WooCommerce 中付费客户的自动折扣

Question

我想向在我的网站上至少购买过一次的每个人自动应用折扣券。这是我尝试过的代码，但我在页面上遇到了致命错误...

function has_bought( $customer_email ){

    $orders = get_posts(array(

        'numberposts' => -1,

        'post_type' => 'shop_order',

        'post_status' => array('wc-completed'),

    )  );

    $email_array = array();

    foreach($orders as $order) {

        $order_obj = wc_get_order($order->ID);

        $order_obj_data = $order_obj->get_data();

        array_push($email_array, $order_obj_data['billing']['email']);

    }

    if (in_array($customer_email, $email_array)) {

        return true;

    } else {

        return false;

    }

}

add_action( 'woocommerce_before_cart', 'apply_matched_coupons' );

function apply_matched_coupons() {

    global $woocommerce;

    $coupon_code = '10fidelity'; // coupon code

    if ( $woocommerce->cart->has_discount( $coupon_code ) ) return;

    if ( has bought() {

        $woocommerce->cart->add_discount( $coupon_code );

        $woocommerce->show_messages();

    }

}