/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2006 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  package ch.elca.el4j.services.remoting.protocol.jaxws;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  import java.util.TreeSet;
  
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.JAXBElement;
  import javax.xml.bind.JAXBException;
  import javax.xml.bind.Marshaller;
  import javax.xml.bind.PropertyException;
  import javax.xml.bind.Unmarshaller;
  import javax.xml.namespace.QName;
  import javax.xml.soap.SOAPHeaderElement;
  import javax.xml.soap.SOAPMessage;
  import javax.xml.ws.handler.MessageContext;
  import javax.xml.ws.handler.soap.SOAPMessageContext;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  
  import com.sun.xml.ws.util.xml.NodeListIterator;
  
  import ch.elca.el4j.core.contextpassing.ImplicitContextPassingRegistry;
  
  /**
   * This class is a JAX-WS Handler that injects the implicit context while
   * sending a SOAP message and extract it while retrieving one.
   *
   * @svnLink $Revision: 4077 $;$Date: 2010-01-06 16:18:36 +0100 (Mi, 06. Jan 2010) $;$Author: swisswheel $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/remoting_jaxws/src/main/java/ch/elca/el4j/services/remoting/protocol/jaxws/JaxwsContextHandler.java $
   *
   * @author Stefan Wismer (SWI)
   */
  public class JaxwsContextHandler extends AbstractJaxwsJaxbContextHandler {
  	/**
  	 * Private logger.
  	 */
  	private static Logger s_logger = LoggerFactory.getLogger(JaxwsContextHandler.class);
  	
  	/**
  	 * The registry to get the context from.
  	 */
  	private ImplicitContextPassingRegistry m_contextPassingRegistry;
  	
  	
  	/**
  	 * Create a new JAX-WS Handler to modify a soap message.
  	 *
  	 * @param registry The registry to take the context from
  	 * @param jaxbContext The context to serialize the implicit context with
  	 */
  	public JaxwsContextHandler(ImplicitContextPassingRegistry registry,
  		JAXBContext jaxbContext) {
  		super(jaxbContext);
  		m_contextPassingRegistry = registry;
  	}
  
  	/** {@inheritDoc} */
  	public boolean handleMessage(SOAPMessageContext context) {
  		Boolean outboundProperty = (Boolean) context
  			.get(MessageContext.MESSAGE_OUTBOUND_PROPERTY);
  
  		if (m_contextPassingRegistry != null) {
  			SOAPMessage msg = context.getMessage();
  			if (outboundProperty.booleanValue()) {
  				handleOutgoingMessage(msg);
  			} else {
  				handleIncomingMessage(msg);
  			}
  		}
  		return true;
  	}
  
  	/**
  	 * Handles an incoming SOAP message.
  	 * Adds the implicit context to the SOAP header.
  	 *
  	 * @param msg    the SOAP message
  	 */
  	@SuppressWarnings("unchecked")
 	protected void handleIncomingMessage(SOAPMessage msg) {
 		Node contextElement = null;
 		try {
 			if (msg.getSOAPHeader() != null) {
 				NodeList list = msg.getSOAPHeader()
 					.getElementsByTagNameNS(CONTEXT_NAMESPACE.getURI(),
 						CONTEXT_ELEMENT_NAME);
 				if (list.getLength() > 0) {
 					contextElement = (Node) list.item(0);
 				}
 			}
 		} catch (Exception e) {
 			s_logger.error("Error getting SOAP header.");
 			return;
 		}
 
 		if (contextElement != null) {
 			Unmarshaller unmarshaller = getUnmarshaller();
 
 			Map<String, Object> map = new HashMap<String, Object>();
 			NodeList nodeList = contextElement.getChildNodes();
 			NodeListIterator it = new NodeListIterator(nodeList);
 
 			while (it.hasNext()) {
 				Node soapNode = (Node) it.next();
 
 				try {
 					// Try to get the passed Object out of the xml
 					JAXBElement element = (JAXBElement) unmarshaller
 						.unmarshal(soapNode);
 
 					map.put(soapNode.getNodeName(), element.getValue());
 				} catch (JAXBException e) {
 					s_logger.error("Unable to unmarshall context element "
 						+ soapNode.getNodeName());
 				}
 			}
 			m_contextPassingRegistry.pushAssembledImplicitContext(map);
 		}
 	}
 
 	/**
 	 * Handles an outgoing SOAP message.
 	 * Extracts the implicit context from the SOAP header.
 	 *
 	 * @param msg    the SOAP message
 	 */
 	@SuppressWarnings("unchecked")
 	protected void handleOutgoingMessage(SOAPMessage msg) {
 		SOAPHeaderElement newElement = null;
 
 		try {
 			if (msg.getSOAPHeader() == null) {
 				// create header
 				msg.getSOAPPart().getEnvelope().addHeader();
 			}
 			newElement = msg.getSOAPHeader().addHeaderElement(
 				new QName(CONTEXT_NAMESPACE.getURI(),
 					CONTEXT_ELEMENT_NAME));
 		} catch (Exception e) {
 			s_logger.error("Error creating SOAP header.");
 			return;
 		}
 
 		Marshaller marshaller = getMarshaller();
 		try {
 			marshaller.setProperty(Marshaller.JAXB_FRAGMENT,
 				Boolean.TRUE);
 		} catch (PropertyException e) {
 			s_logger.error("Error setting marshaller properties.");
 			return;
 		}
 
 		Map assembledContext = m_contextPassingRegistry
 			.getAssembledImplicitContext();
 		Set<String> keys = (Set<String>) assembledContext.keySet();
 		for (String key : keys) {
 			try {
 				Object value = assembledContext.get(key);
 				marshaller.marshal(new JAXBElement(new QName("", key),
 					Object.class, value), newElement);
 			} catch (JAXBException e) {
 				s_logger.error("Unable to marshal context for " + key);
 			}
 		}
 	}
 
 	/** {@inheritDoc} */
 	public boolean handleFault(SOAPMessageContext context) {
 		return true;
 	}
 
 	/** {@inheritDoc} */
 	@SuppressWarnings("unchecked")
 	public Set getHeaders() {
 		return new TreeSet();
 	}
 
 	/** {@inheritDoc} */
 	public void close(MessageContext context) { }
 
 
 	/** {@inheritDoc} */
 	@Override
 	protected Logger getLogger() {
 		return s_logger;
 	}
 }