public ActionResult FacebookLogin()
        {
            var resultMessage = new GenericMessageViewModel();

            Callback = Request.QueryString["callback"];
            ContentTypeAlias = Request.QueryString["contentTypeAlias"];
            PropertyAlias = Request.QueryString["propertyAlias"];

            if (AuthState != null)
            {
                var stateValue = Session["Dialogue_" + AuthState] as string[];
                if (stateValue != null && stateValue.Length == 3)
                {
                    Callback = stateValue[0];
                    ContentTypeAlias = stateValue[1];
                    PropertyAlias = stateValue[2];
                }
            }

            // Get the prevalue options
            if (string.IsNullOrEmpty(Dialogue.Settings().FacebookAppId) || string.IsNullOrEmpty(Dialogue.Settings().FacebookAppSecret))
            {
                resultMessage.Message = "You need to add the Facebook app credentials";
                resultMessage.MessageType = GenericMessages.Danger;
            }
            else
            {

                // Settings valid move on
                // Configure the OAuth client based on the options of the prevalue options
                var client = new FacebookOAuthClient
                {
                    AppId = Dialogue.Settings().FacebookAppId,
                    AppSecret = Dialogue.Settings().FacebookAppSecret,
                    RedirectUri = ReturnUrl
                };

                // Session expired?
                if (AuthState != null && Session["Dialogue_" + AuthState] == null)
                {
                    resultMessage.Message = "Session Expired";
                    resultMessage.MessageType = GenericMessages.Danger;
                }

                // Check whether an error response was received from Facebook
                if (AuthError != null)
                {
                    resultMessage.Message = AuthErrorDescription;
                    resultMessage.MessageType = GenericMessages.Danger;
                }

                // Redirect the user to the Facebook login dialog
                if (AuthCode == null)
                {
                    // Generate a new unique/random state
                    var state = Guid.NewGuid().ToString();

                    // Save the state in the current user session
                    Session["Dialogue_" + state] = new[] { Callback, ContentTypeAlias, PropertyAlias };

                    // Construct the authorization URL
                    var url = client.GetAuthorizationUrl(state, "public_profile", "email"); //"user_friends"

                    // Redirect the user
                    return Redirect(url);
                }

                // Exchange the authorization code for a user access token
                var userAccessToken = string.Empty;
                try
                {
                    userAccessToken = client.GetAccessTokenFromAuthCode(AuthCode);
                }
                catch (Exception ex)
                {
                    resultMessage.Message = string.Format("Unable to acquire access token<br/>{0}", ex.Message);
                    resultMessage.MessageType = GenericMessages.Danger;
                }

                try
                {
                    if (string.IsNullOrEmpty(resultMessage.Message))
                    {
                        // Initialize the Facebook service (no calls are made here)
                        var service = FacebookService.CreateFromAccessToken(userAccessToken);

                        var user = service.Users.GetUser();


                        // Try to get the email - Some FB accounts have protected passwords
                        var email = user.Body.Email;
                        // TODO - Ignore if no email - Have to check PropMemberFacebookAccessToken has a value
                        // TODO - and the me.UserName is there to match existing logged in accounts
                        
     
                        // First see if this user has registered already - Use email address
                        using (UnitOfWorkManager.NewUnitOfWork())
                        {

                            var userExists = AppHelpers.UmbServices().MemberService.GetByEmail(email);

                            if (userExists != null)
                            {
                                // Update access token
                                userExists.Properties[AppConstants.PropMemberFacebookAccessToken].Value = userAccessToken;
                                AppHelpers.UmbServices().MemberService.Save(userExists);

                                // Users already exists, so log them in
                                FormsAuthentication.SetAuthCookie(userExists.Username, true);
                                resultMessage.Message = Lang("Members.NowLoggedIn");
                                resultMessage.MessageType = GenericMessages.Success;
                            }
                            else
                            {
                                // Not registered already so register them
                                var viewModel = new RegisterViewModel
                                {
                                    Email = email,
                                    LoginType = LoginType.Facebook,
                                    Password = AppHelpers.RandomString(8),
                                    UserName = user.Body.Name,
                                    UserAccessToken = userAccessToken
                                };

                                // Get the image and save it
                                var getImageUrl = string.Format("http://graph.facebook.com/{0}/picture?type=square", user.Body.Id);
                                viewModel.SocialProfileImageUrl = getImageUrl;

                                //Large size photo https://graph.facebook.com/{facebookId}/picture?type=large
                                //Medium size photo https://graph.facebook.com/{facebookId}/picture?type=normal
                                //Small size photo https://graph.facebook.com/{facebookId}/picture?type=small
                                //Square photo https://graph.facebook.com/{facebookId}/picture?type=square

                                return RedirectToAction("MemberRegisterLogic", "DialogueLoginRegisterSurface", viewModel);
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    resultMessage.Message = string.Format("Unable to get user information<br/>{0}", ex.Message);
                    resultMessage.MessageType = GenericMessages.Danger;
                }

            }

            ShowMessage(resultMessage);
            return RedirectToUmbracoPage(Dialogue.Settings().ForumId);
        }
        public ActionResult FacebookLogin()
        {
            var resultMessage = new GenericMessageViewModel();

            Callback = Request.QueryString["callback"];
            ContentTypeAlias = Request.QueryString["contentTypeAlias"];
            PropertyAlias = Request.QueryString["propertyAlias"];

            if (AuthState != null)
            {
                var stateValue = Session["MVCForum_" + AuthState] as string[];
                if (stateValue != null && stateValue.Length == 3)
                {
                    Callback = stateValue[0];
                    ContentTypeAlias = stateValue[1];
                    PropertyAlias = stateValue[2];
                }
            }

            // Get the prevalue options
            if (string.IsNullOrEmpty(SiteConstants.Instance.FacebookAppId) ||
                string.IsNullOrEmpty(SiteConstants.Instance.FacebookAppSecret))
            {
                resultMessage.Message = "You need to add the Facebook app credentials";
                resultMessage.MessageType = GenericMessages.danger;
            }
            else
            {

                // Settings valid move on
                // Configure the OAuth client based on the options of the prevalue options
                var client = new FacebookOAuthClient
                {
                    AppId = SiteConstants.Instance.FacebookAppId,
                    AppSecret = SiteConstants.Instance.FacebookAppSecret,
                    RedirectUri = ReturnUrl
                };

                // Session expired?
                if (AuthState != null && Session["MVCForum_" + AuthState] == null)
                {
                    resultMessage.Message = "Session Expired";
                    resultMessage.MessageType = GenericMessages.danger;
                }

                // Check whether an error response was received from Facebook
                if (AuthError != null)
                {
                    Session.Remove("MVCForum_" + AuthState);
                    resultMessage.Message = AuthErrorDescription;
                    resultMessage.MessageType = GenericMessages.danger;
                }

                // Redirect the user to the Facebook login dialog
                if (AuthCode == null)
                {
                    // Generate a new unique/random state
                    var state = Guid.NewGuid().ToString();

                    // Save the state in the current user session
                    Session["MVCForum_" + state] = new[] { Callback, ContentTypeAlias, PropertyAlias };

                    // Construct the authorization URL
                    var url = client.GetAuthorizationUrl(state, "public_profile", "email"); //"user_friends"

                    // Redirect the user
                    return Redirect(url);
                }

                // Exchange the authorization code for a user access token
                var userAccessToken = string.Empty;
                try
                {
                    userAccessToken = client.GetAccessTokenFromAuthCode(AuthCode);
                }
                catch (Exception ex)
                {
                    resultMessage.Message = string.Format("Unable to acquire access token<br/>{0}", ex.Message);
                    resultMessage.MessageType = GenericMessages.danger;
                }

                try
                {
                    if (string.IsNullOrEmpty(resultMessage.Message))
                    {
                        // Initialize the Facebook service (no calls are made here)
                        var service = FacebookService.CreateFromAccessToken(userAccessToken);

                        // Declare the options for the call to the API
                        var options = new FacebookGetUserOptions
                        {
                            Identifier = "me",
                            Fields = new[] { "id", "name", "email", "first_name", "last_name", "gender" }
                        };

                        var user = service.Users.GetUser(options);

                        // Try to get the email - Some FB accounts have protected passwords
                        var email = user.Body.Email;
                        if (string.IsNullOrEmpty(email))
                        {
                            resultMessage.Message = LocalizationService.GetResourceString("Members.UnableToGetEmailAddress");
                            resultMessage.MessageType = GenericMessages.danger;
                            ShowMessage(resultMessage);
                            return RedirectToAction("LogOn", "Members");
                        }

                        // First see if this user has registered already - Use email address
                        using (UnitOfWorkManager.NewUnitOfWork())
                        {
                            var userExists = MembershipService.GetUserByEmail(email);

                            if (userExists != null)
                            {
                                try
                                {
                                    // Users already exists, so log them in
                                    FormsAuthentication.SetAuthCookie(userExists.UserName, true);
                                    resultMessage.Message = LocalizationService.GetResourceString("Members.NowLoggedIn");
                                    resultMessage.MessageType = GenericMessages.success;
                                    ShowMessage(resultMessage);
                                    return RedirectToAction("Index", "Home");
                                }
                                catch (Exception ex)
                                {
                                    LoggingService.Error(ex);
                                }
                            }
                            else
                            {
                                // Not registered already so register them
                                var viewModel = new MemberAddViewModel
                                {
                                    Email = email,
                                    LoginType = LoginType.Facebook,
                                    Password = StringUtils.RandomString(8),
                                    UserName = user.Body.Name,
                                    UserAccessToken = userAccessToken
                                };

                                // Get the image and save it
                                var getImageUrl = string.Format("http://graph.facebook.com/{0}/picture?type=square", user.Body.Id);
                                viewModel.SocialProfileImageUrl = getImageUrl;

                                //Large size photo https://graph.facebook.com/{facebookId}/picture?type=large
                                //Medium size photo https://graph.facebook.com/{facebookId}/picture?type=normal
                                //Small size photo https://graph.facebook.com/{facebookId}/picture?type=small
                                //Square photo https://graph.facebook.com/{facebookId}/picture?type=square

                                // Store the viewModel in TempData - Which we'll use in the register logic
                                TempData[AppConstants.MemberRegisterViewModel] = viewModel;

                                return RedirectToAction("SocialLoginValidator", "Members");
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    resultMessage.Message = string.Format("Unable to get user information<br/>{0}", ex.Message);
                    resultMessage.MessageType = GenericMessages.danger;
                    LoggingService.Error(ex);
                }

            }

            ShowMessage(resultMessage);
            return RedirectToAction("LogOn", "Members");
        }
        protected void Page_Load(object sender, EventArgs e) {

            Callback = Request.QueryString["callback"];
            ContentTypeAlias = Request.QueryString["contentTypeAlias"];
            PropertyAlias = Request.QueryString["propertyAlias"];

            if (AuthState != null) {
                string[] stateValue = Session["Skybrud.Social_" + AuthState] as string[];
                if (stateValue != null && stateValue.Length == 3) {
                    Callback = stateValue[0];
                    ContentTypeAlias = stateValue[1];
                    PropertyAlias = stateValue[2];
                }
            }

            // Get the prevalue options
            FacebookOAuthPreValueOptions options = FacebookOAuthPreValueOptions.Get(ContentTypeAlias, PropertyAlias);
            if (!options.IsValid) {
                Content.Text = "Hold on now! The options of the underlying prevalue editor isn't valid.";
                return;
            }

            // Configure the OAuth client based on the options of the prevalue options
            FacebookOAuthClient client = new FacebookOAuthClient {
                AppId = options.AppId,
                AppSecret = options.AppSecret,
                RedirectUri = options.RedirectUri
            };

            // Session expired?
            if (AuthState != null && Session["Skybrud.Social_" + AuthState] == null) {
                Content.Text = "<div class=\"error\">Session expired?</div>";
                return;
            }

            // Check whether an error response was received from Facebook
            if (AuthError != null) {
                Content.Text = "<div class=\"error\">Error: " + AuthErrorDescription + "</div>";
                return;
            }

            // Redirect the user to the Facebook login dialog
            if (AuthCode == null) {

                // Generate a new unique/random state
                string state = Guid.NewGuid().ToString();

                // Save the state in the current user session
                Session["Skybrud.Social_" + state] = new[] {Callback, ContentTypeAlias, PropertyAlias};

                // Construct the authorization URL
                string url = client.GetAuthorizationUrl(state, "read_stream", "user_status", "user_about_me", "user_photos");
                
                // Redirect the user
                Response.Redirect(url);
                return;
            
            }

            // Exchange the authorization code for a user access token
            string userAccessToken;
            try {
                userAccessToken = client.GetAccessTokenFromAuthCode(AuthCode);
            } catch (Exception ex) {
                Content.Text = "<div class=\"error\"><b>Unable to acquire access token</b><br />" + ex.Message + "</div>";
                return;
            }

            try {

                // Initialize the Facebook service (no calls are made here)
                FacebookService service = FacebookService.CreateFromAccessToken(userAccessToken);

                // Make a call to the Facebook API to get information about the user
                FacebookUser me = service.Users.GetUser("me").Body;

                // Get debug information about the access token
                FacebookDebugToken debug = service.Debug.DebugToken(userAccessToken).Body;

                Content.Text += "<p>Hi <strong>" + me.Name + "</strong></p>";
                Content.Text += "<p>Please wait while you're being redirected...</p>";

                // Set the callback data
                FacebookOAuthData data = new FacebookOAuthData {
                    Id = me.Id,
                    Name = me.Name,
                    AccessToken = userAccessToken,
                    ExpiresAt = debug.Data.ExpiresAt == null ? default(DateTime) : debug.Data.ExpiresAt.Value,
                    Scope = (
                        from scope in debug.Data.Scopes select scope.Name
                    ).ToArray()
                };

                // Update the UI and close the popup window
                Page.ClientScript.RegisterClientScriptBlock(GetType(), "callback", String.Format(
                    "self.opener." + Callback + "({0}); window.close();",
                    data.Serialize()
                ), true);

            } catch (Exception ex) {
                Content.Text = "<div class=\"error\"><b>Unable to get user information</b><br />" + ex.Message + "</div>";
                return;
            }

        }