/*
    *  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.extras.controls.ad_impl;
  
  
  import java.util.Set;
  
  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.ldap.extras.controls.ad.AdDirSyncFlag;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * 
   * Implementation of AdDirSync Response Control. All the actions are declared in
   * this class. As it is a singleton, these declaration are only done once.
   *
   *  The decoded grammar is as follows :
   *  
   *  <pre>
   * realReplControlValue ::= SEQUENCE {
   *     flag                  integer
   *     maxReturnLength       integer
   *     cookie                OCTET STRING
   * }
   * </pre> 
   *  
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public final class AdDirSyncGrammar extends AbstractGrammar<AdDirSyncContainer>
  {
  
      /** the logger */
      private static final Logger LOG = LoggerFactory.getLogger( AdDirSyncGrammar.class );
  
      /** speedup for logger */
      private static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      /** AdDirSyncControlGrammar singleton instance */
      private static final AdDirSyncGrammar INSTANCE = new AdDirSyncGrammar();
  
  
      /**
       * 
       * Creates a new instance of AdDirSyncControlGrammar.
       *
       */
      @SuppressWarnings("unchecked")
      private AdDirSyncGrammar()
      {
          setName( AdDirSyncGrammar.class.getName() );
  
          super.transitions = new GrammarTransition[AdDirSyncStatesEnum.LAST_AD_DIR_SYNC_STATE.ordinal()][256];
  
          /** 
           * Transition from initial state to AdDirSync sequence
           * AdDirSync ::= SEQUENCE {
           *     ...
           *     
           * Initialize the adDirSync object
           */
          super.transitions[AdDirSyncStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] = 
              new GrammarTransition<AdDirSyncContainer>(
              AdDirSyncStatesEnum.START_STATE, AdDirSyncStatesEnum.AD_DIR_SYNC_SEQUENCE_STATE,
              UniversalTag.SEQUENCE.getValue(),
              new GrammarAction<AdDirSyncContainer>( "Initialization" )
              {
                  public void action( AdDirSyncContainer container ) throws DecoderException
                  {
                  }
              } );
  
         
         /**
          * transition from start to flag
          * realReplControlValue ::= SEQUENCE {
          *     flag            integer
          *    ....
          * }
          */
         super.transitions[AdDirSyncStatesEnum.AD_DIR_SYNC_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER
             .getValue()] =
             new GrammarTransition<AdDirSyncContainer>( AdDirSyncStatesEnum.AD_DIR_SYNC_SEQUENCE_STATE,
                 AdDirSyncStatesEnum.FLAG_STATE, UniversalTag.INTEGER.getValue(),
                 new GrammarAction<AdDirSyncContainer>( "Set AdDirSyncControl parentFirst" )
                 {
                     public void action( AdDirSyncContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         try
                         {
                             int flagValue = IntegerDecoder.parse( value );
                             
                             Set<AdDirSyncFlag> flags = AdDirSyncFlag.getFlags( flagValue );
                             
                             if ( flags == null )
                             {
                                 String msg = "Error while decoding the AdDirSync flag, unknown value : " + flagValue;
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
                             
                             if ( IS_DEBUG )
                             {
                                 LOG.debug( "flags = {}", flags.toString() );
                             }
                             
                             container.getAdDirSyncControl().setFlags( flags );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = "Error while decoding the AdDirSync flag : " + ide.getMessage();
                             LOG.error( msg, ide );
                             throw new DecoderException( msg, ide );
                         }
                     }
                 } );
 
         
         /**
          * transition from flag to maxReturnLength
          * realReplControlValue ::= SEQUENCE {
          *     flag                    integer
          *     maxReturnLength         integer
          *    ....
          * }
          */
         super.transitions[AdDirSyncStatesEnum.FLAG_STATE.ordinal()][UniversalTag.INTEGER
             .getValue()] =
             new GrammarTransition<AdDirSyncContainer>( AdDirSyncStatesEnum.FLAG_STATE,
                 AdDirSyncStatesEnum.MAX_RETURN_LENGTH_STATE, UniversalTag.INTEGER.getValue(),
                 new GrammarAction<AdDirSyncContainer>( "Set AdDirSyncControl maxReturnLength" )
                 {
                     public void action( AdDirSyncContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         try
                         {
                             int maxReturnLength = IntegerDecoder.parse( value );
                             
                             if ( IS_DEBUG )
                             {
                                 LOG.debug( "maxReturnLength = {}", maxReturnLength );
                             }
                             
                             container.getAdDirSyncControl().setMaxReturnLength( maxReturnLength );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = "Error while decoding the AdDirSync maxReturnLength : " + ide.getMessage();
                             LOG.error( msg, ide );
                             throw new DecoderException( msg, ide );
                         }
                     }
                 } );
         
         
         /**
          * transition from maxReturnLength to cookie
          *     ...
          *     maxReturnLength         integer
          *     cookie                  OCTET STRING
          * }
          */
         super.transitions[AdDirSyncStatesEnum.MAX_RETURN_LENGTH_STATE.ordinal()][UniversalTag.OCTET_STRING
             .getValue()] =
             new GrammarTransition<AdDirSyncContainer>( AdDirSyncStatesEnum.MAX_RETURN_LENGTH_STATE,
                 AdDirSyncStatesEnum.COOKIE_STATE, UniversalTag.OCTET_STRING.getValue(),
                 new GrammarAction<AdDirSyncContainer>( "Set AdDirSyncControl cookie" )
                 {
                     public void action( AdDirSyncContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         byte[] cookie = value.getData();
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "cookie = {}", Strings.dumpBytes( cookie ) );
                         }
 
                         container.getAdDirSyncControl().setCookie( cookie );
 
                         container.setGrammarEndAllowed( true );
                     }
                 } );
     }
 
 
     /**
      * @return the singleton instance of the AdDirSyncControlGrammar
      */
     public static Grammar<AdDirSyncContainer> getInstance()
     {
         return INSTANCE;
     }
 }