/*
    *  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.server.kerberos.changepwd.messages;
  
  
  import java.nio.ByteBuffer;
  
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswdErrorType;
  import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswordException;
  import org.apache.directory.shared.kerberos.codec.KerberosDecoder;
  import org.apache.directory.shared.kerberos.exceptions.KerberosException;
  import org.apache.directory.shared.kerberos.messages.ApReq;
  import org.apache.directory.shared.kerberos.messages.KrbPriv;
  
  
  /**
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ChangePasswordRequest extends AbstractPasswordMessage
  {
      private ApReq authHeader;
      private KrbPriv privateMessage;
  
      private short authHeaderLen;
      private short privateMessageLen;
      private short messageLength;
  
  
      public ChangePasswordRequest( ApReq authHeader, KrbPriv privateMessage )
      {
          this( PVNO, authHeader, privateMessage );
      }
  
  
      /**
       * Creates a new instance of ChangePasswordRequest.
       *
       * @param versionNumber The version number
       * @param authHeader The authentication header
       * @param privateMessage The private part
       */
      public ChangePasswordRequest( short versionNumber, ApReq authHeader, KrbPriv privateMessage )
      {
          super( versionNumber );
  
          this.authHeader = authHeader;
          this.privateMessage = privateMessage;
      }
  
  
      /**
       * Returns the {@link ApReq}.
       *
       * @return The {@link ApReq}.
       */
      public ApReq getAuthHeader()
      {
          return authHeader;
      }
  
  
      /**
       * Returns the {@link KrbPriv}.
       *
       * @return The {@link KrbPriv}.
       */
      public KrbPriv getPrivateMessage()
      {
          return privateMessage;
      }
  
  
      @Override
      public short computeLength()
      {
          authHeaderLen = ( short ) authHeader.computeLength();
          privateMessageLen = ( short ) privateMessage.computeLength();
  
          messageLength = ( short ) ( HEADER_LENGTH + authHeaderLen + privateMessageLen );
  
          return messageLength;
     }
 
 
     @Override
     public ByteBuffer encode( ByteBuffer buf ) throws EncoderException
     {
         buf.putShort( messageLength );
         buf.putShort( getVersionNumber() );
 
         // Build application request bytes
         buf.putShort( authHeaderLen );
         authHeader.encode( buf );
 
         privateMessage.encode( buf );
 
         return buf;
     }
 
 
     /**
      * Decodes a {@link ByteBuffer} into a {@link ChangePasswordRequest}.
      *
      * @param buf
      * @return The {@link ChangePasswordRequest}.
      * @throws ChangePasswordException If the decoding failed
      */
     public static ChangePasswordRequest decode( ByteBuffer buf ) throws ChangePasswordException
     {
         try
         {
             buf.getShort(); // message length
 
             short pvno = buf.getShort();
 
             short authHeaderLength = buf.getShort();
 
             byte[] undecodedAuthHeader = new byte[authHeaderLength];
             buf.get( undecodedAuthHeader, 0, authHeaderLength );
 
             ApReq authHeader = KerberosDecoder.decodeApReq( undecodedAuthHeader );
 
             byte[] encodedPrivate = new byte[buf.remaining()];
             buf.get( encodedPrivate, 0, buf.remaining() );
 
             KrbPriv privMessage = KerberosDecoder.decodeKrbPriv( encodedPrivate );
 
             return new ChangePasswordRequest( pvno, authHeader, privMessage );
         }
         catch ( KerberosException e )
         {
             throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_MALFORMED, e );
         }
     }
 
 }