
 
             dn.readExternal( in );
 
             return dn;
         }
         catch ( ClassNotFoundException cnfe )
         {
             LOG.error( I18n.err( I18n.ERR_134, cnfe.getLocalizedMessage() ) );
             throw new IOException( cnfe.getLocalizedMessage() );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Dn fromBytes( byte[] buffer ) throws IOException
     {
         return fromBytes( buffer, 0 );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Dn fromBytes( byte[] buffer, int pos ) throws IOException
     {
         int length = buffer.length - pos;
         ObjectInputStream in = new ObjectInputStream( new ByteArrayInputStream( buffer, pos, length ) );
 
         try
         {
             Dn dn = new Dn();
 
             dn.readExternal( in );
 
             return dn;
         }
         catch ( ClassNotFoundException cnfe )
         {
             LOG.error( I18n.err( I18n.ERR_134, cnfe.getLocalizedMessage() ) );
             throw new IOException( cnfe.getLocalizedMessage() );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Class<?> getType()
     {
         return Dn.class;
     }
 }