woothemes/woocommerce

<?php
/**
 * Customer Data Store Interface
 *
 * @version 3.0.0
 * @package WooCommerce\Interface
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * WC Customer Data Store Interface
 *
 * Functions that must be defined by customer store classes.
 *
 * @version  3.0.0
 */
interface WC_Customer_Data_Store_Interface {

    /**
     * Gets the customers last order.
     *
     * @param WC_Customer $customer Customer object.
     * @return WC_Order|false
     */
    public function get_last_order( &$customer );

    /**
     * Return the number of orders this customer has.
     *
     * @param WC_Customer $customer Customer object.
     * @return integer
     */
    public function get_order_count( &$customer );

    /**
     * Return how much money this customer has spent.
     *
     * @param WC_Customer $customer Customer object.
     * @return float
     */
    public function get_total_spent( &$customer );
}