//
// FILE NAME: fb_dnet.js
// DESCRIPTION: JavaScript file, contain interfaces to login/loguot with Facebook.
// CREATED BY: Gabriel Mizrahi, EMGmetrics.
//
// VERSION: V1R1.00
// DATE: 27 Jun 2011.
//

//
// the javascript interfaces.
//

function FBLogout(_app_id, _window_href_redirect) {

    FB.init({ appId: _app_id, status: true, cookie: true, xfbml: true });
    FB.getSession();
    FB.logout(function (response) {
        // user is now logged out
        alert('Facebook logout success.');
    });
    window.location.href = _window_href_redirect;
}

function FBLogin(_app_id, _redirect_uri, _perms) {

    //
    // Initialize Facebook connection. Using application ID.
    //
    FB.init({ appId: _app_id, status: true, cookie: true, xfbml: true });


    //
    // Get Facebook login status to know if user is already loged in.
    //
    FB.getLoginStatus(function (response_login_status) {

        var _window_href = "https://graph.facebook.com/oauth/authorize?client_id=" + _app_id + "&redirect_uri=" + _redirect_uri;

        if (response_login_status.session) {
            
            //
            // logged in and connected user, someone you know.
            // redirect facebook to continue with authorization.
            //

            alert('Already loged-in to Facebook.');
            window.location.href = _window_href;

        } else {

            //
            // no user session available, someone you dont know.
            //

            //
            // Login with Facebook with 'publish_stream' permision.
            //
            FB.login(function (response_login) {

                //
                // User successfully logged in
                //
                if (response_login.session) {

                    //
                    // User successfuly loged in.
                    // redirect facebook to continue with authorization.
                    //
                    alert('Facebook login success');
                    window.location.href = _window_href;

                } else {
                    //
                    // An error occured while tring to Login or user cancelled login.
                    //
                    alert('Facebook login failed.');
                }
            }, { perms: _perms });
        }
    });
}