package com.degloba.boundedContext.webui.servlets;
//import static com.emobus.stuff.LoggerConstants.facebookUserId;
//import static com.emobus.stuff.LoggerConstants.ipAddress;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.w3c.dom.Document;
import com.google.code.facebookapi.FacebookException;
import com.google.code.facebookapi.FacebookWebappHelper;
import com.google.code.facebookapi.FacebookXmlRestClient;
import com.google.code.facebookapi.IFacebookRestClient;
/**
* The Facebook User Filter ensures that a Facebook client that pertains to
* the logged in user is available in the session object named "facebook.user.client".
*
* The session ID is stored as "facebook.user.session". It's important to get
* the session ID only when the application actually needs it. The user has to
* authorise to give the application a session key.
*
* @author Dave
*/
public class FacebookUserFilter implements Filter {
private static final Logger logger = LoggerFactory.getLogger(FacebookUserFilter.class);
private String api_key;
private String secret;
private static final String FACEBOOK_USER_CLIENT = "facebook.user.client";
public void init(FilterConfig filterConfig) throws ServletException {
/* Parametres definits en web.xml */
api_key = filterConfig.getServletContext().getInitParameter("facebook_api_key");
secret = filterConfig.getServletContext().getInitParameter("facebook_secret");
if(api_key == null || secret == null) {
throw new ServletException("Cannot initialise Facebook User Filter because the " +
"facebook_api_key or facebook_secret context init " +
"params have not been set. Check that they're there " +
"in your servlet context descriptor.");
} else {
logger.info("Using facebook API key: " + api_key);
}
}
public void destroy() {
}
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
try {
MDC.put("ipAddress", req.getRemoteAddr());
HttpServletRequest request = (HttpServletRequest)req;
HttpServletResponse response = (HttpServletResponse)res;
HttpSession session = request.getSession(true);
IFacebookRestClient<Document> userClient = getUserClient(session);
if(userClient == null) {
logger.debug("User session doesn't have a Facebook API client setup yet. Creating one and storing it in the user's session.");
userClient = new FacebookXmlRestClient(api_key, secret); // client per connectar a l'aplicació degloba de Facebook
session.setAttribute(FACEBOOK_USER_CLIENT, userClient);
}
logger.trace("Creating a FacebookWebappHelper, which copies fb_ request param data into the userClient");
FacebookWebappHelper<Document> facebook = new FacebookWebappHelper<Document>(request, response, api_key, secret, userClient);
String nextPage = request.getRequestURI();
nextPage = nextPage.substring(nextPage.indexOf("/", 1) + 1); //cut out the first /, the context path and the 2nd /
logger.trace(nextPage);
boolean redirectOccurred = facebook.requireLogin(nextPage);
if(redirectOccurred) {
return;
}
redirectOccurred = facebook.requireFrame(nextPage);
if(redirectOccurred) {
return;
}
long facebookUserID;
try {
facebookUserID = userClient.users_getLoggedInUser();
} catch(FacebookException ex) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Error while fetching user's facebook ID");
logger.error("Error while getting cached (supplied by request params) value " +
"of the user's facebook ID or while fetching it from the Facebook service " +
"if the cached value was not present for some reason. Cached value = {}", userClient.getCacheUserId());
return;
}
MDC.put("facebookUserId", String.valueOf(facebookUserID));
chain.doFilter(request, response);
} finally {
MDC.remove("ipAddress");
MDC.remove("facebookUserId");
}
}
public static FacebookXmlRestClient getUserClient(HttpSession session) {
return (FacebookXmlRestClient)session.getAttribute(FACEBOOK_USER_CLIENT);
}
}