private string EnsureCurrentWorker(AttendanceLog log)
        {
            var workerId = _db.GetWorkerIdByEnrollNumberAndProjectId(log.UserId, log.ProjectId);

            if (!string.IsNullOrWhiteSpace(workerId))
            {
                return(workerId);
            }

            //request
            workerId = _web.FindProjectWorkerByFaceId(log.ProjectId, log.UserId).GetAwaiter().GetResult();
            if (!string.IsNullOrWhiteSpace(workerId))
            {
                _db.AddWorker(new WorkerInfo
                {
                    UserId       = workerId,
                    EnrollNumber = log.UserId,
                    ProjectId    = log.ProjectId
                });
                return(workerId);
            }

            return(string.Empty);
        }