public IActionResult Login(UserLogin user)
        {
            if (ModelState.IsValid)
            {
                var _user = _context.CheckCredential(user);
                if (_user == null)
                {
                    TempData["error"] = "Błędne dane logowania!";
                    return(RedirectToAction("Index", "Auth"));
                }

                var identity = new ClaimsIdentity(CookieAuthenticationDefaults.AuthenticationScheme);
                identity.AddClaim(new Claim(ClaimTypes.Name, _user[0].UserName.ToString()));
                identity.AddClaim(new Claim(ClaimTypes.Role, _user[0].UserRole));
                identity.AddClaim(new Claim(ClaimTypes.Email, _user[0].UserEmail));

                HttpContext.Session.SetString("UserEmail", _user[0].UserEmail);
                HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, new ClaimsPrincipal(identity));

                if (_user[0].UserRole == "Admin")
                {
                    identity.AddClaim(new Claim(ClaimTypes.Role, "Admin"));
                    return(RedirectToAction("Index", "Home"));
                }
                else if (_user[0].UserRole == "User")
                {
                    identity.AddClaim(new Claim(ClaimTypes.Role, "User"));
                    return(RedirectToAction("Index", "Home"));
                }
            }

            return(RedirectToAction("Index", "Auth"));
        }