public IActionResult Login(LoginViewModel loginModel)
        {
            int?isInSession = HttpContext.Session.GetInt32("user");

            if (isInSession == null)
            {
                if (ModelState.IsValid)
                {
                    bool exists = userFactory.CheckUserInDB(loginModel.email);
                    if (!exists)
                    {
                        ViewBag.error = "This email isn't registered. Please register.";
                        return(View("Register"));
                    }
                    User user = userFactory.GetCurrentUser(loginModel.email);
                    HttpContext.Session.SetInt32("user", user.id);
                    return(RedirectToAction("Success"));
                }
                return(View("Login", loginModel));
            }
            return(RedirectToAction("Success"));
        }