protected function _addPendingInvoiceAndSend(Invoice $invoice, Am_Form $form, $vars)
 {
     if ($vars['paysys_id']) {
         try {
             $invoice->setPaysystem($vars['paysys_id'], false);
         } catch (Am_Exception_InputError $e) {
             $form->setError($e->getMessage());
             return false;
         }
     }
     $errors = $invoice->validate();
     if ($errors) {
         $form->setError(current($errors));
         return false;
     }
     $invoice->data()->set('added-by-admin', $this->getDi()->authAdmin->getUserId());
     $invoice->due_date = $vars['tm_due'];
     $invoice->save();
     $et = Am_Mail_Template::load('invoice_pay_link', $invoice->getUser()->lang ? $invoice->getUser()->lang : null);
     $et->setUser($invoice->getUser());
     $et->setUrl(ROOT_SURL . sprintf('/pay/%s', $invoice->getSecureId('payment-link')));
     $et->setMessage($vars['message']);
     $et->setInvoice($invoice);
     $et->setInvoice_text($invoice->render());
     $et->send($invoice->getUser());
     return true;
 }