Unique permalinks

function pm_force_unique_permalinks($post_id, $new_uri, $old_uri) {
    global $permalink_manager_uris;

    while(empty($new_unique_permalink)) {
        $duplicates = array_keys($permalink_manager_uris, $new_uri);

        if(is_array($duplicates)) {
            $duplicated_ids = array_flip($duplicates);

            // Ignore this particular post
            if(isset($duplicated_ids[$post_id])) {
                unset($duplicated_ids[$post_id]);
            }

            // Count duplicates
            $duplicates_count = count($duplicated_ids) + 1;

            // Add numeral prefix to the URL
            if($duplicates_count > 1) {
                preg_match('/(.*)-([\d]{1,3})$/', $new_uri, $out);

                if(!empty($out[2])) {
                    $new_uri = sprintf('%s-%d', $out[1], (int) $out[2] + 1);
                } else {
                    $new_uri = preg_replace('/(.+?)(\.[^\.]+$|$)/', '$1-' . $duplicates_count . '$2', $new_uri);
                }
            } else {
                $new_unique_permalink = $new_uri;
            }
        }
    }

    $permalink_manager_uris[$post_id] = $new_unique_permalink;
    update_option('permalink-manager-uris', $permalink_manager_uris);
}
// Make the new post's permalink unique
add_action('permalink_manager_new_post_uri', 'pm_force_unique_permalinks', 10, 3);

// Make the existing permalink unique after the permalink is updated
add_action('permalink_manager_updated_post_uri', 'pm_force_unique_permalinks', 10, 3);