/*
    *  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.certGeneration;
  
  
  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.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.LdapApiServiceFactory;
  import org.apache.directory.api.ldap.extras.extended.certGeneration.CertGenerationRequestImpl;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * This class implements the Certificate generation 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>
   *   CertGenerateObject ::= SEQUENCE 
   *   {
   *      targetDN        IA5String,
   *      issuerDN        IA5String,
   *      subjectDN       IA5String,
   *      keyAlgorithm    IA5String
   *   }
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  
  public class CertGenerationGrammar extends AbstractGrammar<CertGenerationContainer>
  {
  
      /** logger */
      private static final Logger LOG = LoggerFactory.getLogger( CertGenerationGrammar.class );
  
      /** Speedup for logs */
      static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      /** The instance of grammar. CertGenerationObjectGrammar is a singleton */
      private static Grammar<CertGenerationContainer> instance = new CertGenerationGrammar();
  
  
      @SuppressWarnings("unchecked")
      public CertGenerationGrammar()
      {
          setName( CertGenerationGrammar.class.getName() );
  
          // Create the transitions table
          super.transitions = new GrammarTransition[CertGenerationStatesEnum.LAST_CERT_GENERATION_STATE.ordinal()][256];
  
          /**
           * Transition from init state to certificate generation
           * 
           * CertGenerationObject ::= SEQUENCE {
           *     ...
           *     
           * Creates the CertGenerationObject object
           */
          super.transitions[CertGenerationStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
              new GrammarTransition<CertGenerationContainer>(
                  CertGenerationStatesEnum.START_STATE, CertGenerationStatesEnum.CERT_GENERATION_REQUEST_SEQUENCE_STATE,
                  UniversalTag.SEQUENCE.getValue(), new GrammarAction<CertGenerationContainer>(
                      "Init CertGenerationObject" )
                  {
                      public void action( CertGenerationContainer container )
                      {
                          CertGenerationRequestDecorator certGenerationRequest = new CertGenerationRequestDecorator(
                              LdapApiServiceFactory.getSingleton(), new CertGenerationRequestImpl() );
                          container.setCertGenerationRequest( certGenerationRequest );
                      }
                  } );
  
         /**
          * Transition from certificate generation request to targetDN
          *
          * CertGenerationObject ::= SEQUENCE { 
          *     targetDN IA5String,
          *     ...
          *     
          * Set the targetDN value into the CertGenerationObject instance.
          */
         super.transitions[CertGenerationStatesEnum.CERT_GENERATION_REQUEST_SEQUENCE_STATE.ordinal()][UniversalTag.OCTET_STRING
             .getValue()] =
             new GrammarTransition<CertGenerationContainer>(
                 CertGenerationStatesEnum.CERT_GENERATION_REQUEST_SEQUENCE_STATE,
                 CertGenerationStatesEnum.TARGETDN_STATE, UniversalTag.OCTET_STRING.getValue(),
                 new GrammarAction<CertGenerationContainer>( "Set Cert Generation target Dn value" )
                 {
                     public void action( CertGenerationContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         String targetDN = Strings.utf8ToString( value.getData() );
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "Target Dn = " + targetDN );
                         }
 
                         if ( ( targetDN != null ) && ( targetDN.trim().length() > 0 ) )
                         {
                             if ( !Dn.isValid( targetDN ) )
                             {
                                 String msg = I18n.err( I18n.ERR_04032, targetDN );
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
 
                             container.getCertGenerationRequest().setTargetDN( targetDN );
                         }
                         else
                         {
                             String msg = I18n.err( I18n.ERR_04033, Strings.dumpBytes( value.getData() ) );
                             LOG.error( msg );
                             throw new DecoderException( msg );
                         }
                     }
                 } );
 
         /**
          * Transition from targetDN state to issuerDN
          *
          * CertGenerationObject ::= SEQUENCE { 
          *     ...
          *     issuerDN IA5String,
          *     ...
          *     
          * Set the issuerDN value into the CertGenerationObject instance.
          */
         super.transitions[CertGenerationStatesEnum.TARGETDN_STATE.ordinal()][UniversalTag.OCTET_STRING.getValue()] =
             new GrammarTransition<CertGenerationContainer>( CertGenerationStatesEnum.TARGETDN_STATE,
                 CertGenerationStatesEnum.ISSUER_STATE, UniversalTag.OCTET_STRING.getValue(),
                 new GrammarAction<CertGenerationContainer>( "Set Cert Generation issuer Dn value" )
                 {
                     public void action( CertGenerationContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         String issuerDN = Strings.utf8ToString( value.getData() );
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "Issuer Dn = " + issuerDN );
                         }
 
                         if ( ( issuerDN != null ) && ( issuerDN.trim().length() > 0 ) )
                         {
                             if ( !Dn.isValid( issuerDN ) )
                             {
                                 String msg = I18n.err( I18n.ERR_04034, issuerDN );
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
 
                             container.getCertGenerationRequest().setIssuerDN( issuerDN );
                         }
                     }
                 } );
 
         /**
          * Transition from issuerDN state to subjectDN
          *
          * CertGenerationObject ::= SEQUENCE {
          *     ... 
          *     subjectDN IA5String,
          *     ...
          *     
          * Set the subjectDN value into the CertGenerationObject instance.
          */
         super.transitions[CertGenerationStatesEnum.ISSUER_STATE.ordinal()][UniversalTag.OCTET_STRING.getValue()] =
             new GrammarTransition<CertGenerationContainer>( CertGenerationStatesEnum.ISSUER_STATE,
                 CertGenerationStatesEnum.SUBJECT_STATE, UniversalTag.OCTET_STRING.getValue(),
                 new GrammarAction<CertGenerationContainer>( "Set Cert Generation subject Dn value" )
                 {
                     public void action( CertGenerationContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         String subjectDN = Strings.utf8ToString( value.getData() );
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "subject Dn = " + subjectDN );
                         }
 
                         if ( ( subjectDN != null ) && ( subjectDN.trim().length() > 0 ) )
                         {
                             if ( !Dn.isValid( subjectDN ) )
                             {
                                 String msg = I18n.err( I18n.ERR_04035, subjectDN );
                                 LOG.error( msg );
                                 throw new DecoderException( msg );
                             }
 
                             container.getCertGenerationRequest().setSubjectDN( subjectDN );
                         }
                         else
                         {
                             String msg = I18n.err( I18n.ERR_04033, Strings.dumpBytes( value.getData() ) );
                             LOG.error( msg );
                             throw new DecoderException( msg );
                         }
                     }
                 } );
 
         /**
          * Transition from subjectDN state to keyAlgo
          *
          * CertGenerationObject ::= SEQUENCE { 
          *     ...
          *     keyAlgorithm IA5String
          *     
          * Set the key algorithm value into the CertGenerationObject instance.
          */
         super.transitions[CertGenerationStatesEnum.SUBJECT_STATE.ordinal()][UniversalTag.OCTET_STRING.getValue()] =
             new GrammarTransition<CertGenerationContainer>( CertGenerationStatesEnum.SUBJECT_STATE,
                 CertGenerationStatesEnum.KEY_ALGORITHM_STATE,
                 UniversalTag.OCTET_STRING.getValue(),
                 new GrammarAction<CertGenerationContainer>( "Set Cert Generation key algorithm value" )
                 {
                     public void action( CertGenerationContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         String keyAlgorithm = Strings.utf8ToString( value.getData() );
 
                         if ( IS_DEBUG )
                         {
                             LOG.debug( "key algorithm = " + keyAlgorithm );
                         }
 
                         if ( keyAlgorithm != null && ( keyAlgorithm.trim().length() > 0 ) )
                         {
                             container.getCertGenerationRequest().setKeyAlgorithm( keyAlgorithm );
                         }
 
                         container.setGrammarEndAllowed( true );
                     }
                 } );
 
     }
 
 
     /**
      * This class is a singleton.
      * 
      * @return An instance on this grammar
      */
     public static Grammar<CertGenerationContainer> getInstance()
     {
         return instance;
     }
 }