public IActionResult ImagesConvertor(ImagesConvertorViewModel model)
        {
            if (ModelState.IsValid)
            {
                Guid   guid          = Guid.NewGuid(); // Create a unique code for a folder of images and ZIP file.
                string directoryPath = Path.Combine(webHostEnvironment.WebRootPath, "temporary-files", guid.ToString());

                try
                {
                    foreach (IFormFile image in model.UploadFiles)
                    {
                        // convert original and save
                        if (model.OutputWeb)
                        {
                            imageServices.ConvertImage(image, directoryPath, ImageServices.EImageFormat.WebP);
                        }
                        if (model.OutputJpeg)
                        {
                            imageServices.ConvertImage(image, directoryPath, ImageServices.EImageFormat.Jpeg);
                        }

                        // edit sizes and save
                        foreach (int width in model.Widths)
                        {
                            if (model.OutputWeb)
                            {
                                imageServices.ConvertImage(image, directoryPath, ImageServices.EImageFormat.WebP, width);
                            }
                            if (model.OutputJpeg)
                            {
                                imageServices.ConvertImage(image, directoryPath, ImageServices.EImageFormat.Jpeg, width);
                            }
                        }
                    }

                    ZipFile.CreateFromDirectory(directoryPath, $"{directoryPath}.zip"); // Create a ZIP from the folder in which the edited images.

                    FileStream fileStream = new($"{directoryPath}.zip", FileMode.Open);
                    return(File(fileStream, "application/zip", "kovertované-obrázky.zip"));
                }
                catch (Exception e)
                {
                    logger.LogError(e, e.Message);
                    this.AddFlashMessage("Pri konvertovaní obrázku/ov došlo k chybe. Skúste to ešte raz...", FlashMessageType.Danger);

                    return(RedirectToAction(nameof(ImagesConvertor)));
                }
            }

            return(View(model));
        }