Vfrdtyky

if this is not a proper question please tell me but I am new at WEB API and what I am trying to do is; I want to make a logout method by using this login method. I should also remove UserDevice content. My whole code block at below. Should i make empty UserDevice content?
Thanks

[HttpPost]

    [Route("{guid}/login", Name = "PxLogin")]

    public IHttpActionResult Login(string guid, [FromBody] LoginRequest req)

    {

        Helpers.Logger.Log(JsonConvert.SerializeObject(req));



        LoginResult res = new LoginResult();



        if (IsUserRegistered(guid, req.User))

        {

            var account = _db.Accounts.SingleOrDefault(a => a.Guid == guid);



            if (account != null)

            {

                var client = Core.Common.Helper.CreateRestClient(guid);



                var request = new RestRequest("login", Method.POST);

                request.AddParameter("User", req.User); // replaces matching token in request.Resource

                request.AddParameter("Pass", req.Pass);

                request.AddParameter("Instance", req.Instance);



                var response = client.Execute(request);



                var jsonResponse = JsonConvert.DeserializeObject(response.Content);

                res = JsonConvert.DeserializeObject<LoginResult>(jsonResponse.ToString());



                if (res.IsLogin)

                {

                    var usr = _db.Users.FirstOrDefault(u => u.Account.Guid == guid && u.UserId == req.User);



                    if (usr != null)

                    {

                        if (usr.Language == null)

                        {

                            usr.Language = account.Language;

                        }



                        usr.LoginToken = res.Token;



                        if (!String.IsNullOrEmpty(req.DeviceId))

                        {

                            var userDevice = new UserDevice

                            {

                                AccountId = account.AccountId,

                                UserId = req.User,

                                DeviceType = req.Device,

                                DeviceToken = req.DeviceToken,

                                DeviceId = req.DeviceId

                            };



                            _db.UserDevices.AddOrUpdate(userDevice);

                        }

                        var loginRequest =

                            Encrypter.Encrypt(JsonConvert.SerializeObject(req), "abcdefghil");



                        usr.LoginRequest = loginRequest;



                        _db.SaveChanges();

                    }

                }

            }

    }