Wildcard permalinks

function pm_wildcard_permalinks($element_id, $uri_parts) {
    global $permalink_manager_uris;

    if(empty($element_id) && !empty($uri_parts['uri']) && strpos($uri_parts['uri'], 'product/') !== false) {
        $product_slug = basename($uri_parts['uri']);

        $regex = sprintf("product\/(.*)\/%s$", preg_quote($product_slug, '/'));
        $matches = preg_grep("/{$regex}/i", $permalink_manager_uris);

        if(!empty($matches)) {
            $matches = array_flip($matches);
            $new_element_id = reset($matches);
        }
    }

    return (!empty($new_element_id)) ? $new_element_id : $element_id;
}
add_action('permalink_manager_detected_element_id', 'pm_wildcard_permalinks', 9999, 2);