/*
    *  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.cancel;
  
  
  import org.apache.directory.api.asn1.DecoderException;
  import org.apache.directory.api.asn1.ber.grammar.AbstractGrammar;
  import org.apache.directory.api.asn1.ber.grammar.Grammar;
  import org.apache.directory.api.asn1.ber.grammar.GrammarAction;
  import org.apache.directory.api.asn1.ber.grammar.GrammarTransition;
  import org.apache.directory.api.asn1.ber.tlv.BerValue;
  import org.apache.directory.api.asn1.ber.tlv.IntegerDecoder;
  import org.apache.directory.api.asn1.ber.tlv.IntegerDecoderException;
  import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * This class implements the Cancel operation. All the actions are declared
   * in this class. As it is a singleton, these declaration are only done once.
   * The grammar is :
   * 
   * <pre>
   *  cancelRequestValue ::= SEQUENCE {
   *      cancelId     MessageID 
   *                   -- MessageID is as defined in [RFC2251]
   * }
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public final class CancelRequestGrammar extends AbstractGrammar<CancelRequestContainer>
  {
      /** The logger */
      static final Logger LOG = LoggerFactory.getLogger( CancelRequestGrammar.class );
  
      /** The instance of grammar. CancelGrammar is a singleton */
      private static Grammar<CancelRequestContainer> instance = new CancelRequestGrammar();
  
  
      /**
       * Creates a new GracefulDisconnectGrammar object.
       */
      @SuppressWarnings("unchecked")
      private CancelRequestGrammar()
      {
          setName( CancelRequestGrammar.class.getName() );
  
          // Create the transitions table
          super.transitions = new GrammarTransition[CancelStatesEnum.LAST_CANCEL_STATE.ordinal()][256];
  
          /**
           * Transition from init state to cancel sequence
           * cancelRequestValue ::= SEQUENCE {
           *     ... 
           * 
           * Creates the Cancel object
           */
          super.transitions[CancelStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
              new GrammarTransition<CancelRequestContainer>( CancelStatesEnum.START_STATE,
                  CancelStatesEnum.CANCEL_SEQUENCE_STATE,
                  UniversalTag.SEQUENCE.getValue(),
                  null );
  
          /**
           * Transition from cancel SEQ to cancelId
           * 
           * cancelRequestValue ::= SEQUENCE {
           *     cancelId   MessageID 
           * }
           *     
           * Set the cancelId value into the Cancel object.    
           */
          super.transitions[CancelStatesEnum.CANCEL_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER.getValue()] =
              new GrammarTransition<CancelRequestContainer>( CancelStatesEnum.CANCEL_SEQUENCE_STATE,
                  CancelStatesEnum.CANCEL_ID_STATE,
                  UniversalTag.INTEGER.getValue(),
                  new GrammarAction<CancelRequestContainer>( "Stores CancelId" )
                  {
                     public void action( CancelRequestContainer cancelContainer ) throws DecoderException
                     {
                         BerValue value = cancelContainer.getCurrentTLV().getValue();
 
                         try
                         {
                             int cancelId = IntegerDecoder.parse( value, 0, Integer.MAX_VALUE );
 
                             if ( LOG.isDebugEnabled() )
                             {
                                 LOG.debug( I18n.msg( I18n.MSG_08200_CANCEL_ID, cancelId ) );
                             }
 
                             cancelContainer.getCancelRequest().setCancelId( cancelId );
                             
                             cancelContainer.setGrammarEndAllowed( true );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = I18n.err( I18n.ERR_08200_CANCELID_DECODING_FAILED, Strings.dumpBytes( value.getData() ) );
                             LOG.error( msg );
                             throw new DecoderException( msg, ide );
                         }
                     }
                 } );
     }
 
 
     /**
      * This class is a singleton.
      * 
      * @return An instance on this grammar
      */
     public static Grammar<CancelRequestContainer> getInstance()
     {
         return instance;
     }
 }