public async Task <IActionResult> AttachUser(Guid reportId, string email) { if (await _reportService.ContainsUser(reportId, email)) { return(BadRequest($"User with email='{email}' already attached to report with id='{reportId}'")); } await _reportService.AttachUserAsync(reportId, email); return(Ok($"User with email='{email}' was successfully attached to report with id='{reportId}'")); }