/*
    ~ Copyright 2006-2007 Nicolas De Loof.
    ~
    ~ Licensed 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.jmonit.support.jaxrpc;
  
  import java.util.Iterator;
  
  import javax.xml.namespace.QName;
  import javax.xml.rpc.Call;
  import javax.xml.rpc.handler.GenericHandler;
  import javax.xml.rpc.handler.MessageContext;
  import javax.xml.rpc.handler.soap.SOAPMessageContext;
  import javax.xml.soap.AttachmentPart;
  import javax.xml.soap.SOAPException;
  import javax.xml.soap.SOAPMessage;
  
  import org.jmonit.Monitoring;
  import org.jmonit.Probe;
  import org.jmonit.log.Log;
  
  /**
   * Axis handler to monitor Time for SAOP invocation. Three jMonit domains are
   * used for Axis SOAP monitoring :
   * <ul>
   * <li><b>axis</b> for timing.</li>
   * <li><b>axis.sent</b> for bytes sent.</li>
   * <li><b>axis.received</b> for bytes received.</li>
   * </ul>
   * <p>
   * You have to configure your Axis client by including in the client-config.wsdd
   * file (Axis client configuration file):
   * 
   * <pre>
   *      &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
   *      &lt;deployment xmlns=&quot;http://xml.apache.org/axis/wsdd/&quot;
   *      xmlns:java=&quot;http://xml.apache.org/axis/wsdd/providers/java&quot;&gt;
   * 
   *        &lt;handler name=&quot;jmonit&quot; type=&quot;java:info.jmonit.support.soap.AxisMonitoringHandler&quot;&gt;
   *          &lt;parameter name=&quot;domain&quot; value=&quot;soap.axis&quot;/&gt;
   *          &lt;parameter name=&quot;requestDomain&quot; value=&quot;soap.axis.request&quot;/&gt;
   *          &lt;parameter name=&quot;responseDomain&quot; value=&quot;soap.axis.response&quot;/&gt;
   *        &lt;/handler&gt;
   * 
   *        &lt;transport name=&quot;http&quot;
   *        pivot=&quot;java:org.apache.axis.transport.http.HTTPSender&quot;&gt;
   *          &lt;requestFlow&gt;
   *            &lt;handler type=&quot;jmonit&quot;/&gt;
   *          &lt;/requestFlow&gt;
   *          &lt;responseFlow&gt;
   *            &lt;handler type=&quot;jmonit&quot;/&gt;
   *          &lt;/responseFlow&gt;
   *        &lt;/transport&gt;
   * 
   *      &lt;/deployment&gt;
   * </pre>
   * 
   * Handler parameter can be used to override default domains. This can be
   * usefull if you are both using Axis as Web service client and as server-side
   * SOAP stack, where request/response have inverted roles.
   * 
   * @author <a href="mailto:ndeloof@sourceforge.net">Nicolas De Loof</a>
   */
  public class JaxRpcMonitoringHandler
      extends GenericHandler
  {
      private static final String PROBE = Probe.class.getName();
  
      /** Logger */
      private static Log log = Log.getLog( JaxRpcMonitoringHandler.class );
  
      public boolean handleRequest( MessageContext context )
      {
          Probe probe = Monitoring.start( getAction( context ) );
          context.setProperty( PROBE, probe );
          return true;
      };
  
      public boolean handleResponse( MessageContext context )
      {
          stopMonitoring( context, true );
          return true;
      };
  
      public boolean handleFault( MessageContext context )
      {
          stopMonitoring( context, false );
          return true;
     };
 
     /**
      * Extract the Action from the message, either by getting the Jax-rpc
      * header, or by getting the SOAP message first element.
      * <p>
      * TODO : Does this work for any SOAP message ?
      * 
      * @param context Jax-rpc context
      * @return soapAction of the SOAP message
      */
     protected String getAction( MessageContext context )
     {
         String soapAction = (String) context.getProperty( Call.SOAPACTION_URI_PROPERTY );
         if ( soapAction == null && context instanceof SOAPMessageContext )
         {
             SOAPMessageContext soapContext = (SOAPMessageContext) context;
             SOAPMessage message = soapContext.getMessage();
             try
             {
                 soapAction = message.getSOAPBody().getFirstChild().getNodeName();
             }
             catch ( Exception e )
             {
                 // ignored
             }
         }
 
         if ( soapAction == null )
         {
             log.warn( "Failed to extract the SOAP action" );
             soapAction = "unknown";
         }
 
         // Experiment on Axis shows "ns1:" namespace is set on response, and not
         // set on request, so remove any namespace prefix
         int i = soapAction.indexOf( ':' );
         if ( i >= 0 )
         {
             soapAction = soapAction.substring( i + 1 );
         }
 
         return soapAction;
     }
 
     /**
      * End monitoring for a SOAP invocation.
      * <p>
      * Stops the running probe and add messages weight to request/response bytes
      * monitors.
      * 
      * @param msgContext Axis message context
      */
     protected void stopMonitoring( MessageContext context, boolean success )
     {
         Probe probe = (Probe) context.getProperty( PROBE );
         if ( !success )
         {
             Monitoring.add( getAction( context ) + ".faults", probe.getElapsedTime() );
         }
         probe.stop( success );
         context.removeProperty( PROBE );
 
         if ( context instanceof SOAPMessageContext )
         {
             SOAPMessageContext soapContext = (SOAPMessageContext) context;
             SOAPMessage message = soapContext.getMessage();
             try
             {
                 long size = 0;
                 for ( Iterator iterator = message.getAttachments(); iterator.hasNext(); )
                 {
                     AttachmentPart attachment = (AttachmentPart) iterator.next();
                     size += attachment.getSize();
                 }
                 size += 0; // FIXME : HOW to get the SOAP message weight
             }
             catch ( SOAPException e )
             {
                 // Failed to compute SOAP message weight
             }
         }
     }
 
     /**
      * {@inheritDoc}
      * 
      * @see javax.xml.rpc.handler.GenericHandler#getHeaders()
      */
     public QName[] getHeaders()
     {
         return new QName[0];
     }
 }