package org.apache.savan.messagereceiver;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.StringTokenizer;

import javax.xml.namespace.QName;

import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMException;
import org.apache.axiom.soap.SOAPEnvelope;
import org.apache.axis2.AxisFault;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.context.ServiceContext;
import org.apache.axis2.engine.MessageReceiver;
import org.apache.savan.atom.AtomConstants;
import org.apache.savan.eventing.EventingConstants;
import org.apache.savan.publication.client.PublicationClient;

/**
 * This Message reciver handles the publish requests. It will received all messages sent to SOAP/WS action 
 * http://ws.apache.org/ws/2007/05/eventing-extended/Publish, or request URL http://<host>:port//services/<service-name>/publish. 
 * It will search for topic in URL query parameter "topic" or
 * Soap Header <eevt::topic xmlns="http://ws.apache.org/ws/2007/05/eventing-extended">...</topic>
 * @author Srinath Perera (hemapani@apache.org)
 */
public class PublishingMessageReceiver implements MessageReceiver{
	
	public void receive(MessageContext messageCtx) throws AxisFault {
		try {
			String toAddress = messageCtx.getTo().getAddress();
			//Here we try to locate the topic. It can be either a query parameter of the input address or a header
			//in the SOAP evvelope
			URI topic = null;
			
			SOAPEnvelope requestEnvelope = messageCtx.getEnvelope();
			int querySeperatorIndex = toAddress.indexOf('?');
			if(querySeperatorIndex > 0){
				String queryString = toAddress.substring(querySeperatorIndex+1);
				HashMap map = new HashMap();
				StringTokenizer t = new StringTokenizer(queryString,"=&");
				while(t.hasMoreTokens()){
					map.put(t.nextToken(), t.nextToken());
				}
				if(map.containsKey(EventingConstants.ElementNames.Topic)){
					topic = new URI((String)map.get(EventingConstants.ElementNames.Topic));
				}
			}else{
				OMElement topicHeader = requestEnvelope.getHeader().getFirstChildWithName(new QName(EventingConstants.EXTENDED_EVENTING_NAMESPACE,
						EventingConstants.ElementNames.Topic));
				if(topicHeader != null){
					topic = new URI(topicHeader.getText());
				}
			}
			
			//Here we locate the content of the Event. If this is APP we unwrap APP wrapping elements. 
			OMElement eventData = requestEnvelope.getBody().getFirstElement();
			if(AtomConstants.ATOM_NAMESPACE.equals(eventData.getNamespace().getNamespaceURI()) && 
					AtomConstants.ElementNames.Entry.equals(eventData.getLocalName())){
				OMElement content = eventData.getFirstChildWithName(new QName(AtomConstants.ATOM_NAMESPACE,AtomConstants.ElementNames.Content));
				if(content != null && content.getFirstElement() != null){
					eventData.getFirstElement();
				}
			}
			//Use in memory API to publish the event
			ServiceContext serviceContext = messageCtx.getServiceContext();
			PublicationClient client = new PublicationClient(serviceContext.getConfigurationContext());
			client.sendPublication(eventData,serviceContext.getAxisService(),topic);
		} catch (OMException e) {
			throw new AxisFault(e);
		} catch (URISyntaxException e) {
			throw new AxisFault(e);
		}
	}
}