/*
    *  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.server.ldap.handlers.extended;
  
  
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.apache.directory.api.ldap.extras.extended.startTransaction.StartTransactionRequest;
  import org.apache.directory.api.ldap.extras.extended.startTransaction.StartTransactionResponse;
  import org.apache.directory.api.ldap.extras.extended.startTransaction.StartTransactionResponseImpl;
  import org.apache.directory.api.ldap.model.message.ExtendedRequest;
  import org.apache.directory.api.ldap.model.message.ExtendedResponse;
  import org.apache.directory.server.core.api.CoreSession;
  import org.apache.directory.server.ldap.ExtendedOperationHandler;
  import org.apache.directory.server.ldap.LdapServer;
  import org.apache.directory.server.ldap.LdapSession;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import jdbm.helper.Conversion;
  
  
  /**
   * An handler to manage the StartTransaction extended request operation
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class StartTransactionHandler implements ExtendedOperationHandler<ExtendedRequest, ExtendedResponse>
  {
      private static final Logger LOG = LoggerFactory.getLogger( StartTransactionHandler.class );
      public static final Set<String> EXTENSION_OIDS;
  
      static
      {
          Set<String> set = new HashSet<>( 2 );
          set.add( StartTransactionRequest.EXTENSION_OID );
          EXTENSION_OIDS = Collections.unmodifiableSet( set );
      }
  
  
      /**
       * {@inheritDoc}
       */
      public String getOid()
      {
          return StartTransactionRequest.EXTENSION_OID;
      }
  
  
      /**
       * {@inheritDoc}
       */
      public void handleExtendedOperation( LdapSession session, ExtendedRequest req ) throws Exception
      {
          LOG.debug( "StartTransaction requested" );
          
          // We need to create a new transaction ID for the current session.
          // If the current session is already processing a transaction, we will return an error
          CoreSession coreSession = session.getCoreSession();
          long transactionId = coreSession.beginSessionTransaction();
  
          StartTransactionResponse startTransactionResponse = new StartTransactionResponseImpl( 
                  req.getMessageId(), Conversion.convertToByteArray( transactionId ) );
          
          // Store the StartTransaction request name in the response, to be able to
          // encode the response properly.
          // Kurt Zeilenga should have set a responseName to make it easier to 
          // implement in RFC 5805 :/
          startTransactionResponse.setResponseName( StartTransactionRequest.EXTENSION_OID );
  
          // write the response
          session.getIoSession().write( startTransactionResponse );
      }
  
  
      /**
       * {@inheritDoc}
       */
      public Set<String> getExtensionOids()
      {
         return EXTENSION_OIDS;
     }
 
 
     /**
      * {@inheritDoc}
      */
     public void setLdapServer( LdapServer ldapServer )
     {
     }
 }