Schedule a task to run daily to delete WooCommerce persistent carts

wc-clear-persistent-carts-daily.php

<?php
/**
 * Plugin Name: Clear persistent carts daily
 * Plugin URI: https://gist.github.com/
 * Description: Schedule a task to run daily to delete WooCommerce persistent carts
 * Version: 1.0.0
 * Author: Kathy Darling
 * Author URI: http://kathyisawesome.com/
 * WC requires at least: 6.3.0
 * WC tested up to: 6.3.0
 * Requires at least: 5.9.0
 *
 * Copyright: © 2022
 * License: GNU General Public License v3.0
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 */
function kia_install_clear_cart_action() {

    if ( ! function_exists( 'WC') ) {
		return;
	}

    $next_scheduled_date = WC()->queue()->get_next( 'kia_run_batch_user_cart_update', null, 'kia-persistent-cart-updates' );

	if ( ! $next_scheduled_date && false === get_transient( 'kia_clear_persistent_carts_scheduled' ) ) {
        WC()->queue()->schedule_cron(
						'15 1 * * *', // Daily at 1:15am (I hope)
						'kia_run_batch_user_cart_update',
						array(
							'step' => 1,
						),
						'kia-persistent-cart-updates'
					);
        set_transient( 'kia_clear_persistent_carts_scheduled', 'yes' );
    }
}
add_action( 'admin_init', 'kia_install_clear_cart_action' );



/**
 * Batch process all user meta
 *
 * @param  int $step - count of interations
 */
function kia_batch_clear_persitent_carts( $step = 1 ) {

    if ( apply_filters( 'woocommerce_persistent_cart_enabled', true ) ) {

        $batch_size = 20;
        $step = $step ? intval( $step ) : 1;
        $offset = $batch_size * ( $step - 1 );

        $user_query = new WP_User_Query( array(
            'number' => $batch_size,
            'offset' => $offset
            'fields' => 'ID',
        );

        if ( $user_query ) {

            $get_current_blog_id = get_current_blog_id();

            foreach( $user_query as $user_id ) {
                delete_user_meta( $user_id, '_woocommerce_persistent_cart_' . $get_current_blog_id ); // This might be more efficient as an SQL query (no do_action()).
            }

            $step++;
            
            // Schedule the next batch.		
            WC()->queue()->schedule_single(
                time(),
                'kia_run_batch_user_cart_update',
                array(
                    'step'=> $step,
                ),
                'kia-group'
            );

        }

		
	}

}
add_action( 'kia_run_batch_user_cart_update', 'kia_batch_clear_persitent_carts' );