woothemes/woocommerce

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

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

/**
 * WC Coupon Data Store Interface
 *
 * Functions that must be defined by coupon store classes.
 *
 * @version  3.0.0
 */
interface WC_Coupon_Data_Store_Interface {
    /**
     * Increase usage count for current coupon.
     *
     * @param WC_Coupon $coupon Coupon object.
     * @param string    $used_by Either user ID or billing email.
     */
    public function increase_usage_count( &$coupon, $used_by = '' );

    /**
     *  Decrease usage count for current coupon.
     *
     * @param WC_Coupon $coupon Coupon object.
     * @param string    $used_by Either user ID or billing email.
     */
    public function decrease_usage_count( &$coupon, $used_by = '' );

    /**
     * Get the number of uses for a coupon by user ID.
     *
     * @param WC_Coupon $coupon Coupon object.
     * @param int       $user_id User ID.
     * @return int
     */
    public function get_usage_by_user_id( &$coupon, $user_id );

    /**
     * Return a coupon code for a specific ID.
     *
     * @param int $id Coupon ID.
     * @return string Coupon Code.
     */
    public function get_code_by_id( $id );

    /**
     * Return an array of IDs for for a specific coupon code.
     * Can return multiple to check for existence.
     *
     * @param string $code Coupon code.
     * @return array Array of IDs.
     */
    public function get_ids_by_code( $code );
}