/*
    *  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.shared.kerberos.components;
  
  
  import java.nio.BufferOverflowException;
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.Asn1Object;
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.ber.tlv.BerValue;
  import org.apache.directory.api.asn1.ber.tlv.TLV;
  import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
  import org.apache.directory.api.util.Strings;
  import org.apache.directory.server.i18n.I18n;
  import org.apache.directory.shared.kerberos.KerberosConstants;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * The AdAndOr structure is used to store a AD-AND-OR associated to a type.
   * 
   * The ASN.1 grammar is :
   * <pre>
   * AD-AND-OR               ::= SEQUENCE {
   *         condition-count [0] Int32,
   *         elements        [1] &lt;AuthorizationData&gt;
   * }
   * </pre>
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class AdAndOr implements Asn1Object
  {
      /** The logger */
      private static final Logger LOG = LoggerFactory.getLogger( AdAndOr.class );
  
      /** Speedup for logs */
      private static final boolean IS_DEBUG = LOG.isDebugEnabled();
  
      /** The condition-count */
      private int conditionCount;
  
      /** The elements */
      private AuthorizationData elements;
  
      // Storage for computed lengths
      private int conditionCountTagLength;
      private int elementsTagLength;
      private int adAndOrSeqLength;
  
  
      /**
       * Creates a new instance of AdAndOr
       */
      public AdAndOr()
      {
      }
  
  
      /**
       * @return the conditionCount
       */
      public int getConditionCount()
      {
          return conditionCount;
      }
  
  
      /**
       * @param conditionCount the conditionCount to set
       */
      public void setConditionCount( int conditionCount )
      {
          this.conditionCount = conditionCount;
      }
  
  
      /**
       * @return the elements
       */
      public AuthorizationData getElements()
     {
         return elements;
     }
 
 
     /**
      * @param elements the elements to set
      */
     public void setElements( AuthorizationData elements )
     {
         this.elements = elements;
     }
 
 
     /**
      * Compute the AD-AND-OR length
      * <pre>
      * 0x30 L1 AD-AND-OR sequence
      *  |
      *  +--&gt; 0xA1 L2 condition count tag
      *  |     |
      *  |     +--&gt; 0x02 L2-1 condition count (int)
      *  |
      *  +--&gt; 0xA2 L3 elements tag
      *        |
      *        +--&gt; 0x30 L3-1 elements (AuthorizationData)
      * </pre>
      */
     @Override
     public int computeLength()
     {
         // Compute the condition count length
         int conditionCountLength = BerValue.getNbBytes( conditionCount );
         conditionCountTagLength = 1 + TLV.getNbBytes( conditionCountLength ) + conditionCountLength;
         adAndOrSeqLength = 1 + TLV.getNbBytes( conditionCountTagLength ) + conditionCountTagLength;
 
         // Compute the elements length
         elementsTagLength = elements.computeLength();
         adAndOrSeqLength += 1 + TLV.getNbBytes( elementsTagLength ) + elementsTagLength;
 
         // Compute the whole sequence length
         return 1 + TLV.getNbBytes( adAndOrSeqLength ) + adAndOrSeqLength;
     }
 
 
     /**
      * Encode the AD-AND-OR message to a PDU.
      * 
      * @param buffer The buffer where to put the PDU. It should have been allocated
      * before, with the right size.
      * @return The constructed PDU.
      */
     @Override
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_148 ) );
         }
 
         try
         {
             // The AD-AND-OR SEQ OF Tag
             buffer.put( UniversalTag.SEQUENCE.getValue() );
             buffer.put( TLV.getBytes( adAndOrSeqLength ) );
 
             // the condition-count
             buffer.put( ( byte ) KerberosConstants.AD_AND_OR_CONDITION_COUNT_TAG );
             buffer.put( ( byte ) conditionCountTagLength );
             BerValue.encode( buffer, conditionCount );
 
             // the elements
             buffer.put( ( byte ) KerberosConstants.AD_AND_OR_ELEMENTS_TAG );
             buffer.put( ( byte ) elementsTagLength );
 
             elements.encode( buffer );
         }
         catch ( BufferOverflowException boe )
         {
             LOG.error( I18n.err( I18n.ERR_139, 1 + TLV.getNbBytes( adAndOrSeqLength )
                 + adAndOrSeqLength, buffer.capacity() ) );
             throw new EncoderException( I18n.err( I18n.ERR_138 ), boe );
         }
 
         if ( IS_DEBUG )
         {
             LOG.debug( "AD-AND-OR encoding : {}", Strings.dumpBytes( buffer.array() ) );
             LOG.debug( "AD-AND-OR initial value : {}", this );
         }
 
         return buffer;
     }
 
 
     /**
      * @see Object#toString()
      */
     public String toString()
     {
         return toString( "" );
     }
 
 
     /**
      * @see Object#toString()
      */
     public String toString( String tabs )
     {
         StringBuilder sb = new StringBuilder();
 
         sb.append( tabs ).append( "AD-AND-OR : {\n" );
         sb.append( tabs ).append( "    condition-count: " ).append( conditionCount ).append( '\n' );
         sb.append( tabs + "    elements:" ).append( elements ).append( '\n' );
         sb.append( tabs + "}\n" );
 
         return sb.toString();
     }
 }