redeem.php

<?php

/**
 * This file contains package_quiqqer_coupons_ajax_delete
 */

use QUI\ERP\Coupons\Handler;

/**
 * Redeem a CouponCode
 *
 * @param int $id - CouponCode ID
 * @return bool - success
 */
QUI::$Ajax->registerFunction(
    'package_quiqqer_coupons_ajax_frontend_redeem',
    function ($code, $orderHash) {
        try {
            $code       = Handler::sanitizeCode($code);
            $CouponCode = Handler::getCouponCodeByCode($code);
            $CouponCode->checkRedemption(QUI::getUserBySession());
        } catch (QUI\ERP\Coupons\CouponCodeException $Exception) {
            QUI\System\Log::writeDebugException($Exception);

            QUI::getMessagesHandler()->addError($Exception->getMessage());

            return false;
        } catch (\Exception $Exception) {
            QUI\System\Log::writeException($Exception);

            QUI::getMessagesHandler()->addError(
                QUI::getLocale()->get(
                    'quiqqer/coupons',
                    'message.ajax.general_error'
                )
            );

            return false;
        }

        $Order   = QUI\ERP\Order\Handler::getInstance()->getOrderByHash($orderHash);
        $coupons = $Order->getDataEntry('quiqqer-coupons');

        if (empty($coupons)) {
            $coupons = [];
        }

        $coupons[] = $code;

        $coupons = \array_unique($coupons);

        $Order->setData('quiqqer-coupons', $coupons);
        $Order->update();

        // add
        if ($Order instanceof QUI\ERP\Order\OrderInProcess) {
            $CouponCode->addToOrder($Order);
        }

        return true;
    },
    ['code', 'orderHash']
);