/*
    *  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.protocol;
  
  
  import java.io.UnsupportedEncodingException;
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  import java.nio.ByteBuffer;
  
  import javax.security.auth.kerberos.KerberosPrincipal;
  
  import org.apache.directory.server.i18n.I18n;
  import org.apache.directory.server.kerberos.changepwd.ChangePasswordServer;
  import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswdErrorType;
  import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswordException;
  import org.apache.directory.server.kerberos.changepwd.messages.ChangePasswordError;
  import org.apache.directory.server.kerberos.changepwd.messages.ChangePasswordRequest;
  import org.apache.directory.server.kerberos.changepwd.service.ChangePasswordContext;
  import org.apache.directory.server.kerberos.changepwd.service.ChangePasswordService;
  import org.apache.directory.server.kerberos.shared.store.PrincipalStore;
  import org.apache.directory.shared.kerberos.KerberosTime;
  import org.apache.directory.shared.kerberos.components.PrincipalName;
  import org.apache.directory.shared.kerberos.exceptions.ErrorType;
  import org.apache.directory.shared.kerberos.exceptions.KerberosException;
  import org.apache.directory.shared.kerberos.messages.KrbError;
  import org.apache.mina.core.service.IoHandlerAdapter;
  import org.apache.mina.core.session.IdleStatus;
  import org.apache.mina.core.session.IoSession;
  import org.apache.mina.filter.codec.ProtocolCodecFilter;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ChangePasswordProtocolHandler extends IoHandlerAdapter
  {
      private static final Logger LOG = LoggerFactory.getLogger( ChangePasswordProtocolHandler.class );
  
      private ChangePasswordServer server;
      private PrincipalStore store;
      private String contextKey = "context";
  
  
      /**
       * Creates a new instance of ChangePasswordProtocolHandler.
       *
       * @param config The ChangePassword server configuration
       * @param store The Principal store
       */
      public ChangePasswordProtocolHandler( ChangePasswordServer config, PrincipalStore store )
      {
          this.server = config;
          this.store = store;
      }
  
  
      @Override
      public void sessionCreated( IoSession session ) throws Exception
      {
          if ( LOG.isDebugEnabled() )
          {
              LOG.debug( "{} CREATED:  {}", session.getRemoteAddress(), session.getTransportMetadata() );
          }
  
          session.getFilterChain().addFirst( "codec",
              new ProtocolCodecFilter( ChangePasswordProtocolCodecFactory.getInstance() ) );
      }
  
  
      @Override
      public void sessionOpened( IoSession session )
      {
          LOG.debug( "{} OPENED", session.getRemoteAddress() );
      }
  
  
      @Override
      public void sessionClosed( IoSession session )
     {
         LOG.debug( "{} CLOSED", session.getRemoteAddress() );
     }
 
 
     @Override
     public void sessionIdle( IoSession session, IdleStatus status )
     {
         LOG.debug( "{} IDLE ({})", session.getRemoteAddress(), status );
     }
 
 
     @Override
     public void exceptionCaught( IoSession session, Throwable cause )
     {
         LOG.debug( session.getRemoteAddress() + " EXCEPTION", cause );
         session.closeNow();
     }
 
 
     @Override
     public void messageReceived( IoSession session, Object message )
     {
         LOG.debug( "{} RCVD:  {}", session.getRemoteAddress(), message );
 
         InetAddress clientAddress = ( ( InetSocketAddress ) session.getRemoteAddress() ).getAddress();
         ChangePasswordRequest/../org/apache/directory/server/kerberos/changepwd/messages/ChangePasswordRequest.html#ChangePasswordRequest">ChangePasswordRequest request = ( ChangePasswordRequest ) message;
 
         try
         {
             ChangePasswordContextpwd/service/ChangePasswordContext.html#ChangePasswordContext">ChangePasswordContext changepwContext = new ChangePasswordContext();
             changepwContext.setConfig( server.getConfig() );
             changepwContext.setStore( store );
             changepwContext.setClientAddress( clientAddress );
             changepwContext.setRequest( request );
             changepwContext.setReplayCache( server.getReplayCache() );
             session.setAttribute( getContextKey(), changepwContext );
 
             ChangePasswordService.execute( session, changepwContext );
 
             session.write( changepwContext.getReply() );
         }
         catch ( KerberosException ke )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.warn( ke.getLocalizedMessage(), ke );
             }
             else
             {
                 LOG.warn( ke.getLocalizedMessage() );
             }
 
             KrbError errorMessage = getErrorMessage( server.getConfig().getServicePrincipal(), ke );
 
             session.write( new ChangePasswordError( request.getVersionNumber(), errorMessage ) );
         }
         catch ( Exception e )
         {
             LOG.error( I18n.err( I18n.ERR_152, e.getLocalizedMessage() ), e );
 
             KrbError error = getErrorMessage( server.getConfig().getServicePrincipal(), new ChangePasswordException(
                 ChangePasswdErrorType.KRB5_KPASSWD_UNKNOWN_ERROR ) );
             session.write( new ChangePasswordError( request.getVersionNumber(), error ) );
         }
     }
 
 
     @Override
     public void messageSent( IoSession session, Object message )
     {
         if ( LOG.isDebugEnabled() )
         {
             LOG.debug( "{} SENT:  {}", session.getRemoteAddress(), message );
         }
     }
 
 
     protected String getContextKey()
     {
         return ( this.contextKey );
     }
 
 
     private KrbError getErrorMessage( KerberosPrincipal principal, KerberosException exception )
     {
         KrbErrorared/kerberos/messages/KrbError.html#KrbError">KrbError krbError = new KrbError();
 
         KerberosTimehared/kerberos/KerberosTime.html#KerberosTime">KerberosTime now = new KerberosTime();
 
         //FIXME not sure if this is the correct error to set for KrbError instance
         // the correct change password protocol related error code is set in e-data anyway
         krbError.setErrorCode( ErrorType.KRB_ERR_GENERIC );
         krbError.setEText( exception.getLocalizedMessage() );
         krbError.setSName( new PrincipalName( principal ) );
         krbError.setSTime( now );
         krbError.setSusec( 0 );
         krbError.setRealm( principal.getRealm() );
         krbError.setEData( buildExplanatoryData( exception ) );
 
         return krbError;
     }
 
 
     private byte[] buildExplanatoryData( KerberosException exception )
     {
         short resultCode = ( short ) exception.getErrorCode();
 
         byte[] resultString =
             { ( byte ) 0x00 };
 
         if ( exception.getExplanatoryData() == null || exception.getExplanatoryData().length == 0 )
         {
             try
             {
                 resultString = exception.getLocalizedMessage().getBytes( "UTF-8" );
             }
             catch ( UnsupportedEncodingException uee )
             {
                 LOG.error( uee.getLocalizedMessage() );
             }
         }
         else
         {
             resultString = exception.getExplanatoryData();
         }
 
         ByteBuffer byteBuffer = ByteBuffer.allocate( 2 + resultString.length );
         byteBuffer.putShort( resultCode );
         byteBuffer.put( resultString );
 
         return byteBuffer.array();
     }
 
     
     @Override
     public void inputClosed( IoSession session )
     {
     }
 }