/*
    *   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.sort;
  
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  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.asn1.util.Asn1StringUtils;
  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.SortKey;
  import org.apache.directory.api.ldap.model.message.controls.SortRequest;
  import org.apache.directory.api.ldap.model.message.controls.SortRequestControlImpl;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * Decorator of SortRequestControl.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class SortRequestDecorator extends ControlDecorator<SortRequest> implements SortRequest
  {
      private static final Asn1Decoder DECODER = new Asn1Decoder();
  
      private int sortReqLen = 0;
  
      private List<Integer> sortKeyLenList = new ArrayList<>();
  
      /** ASN.1 BER tag for the forward ordering rule */
      public static final int ORDERING_RULE_TAG = 0x80;
  
      /** ASN.1 BER tag for the backward ordering rule */
      public static final int REVERSE_ORDER_TAG = 0x81;
  
  
      /**
       * Creates a new instance of SortRequestDecorator.
       *
       * @param codec the LDAP codec
       */
      public SortRequestDecorator( LdapApiService codec )
      {
          super( codec, new SortRequestControlImpl() );
      }
  
  
      /**
       * Creates a new instance of SortRequestDecorator.
       *
       * @param codec the LDAP codec
       * @param control the control instance
       */
      public SortRequestDecorator( LdapApiService codec, SortRequest control )
      {
          super( codec, control );
      }
  
  
      /**
       * @return the control length.
       */
      @Override
      public int computeLength()
      {
          sortReqLen = 0;
          sortKeyLenList.clear();
          valueLength = 0;
  
          for ( SortKey sk : getSortKeys() )
          {
              int skLen = 0;
 
             byte[] atBytes = Strings.getBytesUtf8( sk.getAttributeTypeDesc() );
             skLen += 1 + TLV.getNbBytes( atBytes.length ) + atBytes.length;
 
             if ( sk.getMatchingRuleId() != null )
             {
                 byte[] mrBytes = Strings.getBytesUtf8( sk.getMatchingRuleId() );
                 skLen += 1 + TLV.getNbBytes( mrBytes.length ) + mrBytes.length;
             }
 
             if ( sk.isReverseOrder() )
             {
                 // reverse order flag
                 skLen += 1 + 1 + 1;
             }
 
             sortKeyLenList.add( skLen );
 
             // the sequence
             sortReqLen += 1 + TLV.getNbBytes( skLen ) + skLen;
         }
 
         valueLength = 1 + TLV.getNbBytes( sortReqLen ) + sortReqLen;
 
         return valueLength;
     }
 
 
     @Override
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
         }
 
         buffer.put( UniversalTag.SEQUENCE.getValue() );
         buffer.put( TLV.getBytes( sortReqLen ) );
 
         List<SortKey> lst = getSortKeys();
 
         for ( int i = 0; i < lst.size(); i++ )
         {
             SortKey sk = lst.get( i );
             int skLen = sortKeyLenList.get( i );
 
             buffer.put( UniversalTag.SEQUENCE.getValue() );
             buffer.put( TLV.getBytes( skLen ) );
 
             BerValue.encode( buffer, sk.getAttributeTypeDesc() );
 
             String mrId = sk.getMatchingRuleId();
             if ( mrId != null )
             {
                 buffer.put( ( byte ) ORDERING_RULE_TAG );
                 byte[] value = Asn1StringUtils.getBytesUtf8( mrId );
 
                 buffer.put( TLV.getBytes( value.length ) );
                 buffer.put( value );
             }
 
             if ( sk.isReverseOrder() )
             {
                 buffer.put( ( byte ) REVERSE_ORDER_TAG );
                 buffer.put( ( byte ) 0x01 );
                 buffer.put( BerValue.TRUE_VALUE );
             }
         }
 
         return buffer;
     }
 
 
     @Override
     public Asn1Object decode( byte[] controlBytes ) throws DecoderException
     {
         ByteBuffer buffer = ByteBuffer.wrap( controlBytes );
         SortRequestContainer container = new SortRequestContainer( getCodecService(), this );
         DECODER.decode( buffer, container );
         return this;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public byte[] getValue()
     {
         if ( value == null )
         {
             try
             {
                 computeLength();
                 ByteBuffer buffer = ByteBuffer.allocate( valueLength );
 
                 value = encode( buffer ).array();
             }
             catch ( Exception e )
             {
                 return null;
             }
         }
 
         return value;
     }
 
 
     @Override
     public void setSortKeys( List<SortKey> sortKeys )
     {
         getDecorated().setSortKeys( sortKeys );
     }
 
 
     @Override
     public List<SortKey> getSortKeys()
     {
         return getDecorated().getSortKeys();
     }
 
 
     @Override
     public void addSortKey( SortKey sortKey )
     {
         getDecorated().addSortKey( sortKey );
     }
 
 }