private async Task SignInAsync(ApplicationUser user, bool isPersistent)
 {
     AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
     AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent }, await user.GenerateUserIdentityAsync(UserManager));
 }
        public async Task<ActionResult> ExternalLoginConfirmation(ExternalLoginConfirmationViewModel model, string returnUrl)
        {
            if (User.Identity.IsAuthenticated)
            {
                return RedirectToAction("Manage");
            }

            if (ModelState.IsValid)
            {
                // Get the information about the user from the external login provider
                var info = await AuthenticationManager.GetExternalLoginInfoAsync();
                if (info == null)
                {
                    return View("ExternalLoginFailure");
                }
                var user = new ApplicationUser() { UserName = model.Email, Email = model.Email };
                IdentityResult result = await UserManager.CreateAsync(user);
                if (result.Succeeded)
                {
                    result = await UserManager.AddLoginAsync(user.Id, info.Login);
                    if (result.Succeeded)
                    {
                        await SignInAsync(user, isPersistent: false);

                        // For more information on how to enable account confirmation and password reset please visit http://go.microsoft.com/fwlink/?LinkID=320771
                        // Send an email with this link
                        // string code = await UserManager.GenerateEmailConfirmationTokenAsync(user.Id);
                        // var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);
                        // SendEmail(user.Email, callbackUrl, "Confirm your account", "Please confirm your account by clicking this link");

                        return RedirectToLocal(returnUrl);
                    }
                }
                AddErrors(result);
            }

            ViewBag.ReturnUrl = returnUrl;
            return View(model);
        }