public static function getPurgeEstimate($settings = null)
    {
        if (is_null($settings)) {
            $settings = self::getPurgeDataSettings();
        }

        $result = array();

        if ($settings['delete_logs_enable']) {
            /** @var LogDataPurger $logDataPurger */
            $logDataPurger = StaticContainer::get('Piwik\Plugins\PrivacyManager\LogDataPurger');
            $result = array_merge($result, $logDataPurger->getPurgeEstimate($settings['delete_logs_older_than']));
        }

        if ($settings['delete_reports_enable']) {
            $reportsPurger = ReportsPurger::make($settings, self::getAllMetricsToKeep());
            $result = array_merge($result, $reportsPurger->getPurgeEstimate());
        }

        return $result;
    }