private bool ValidateFileUpload(FileUpload[] fileUploads)
        {
            var isInvalidFiles = false;

            foreach (var file in fileUploads)
            {
                var validate = CloudinaryUploadHelper.ValidateFileUpload(file);
                if (validate >= 0)
                {
                    var errorsLibrary = CloudinaryUploadHelper.FileUploadErrorsDictionary;
                    ModelState.AddModelError(errorsLibrary.Keys.ElementAt(validate),
                                             errorsLibrary[errorsLibrary.Keys.ElementAt(validate)]);
                    isInvalidFiles = true;
                }
            }

            return(isInvalidFiles);
        }
        public async Task <IHttpActionResult> UpdateByFaceScan([FromUri] int timeTableId)
        {
            var timeTable = await _unitOfWork.TimeTables.GetTimeTable(timeTableId);

            if (timeTable == null)
            {
                return(NotFound());
            }
            var provider = await Request.Content.ReadAsMultipartAsync();

            var fileUploads = new List <FileUpload>();

            foreach (var content in provider.Contents)
            {
                if (content.Headers != null)
                {
                    fileUploads.Add(new FileUpload
                    {
                        FileStream = await content.ReadAsStreamAsync(),
                        FileName   = content.Headers.ContentDisposition.FileName
                    });
                }
            }

            var isInvalidFile = ValidateFileUpload(fileUploads.ToArray());

            if (isInvalidFile)
            {
                return(BadRequest(ModelState));
            }
            var uploadResults = (await CloudinaryUploadHelper.UploadImagesToCloudinary(fileUploads)).ToArray();

            foreach (var result in uploadResults)
            {
                var recognitionImage = new RecognitionImage
                {
                    TimeTableId = timeTableId,
                    Uri         = result.Uri,
                    SecureUri   = result.SecureUri
                };
                _unitOfWork.RecognitionImages.Add(recognitionImage);
            }

            await _unitOfWork.Completed();

            var identifiedPersons = (await FaceAPI.RecognizeFaces(new RecognizeFacesBindingModel
            {
                PersonGroupId = FaceAPI.PersonGroupId,
                FacesUrl = uploadResults.Select(c => c.SecureUri)
            })).ToList();

            var studentIds = (await _unitOfWork.Attendances.GetStudentIdListForTimeTable(timeTableId)).ToArray();
            var statusAttendanceListInDb = (await _unitOfWork.StatusAttendances.GetStatusAttendanceList()).ToArray();
            var attendedStatus           =
                statusAttendanceListInDb.FirstOrDefault(c => c.Id == (int)StatusAttendanceType.Attended);
            var absentStatus = statusAttendanceListInDb.FirstOrDefault(c => c.Id == (int)StatusAttendanceType.Absent);
            var attendancesListWillBeUpdated =
                (await _unitOfWork.Attendances.GetAttendanceListForStudentsList(timeTableId, studentIds)).ToList();

            if (identifiedPersons.Count == 0)
            {
                attendancesListWillBeUpdated.ForEach(a =>
                {
                    a.StatusAttendanceId = (int)StatusAttendanceType.Absent;
                    a.StatusAttendance   = absentStatus;
                });
            }
            else
            {
                attendancesListWillBeUpdated.ForEach(a =>
                {
                    var identifiedPerson = identifiedPersons.FirstOrDefault
                                               (ad => ad.Name.Equals(a.StudentId, StringComparison.CurrentCultureIgnoreCase));
                    if (identifiedPerson != null)
                    {
                        a.StatusAttendanceId = (int)StatusAttendanceType.Attended;
                        a.StatusAttendance   = attendedStatus;
                    }

                    else
                    {
                        a.StatusAttendanceId = (int)StatusAttendanceType.Absent;
                        a.StatusAttendance   = absentStatus;
                    }
                });
            }
            var statusAttendancesList =
                await _unitOfWork.Attendances.UpdateAttendanceForStudentList(attendancesListWillBeUpdated);

            timeTable.StatusTakeAttendanceId = (int)StatusTakeAttendanceType.Taken;
            _unitOfWork.TimeTables.Update(timeTable);
            await _unitOfWork.Completed();

            return(Ok(statusAttendancesList));
        }