/*
    *   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
    *
   *     https://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.extended.ads_impl.whoAmI;
  
  
  import org.apache.directory.api.asn1.DecoderException;
  import org.apache.directory.api.asn1.util.Asn1Buffer;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.AbstractExtendedOperationFactory;
  import org.apache.directory.api.ldap.codec.api.ExtendedOperationFactory;
  import org.apache.directory.api.ldap.codec.api.LdapApiService;
  import org.apache.directory.api.ldap.extras.extended.whoAmI.WhoAmIRequest;
  import org.apache.directory.api.ldap.extras.extended.whoAmI.WhoAmIRequestImpl;
  import org.apache.directory.api.ldap.extras.extended.whoAmI.WhoAmIResponse;
  import org.apache.directory.api.ldap.extras.extended.whoAmI.WhoAmIResponseImpl;
  import org.apache.directory.api.ldap.model.exception.LdapInvalidDnException;
  import org.apache.directory.api.ldap.model.message.ExtendedResponse;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * An {@link ExtendedOperationFactory} for creating WhoAmI extended request response 
   * pairs.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class WhoAmIFactory extends AbstractExtendedOperationFactory
  {
      /** logger */
      private static final Logger LOG = LoggerFactory.getLogger( WhoAmIFactory.class );
      
      /**
       * Creates a new instance of WhoAmIFactory.
       *
       * @param codec The codec for this factory.
       */
      public WhoAmIFactory( LdapApiService codec )
      {
          super( codec, WhoAmIRequest.EXTENSION_OID );
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public WhoAmIRequest newRequest()
      {
          return new WhoAmIRequestImpl();
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public WhoAmIRequest newRequest( byte[] value ) throws DecoderException
      {
          WhoAmIRequest whoAmIRequest = new WhoAmIRequestImpl();
  
          if ( value != null )
          {
              decodeValue( whoAmIRequest, value );
          }
  
          return whoAmIRequest;
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public WhoAmIResponse newResponse() throws DecoderException
      {
          return new WhoAmIResponseImpl();
      }
  
  
     /**
      * {@inheritDoc}
      */
     @Override
     public WhoAmIResponse newResponse( byte[] value ) throws DecoderException
     {
         WhoAmIResponse whoAmIResponse = new WhoAmIResponseImpl();
 
         if ( value != null )
         {
             decodeValue( whoAmIResponse, value );
         }
 
         return whoAmIResponse;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void encodeValue( Asn1Buffer buffer, ExtendedResponse extendedResponse )
     {
         if ( extendedResponse == null )
         {
             return;
         }
 
         // Reset the responseName, it should always be null for a WhoAMI extended operation
         extendedResponse.setResponseName( null );
         
         // The authzID as a opaque byte array
         byte[] authzid =  ( ( WhoAmIResponse ) extendedResponse ).getAuthzId();
         
         if ( !Strings.isEmpty( authzid ) )
         {
             buffer.put( authzid );
         }
     }
     
     
     /**
      * Decode a PDU which must contain a WhoAmIResponse extended operation.
      * Note that the stream of bytes much contain a full PDU, not a partial one.
      * 
      * @param whoAmIResponse The WhoAmI extended response that will be feed
      * @param data The bytes to be decoded
      * @return a WhoAmIRequest object
      * @throws org.apache.directory.api.asn1.DecoderException If the decoding failed
      */
     public static WhoAmIResponse decode( WhoAmIResponse whoAmIResponse, byte[] data ) throws DecoderException
     {
         if ( Strings.isEmpty( data ) )
         {
             ( ( WhoAmIResponseImpl ) whoAmIResponse ).setAuthzId( null );
         }
         else
         {
             switch ( data.length )
             {
                 case 0:
                     // Error
                 case 1:
                     // Error
                     String msg = I18n.err( I18n.ERR_08226_AUTHZID_TOO_SHORT_MISSING_U_OR_DN );
                     LOG.error( msg );
                     throw new DecoderException( msg );
 
                 case 2 :
                     if ( ( data[0] == 'u' ) && ( data[1] == ':' ) )
                     {
                         ( ( WhoAmIResponseImpl ) whoAmIResponse ).setAuthzId( data );
                         ( ( WhoAmIResponseImpl ) whoAmIResponse ).setUserId( Strings.utf8ToString( data, 2, data.length - 2 ) );
                     }
                     else
                     {
                         msg = I18n.err( I18n.ERR_08227_AUTHZID_MUST_START_WITH_U_OR_DN, Strings.utf8ToString( data ) );
                         LOG.error( msg );
                         throw new DecoderException( msg );
                     }
                     
                     break;
                     
                 default :
                     switch ( data[0] )
                     {
                         case 'u' :
                             if ( data[1] == ':' )
                             {
                                 ( ( WhoAmIResponseImpl ) whoAmIResponse ).setAuthzId( data );
                                 ( ( WhoAmIResponseImpl ) whoAmIResponse ).setUserId( Strings.utf8ToString( data, 2, data.length - 2 ) );
                             }
                             else
                             {
                                 msg = I18n.err( I18n.ERR_08227_AUTHZID_MUST_START_WITH_U_OR_DN, Strings.utf8ToString( data ) );
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
                             
                             break;
                             
                         case 'd' :
                             if ( ( data[1] == 'n' ) && ( data[2] == ':' ) )
                             {
                                 // Check that the remaining bytes are a valid DN
                                 if ( Dn.isValid( Strings.utf8ToString( data, 3, data.length - 3 ) ) )
                                 {
                                     ( ( WhoAmIResponseImpl ) whoAmIResponse ).setAuthzId( data );
                                     
                                     try
                                     {
                                         ( ( WhoAmIResponseImpl ) whoAmIResponse ).setDn( new Dn( Strings.utf8ToString( data, 3, data.length - 3 ) ) );
                                     }
                                     catch ( LdapInvalidDnException e )
                                     {
                                         // Should never happen
                                     }
                                 }
                                 else
                                 {
                                     msg = I18n.err( I18n.ERR_08227_AUTHZID_MUST_START_WITH_U_OR_DN, Strings.utf8ToString( data ) );
                                     LOG.error( msg );
                                     throw new DecoderException( msg );
                                 }
                             }
                             else
                             {
                                 msg = I18n.err( I18n.ERR_08227_AUTHZID_MUST_START_WITH_U_OR_DN, Strings.utf8ToString( data ) );
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
                             
                             break;
 
                         default :
                             msg = I18n.err( I18n.ERR_08227_AUTHZID_MUST_START_WITH_U_OR_DN, Strings.utf8ToString( data ) );
                             LOG.error( msg );
                             throw new DecoderException( msg );
                     }
                     
                     break;
             }
         }
 
         return whoAmIResponse;
     }
 
     
     /**
      * {@inheritDoc}
      */
     @Override
     public void decodeValue( ExtendedResponse extendedResponse, byte[] responseValue ) throws DecoderException
     {
         decode( ( WhoAmIResponse ) extendedResponse, responseValue );
     }
 }