public function downloadAction($ticketMessageId)
    {
        $ticketManager = $this->get('hackzilla_ticket.ticket_manager');
        $ticketMessage = $ticketManager->getMessageById($ticketMessageId);

        if (!$ticketMessage || !$ticketMessage instanceof TicketMessageWithAttachment) {
            throw $this->createNotFoundException($this->get('translator')->trans('ERROR_FIND_TICKET_ENTITY', [], 'HackzillaTicketBundle'));
        }

        // check permissions
        $userManager = $this->get('hackzilla_ticket.user_manager');
        $userManager->hasPermission($userManager->getCurrentUser(), $ticketMessage->getTicket());

        $downloadHandler = $this->get('vich_uploader.download_handler');

        return $downloadHandler->downloadObject($ticketMessage, 'attachmentFile');
    }