/*
    *  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.api;
  
  
  import java.nio.BufferOverflowException;
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.ber.tlv.TLV;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.decorators.LdapResultDecorator;
  import org.apache.directory.api.ldap.codec.decorators.ResponseDecorator;
  import org.apache.directory.api.ldap.model.message.ExtendedResponse;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A decorator for the ExtendedResponse message
   *
   * @param <R> The extended response to decorate
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ExtendedResponseDecorator<R extends ExtendedResponse> extends ResponseDecorator<R>
      implements ExtendedResponse
  {
      /** The response name (OID) as a byte[] */
      private byte[] responseNameBytes;
  
      /** The encoded extendedResponse length */
      private int extendedResponseLength;
  
      /** The response value */
      protected byte[] responseValue;
  
  
      /**
       * Makes a ExtendedResponse encodable.
       *
       * @param codec The LDAP service instance
       * @param decoratedMessage the decorated ExtendedResponse
       */
      public ExtendedResponseDecorator( LdapApiService codec, R decoratedMessage )
      {
          super( codec, decoratedMessage );
      }
  
  
      //-------------------------------------------------------------------------
      // The ExtendedResponse methods
      //-------------------------------------------------------------------------
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String getResponseName()
      {
          return getDecorated().getResponseName();
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void setResponseName( String oid )
      {
          getDecorated().setResponseName( oid );
      }
  
  
      /**
       * Gets the Extended response payload 
       * 
       * @return The extended payload
       */
      public byte[] getResponseValue()
      {
          return responseValue;
      }
 
 
     /**
      * sets the Extended response payload 
      * 
      * @param responseValue The extended payload
      */
     public void setResponseValue( byte[] responseValue )
     {
         this.responseValue = responseValue;
     }
 
 
     //-------------------------------------------------------------------------
     // The Decorator methods
     //-------------------------------------------------------------------------
     /**
      * Compute the ExtendedResponse length
      * <br>
      * ExtendedResponse :
      * <pre>
      * 0x78 L1
      *  |
      *  +--&gt; LdapResult
      * [+--&gt; 0x8A L2 name
      * [+--&gt; 0x8B L3 response]]
      * 
      * L1 = Length(LdapResult)
      *      [ + Length(0x8A) + Length(L2) + L2
      *       [ + Length(0x8B) + Length(L3) + L3]]
      * 
      * Length(ExtendedResponse) = Length(0x78) + Length(L1) + L1
      * </pre>
      * 
      * @return The ExtendedResponse length
      */
     @Override
     public int computeLength()
     {
         int ldapResultLength = ( ( LdapResultDecorator ) getLdapResult() ).computeLength();
 
         extendedResponseLength = ldapResultLength;
 
         String id = getResponseName();
 
         if ( !Strings.isEmpty( id ) )
         {
             responseNameBytes = Strings.getBytesUtf8( id );
             int idLength = responseNameBytes.length;
             extendedResponseLength += 1 + TLV.getNbBytes( idLength ) + idLength;
         }
 
         byte[] encodedValue = getResponseValue();
 
         if ( encodedValue != null )
         {
             extendedResponseLength += 1 + TLV.getNbBytes( encodedValue.length ) + encodedValue.length;
         }
 
         return 1 + TLV.getNbBytes( extendedResponseLength ) + extendedResponseLength;
     }
 
 
     /**
      * Encode the ExtendedResponse message to a PDU. 
      * <br>
      * ExtendedResponse :
      * <pre>
      * LdapResult.encode()
      * [0x8A LL response name]
      * [0x8B LL response]
      * </pre>
      * 
      * @param buffer The buffer where to put the PDU
      * @return The PDU.
      */
     @Override
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         try
         {
             // The ExtendedResponse Tag
             buffer.put( LdapCodecConstants.EXTENDED_RESPONSE_TAG );
             buffer.put( TLV.getBytes( extendedResponseLength ) );
 
             // The LdapResult
             ( ( LdapResultDecorator ) getLdapResult() ).encode( buffer );
 
             // The ID, if any
             if ( responseNameBytes != null )
             {
                 buffer.put( ( byte ) LdapCodecConstants.EXTENDED_RESPONSE_RESPONSE_NAME_TAG );
                 buffer.put( TLV.getBytes( responseNameBytes.length ) );
 
                 if ( responseNameBytes.length != 0 )
                 {
                     buffer.put( responseNameBytes );
                 }
             }
 
             // The encodedValue, if any
             byte[] encodedValue = getResponseValue();
 
             if ( encodedValue != null )
             {
                 buffer.put( ( byte ) LdapCodecConstants.EXTENDED_RESPONSE_RESPONSE_TAG );
 
                 buffer.put( TLV.getBytes( encodedValue.length ) );
 
                 if ( encodedValue.length != 0 )
                 {
                     buffer.put( encodedValue );
                 }
             }
         }
         catch ( BufferOverflowException boe )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04005 ), boe );
         }
 
         return buffer;
     }
 }