/*
    *  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.codec.protocol.mina;
  
  
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.util.Asn1Buffer;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.LdapApiService;
  import org.apache.directory.api.ldap.codec.api.LdapApiServiceFactory;
  import org.apache.directory.api.ldap.codec.api.LdapEncoder;
  import org.apache.directory.api.ldap.model.constants.Loggers;
  import org.apache.directory.api.ldap.model.message.Message;
  import org.apache.directory.api.util.Strings;
  import org.apache.mina.core.buffer.IoBuffer;
  import org.apache.mina.core.session.IoSession;
  import org.apache.mina.filter.codec.ProtocolEncoder;
  import org.apache.mina.filter.codec.ProtocolEncoderOutput;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * A LDAP message encoder. It is based on api-ldap encoder.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class LdapProtocolEncoder implements ProtocolEncoder
  {
      /** logger for reporting errors that might not be handled properly upstream */
      private static final Logger CODEC_LOG = LoggerFactory.getLogger( Loggers.CODEC_LOG.getName() );
  
      /** The LDAP API Service instance */
      private LdapApiService codec;
      
      /** A thread local storage used to store the Asn1Buffer instance */
      private ThreadLocal<Asn1Buffer> threadLocalStorage = new ThreadLocal<>();
      
      /**
       * Creates a new instance of LdapProtocolEncoder.
       */
      public LdapProtocolEncoder()
      {
          this( LdapApiServiceFactory.getSingleton() );
      }
  
      /**
       * Creates a new instance of LdapProtocolEncoder.
       *
       * @param ldapApiService The Service to use
       */
      public LdapProtocolEncoder( LdapApiService ldapApiService )
      {
          codec = ldapApiService;
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void encode( IoSession session, Object message, ProtocolEncoderOutput out ) throws Exception
      {
          Asn1Buffer asn1Buffer = threadLocalStorage.get();
          
          if ( asn1Buffer == null )
          {
              asn1Buffer = new Asn1Buffer();
              threadLocalStorage.set( asn1Buffer );
          }
  
          ByteBuffer encoded;
          
          try
          { 
              LdapEncoder.encodeMessage( asn1Buffer, codec, ( Message ) message );
              encoded = asn1Buffer.getBytes();
          }
          catch ( EncoderException e )
          {
             CODEC_LOG.error( I18n.err( I18n.ERR_14000_ERROR_ENCODING_MESSAGE, message, e.getMessage() ) );
             throw e;
         }
         finally 
         {
             asn1Buffer.clear();
         }
         
         IoBuffer ioBuffer = IoBuffer.wrap( encoded );
     
         if ( CODEC_LOG.isDebugEnabled() )
         {
             byte[] dumpBuffer = new byte[encoded.limit()];
             encoded.get( dumpBuffer );
             encoded.flip();
             CODEC_LOG.debug( I18n.msg( I18n.MSG_14003_ENCODED_LDAP_MESSAGE, message, Strings.dumpBytes( dumpBuffer ) ) );
         }
 
         out.write( ioBuffer );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void dispose( IoSession session ) throws Exception
     {
         // Nothing to do
     }
 }