public IActionResult DeleteFile(int id)
        {
            _loggerManager.Info($"DeleteFile({id}) was requested");

            var file = _fileRepository.GetFile(id);

            if (file == null)
            {
                _loggerManager.Warn($"DeleteFile({id}) request is a bad request");
                return(BadRequest());
            }

            var result = _fileRepository.Delete(id);

            if (result)
            {
                _loggerManager.Info($"DeleteFile({id}) deleted a file info from database");

                if (UploadHelper.Delete(file.Path))
                {
                    _loggerManager.Info($"DeleteFile({id}) deleted a file from a directory");
                }
                else
                {
                    _loggerManager.Info($"DeleteFile({id}) was unable to delete a file from a directory");
                }
            }

            return(Ok(new { result }));
        }
        public IActionResult UploadIntroduction(IntroductionDTO introduction)
        {
            _loggerManager.Info($"UploadIntroduction was requested");

            var files = HttpContext.Request.Form.Files;

            if (files == null || files.Count != 1)
            {
                ModelState.AddModelError(string.Empty, sharedResource.manageIntroductionInvalidFile);

                _loggerManager.Warn($"UploadIntroduction : A file is invalid");

                return(View("Introduction", introduction));
            }

            //validates step's index
            if (!_planRepository.GetStepList().Contains(introduction.Step))
            {
                _loggerManager.Warn($"UploadIntroduction : Step index is wrong");
                return(BadRequest());
            }

            var uploadlimit = int.Parse(_settingRepository.Get(Settings.FileUploadLimit));

            if (!ValidationHelper.ValidateFileSize(files[0], uploadlimit))
            {
                ModelState.AddModelError(string.Empty, sharedResource.manageIntroductionFileLimitError);

                _loggerManager.Warn($"UploadIntroduction : A file exceed a limit");

                return(View("Introduction", introduction));
            }

            var userId = HttpContext.GetUserId();

            //upload a file in wwwroot directory
            var uploadRelPath = UploadHelper.Upload(files[0]);

            //creates a new file record
            var fileDto = _fileRepository.CreateNewFile(Path.GetFileNameWithoutExtension(files[0].FileName), Path.GetExtension(files[0].FileName), uploadRelPath, userId);

            //boolean that determines a result for updating of an introduction
            var result = false;


            if (fileDto != null)//A file record created, updates an introduction record
            {
                _loggerManager.Info($"UploadIntroduction : A file was created");

                //takes an older video version
                var oldVideo = _planRepository.GetIntroduction(introduction.Step)?.Video;

                //updaates an introduction for a step
                result = _planRepository.UpdateIntroduction(introduction.Step, fileDto.Id, userId);

                if (result && oldVideo != null)//If a update was succeessful and the introduction had a video before, deletes an older video
                {
                    //a result boolean
                    bool oldFileDelete;

                    //Deletes corresponding record in a repository and corresponding file in a directory, If any fails a result boolean is false
                    oldFileDelete = UploadHelper.Delete(oldVideo.Path);
                    oldFileDelete = _fileRepository.Delete(oldVideo.Id) && oldFileDelete;

                    if (oldFileDelete)
                    {
                        _loggerManager.Warn($"UploadIntroduction : An old file was deleted");
                    }
                    else
                    {
                        _loggerManager.Warn($"UploadIntroduction : An old file was not deleted");
                    }
                }
            }

            if (!result)
            {
                ModelState.AddModelError(string.Empty, sharedResource.manageServerError);
                _loggerManager.Warn($"UploadIntroduction was unable to update");

                return(View("Introduction", introduction));
            }
            else
            {
                _loggerManager.Info($"UploadIntroduction successfully updated");
            }

            return(RedirectToAction("GetIntroduction", new { stepIndex = introduction.Step }));
        }