/*
 * Copyright (C) 2011 The University of Manchester
 * 
 * See the file "LICENSE" for license terms.
 */

package org.taverna.server.master.notification;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jivesoftware.smack.Chat;
import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.MessageListener;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.packet.Message;
import org.taverna.server.master.interfaces.MessageDispatcher;
import org.taverna.server.master.interfaces.TavernaRun;

/**
 * Send notifications by Jabber/XMPP.
 * 
 * @author Donal Fellows
 */
public class JabberDispatcher implements MessageDispatcher {
	@Override
	public String getName() {
		return "xmpp";
	}

	private Log log = LogFactory.getLog("Taverna.Server.Notification");
	private XMPPConnection conn;
	private String resource = "TavernaServer";
	private String host = "";
	private String user = "";
	private String pass = "";

	/**
	 * @param resource
	 *            The XMPP resource to use when connecting the server. This
	 *            defaults to "<tt>TavernaServer</tt>".
	 */
	public void setResource(String resource) {
		this.resource = resource;
	}

	/**
	 * @param service
	 *            The XMPP service URL.
	 */
	public void setHost(String service) {
		if (service == null || service.trim().isEmpty()
				|| service.trim().startsWith("$"))
			this.host = "";
		else
			this.host = service.trim();
	}

	/**
	 * @param user
	 *            The user identity to use with the XMPP service.
	 */
	public void setUsername(String user) {
		if (user == null || user.trim().isEmpty()
				|| user.trim().startsWith("$"))
			this.user = "";
		else
			this.user = user.trim();
	}

	/**
	 * @param pass
	 *            The password to use with the XMPP service.
	 */
	public void setPassword(String pass) {
		if (pass == null || pass.trim().isEmpty()
				|| pass.trim().startsWith("$"))
			this.pass = "";
		else
			this.pass = pass.trim();
	}

	@PostConstruct
	void setup() {
		try {
			if (host.isEmpty() || user.isEmpty() || pass.isEmpty()) {
				log.info("disabling XMPP support; incomplete configuration");
				conn = null;
				return;
			}
			ConnectionConfiguration cfg = new ConnectionConfiguration(host);
			cfg.setSendPresence(false);
			XMPPConnection c = new XMPPConnection(cfg);
			c.connect();
			c.login(user, pass, resource);
			conn = c;
			log.info("connected to XMPP service <" + host + "> as user <"
					+ user + ">");
		} catch (Exception e) {
			log.info("failed to connect to XMPP server", e);
		}
	}

	@PreDestroy
	public void close() {
		if (conn != null)
			conn.disconnect();
		conn = null;
	}

	@Override
	public boolean isAvailable() {
		return conn != null;
	}

	@Override
	public void dispatch(TavernaRun ignored, String messageSubject,
			String messageContent, String targetParameter) throws Exception {
		Chat chat = conn.getChatManager().createChat(targetParameter,
				new DroppingListener());
		Message m = new Message();
		m.addBody(null, messageContent);
		m.setSubject(messageSubject);
		chat.sendMessage(m);
	}

	static class DroppingListener implements MessageListener {
		private Log log = LogFactory
				.getLog("Taverna.Server.Notification.Jabber");

		@Override
		public void processMessage(Chat chat, Message message) {
			if (log.isDebugEnabled())
				log.debug("unexpectedly received XMPP message from <"
						+ message.getFrom() + ">; ignoring");
		}
	}
}