public async Task <IActionResult> OnGetLinkLoginCallbackAsync()
{
var user = await _userManager.GetUserAsync(User);
if (user == null)
{
return(NotFound($"Unable to load user with ID '{_userManager.GetUserId(User)}'."));
}
var info = await _signInManager.GetExternalLoginInfoAsync(await _userManager.GetUserIdAsync(user));
if (info == null)
{
throw new InvalidOperationException($"Unexpected error occurred loading external login info for user with ID '{user.Id}'.");
}
var logins = await _userManager.GetLoginsAsync(user);
if (logins.Any(l => l.LoginProvider == info.LoginProvider && l.ProviderKey == info.ProviderKey))
{
StatusMessage = "The external login is already linked to your account.";
return(RedirectToPage());
}
var email = info.Principal.Claims.FindEmail();
var result = await _userManager.AddLoginAsync(user, info, email);
if (!result.Succeeded)
{
throw new InvalidOperationException($"Unexpected error occurred adding external login for user with ID '{user.Id}'.");
}
// Clear the existing external cookie to ensure a clean login process
await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
StatusMessage = "The external login was added.";
return(RedirectToPage());
}