yf_shop_basket_add user module

    public function basket_add()
    {
        $product = db()->query_fetch('SELECT id FROM ' . db('shop_products') . " WHERE active = '1' AND " . (is_numeric(($_GET['id'] ?? null)) ? 'id=' . (int) (($_GET['id'] ?? null)) : "url='" . _es(($_GET['id'] ?? null)) . "'"));
        if ( ! empty($product)) {
            $_GET['id'] = $product['id'];
        }
        $atts = module('shop')->_products_get_attributes($product['id']);
        if (($_GET['id'] ?? null)) {
            $_GET['id'] = (int) (($_GET['id'] ?? null));
            $_POST['quantity'][$_GET['id']] = 1;
        }
        if ( ! empty($atts) && empty($_POST['atts'])) {
            module('shop')->_basket_is_processed = true;
            return js_redirect('./?object=shop&action=product_details&id=' . ($_GET['id'] ?? null));
        }
        if ( ! empty($_POST['quantity']) && ! module('shop')->_basket_is_processed) {
            foreach ((array) ($_POST['quantity'] ?? null) as $_product_id => $_quantity) {
                $_product_id = (int) $_product_id;
                $_old_quantity = (int) module('shop')->_basket_api()->get($_product_id, 'quantity');
                $_quantity = (int) $_quantity + (int) $_old_quantity;
                if ($_product_id && $_quantity) {
                    module('shop')->_basket_api()->set($_product_id, [
                        'product_id' => $_product_id,
                        'quantity' => $_quantity,
                        'atts' => ($_POST['atts'][$_product_id] ?? null),
                    ]);
                }
            }
            // Prevent double processing
            module('shop')->_basket_is_processed = true;
        }
        return js_redirect('./?object=shop');
    }