/*
    *  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.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  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.server.i18n.I18n;
  import org.apache.directory.shared.kerberos.KerberosConstants;
  import org.apache.directory.shared.kerberos.KerberosMessageType;
  import org.apache.directory.shared.kerberos.messages.KerberosMessage;
  
  
  /**
   * The KDC-REQ data structure. It will store the object described by the ASN.1 grammar :
   * <pre>
   * KDC-REQ    ::= SEQUENCE {
   *      -- NOTE: first tag is [1], not [0]
   *      pvno            [1] INTEGER (5) ,
   *      msg-type        [2] INTEGER (10 -- AS -- | 12 -- TGS --),
   *      padata          [3] SEQUENCE OF &lt;PA-DATA&gt; OPTIONAL
                              -- NOTE: not empty --,
   *      req-body        [4] &lt;KDC-REQ-BODY&gt;
   * }
   * </pre>
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public abstract class KdcReq extends KerberosMessage
  {
      /** The PA-DATAs */
      private List<PaData> paData;
  
      /** The KDC-REQ-BODY */
      private KdcReqBody kdcReqBody;
  
      // Storage for computed lengths
      private int pvnoLength;
      private int msgTypeLength;
      private int paDataLength;
      private int paDataSeqLength;
      private int[] paDataLengths;
      private int kdcReqBodyLength;
      private int kdcReqSeqLength;
      private int kdcReqLength;
  
  
      /**
       * Creates a new instance of KDC-REQ.
       */
      public KdcReq( KerberosMessageType msgType )
      {
          super( msgType );
          paData = new ArrayList<>();
      }
  
  
      /**
       * @return the pvno
       */
      public int getPvno()
      {
          return getProtocolVersionNumber();
      }
  
  
      /**
       * @param pvno the pvno to set
       */
      public void setPvno( int pvno )
      {
          setProtocolVersionNumber( pvno );
      }
  
  
      /**
       * @return the paData
      */
     public List<PaData> getPaData()
     {
         return paData;
     }
 
 
     /**
      * @param paData the paData to set
      */
     public void addPaData( PaData paData )
     {
         this.paData.add( paData );
     }
 
 
     /**
      * @return the kdcReqBody
      */
     public KdcReqBody getKdcReqBody()
     {
         return kdcReqBody;
     }
 
 
     /**
      * @param kdcReqBody the kdcReqBody to set
      */
     public void setKdcReqBody( KdcReqBody kdcReqBody )
     {
         this.kdcReqBody = kdcReqBody;
     }
 
 
     /**
      * Compute the KDC-REQ length
      * <pre>
      * KDC-REQ :
      * 
      * 0x30 L1 KDC-REQ sequence
      *  |
      *  +--&gt; 0xA1 0x03 pvno tag
      *  |     |
      *  |     +--&gt; 0x02 0x01 0x05 pvno (5)
      *  |
      *  +--&gt; 0xA2 0x03 msg-type tag
      *  |     |
      *  |     +--&gt; 0x02 0x01 0x0A/0x0C msg-type : either AS-REQ (0x0A) or TGS-REQ (0x0C)
      *  |     
      *  +--&gt; 0xA3 L2 pa-data tag
      *  |     |
      *  |     +--&gt; 0x30 L2-1 pa-data SEQ
      *  |           |
      *  |           +--&gt; 0x30 L2-1-1 pa-data
      *  |           |
      *  |           +--&gt; 0x30 L2-1-2 pa-data
      *  |           :
      *  |     
      *  +--&gt; 0xA4 L3 req-body tag
      *  |     |
      *  |     +--&gt; 0x30 L3-1 req-body (KDC-REQ-BODY)
      * </pre>       
      */
     public int computeLength()
     {
         // The pvno length
         pvnoLength = 1 + 1 + 1;
         kdcReqSeqLength = 1 + TLV.getNbBytes( pvnoLength ) + pvnoLength;
 
         // The msg-type length
         msgTypeLength = 1 + 1 + 1;
         kdcReqSeqLength += 1 + TLV.getNbBytes( msgTypeLength ) + msgTypeLength;
 
         // Compute the pa-data length.
         if ( !paData.isEmpty() )
         {
             paDataLengths = new int[paData.size()];
             int pos = 0;
             paDataSeqLength = 0;
 
             for ( PaData paDataElem : paData )
             {
                 paDataLengths[pos] = paDataElem.computeLength();
                 paDataSeqLength += paDataLengths[pos];
                 pos++;
             }
 
             paDataLength = 1 + TLV.getNbBytes( paDataSeqLength ) + paDataSeqLength;
             kdcReqSeqLength += 1 + TLV.getNbBytes( paDataLength ) + paDataLength;
         }
 
         // The KDC-REQ-BODY length
         kdcReqBodyLength = kdcReqBody.computeLength();
         kdcReqSeqLength += 1 + TLV.getNbBytes( kdcReqBodyLength ) + kdcReqBodyLength;
 
         // compute the global size
         kdcReqLength = 1 + TLV.getNbBytes( kdcReqSeqLength ) + kdcReqSeqLength;
 
         return kdcReqLength;
     }
 
 
     /**
      * Encode the KDC-REQ component
      * 
      * @param buffer The buffer containing the encoded result
      * @return The encoded component
      * @throws EncoderException If the encoding failed
      */
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_148 ) );
         }
 
         // The KDC-REQ SEQ Tag
         buffer.put( UniversalTag.SEQUENCE.getValue() );
         buffer.put( TLV.getBytes( kdcReqSeqLength ) );
 
         // The PVNO -----------------------------------------------------------
         // The tag
         buffer.put( ( byte ) KerberosConstants.KDC_REQ_PVNO_TAG );
         buffer.put( TLV.getBytes( pvnoLength ) );
 
         // The value
         BerValue.encode( buffer, getProtocolVersionNumber() );
 
         // The msg-type if any ------------------------------------------------
         // The tag
         buffer.put( ( byte ) KerberosConstants.KDC_REQ_MSG_TYPE_TAG );
         buffer.put( TLV.getBytes( msgTypeLength ) );
 
         // The value
         BerValue.encode( buffer, getMessageType().getValue() );
 
         // The PD-DATA if any -------------------------------------------------
         if ( !paData.isEmpty() )
         {
             // The tag
             buffer.put( ( byte ) KerberosConstants.KDC_REQ_PA_DATA_TAG );
             buffer.put( TLV.getBytes( paDataLength ) );
 
             // The sequence
             buffer.put( UniversalTag.SEQUENCE.getValue() );
             buffer.put( TLV.getBytes( paDataSeqLength ) );
 
             // The values
             for ( PaData paDataElem : paData )
             {
                 paDataElem.encode( buffer );
             }
         }
 
         // The KDC-REQ-BODY ---------------------------------------------------
         // The tag
         buffer.put( ( byte ) KerberosConstants.KDC_REQ_KDC_REQ_BODY_TAG );
         buffer.put( TLV.getBytes( kdcReqBodyLength ) );
 
         // The value
         kdcReqBody.encode( buffer );
 
         return buffer;
     }
 
 
     /**
      * Pretty print the instance
      */
     public String toString( String tabs )
     {
         StringBuilder sb = new StringBuilder();
 
         sb.append( tabs ).append(
             "\n>-------------------------------------------------------------------------------\n" );
         if ( getMessageType() == KerberosMessageType.AS_REQ )
         {
             sb.append( tabs ).append( "AS-REQ" ).append( '\n' );
         }
         else if ( getMessageType() == KerberosMessageType.TGS_REQ )
         {
             sb.append( tabs ).append( "TGS-REQ" ).append( '\n' );
         }
         else
         {
             sb.append( tabs ).append( "Unknown" ).append( '\n' );
         }
 
         sb.append( tabs ).append( "pvno : " ).append( getProtocolVersionNumber() ).append( '\n' );
 
         sb.append( tabs ).append( "msg-type : " ).append( getMessageType() ).append( "\n" );
 
         for ( PaData paDataElem : paData )
         {
             sb.append( tabs ).append( "padata :\n" );
             sb.append( paDataElem.toString( tabs + "    " ) ).append( '\n' );
         }
 
         sb.append( tabs ).append( "kdc-req-body : \n" );
         sb.append( kdcReqBody.toString( tabs + "    " ) ).append( '\n' );
         sb.append( tabs ).append( "\n-------------------------------------------------------------------------------<\n" );
 
         return sb.toString();
     }
 
 
     /**
      * @see Object#toString()
      */
     public String toString()
     {
         return toString( "" );
     }
 }