public async Task <IActionResult> UploadCampaignAttachment([FromRoute] Guid campaignId, [FromForm] IFormFile file)
{
if (file == null)
{
ModelState.AddModelError(nameof(file), "File is empty.");
return(BadRequest(new ValidationProblemDetails(ModelState)));
}
var campaign = await CampaignService.GetCampaignById(campaignId);
if (campaign is null)
{
return(NotFound());
}
var attachment = await CampaignService.CreateAttachment(file);
await CampaignService.AssociateCampaignAttachment(campaignId, attachment.Id);
return(Ok(attachment));
}