Fixes in response to code review

ParseSpecialEpisode now follows similar pattern to Map() method and accepts TvRageId and SearchCriteria
Fixed normalize episode title to handle punctuation separately from spaces and removed special episode words
Removed comments

src/NzbDrone.Core/DecisionEngine/DownloadDecisionMaker.cs

@@ -52,13 +52,6 @@ namespace NzbDrone.Core.DecisionEngine
                 _logger.ProgressInfo("No reports found");
             }
 
-            // get series from search criteria
-            Tv.Series series = null;
-            if (searchCriteria != null)
-            {
-                series = searchCriteria.Series;
-            }
-
             var reportNumber = 1;
 
             foreach (var report in reports)
@@ -68,17 +61,13 @@ namespace NzbDrone.Core.DecisionEngine
 
                 try
                 {
-                    // use parsing service to parse episode info (this allows us to do episode title searches against the episode repository)
                     var parsedEpisodeInfo = Parser.Parser.ParseTitle(report.Title);
 
-                    // do we have a possible special episode?
                     if (parsedEpisodeInfo == null || parsedEpisodeInfo.IsPossibleSpecialEpisode())
                     {
-                        // try to parse as a special episode
+                        var specialEpisodeInfo = _parsingService.ParseSpecialEpisodeTitle(report.Title, report.TvRageId, searchCriteria);
-                        var specialEpisodeInfo = _parsingService.ParseSpecialEpisodeTitle(report.Title, series);
                         if (specialEpisodeInfo != null)
                         {
-                            // use special episode
                             parsedEpisodeInfo = specialEpisodeInfo;
                         }
                     }

src/NzbDrone.Core/Parser/Parser.cs

@@ -114,8 +114,11 @@ namespace NzbDrone.Core.Parser
         private static readonly Regex YearInTitleRegex = new Regex(@"^(?<title>.+?)(?:\W|_)?(?<year>\d{4})",
                                                                    RegexOptions.IgnoreCase | RegexOptions.Compiled);
 
-        private static readonly Regex NonWordRegex = new Regex(@"\W+", RegexOptions.Compiled);
+        private static readonly Regex WordDelimiterRegex = new Regex(@"(\s|\.|,|_|-|=|\|)+", RegexOptions.Compiled);
-        private static readonly Regex CommonWordRegex = new Regex(@"\b(a|an|the|and|or|of|part)\b\s?",
+        private static readonly Regex PunctuationRegex = new Regex(@"[^\w\s]", RegexOptions.Compiled);
+        private static readonly Regex CommonWordRegex = new Regex(@"\b(a|an|the|and|or|of)\b\s?",
+                                                         RegexOptions.IgnoreCase | RegexOptions.Compiled);
+        private static readonly Regex SpecialEpisodeWordRegex = new Regex(@"\b(part|special|edition)\b\s?",
                                                          RegexOptions.IgnoreCase | RegexOptions.Compiled);
 
 
@@ -227,11 +230,11 @@ namespace NzbDrone.Core.Parser
 
         public static string NormalizeEpisodeTitle(string title)
         {
-            // convert any non-word characters to a single space
+            string singleSpaces  = WordDelimiterRegex.Replace(title, " ");
-            string normalizedSpaces = NonWordRegex.Replace(title, " ").ToLower();
+            string noPunctuation = PunctuationRegex.Replace(singleSpaces, String.Empty);
-            // remove common words
+            string noCommonWords = CommonWordRegex.Replace(noPunctuation, String.Empty);
-            string normalized = CommonWordRegex.Replace(normalizedSpaces, String.Empty);
+            string normalized    = SpecialEpisodeWordRegex.Replace(noCommonWords, String.Empty);
-            return normalized;
+            return normalized.Trim().ToLower();
         }
 
         public static string ParseReleaseGroup(string title)

src/NzbDrone.Core/Parser/ParsingService.cs

@@ -12,6 +12,7 @@ namespace NzbDrone.Core.Parser
 {
     public interface IParsingService
     {
+        ParsedEpisodeInfo ParseSpecialEpisodeTitle(string title, int tvRageId, SearchCriteriaBase searchCriteria = null);
         ParsedEpisodeInfo ParseSpecialEpisodeTitle(string title, Series series);
         LocalEpisode GetEpisodes(string filename, Series series, bool sceneSource);
         Series GetSeries(string title);
@@ -40,49 +41,63 @@ namespace NzbDrone.Core.Parser
             _logger = logger;
         }
 
-        public ParsedEpisodeInfo ParseSpecialEpisodeTitle(string title, Series series)
+        public ParsedEpisodeInfo ParseSpecialEpisodeTitle(string title, int tvRageId, SearchCriteriaBase searchCriteria = null)
         {
-            try
+            if (searchCriteria != null)
             {
-                if (series == null)
+                var tvdbId = _sceneMappingService.GetTvDbId(title);
+                if (tvdbId.HasValue)
                 {
-                    // find series if we dont have it already
+                    if (searchCriteria.Series.TvdbId == tvdbId)
-                    // we use an inexact match here since the series name is often mangled with the episode title
-                    series = _seriesService.FindByTitleInexact(title);
-                    if (series == null)
                     {
-                        // no series matched
+                        return ParseSpecialEpisodeTitle(title, searchCriteria.Series);
-                        return null;
                     }
                 }
 
-                // find special episode in series season 0
+                if (tvRageId == searchCriteria.Series.TvRageId)
-                Episode episode = _episodeService.FindEpisodeByName(series.Id, 0, title);
-                if (episode != null)
                 {
-                    // created parsed info from tv episode that we found
+                    return ParseSpecialEpisodeTitle(title, searchCriteria.Series);
-                    var info = new ParsedEpisodeInfo();
-                    info.SeriesTitle = series.Title;
-                    info.SeriesTitleInfo = new SeriesTitleInfo();
-                    info.SeriesTitleInfo.Title = info.SeriesTitle;
-                    info.SeasonNumber = episode.SeasonNumber;
-                    info.EpisodeNumbers = new int[1] { episode.EpisodeNumber };
-                    info.FullSeason = false;
-                    info.Quality = QualityParser.ParseQuality(title);
-                    info.ReleaseGroup = Parser.ParseReleaseGroup(title);
-
-                    _logger.Info("Found special episode {0} for title '{1}'", info, title);
-                    return info;
                 }
             }
-            catch (Exception e)
+
+            var series = _seriesService.FindByTitleInexact(title);
+            if (series == null && tvRageId > 0)
             {
-                _logger.ErrorException("An error has occurred while trying to parse special episode " + title, e);
+                series = _seriesService.FindByTvRageId(tvRageId);
             }
 
-            return null;
+            if (series == null)
+            {
+                _logger.Trace("No matching series {0}", title);
+                return null;
+            }
+
+            return ParseSpecialEpisodeTitle(title, series);
         }
 
+        public ParsedEpisodeInfo ParseSpecialEpisodeTitle(string title, Series series)
+        {
+            // find special episode in series season 0
+            var episode = _episodeService.FindEpisodeByName(series.Id, 0, title);
+            if (episode != null)
+            {
+                // create parsed info from tv episode
+                var info = new ParsedEpisodeInfo();
+                info.SeriesTitle = series.Title;
+                info.SeriesTitleInfo = new SeriesTitleInfo();
+                info.SeriesTitleInfo.Title = info.SeriesTitle;
+                info.SeasonNumber = episode.SeasonNumber;
+                info.EpisodeNumbers = new int[1] { episode.EpisodeNumber };
+                info.FullSeason = false;
+                info.Quality = QualityParser.ParseQuality(title);
+                info.ReleaseGroup = Parser.ParseReleaseGroup(title);
+
+                _logger.Info("Found special episode {0} for title '{1}'", info, title);
+                return info;
+            }
+
+            return null;
+        }
 
 
         public LocalEpisode GetEpisodes(string filename, Series series, bool sceneSource)

src/NzbDrone.Core/Tv/SeriesService.cs

@@ -103,9 +103,6 @@ namespace NzbDrone.Core.Tv
 
         public Series FindByTitleInexact(string title)
         {
-            // perform fuzzy matching of series name
-            // TODO: can replace this search mechanism with something smarter/faster/better
-
             // find any series clean title within the provided release title
             string cleanTitle = Parser.Parser.CleanSeriesTitle(title);
             var list = _seriesRepository.All().Where(s => cleanTitle.Contains(s.CleanTitle)).ToList();
@@ -137,7 +134,6 @@ namespace NzbDrone.Core.Tv
 
                 // get the leftmost series that is the longest
                 // series are usually the first thing in release title, so we select the leftmost and longest match
-                // we could have multiple matches for series which have a common prefix like "Love it", "Love it Too" so we pick the longest one
                 var match = query.First().series;
 
                 _logger.Trace("Multiple series matched {0} from title {1}", match.Title, title);