Order product search results by total sales

searchwp-customisations.php

<?php

// Order product search results by total sales
add_filter( 'searchwp\query\mods', function( $mods, $query ) {
    global $wpdb;
 
    $mod        = new \SearchWP\Mod();
    $alias      = \SearchWP::$index->get_alias();
    $meta_alias = 'my_searchwp_sort_products';
    $meta_key   = 'total_sales';
 
    $mod->column_as( $wpdb->prepare( "(
        SELECT meta_value
        FROM {$wpdb->postmeta}
        WHERE
            {$wpdb->postmeta}.post_id = {$alias}.id
            AND {$wpdb->postmeta}.meta_key = %s
        )", $meta_key ),
        $meta_alias );
    $mod->order_by( "{$meta_alias} + 0", 'DESC', 5 );
 
    $mods[] = $mod;
 
    return $mods;
}, 30, 2 );