public function add_customer_data( $order_data, $order ) {

		if ( 0 == $order->get_user_id() ) {

			// add customer data from order
			$order_data['customer'] = array(
				'id'               => 0,
				'email'            => $order->get_billing_email(),
				'first_name'       => $order->get_billing_first_name(),
				'last_name'        => $order->get_billing_last_name(),
				'billing_address'  => array(
					'first_name' => $order->get_billing_first_name(),
					'last_name'  => $order->get_billing_last_name(),
					'company'    => $order->get_billing_company(),
					'address_1'  => $order->get_billing_address_1(),
					'address_2'  => $order->get_billing_address_2(),
					'city'       => $order->get_billing_city(),
					'state'      => $order->get_billing_state(),
					'postcode'   => $order->get_billing_postcode(),
					'country'    => $order->get_billing_country(),
					'email'      => $order->get_billing_email(),
					'phone'      => $order->get_billing_phone(),
				),
				'shipping_address' => array(
					'first_name' => $order->get_shipping_first_name(),
					'last_name'  => $order->get_shipping_last_name(),
					'company'    => $order->get_shipping_company(),
					'address_1'  => $order->get_shipping_address_1(),
					'address_2'  => $order->get_shipping_address_2(),
					'city'       => $order->get_shipping_city(),
					'state'      => $order->get_shipping_state(),
					'postcode'   => $order->get_shipping_postcode(),
					'country'    => $order->get_shipping_country(),
				),
			);

		} else {

			$order_data['customer'] = current( $this->get_customer( $order->get_user_id() ) );
		}

		return $order_data;
	}