/*
    *  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.extended.ads_impl.pwdModify;
  
  
  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.UniversalTag;
  import org.apache.directory.api.ldap.codec.api.LdapApiServiceFactory;
  import org.apache.directory.api.ldap.extras.extended.pwdModify.PasswordModifyResponseImpl;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * This class implements the PasswordModifyResponse extended operation's ASN.1 grammer. 
   * All the actions are declared in this class. As it is a singleton, 
   * these declaration are only done once. The grammar is :
   * 
   * <pre>
   *  PasswdModifyResponseValue ::= SEQUENCE {
   *      genPasswd       [0]     OCTET STRING OPTIONAL }
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  
  public class PasswordModifyResponseGrammar extends AbstractGrammar<PasswordModifyResponseContainer>
  {
  
      /** logger */
      private static final Logger LOG = LoggerFactory.getLogger( PasswordModifyResponseGrammar.class );
  
      /** Speedup for logs */
      static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      /** The instance of grammar. PasswdModifyResponseGrammar is a singleton */
      private static Grammar<PasswordModifyResponseContainer> instance = new PasswordModifyResponseGrammar();
  
  
      @SuppressWarnings("unchecked")
      public PasswordModifyResponseGrammar()
      {
          setName( PasswordModifyResponseGrammar.class.getName() );
  
          // Create the transitions table
          super.transitions = new GrammarTransition[PasswordModifyResponseStatesEnum.LAST_PASSWORD_MODIFY_RESPONSE_STATE
              .ordinal()][256];
  
          /**
           * Transition from init state to PasswordModify Response Value
           * 
           * PasswdModifyResponseValue ::= SEQUENCE {
           *     ...
           *     
           * Creates the PasswdModifyResponse object
           */
          super.transitions[PasswordModifyResponseStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
              new GrammarTransition<PasswordModifyResponseContainer>(
                  PasswordModifyResponseStatesEnum.START_STATE,
                  PasswordModifyResponseStatesEnum.PASSWORD_MODIFY_RESPONSE_SEQUENCE_STATE,
                  UniversalTag.SEQUENCE.getValue(), new GrammarAction<PasswordModifyResponseContainer>(
                      "Init PasswordModifyResponse" )
                  {
                      public void action( PasswordModifyResponseContainer container )
                      {
                          PasswordModifyResponseDecorator passwordModifyResponse = new PasswordModifyResponseDecorator(
                              LdapApiServiceFactory.getSingleton(), new PasswordModifyResponseImpl() );
                          container.setPasswordModifyResponse( passwordModifyResponse );
  
                          // We may have nothing left
                          container.setGrammarEndAllowed( true );
                      }
                  } );
  
          /**
           * Transition from PasswordModify Response Value to genPassword
          *
          * PasswdModifyResponseValue ::= SEQUENCE {
          *     genPassword    [0]  OCTET STRING OPTIONAL
          *     ...
          *     
          * Set the userIdentity into the PasswdModifyResponset instance.
          */
         super.transitions[PasswordModifyResponseStatesEnum.PASSWORD_MODIFY_RESPONSE_SEQUENCE_STATE.ordinal()][PasswordModifyResponseConstants.GEN_PASSWORD_TAG] =
             new GrammarTransition<PasswordModifyResponseContainer>(
                 PasswordModifyResponseStatesEnum.PASSWORD_MODIFY_RESPONSE_SEQUENCE_STATE,
                 PasswordModifyResponseStatesEnum.GEN_PASSWORD_STATE,
                 PasswordModifyResponseConstants.GEN_PASSWORD_TAG,
                 new GrammarAction<PasswordModifyResponseContainer>( "Set PasswordModifyResponse user identity" )
                 {
                     public void action( PasswordModifyResponseContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         byte[] genPassword = value.getData();
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "GenPassword = " + Strings.dumpBytes( genPassword ) );
                         }
 
                         if ( genPassword == null )
                         {
                             genPassword = Strings.EMPTY_BYTES;
                         }
 
                         ( ( PasswordModifyResponseDecorator ) container.getPwdModifyResponse() )
                             .setGenPassword( genPassword );
 
                         // We may have nothing left
                         container.setGrammarEndAllowed( true );
                     }
                 } );
     }
 
 
     /**
      * This class is a singleton.
      * 
      * @return An instance on this grammar
      */
     public static Grammar<PasswordModifyResponseContainer> getInstance()
     {
         return instance;
     }
 }