package ora.jwsnut.chapter4.ebXMLecho;

import java.util.Date;
import java.util.Iterator;
import java.util.Vector;
import java.io.ByteArrayOutputStream;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.xml.messaging.Endpoint;
import javax.xml.messaging.JAXMServlet;
import javax.xml.messaging.OnewayListener;
import javax.xml.messaging.ProviderConnection;
import javax.xml.messaging.ProviderConnectionFactory;
import javax.xml.soap.AttachmentPart;
import javax.xml.soap.MessageFactory;
import javax.xml.soap.SOAPBody;
import javax.xml.soap.SOAPElement;
import javax.xml.soap.SOAPMessage;
import com.sun.xml.messaging.jaxm.ebxml.EbXMLMessageImpl;

/**
 * A servlet that recieves an ebXML message and
 * returns it to its sender.
 */
public class EBXMLEchoServlet extends JAXMServlet implements OnewayListener {
   
    /**
     * Output stream used to save a SOAP message
     * for logging.
     */
    private ByteArrayOutputStream os = new ByteArrayOutputStream();
    
    /**
     * ProviderConnection used to send reply messages
     */
    private ProviderConnection conn;

    /**
     * MessageFactory for ebXML messages
     */
    private MessageFactory messageFactory;
    
    /**
     * Initialize by installing the appropriate MessageFactory
     */
    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);

        // Workaround for hang when deploying in J2EE container.
        // Do not connect to the provider here - defer to another thread.
        new Thread(new Runnable() { 
            public void run() {
                try {
                    // Create the connection to the provider
                    conn = ProviderConnectionFactory.newInstance().createConnection();

                    // Work around for a JAXM bug
                    conn.getMetaData();

                    // Install the message factory for the ebXML profile
                    messageFactory = conn.createMessageFactory("ebxml");
                    setMessageFactory(messageFactory);
                } catch (Exception e) {
                    log("Exception when initializing", e);
                }
           }
        }).start();
    }
    
    /**
     * Handles a received SOAP message
     */
    public void onMessage(SOAPMessage message) {
        
        // Convert the message to string representation
        // and log it.
        try {
            message.writeTo(os);
            log("Received SOAP message:\n" + os.toString());
            os.reset();
            
            // Create a copy of the message with the same body
            // and with the to and from addresses exchanged.
            EbXMLMessageImpl soapMsg = (EbXMLMessageImpl)message;
            
            // Create a reply message
            EbXMLMessageImpl replyMsg = (EbXMLMessageImpl)messageFactory.createMessage();
            
            // Move the body content from the received message to the source.
            SOAPBody body = soapMsg.getSOAPPart().getEnvelope().getBody();
            SOAPBody replyBody = replyMsg.getSOAPPart().getEnvelope().getBody();
            Iterator iter = body.getChildElements();
            while (iter.hasNext()) {
                SOAPElement element = (SOAPElement)iter.next();
                replyBody.addChildElement(element);
            }
            
            // Add an element after the body that contains the date.
            SOAPElement element = 
                    replyMsg.getSOAPPart().getEnvelope().addChildElement("Date", "tns", "urn:ebXMLEcho");
            element.addTextNode(new Date().toString());
            
            // Copy any attachments
            iter = soapMsg.getAttachments();
            while (iter.hasNext()) {
                replyMsg.addAttachmentPart((AttachmentPart)iter.next());
            }
            
            // Get the message ID and install it as the "RefToMessageId" value
            replyMsg.setRefToMessageId(soapMsg.getMessageId());
            
            // Get the the "Reciever" address and install it as the "Sender" address
            replyMsg.setSender(soapMsg.getReceiver());
            
            // Get the "Sender" address an install it as the "Receiver" address
            replyMsg.setReceiver(soapMsg.getSender());
            
            // Copy values from the ebXML MessageHeader
            replyMsg.setAction(soapMsg.getAction());
            replyMsg.setConversationId(soapMsg.getConversationId());
            replyMsg.setCPAId(soapMsg.getCPAId());
            replyMsg.setManifest(soapMsg.getManifest());
            replyMsg.setMessageHeaderVersion(soapMsg.getMessageHeaderVersion());
            replyMsg.setService(soapMsg.getService());    
            
            // Send the reply message
            conn.send(replyMsg);
        } catch (Exception ex) {
            log("Exception", ex);
        }
    }
}