/*
    *  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.gracefulShutdown;
  
  
  import org.apache.directory.api.asn1.DecoderException;
  import org.apache.directory.api.asn1.ber.grammar.AbstractGrammar;
  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.ldap.codec.api.LdapApiServiceFactory;
  import org.apache.directory.api.ldap.extras.extended.ads_impl.gracefulDisconnect.GracefulActionConstants;
  import org.apache.directory.api.ldap.extras.extended.gracefulShutdown.GracefulShutdownRequestImpl;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * This class implements the Graceful shutdown. All the actions are declared in
   * this class. As it is a singleton, these declaration are only done once. The
   * grammar is :
   * 
   * <pre>
   *  GracefulShutdwon ::= SEQUENCE {
   *      timeOffline INTEGER (0..720) DEFAULT 0,
   *      delay [0] INTEGER (0..86400) DEFAULT 0
   *  }
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public final class GracefulShutdownGrammar extends AbstractGrammar<GracefulShutdownContainer>
  {
      /** The logger */
      static final Logger LOG = LoggerFactory.getLogger( GracefulShutdownGrammar.class );
  
      /** Speedup for logs */
      static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      /** The instance of grammar. GracefulShutdownGrammar is a singleton */
      private static GracefulShutdownGrammar instance = new GracefulShutdownGrammar();
  
  
      /**
       * Creates a new GracefulShutdownGrammar object.
       */
      @SuppressWarnings("unchecked")
      private GracefulShutdownGrammar()
      {
          setName( GracefulShutdownGrammar.class.getName() );
  
          // Create the transitions table
          super.transitions = new GrammarTransition[GracefulShutdownStatesEnum.LAST_GRACEFUL_SHUTDOWN_STATE.ordinal()][256];
  
          /**
           * Transition from init state to graceful shutdown
           * 
           * GracefulShutdown ::= SEQUENCE {
           *     ...
           *     
           * Creates the GracefulShutdown object
           */
          super.transitions[GracefulShutdownStatesEnum.START_STATE.ordinal()][UniversalTag.SEQUENCE.getValue()] =
              new GrammarTransition<GracefulShutdownContainer>( GracefulShutdownStatesEnum.START_STATE,
                  GracefulShutdownStatesEnum.GRACEFUL_SHUTDOWN_SEQUENCE_STATE,
                  UniversalTag.SEQUENCE.getValue(),
                  new GrammarAction<GracefulShutdownContainer>( "Init GracefulShutdown" )
                  {
                      public void action( GracefulShutdownContainer container )
                      {
                          GracefulShutdownRequestDecorator gracefulShutdownRequest = new GracefulShutdownRequestDecorator(
                              LdapApiServiceFactory.getSingleton(),
                              new GracefulShutdownRequestImpl() );
                          container.setGracefulShutdownRequest( gracefulShutdownRequest );
                          container.setGrammarEndAllowed( true );
                      }
                  } );
 
         /**
          * Transition from graceful shutdown to time offline
          *
          * GracefulShutdown ::= SEQUENCE { 
          *     timeOffline INTEGER (0..720) DEFAULT 0,
          *     ...
          *     
          * Set the time offline value into the GracefulShutdown
          * object.
          */
         super.transitions[GracefulShutdownStatesEnum.GRACEFUL_SHUTDOWN_SEQUENCE_STATE.ordinal()][UniversalTag.INTEGER
             .getValue()] =
             new GrammarTransition<GracefulShutdownContainer>(
                 GracefulShutdownStatesEnum.GRACEFUL_SHUTDOWN_SEQUENCE_STATE,
                 GracefulShutdownStatesEnum.TIME_OFFLINE_STATE,
                 UniversalTag.INTEGER.getValue(),
                 new GrammarAction<GracefulShutdownContainer>( "Set Graceful Shutdown time offline" )
                 {
                     public void action( GracefulShutdownContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         try
                         {
                             int timeOffline = IntegerDecoder.parse( value, 0, 720 );
 
                             if ( IS_DEBUG )
                             {
                                 LOG.debug( "Time Offline = " + timeOffline );
                             }
 
                             container.getGracefulShutdownRequest().setTimeOffline( timeOffline );
                             container.setGrammarEndAllowed( true );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = I18n.err( I18n.ERR_04037, Strings.dumpBytes( value.getData() ) );
                             LOG.error( msg );
                             throw new DecoderException( msg, ide );
                         }
                     }
                 } );
 
         /**
          * Transition from time offline to delay
          * 
          * GracefulShutdown ::= SEQUENCE { 
          *     ... 
          *     delay [0] INTEGER (0..86400) DEFAULT 0 }
          * 
          * Set the delay value into the GracefulShutdown
          * object.
          */
         super.transitions[GracefulShutdownStatesEnum.TIME_OFFLINE_STATE.ordinal()][GracefulActionConstants.GRACEFUL_ACTION_DELAY_TAG] =
             new GrammarTransition<GracefulShutdownContainer>( GracefulShutdownStatesEnum.TIME_OFFLINE_STATE,
                 GracefulShutdownStatesEnum.DELAY_STATE,
                 GracefulActionConstants.GRACEFUL_ACTION_DELAY_TAG,
 
                 new GrammarAction<GracefulShutdownContainer>( "Set Graceful Shutdown Delay" )
                 {
                     public void action( GracefulShutdownContainer container ) throws DecoderException
                     {
                         BerValue value = container.getCurrentTLV().getValue();
 
                         try
                         {
                             int delay = IntegerDecoder.parse( value, 0, 86400 );
 
                             if ( IS_DEBUG )
                             {
                                 LOG.debug( "Delay = " + delay );
                             }
 
                             container.getGracefulShutdownRequest().setDelay( delay );
                             container.setGrammarEndAllowed( true );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = I18n.err( I18n.ERR_04036, Strings.dumpBytes( value.getData() ) );
                             LOG.error( msg );
                             throw new DecoderException( msg, ide );
                         }
                     }
                 } );
 
         /**
          * Transition from graceful shutdown to delay
          * 
          * GracefulShutdown ::= SEQUENCE { 
          *     ... 
          *     delay [0] INTEGER (0..86400) DEFAULT 0 }
          * 
          * Set the delay value into the GracefulShutdown
          * object.
          */
         super.transitions[GracefulShutdownStatesEnum.GRACEFUL_SHUTDOWN_SEQUENCE_STATE.ordinal()][GracefulActionConstants.GRACEFUL_ACTION_DELAY_TAG] =
             new GrammarTransition<GracefulShutdownContainer>(
                 GracefulShutdownStatesEnum.GRACEFUL_SHUTDOWN_SEQUENCE_STATE,
                 GracefulShutdownStatesEnum.DELAY_STATE,
                 GracefulActionConstants.GRACEFUL_ACTION_DELAY_TAG,
 
                 new GrammarAction<GracefulShutdownContainer>( "Set Graceful Shutdown Delay" )
                 {
                     public void action( GracefulShutdownContainer container ) throws DecoderException
                     {
                         GracefulShutdownContainer gracefulShutdownContainer = container;
                         BerValue value = gracefulShutdownContainer.getCurrentTLV().getValue();
 
                         try
                         {
                             int delay = IntegerDecoder.parse( value, 0, 86400 );
 
                             if ( IS_DEBUG )
                             {
                                 LOG.debug( "Delay = " + delay );
                             }
 
                             gracefulShutdownContainer.getGracefulShutdownRequest().setDelay( delay );
                             gracefulShutdownContainer.setGrammarEndAllowed( true );
                         }
                         catch ( IntegerDecoderException ide )
                         {
                             String msg = I18n.err( I18n.ERR_04036, 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 GracefulShutdownGrammar getInstance()
     {
         return instance;
     }
 }