package com.almende.eve.transport.xmpp.google;
import java.io.IOException;
import java.util.logging.Logger;
import javax.servlet.http.*;
import com.almende.eve.agent.AgentFactory;
import com.almende.eve.agent.annotation.Sender;
import com.almende.eve.config.Config;
import com.almende.eve.rpc.RequestParams;
import com.almende.eve.rpc.jsonrpc.JSONRPCException;
import com.almende.eve.rpc.jsonrpc.JSONRequest;
import com.almende.eve.rpc.jsonrpc.JSONResponse;
import com.almende.eve.rpc.jsonrpc.jackson.JOM;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.appengine.api.xmpp.JID;
import com.google.appengine.api.xmpp.Message;
import com.google.appengine.api.xmpp.MessageBuilder;
import com.google.appengine.api.xmpp.XMPPService;
import com.google.appengine.api.xmpp.XMPPServiceFactory;
@SuppressWarnings("serial")
public class GaeXmppServlet extends HttpServlet {
protected AgentFactory agentFactory = null;
protected GaeXmppService xmppService = null;
private Logger logger = Logger.getLogger(this.getClass().getSimpleName());
/**
* Handle a post request containing an xmpp chat message
* @param req
* @param res
*/
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws IOException {
XMPPService xmpp = XMPPServiceFactory.getXMPPService();
// receive message
Message message = xmpp.parseMessage(req);
JID from = message.getFromJid();
JID[] recipients = message.getRecipientJids();
JID to = (recipients.length > 0) ? recipients[0] : null;
String body = message.getBody();
if (body != null && body.startsWith("{") || body.trim().startsWith("{")) {
// the body contains a JSON object
ObjectNode json = null;
try {
String agentUrl = "xmpp:" + to.getId();
String agentId = xmppService != null ? xmppService.getAgentId(agentUrl) : null;
json = JOM.getInstance().readValue(body, ObjectNode.class);
if (isResponse(json)) {
// TODO: handle response
}
else if (isRequest(json)) {
// this is a request
// append the sender to the request parameters
RequestParams params = new RequestParams();
params.put(Sender.class, from.getId());
// TODO: cleanup logger info
logger.info("request agentUrl =" + agentUrl + ", agentId=" + agentId + " request=" + json + ", sender=" + from.getId());
// invoke the agent
JSONRequest request = new JSONRequest(json);
JSONResponse response = agentFactory.receive(agentId, request, params);
// reply to message
Message msg = new MessageBuilder()
.withRecipientJids(from)
.withFromJid(to)
.withBody(response.toString())
.build();
xmpp.sendMessage(msg);
}
else {
throw new Exception("Request does not contain a valid JSON-RPC request or response");
}
}
catch (Exception err) {
// generate JSON error response
JSONRPCException jsonError = new JSONRPCException(
JSONRPCException.CODE.INTERNAL_ERROR, err.getMessage());
JSONResponse response = new JSONResponse(jsonError);
// send exception as response
Message msg = new MessageBuilder()
.withRecipientJids(from)
.withFromJid(to)
.withBody(response.toString())
.build();
xmpp.sendMessage(msg);
}
}
}
/**
* Check if given json object contains all fields required for a
* json-rpc request (id, method, params)
* @param json
* @return
*/
private boolean isRequest(ObjectNode json) {
return json.has("method");
}
/**
* Check if given json object contains all fields required for a
* json-rpc response (id, result or error)
* @param json
* @return
*/
private boolean isResponse(ObjectNode json) {
return (json.has("result") || json.has("error"));
}
@Override
public void init() {
try {
initAgentFactory();
initTransportService();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* initialize the agent factory
* @throws Exception
*/
private void initAgentFactory() throws Exception {
// TODO: be able to choose a different namespace
agentFactory = AgentFactory.getInstance();
if (agentFactory == null) {
// if the agent factory is not yet loaded, load it from config
String filename = getInitParameter("config");
if (filename == null) {
filename = "eve.yaml";
logger.warning(
"Init parameter 'config' missing in servlet configuration web.xml. " +
"Trying default filename '" + filename + "'.");
}
String fullname = "/WEB-INF/" + filename;
logger.info("loading configuration file '" +
getServletContext().getRealPath(fullname) + "'...");
Config config = new Config(getServletContext().getResourceAsStream(fullname));
agentFactory = AgentFactory.createInstance(config);
}
}
/**
* Register a new gae xmpp service at the agent factory
* @throws Exception
*/
private void initTransportService() throws Exception {
if (agentFactory == null) {
throw new Exception(
"Cannot initialize GaeXmppService: no AgentFactory initialized.");
}
xmppService = new GaeXmppService();
agentFactory.addTransportService(xmppService);
}
}