oldtest.cs

private void CheckFilesInFolder(Sftp connection, string directory, List<string> errors)
{
    if (!connection.DirectoryExists(directory))
        return;

    var items = connection.GetList(directory);

    var files = items.Where(x => x.IsFile).ToList();
    if (files.Any(f => f.Name.EndsWith(".mp4") || f.Name.EndsWith(".mp3")))
    {
        var guid = GetFileNameWithoutQuality(files.First().Name);
        if (!files.All(f => f.Name.StartsWith(guid+"_")))
        {
            Console.WriteLine("Failing for program with directory " + directory + " and guid " + guid);
            errors.Add(directory);
        }
    }

    var directories = items.Where(x => x.IsDirectory).ToList();
    directories.ForEach(x => CheckFilesInFolder(connection, directory + "/" + x.Name, errors));
}