/*
    *  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.api.ldap.codec.controls.search.persistentSearch;
  
  
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.Asn1Object;
  import org.apache.directory.api.asn1.DecoderException;
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.ber.Asn1Decoder;
  import org.apache.directory.api.asn1.ber.tlv.BerValue;
  import org.apache.directory.api.asn1.ber.tlv.TLV;
  import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.ControlDecorator;
  import org.apache.directory.api.ldap.codec.api.LdapApiService;
  import org.apache.directory.api.ldap.model.message.controls.ChangeType;
  import org.apache.directory.api.ldap.model.message.controls.PersistentSearch;
  import org.apache.directory.api.ldap.model.message.controls.PersistentSearchImpl;
  
  
  /**
   * A persistence search object
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class PersistentSearchDecorator extends ControlDecorator<PersistentSearch> implements PersistentSearch
  {
      /** A temporary storage for a psearch length */
      private int psearchSeqLength;
  
      /** An instance of this decoder */
      private static final Asn1Decoder decoder = new Asn1Decoder();
  
  
      /**
       * Default constructor creates a PersistentSearch Control automatically
       * wrapped in a decorator object inside this container.
       */
      public PersistentSearchDecorator( LdapApiService codec )
      {
          this( codec, new PersistentSearchImpl() );
      }
  
  
      /**
       * Creates a PersistentSearch Control wrapping a supplied PersistentSearch
       * Control.
       *
       * @param control The PersistentSearch Control to wrap.
       */
      public PersistentSearchDecorator( LdapApiService codec, PersistentSearch control )
      {
          super( codec, control );
      }
  
  
      /**
       * Compute the PagedSearchControl length, which is the sum
       * of the control length and the value length.
       * 
       * <pre>
       * PersistentSearchDecorator value length :
       * 
       * 0x30 L1 
       *   | 
       *   +--> 0x02 0x0(1-4) [0..2^31-1] (changeTypes) 
       *   +--> 0x01 0x01 [0x00 | 0xFF] (changeOnly) 
       *   +--> 0x01 0x01 [0x00 | 0xFF] (returnRCs)
       * </pre> 
       */
      public int computeLength()
      {
          int changeTypesLength = 1 + 1 + BerValue.getNbBytes( getChangeTypes() );
          int changesOnlyLength = 1 + 1 + 1;
          int returnRCsLength = 1 + 1 + 1;
  
          psearchSeqLength = changeTypesLength + changesOnlyLength + returnRCsLength;
          int valueLength = 1 + TLV.getNbBytes( psearchSeqLength ) + psearchSeqLength;
  
          return valueLength;
     }
 
 
     /**
      * Encodes the persistent search control.
      * 
      * @param buffer The encoded sink
      * @return A ByteBuffer that contains the encoded PDU
      * @throws EncoderException If anything goes wrong.
      */
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
         }
 
         // Now encode the PagedSearch specific part
         buffer.put( UniversalTag.SEQUENCE.getValue() );
         buffer.put( TLV.getBytes( psearchSeqLength ) );
 
         BerValue.encode( buffer, getChangeTypes() );
         BerValue.encode( buffer, isChangesOnly() );
         BerValue.encode( buffer, isReturnECs() );
 
         return buffer;
     }
 
 
     /**
      * {@inheritDoc}
      */
     public byte[] getValue()
     {
         if ( value == null )
         {
             try
             {
                 computeLength();
                 ByteBuffer buffer = ByteBuffer.allocate( valueLength );
 
                 // Now encode the PagedSearch specific part
                 buffer.put( UniversalTag.SEQUENCE.getValue() );
                 buffer.put( TLV.getBytes( psearchSeqLength ) );
 
                 BerValue.encode( buffer, getChangeTypes() );
                 BerValue.encode( buffer, isChangesOnly() );
                 BerValue.encode( buffer, isReturnECs() );
 
                 value = buffer.array();
             }
             catch ( Exception e )
             {
                 return null;
             }
         }
 
         return value;
     }
 
 
     private PersistentSearch getPersistentSearch()
     {
         return ( PersistentSearch ) getDecorated();
     }
 
 
     public void setChangesOnly( boolean changesOnly )
     {
         getPersistentSearch().setChangesOnly( changesOnly );
     }
 
 
     public boolean isChangesOnly()
     {
         return getPersistentSearch().isChangesOnly();
     }
 
 
     public void setReturnECs( boolean returnECs )
     {
         getPersistentSearch().setReturnECs( returnECs );
     }
 
 
     public boolean isReturnECs()
     {
         return getPersistentSearch().isReturnECs();
     }
 
 
     public void setChangeTypes( int changeTypes )
     {
         getPersistentSearch().setChangeTypes( changeTypes );
     }
 
 
     public int getChangeTypes()
     {
         return getPersistentSearch().getChangeTypes();
     }
 
 
     public boolean isNotificationEnabled( ChangeType changeType )
     {
         return getPersistentSearch().isNotificationEnabled( changeType );
     }
 
 
     public void enableNotification( ChangeType changeType )
     {
         getPersistentSearch().enableNotification( changeType );
     }
 
 
     /**
      * {@inheritDoc}
      */
     public Asn1Object decode( byte[] controlBytes ) throws DecoderException
     {
         ByteBuffer bb = ByteBuffer.wrap( controlBytes );
         PersistentSearchContainer container = new PersistentSearchContainer( getCodecService(), this );
         decoder.decode( bb, container );
         return this;
     }
 }