Define maximum number of invoices allowed per user within 24 hours

This example prevents a logged-in user from creating more than 10 invoices within 24 hours.

Add this code to site.php file:

Am_Di::getInstance()->hook->add(Am_Event::VALIDATE_SAVED_FORM, function (Am_Event_ValidateSavedForm $event) {
    $savedForm = $event->getSavedForm();
    if (!$savedForm || !$savedForm->isSignup()) {
        return;
    }

    if (!$userId = $event->getDi()->auth->getUserId()) {
        return;
    }

    $invoiceLimit = 10;
    $invoiceCount = $event->getDi()->db->selectCell(
        "SELECT COUNT(*) FROM ?_invoice WHERE user_id=?d AND tm_added>?",
        $userId,
        sqlTime('-24 hours')
    );

    if ($invoiceCount >= $invoiceLimit) {
        $event->addError(___('Registration from you IP is temporary disabled'));
    }
});