ADBaseLibrary.TemplateParser.FilenameFromEpisode C# (CSharp) Method

        public static string FilenameFromEpisode(Episode ep, Quality q, string template)
        {
            List<object> vars=new List<object>();
            MatchCollection m = _varRegex.Matches(template);
            int cnt = 0;
            foreach (Match match in m)
            {
                if (match.Success)
                {
                    string t = match.Groups["variable"].Value.ToLower();
                    int idx = t.IndexOf(":", StringComparison.InvariantCulture);
                    if (idx > 0)
                        t = t.Substring(0, idx);
                    if (Variables.Contains(t))
                    {
                        TemplateVariables tv = (TemplateVariables) Enum.Parse(typeof (TemplateVariables), t);
                        switch (tv)
                        {
                            case TemplateVariables.show:
                                vars.Add(ep.ShowName);
                                break;
                            case TemplateVariables.episodealpha:
                                vars.Add(ep.EpisodeAlpha ?? string.Empty);
                                break;
                            case TemplateVariables.episodenumeric:
                                vars.Add(ep.EpisodeNumeric);
                                break;
                            case TemplateVariables.seasonalpha:
                                vars.Add(ep.SeasonAlpha ?? string.Empty);
                                break;
                            case TemplateVariables.seasonalphaorshow:
                                if (string.IsNullOrEmpty(ep.SeasonAlpha))
                                    vars.Add(ep.ShowName ?? string.Empty);
                                else
                                    vars.Add(ep.SeasonAlpha);
                                break;
                            case TemplateVariables.seasonnumeric:
                                vars.Add(ep.SeasonNumeric);
                                break;
                            case TemplateVariables.index:
                                vars.Add(ep.Index);
                                break;
                            case TemplateVariables.plugin:
                                vars.Add(ep.PluginName);
                                break;
                            case TemplateVariables.resolution:
                                vars.Add(q.ToText());
                                break;
                        }
                        template = template.Replace("{" + t, "{" + cnt);
                        cnt++;
                    }
                }
            }
            string fname= string.Format(template, vars.ToArray());
            foreach (char c in System.IO.Path.GetInvalidFileNameChars())
                fname = fname.Replace(c.ToString(), string.Empty);
            return fname;
        }
    }

 public DownloadItem(EpisodeWithDownloadSettings ep, string template, string path, DownloadManager manager, DownloadStatus status)
 {
     _ep                    = ep;
     Status                 = status;
     DownloadInfo           = new DownloadInfo();
     DownloadInfo.FileName  = TemplateParser.FilenameFromEpisode(ep, ep.Quality, template);
     DownloadInfo.FullPath  = Path.Combine(path, DownloadInfo.FileName);
     DownloadInfo.Quality   = ep.Quality;
     DownloadInfo.Format    = ep.Format;
     DownloadInfo.Languages = new List <string>();
     DownloadInfo.Status    = string.Empty;
     DownloadInfo.Percent   = 0;
     _template              = template;
     _path                  = path;
     Id         = Guid.NewGuid().ToString();
     _manager   = manager;
     _scheduler = TaskScheduler.FromCurrentSynchronizationContext();
 }