/*
    *  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.decorators;
  
  
  import java.nio.BufferOverflowException;
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.ber.tlv.BerValue;
  import org.apache.directory.api.asn1.ber.tlv.TLV;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.Decorator;
  import org.apache.directory.api.ldap.codec.api.LdapApiService;
  import org.apache.directory.api.ldap.codec.api.LdapEncoder;
  import org.apache.directory.api.ldap.model.message.LdapResult;
  import org.apache.directory.api.ldap.model.message.Referral;
  import org.apache.directory.api.ldap.model.message.ResultCodeEnum;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A decorator for the LdapResultResponse message
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class LdapResultDecorator implements LdapResult, Decorator<LdapResult>
  {
      /** The decorated LdapResult */
      private final LdapResult decoratedLdapResult;
  
      /** Temporary storage for message bytes */
      private byte[] errorMessageBytes;
  
      /** Temporary storage of the byte[] representing the matchedDN */
      private byte[] matchedDnBytes;
  
      /** The codec responsible for encoding and decoding this object. */
      private LdapApiService codec;
  
      private static final byte[] DEFAULT_SUCCESS = new byte[]
          { 0x0A, 0x01, 0x00, 0x04, 0x00, 0x04, 0x00 };
  
  
      /**
       * Makes a LdapResult encodable.
       *
       * @param codec The LDAP service instance
       * @param decoratedLdapResult the decorated LdapResult
       */
      public LdapResultDecorator( LdapApiService codec, LdapResult decoratedLdapResult )
      {
          this.decoratedLdapResult = decoratedLdapResult;
          this.codec = codec;
      }
  
  
      //-------------------------------------------------------------------------
      // The LdapResult methods
      //-------------------------------------------------------------------------
  
      /**
       * {@inheritDoc}
       */
      @Override
      public ResultCodeEnum getResultCode()
      {
          return decoratedLdapResult.getResultCode();
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void setResultCode( ResultCodeEnum resultCode )
      {
          decoratedLdapResult.setResultCode( resultCode );
      }
  
  
     /**
      * {@inheritDoc}
      */
     @Override
     public Dn getMatchedDn()
     {
         return decoratedLdapResult.getMatchedDn();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setMatchedDn( Dn dn )
     {
         decoratedLdapResult.setMatchedDn( dn );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public String getDiagnosticMessage()
     {
         return decoratedLdapResult.getDiagnosticMessage();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setDiagnosticMessage( String diagnosticMessage )
     {
         decoratedLdapResult.setDiagnosticMessage( diagnosticMessage );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isReferral()
     {
         return decoratedLdapResult.isReferral();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Referral getReferral()
     {
         return decoratedLdapResult.getReferral();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setReferral( Referral referral )
     {
         decoratedLdapResult.setReferral( referral );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public String toString()
     {
         return decoratedLdapResult.toString();
     }
 
 
     //-------------------------------------------------------------------------
     // The Decorator methods
     //-------------------------------------------------------------------------
     /**
      * Compute the LdapResult length 
      * <br>
      * LdapResult :
      * <pre> 
      *   0x0A 01 resultCode (0..80)
      *   0x04 L1 matchedDN (L1 = Length(matchedDN)) 
      *   0x04 L2 errorMessage (L2 = Length(errorMessage)) 
      *   [0x83 L3] referrals 
      *     | 
      *     +--&gt; 0x04 L4 referral 
      *     +--&gt; 0x04 L5 referral 
      *     +--&gt; ... 
      *     +--&gt; 0x04 Li referral 
      *     +--&gt; ... 
      *     +--&gt; 0x04 Ln referral 
      *     
      * L1 = Length(matchedDN) 
      * L2 = Length(errorMessage) 
      * L3 = n*Length(0x04) + sum(Length(L4) .. Length(Ln)) + sum(L4..Ln) 
      * L4..n = Length(0x04) + Length(Li) + Li 
      * Length(LdapResult) = Length(0x0x0A) +
      *      Length(0x01) + 1 + Length(0x04) + Length(L1) + L1 + Length(0x04) +
      *      Length(L2) + L2 + Length(0x83) + Length(L3) + L3
      * </pre>
      */
     @Override
     public int computeLength()
     {
         if ( decoratedLdapResult.isDefaultSuccess() )
         {
             // The length of a default success PDU : 0xA0 0x01 0x00 0x04 0x00 0x04 0x00
             return DEFAULT_SUCCESS.length;
         }
 
         int ldapResultLength;
 
         // The result code
         ldapResultLength = 1 + 1 + BerValue.getNbBytes( getResultCode().getValue() );
 
         // The matchedDN length
         if ( getMatchedDn() == null )
         {
             ldapResultLength += 1 + 1;
         }
         else
         {
             matchedDnBytes = Strings.getBytesUtf8Ascii( Strings.trimLeft( getMatchedDn().getName() ) );
             ldapResultLength += 1 + TLV.getNbBytes( matchedDnBytes.length ) + matchedDnBytes.length;
         }
 
         // The errorMessage length
         errorMessageBytes = Strings.getBytesUtf8Ascii( getDiagnosticMessage() );
         ldapResultLength += 1 + TLV.getNbBytes( errorMessageBytes.length ) + errorMessageBytes.length;
 
         int referralLength = LdapEncoder.computeReferralLength( getReferral() );
 
         if ( referralLength != 0 )
         {
             // The referrals
             ldapResultLength += 1 + TLV.getNbBytes( referralLength ) + referralLength;
         }
 
         return ldapResultLength;
     }
 
 
     /**
      * Encode the LdapResult message to a PDU.
      * 
      * @param buffer The buffer where to put the PDU
      * @return The PDU.
      */
     @Override
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
         }
 
         if ( decoratedLdapResult.isDefaultSuccess() )
         {
             // The length of a default success PDU : 0xA0 0x01 0x00 0x04 0x00 0x04 0x00
             buffer.put( DEFAULT_SUCCESS );
 
             return buffer;
         }
 
         try
         {
             // The result code
             BerValue.encodeEnumerated( buffer, getResultCode().getValue() );
         }
         catch ( BufferOverflowException boe )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04005 ), boe );
         }
 
         // The matchedDN
         BerValue.encode( buffer, matchedDnBytes );
 
         // The error message
         BerValue.encode( buffer, errorMessageBytes );
 
         // The referrals, if any
         Referral referral = getReferral();
 
         if ( referral != null )
         {
             LdapEncoder.encodeReferral( buffer, referral );
         }
 
         return buffer;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public LdapResult getDecorated()
     {
         return decoratedLdapResult;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public LdapApiService getCodecService()
     {
         return codec;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isDefaultSuccess()
     {
         return decoratedLdapResult.isDefaultSuccess();
     }
 }