public HttpResponseMessage PutUsers(PersonalizationRequsetDTO personalizationrequset)
        {
            string callerMethodName = string.Empty;

            try
            {
                //Get Caller Method name from CallerInformation class
                callerMethodName = CallerInformation.TrackCallerMethodName();
                InsightLogger.TrackEvent("PersonalizationAPIController ::endpoint : api/personalizationapi/users/{userID}, action: start put user");
                //BL object instances created
                Personalization personalization = new Personalization();
                UserBackend     userbackend     = new UserBackend();
                UserDevice      userdevice      = new UserDevice();
                //if userID is available in requset then check user exist or not.
                if (personalizationrequset != null && !string.IsNullOrEmpty(personalizationrequset.user.UserID))
                {
                    Boolean isUserExists = personalization.CheckUser(personalizationrequset.user.UserID);
                    Boolean isDevicesProvided, isBackendsProvided;

                    //retrackting individual objects from request
                    IEnumerable <UserDeviceDTO>  userdevicesdto = personalizationrequset.user.userdevices;
                    IEnumerable <UserBackendDTO> userbackendsdto = personalizationrequset.user.userbackends;
                    UserDTO    user       = personalizationrequset.user;
                    UserEntity userentity = personalization.UserEntityGenerator(user);
                    IEnumerable <UserDeviceEntity>  userprovideddevices  = null;
                    IEnumerable <UserBackendEntity> userprovidedbackends = null;

                    //to check if requset has userdevices or not
                    if (userdevicesdto != null)
                    {
                        isDevicesProvided   = true;
                        userprovideddevices = userdevice.UserDeviceEntityGenerator(userdevicesdto);
                    }
                    else
                    {
                        isDevicesProvided = false;
                    }

                    //to check if requset has userbackends or not
                    if (userbackendsdto != null)
                    {
                        isBackendsProvided   = true;
                        userprovidedbackends = userbackend.UserBackendEntityGenerator(userbackendsdto);
                    }
                    else
                    {
                        isBackendsProvided = false;
                    }
                    UserDTO updateduser;
                    //create if user not exists else update
                    if (!isUserExists)
                    {
                        InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: check user, response: false,userID: " + personalizationrequset.user.UserID);
                        personalization.CreateUser(userentity);
                        InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: create new user, response: success,userID: " + personalizationrequset.user.UserID);
                        //add user devices if provided in request
                        if (isDevicesProvided)
                        {
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: devices provided, response: true");
                            userdevice.AddDevices(userprovideddevices.ToList());
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: create and/or associate devices to user, response: success");
                        }
                        //associate user backends if provided in request other wise associate all backends in system
                        if (isBackendsProvided)
                        {
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: backends provided, response: true");
                            userbackend.AddBackends(userprovidedbackends.ToList());
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: create and/or associate backends to user, response: success");
                        }
                        else
                        {
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: backends provided, response: false");
                            userbackend.AddAllBackends(user.UserID);
                            InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: create and/or associate all backends to user, response: success");
                        }
                        updateduser = personalization.GetUser(personalizationrequset.user.UserID);
                        personalization.TriggerUserRequests(personalizationrequset.user.UserID, updateduser.userbackends);
                        InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: trigger a user requests update, response: success");
                        int SynchTime = personalization.CalcSynchTime(userprovidedbackends);
                        InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: calculate synch waiting time, response: success, synchWaitingtime:" + SynchTime);
                    }
                    else
                    {
                        InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: check user, response: true");
                        personalization.UpdateUserProp(userentity);
                        //remove existing devices to user and add the provided userdevices in requset
                        if (isDevicesProvided)
                        {
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: devices provided, response: true");
                            userdevice.RemoveDevices(personalizationrequset.user.UserID);
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: remove all existing associated devices , response: success");
                            userdevice.AddDevices(userprovideddevices.ToList());
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: create associated devices to user, response: success");
                        }
                        //remove existing backends to user and add the provided userbackends in requset
                        if (isBackendsProvided)
                        {
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: backends provided, response: true");
                            userbackend.RemoveBackends(personalizationrequset.user.UserID);
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: remove all existing associated backends , response: success");
                            userbackend.AddBackends(userprovidedbackends.ToList());
                            InsightLogger.TrackEvent("PersonalizationAPIController ::  endpoint : api/personalizationapi/users/{userID}, action: create associated backends to user, response: success");
                        }
                        else
                        {
                            userbackend.RemoveBackends(personalizationrequset.user.UserID);
                        }
                        updateduser = personalization.GetUser(personalizationrequset.user.UserID);
                    }
                    var ResponseUser = new PersonalizationResponseDTO <UserDTO>();
                    ResponseUser.result = updateduser;
                    ResponseUser.query  = personalizationrequset;
                    InsightLogger.TrackEvent("PersonalizationAPIController :: endpoint : api/personalizationapi/users/{userID}, action: populate user object to response, response: success, userid: " + personalizationrequset.user.UserID);
                    return(Request.CreateResponse(HttpStatusCode.OK, ResponseUser));
                }
                else
                {
                    InsightLogger.TrackEvent("PersonalizationAPIController ::endpoint : api/personalizationapi/users/{userID} , action : put user, response : userid is null");
                    return(Request.CreateResponse(HttpStatusCode.BadRequest, DataProvider.PersonalizationResponseError <UserBackendDTO>("400", "Error in updating user", "")));
                }
            }
            catch (DataAccessException dalexception)
            {
                InsightLogger.Exception(dalexception.Message, dalexception, callerMethodName);
                return(Request.CreateResponse(HttpStatusCode.NotFound, DataProvider.PersonalizationResponseError <UserDTO>("400", dalexception.Message, dalexception.Message)));
            }
            catch (BusinessLogicException blexception)
            {
                InsightLogger.Exception(blexception.Message, blexception, callerMethodName);
                return(Request.CreateResponse(HttpStatusCode.NotFound, DataProvider.PersonalizationResponseError <UserDTO>("400", blexception.Message, blexception.Message)));
            }
            catch (Exception exception)
            {
                InsightLogger.Exception(exception.Message, exception, callerMethodName);
                //LoggerHelper.WriteToLog(exception + " - exception in controller action while inserting/updating user : "******"400", exception.Message, exception.StackTrace)));
            }
        }