/*
    *  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.extras.controls.ad_impl;
  
  import java.nio.ByteBuffer;
  import java.util.Set;
  
  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.extras.controls.ad.AdDirSync;
  import org.apache.directory.api.ldap.extras.controls.ad.AdDirSyncFlag;
  import org.apache.directory.api.ldap.extras.controls.ad.AdDirSyncImpl;
  import org.apache.directory.api.util.Strings;
  
  /**
   * A decorator around AdDirSync control. It will encode and decode this control.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class AdDirSyncDecorator extends ControlDecorator<AdDirSync> implements AdDirSync
  {
      /** The global length for this control */
      private int adDirSyncLength;
  
      /** An instance of this decoder */
      private static final Asn1Decoder DECODER = new Asn1Decoder();
  
  
      /**
       * Creates a new instance of AdDirSyncDecorator.
       * 
       * @param codec The LDAP Service to use
       */
      public AdDirSyncDecorator( LdapApiService codec )
      {
          super( codec, new AdDirSyncImpl() );
      }
  
  
      /**
       * Creates a new instance of AdDirSyncDecorator.
       *
       * @param codec The LDAP Service to use
       * @param control The control to be decorated
       */
      public AdDirSyncDecorator( LdapApiService codec, AdDirSync control )
      {
          super( codec, control );
      }
      
      
      /**
       * {@inheritDoc}
       */
      @Override
      public Set<AdDirSyncFlag> getFlags()
      {
          return getDecorated().getFlags();
      }
  
      
      /**
       * {@inheritDoc}
       */
      @Override
      public void setFlags( Set<AdDirSyncFlag> flags )
      {
          getDecorated().setFlags( flags );
      }
      
      
      /**
       * {@inheritDoc}
       */
     @Override
     public void addFlag( AdDirSyncFlag flag )
     {
         getDecorated().addFlag( flag );
     }
 
     
     /**
      * {@inheritDoc}
      */
     @Override
     public void removeFlag( AdDirSyncFlag flag )
     {
         getDecorated().removeFlag( flag );
     }
 
     
     /**
      * {@inheritDoc}
      */
     @Override
     public int getMaxReturnLength()
     {
         return getDecorated().getMaxReturnLength();
     }
 
     
     /**
      * {@inheritDoc}
      */
     @Override
     public void setMaxReturnLength( int maxReturnLength )
     {
         getDecorated().setMaxReturnLength( maxReturnLength );
     }
     
 
     /**
      * {@inheritDoc}
      */
     @Override
     public byte[] getCookie()
     {
         return getDecorated().getCookie();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setCookie( byte[] cookie )
     {
         // Copy the bytes
         if ( !Strings.isEmpty( cookie ) )
         {
             byte[] copy = new byte[cookie.length];
             System.arraycopy( cookie, 0, copy, 0, cookie.length );
             getDecorated().setCookie( copy );
         }
         else
         {
             getDecorated().setCookie( null );
         }
     }
 
 
     /**
      * Compute the AdDirSync length. We use the client side control.
      * <pre>
      * 0x30 L1
      * |
      * +--&gt; 0x02 0x0(1-4) nnn  (flags)
      * +--&gt; 0x02 0x0(1-4) nnn  (maxReturnLength)
      * +--&gt; 0x04 L2 xkcd!!!...     (cookie)
      * </pre>
      */
     @Override
     public int computeLength()
     {
         // the flags length
         int flagsLength = BerValue.getNbBytes( AdDirSyncFlag.getBitmask( getFlags() ) );
         adDirSyncLength = 1 + TLV.getNbBytes( flagsLength ) + flagsLength;
 
         // the maxReturnLength length
         int maxReturnLengthLength = BerValue.getNbBytes( getMaxReturnLength() );
         adDirSyncLength += 1 + TLV.getNbBytes( maxReturnLengthLength ) + maxReturnLengthLength;
 
         // cookie's length
         byte[] cookie = getCookie();
         
         if ( cookie == null )
         {
             adDirSyncLength += 1 + 1;
         }
         else
         {
             adDirSyncLength += 1 + TLV.getNbBytes( cookie.length ) + cookie.length;
         }
 
         valueLength = 1 + TLV.getNbBytes( adDirSyncLength ) + adDirSyncLength;
 
         // Call the super class to compute the global control length
         return valueLength;
     }
 
 
     /**
      * Encode the AdDirSync control. We use the client side control.
      *
      * @param buffer The encoded sink
      * @return A ByteBuffer that contains the encoded PDU
      * @throws EncoderException If anything goes wrong while encoding.
      */
     @Override
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
         }
 
         // Encode the SEQ
         buffer.put( UniversalTag.SEQUENCE.getValue() );
         buffer.put( TLV.getBytes( adDirSyncLength ) );
 
         // Encode the flags
         BerValue.encode( buffer, AdDirSyncFlag.getBitmask( getFlags() ) );
 
         // Encode the MaxReturnLength
         BerValue.encode( buffer, getMaxReturnLength() );
         
         // Encode the cookie
         BerValue.encode( buffer, getCookie() );
 
         return buffer;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public byte[] getValue()
     {
         if ( value == null )
         {
             try
             {
                 computeLength();
                 ByteBuffer buffer = ByteBuffer.allocate( valueLength );
 
                 // Encode the SEQ
                 buffer.put( UniversalTag.SEQUENCE.getValue() );
                 buffer.put( TLV.getBytes( adDirSyncLength ) );
 
                 // Encode the Flags flag
                 BerValue.encode( buffer, AdDirSyncFlag.getBitmask( getFlags() ) );
 
                 // Encode the MaxReturnLength
                 BerValue.encode( buffer, getMaxReturnLength() );
                 
                 // Encode the cookie
                 BerValue.encode( buffer, getCookie() );
 
                 value = buffer.array();
             }
             catch ( Exception e )
             {
                 return null;
             }
         }
 
         return value;
     }
     
     
     /**
      * {@inheritDoc}
      */
     @Override
     public Asn1Object decode( byte[] controlBytes ) throws DecoderException
     {
         ByteBuffer bb = ByteBuffer.wrap( controlBytes );
         AdDirSyncContainer container = new AdDirSyncContainer( getCodecService(), this );
         DECODER.decode( bb, container );
         return this;
     }
 }