Sulu\Bundle\MediaBundle\Media\Storage\LocalStorage::getUniqueFileName PHP Method

    private function getUniqueFileName($folder, $fileName, $counter = 0)
    {
        $newFileName = $fileName;
        if ($counter > 0) {
            $fileNameParts = explode('.', $fileName, 2);
            $newFileName = $fileNameParts[0] . '-' . $counter;
            if (isset($fileNameParts[1])) {
                $newFileName .= '.' . $fileNameParts[1];
            }
        }
        $filePath = $this->getPathByFolderAndFileName($folder, $newFileName);
        $this->logger->debug('Check FilePath: ' . $filePath);
        if (!$this->filesystem->exists($filePath)) {
            return $newFileName;
        }
        ++$counter;
        return $this->getUniqueFileName($folder, $fileName, $counter);
    }