package cz.xelfi.feedbook;

 import com.google.code.facebookapi.FacebookException;

 import com.google.code.facebookapi.FacebookJaxbRestClient;

 import com.google.code.facebookapi.Permission;

 import com.sun.syndication.feed.rss.Channel;

 import com.sun.syndication.feed.rss.Item;

 import com.sun.syndication.io.WireFeedInput;

 import java.awt.Desktop;

 import java.io.IOException;

 import java.net.URI;

 import java.net.URISyntaxException;

 import java.net.URL;

 import java.util.prefs.Preferences;

 import org.xml.sax.InputSource;

 public class Main {

     private static String APP_KEY;

     private static String APP_SEC;

     private static String APP_FEED;

     // BEGIN: feedbook-login

     private static String login() 

     throws IOException, FacebookException, URISyntaxException {

         FacebookJaxbRestClient login = new FacebookJaxbRestClient(

             APP_KEY, APP_SEC

         );

         final String token = login.auth_createToken();

         final URI u = new URI("http://www.facebook.com/login.php?"

                 + "api_key=" + APP_KEY + "&auth_token=" + token);

         String msg = "authentication";

         browser(msg, u);

         return login.auth_getSession(token, false); 

     }

     // END: feedbook-login

     private static void browser(String msg, URI u) throws IOException {

         System.out.println(msg + ": " + u);

         try {

             Desktop.getDesktop().browse(u);

         } catch (Exception ex) {

             Runtime.getRuntime().exec("xdg-open " + u);

         }

         System.out.println("Visit the browser and press enter...");

         System.in.read();

     }

     public static void main( String[] args) throws Exception {

         Preferences prefs = Preferences.userNodeForPackage(Main.class);

         if (args.length == 3) {

             prefs.put("id", args[0]);

             prefs.put("secret", args[1]);

             prefs.put("feed", args[2]);

         } else {

             if (args.length != 0) {

                 usage();

                 return;

             }

         }

         APP_KEY = prefs.get("id", null);

         APP_SEC = prefs.get("secret", null);

         APP_FEED = prefs.get("feed", null);

         if (APP_FEED == null || APP_SEC == null || APP_KEY == null) {

             usage();

             return;

         }

         WireFeedInput rssInput = new WireFeedInput();

         URL rssUrl = new URL(APP_FEED);

         Channel rss = (Channel)rssInput.build(new InputSource(rssUrl.openStream()));;

         FacebookJaxbRestClient fb;

         Long user;

         for (;;) {

             final String stored = prefs.get("session", null);

             if (stored != null) {

                 try {

                     fb = new FacebookJaxbRestClient(APP_KEY, APP_SEC, stored);

                     user = fb.users_getLoggedInUser();

                     break;

                 } catch (FacebookException ex) {

                     System.err.println(ex.getMessage());

                 }

             }

             final String session = login();

             fb = new FacebookJaxbRestClient(APP_KEY, APP_SEC, session);

             user = fb.users_getLoggedInUser();

             prefs.put("session", session);

             break;

         }

         // BEGIN: feedbook-permission

         while (!fb.users_hasAppPermission(Permission.SHARE_ITEM)) {

             URI u = new URI("https://graph.facebook.com/oauth/authorize?"

                     + "client_id=" + APP_KEY

                     + "&redirect_uri=http://www.facebook.com/connect/login_success.html"

                     + "&scope=publish_stream");

             browser("Need permission to publish links", u);

         }

         // END: feedbook-permission

         Preferences n = prefs.node("feeds");

         int cnt = 0;

         for (Object o : rss.getItems()) {

             Item item = (Item) o;

             String hex = Integer.toHexString(item.getLink().hashCode());

             if (n.getLong(hex, -1L) != -1L) {

                 continue;

             }

             cnt++;

             // BEGIN: feedbook-publish-link

             System.out.printf(

                 "link: %s date: %s title: %s\n", 

                 item.getLink(), item.getPubDate(), item.getTitle()

             );

             Long ok = fb.links_post(user, item.getLink(), item.getTitle());

             System.out.println("posted as " + ok);

             // END: feedbook-publish-link

             n.putLong(hex, ok);

             n.put(hex + ".url", item.getLink());

         }

         System.out.println("Published " + cnt + " feed item(s)");

     }

     private static void usage() {

         System.out.println("Invoke with three parameters: "

                 + "<facebook_app_key> "

                 + "<facebook_app_secret "

                 + "<rss_feed_url>");

     }

 }