/*
 * Copyright © 2010 Garrett Brown <http://www.mediawiki.org/wiki/User:Gbruin>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * fbconnect.js and fbconnect-min.js
 * 
 * FBConnect relies on several different libraries and frameworks for its JavaScript
 * code. Each framework has its own method to verify that the propper code won't be
 * called before it's ready. (Below, lambda represents a named or anonymous function.)
 * 
 * MediaWiki:             addOnloadHook(lambda);
 *     This function manages an array of window.onLoad event handlers to be called
 *     be called by a MediaWiki script when the window is fully loaded. Because the
 *     DOM may be ready before the window (due to large images to be downloaded) a
 *     faster alternative is JQuery's document-ready function.
 * 
 * FaceBook Connect SDK:  window.fbAsyncInit = lambda;
 *     This global variable is called when the Facebook Connect SDK is fully
 *     initialized asynchronously to the document's state. This might be long
 *     after the document is finished rendering the first time the script is
 *     downloaded. Subsequently, it may even be called before the DOM is ready.
 * 
 * jQuery:                $(document).ready(lambda);
 *     Self-explanatory -- to be called when the DOM is ready to be manipulated.
 *     Typically this should occur sooner than MediaWiki's addOnloadHook function
 *     is called.
 */

/**
 * After the Facebook Connect JavaScript SDK has been asynchronously loaded,
 * it looks for the global fbAsyncInit and executes the function when found.
 */
window.fbAsyncInit = function() {
	// Initialize the library with the API key
	FB.init({
		apiKey : window.fbApiKey,
		status : true, // Check login status
		cookie : true, // Enable cookies to allow the server to access the session
		xfbml  : window.fbUseMarkup // Whether XFBML should be automatically parsed
	});
	
	// Register a function for when the user logs in to Facebook
	FB.Event.subscribe('auth.login', function(response) {
		// Refresh the page to transfer the session to the server
		window.location.reload(true);
	});
	
	// Register a function for when the user logs out of Facebook
	FB.Event.subscribe('auth.logout', function(response) {
		var login = confirm("Not logged in.\n\nWe detected that you have been logged " +
		                    "out of Facebook. If this isn't the case, don't worry! " +
		                    "Facebook's new library seems to have some growing pains. " +
		                    "Just press Cancel to stay on the current page. Otherwise, " +
		                    "Press OK to log in via Facebook Connect again.");
		if (login) {
			window.location = window.wgArticlePath.replace(/\$1/, "Special:Connect");
		}
	});
};

/**
 * jQuery code to be run when the DOM is ready to be manhandled.
 */
$(document).ready(function() {
	// Add a pretty logo to Facebook links
	$('#pt-fbconnect,#pt-fblink,#pt-fbconvert').addClass('mw-fblink');
	
	// Add the logout behaviour to the "Logout of Facebook" button
	$('#pt-fblogout').click(function() {
		// TODO: Where did the fancy DHTML window go? Maybe consider jQuery Alert Dialogs:
		// http://abeautifulsite.net/2008/12/jquery-alert-dialogs/
		var logout = confirm("You are loggin out of both this site and Facebook.");
		if (logout) {
			FB.logout(function(response) {
				window.location = window.fbLogoutURL;
			});
		}
	});
});