Query building function for getting users by role and taxonomy

get_users_by_role_tax_intersection.php

function get_user_role_tax_intersection($args = array()){
    global $wpdb;

    $default_args = array(
        'hide_untaxed' => true
        'terms'         => array(),
        'roles'         => array('administrator')
    );

    $args = array_merge($default_args, $args);
    
    $roles = implode("|", $args['roles']);

    $query['SELECT'] = array(
        'SELECT DISTINCT u.ID, u.user_login, u.user_nicename, u.user_email, u.display_name, m2.meta_value as role, GROUP_CONCAT(DISTINCT m.meta_value) AS terms'
    );

    $query['JOIN'] = array(
        "JOIN wp_usermeta AS m  ON u.ID = m.user_id AND m.meta_key = 'um-taxonomy-category'",
        "JOIN wp_usermeta AS m2 ON m2.meta_value REGEXP '{$roles}'"
    );

    $query['GROUP'] = 'GROUP BY u.ID';
    $query['ORDER'] = 'ORDER BY m.meta_key';

    if($args['hide_untaxed'] == false){
        $query['JOIN'][0] = 'LEFT '. $query['JOIN'][0];
    }

    if(!empty($args['terms'])){
        $terms = implode(', ', $args['terms']);
        $query['JOIN'][0] .= 'AND m.meta_value IN ($terms)';
    }

    $query['JOIN'] = implode(' ', $query['JOIN']);

    return  implode(' ', $query);

}