Fixed: Improve TrackMatching when title is slightly longer/shorter than DB (#491)

* improve TrackMatching

* Add unit test for TrackMatching

* rename NormalizeEpisodeTitle to NormalizeTrackTitle

* correct typo

src/NzbDrone.Core.Test/MusicTests/TitleMatchingTests/TitleMatchingFixture.cs

@@ -0,0 +1,69 @@
+using System.Linq;
+using FluentAssertions;
+using NLog;
+using NUnit.Framework;
+using NzbDrone.Core.Configuration;
+using NzbDrone.Core.Music;
+using NzbDrone.Core.Test.Framework;
+
+namespace NzbDrone.Core.Test.MusicTests.TitleMatchingTests
+{
+    [TestFixture]
+    public class TitleMatchingFixture : DbTest<TrackService, Track>
+    {
+        private TrackRepository _trackRepository;
+        private TrackService _trackService;
+
+        [SetUp]
+        public void Setup()
+        {
+            _trackRepository = Mocker.Resolve<TrackRepository>();
+            _trackService =
+                new TrackService(_trackRepository, Mocker.Resolve<ConfigService>(), Mocker.Resolve<Logger>());
+
+            _trackRepository.Insert(new Track
+            {
+                Title = "This is the short test title",
+                ForeignTrackId = "this is a fake id2",
+                AlbumId = 4321,
+                AbsoluteTrackNumber = 1,
+                MediumNumber = 1,
+                TrackFileId = 1
+            });
+
+            _trackRepository.Insert(new Track
+            {
+                Title = "This is the long test title",
+                ForeignTrackId = "this is a fake id",
+                AlbumId = 4321,
+                AbsoluteTrackNumber = 2,
+                MediumNumber = 1,
+                TrackFileId = 2
+            });
+        }
+
+        [Test]
+        public void should_find_track_in_db_by_tracktitle_longer_then_relaeasetitle()
+        {
+            var track = _trackService.FindTrackByTitle(1234, 4321, 1, 1, "This is the short test title with some bla");
+
+            track.Title.Should().Be(_trackRepository.GetTracksByFileId(1).First().Title);
+        }
+
+        [Test]
+        public void should_find_track_in_db_by_tracktitle_shorter_then_relaeasetitle()
+        {
+            var track = _trackService.FindTrackByTitle(1234, 4321, 1, 2, "test title");
+
+            track.Title.Should().Be(_trackRepository.GetTracksByFileId(2).First().Title);
+        }
+
+        [Test]
+        public void should_not_find_track_in_db_by_wrong_title()
+        {
+            var track = _trackService.FindTrackByTitle(1234, 4321, 1, 1, "the short title");
+
+            track.Should().BeNull();
+        }
+    }
+}

src/NzbDrone.Core.Test/NzbDrone.Core.Test.csproj

@@ -306,6 +306,7 @@
     <Compile Include="MusicTests\ArtistServiceTests\UpdateMultipleArtistFixture.cs" />
     <Compile Include="MusicTests\RefreshAlbumServiceFixture.cs" />
     <Compile Include="MusicTests\ShouldRefreshAlbumFixture.cs" />
+    <Compile Include="MusicTests\TitleMatchingTests\TitleMatchingFixture.cs" />
     <Compile Include="NotificationTests\NotificationBaseFixture.cs" />
     <Compile Include="NotificationTests\SynologyIndexerFixture.cs" />
     <Compile Include="OrganizerTests\FileNameBuilderTests\CleanTitleFixture.cs" />

src/NzbDrone.Core/Music/TrackService.cs

@@ -79,35 +79,25 @@ namespace NzbDrone.Core.Music
         public Track FindTrackByTitle(int artistId, int albumId, int mediumNumber, int trackNumber, string releaseTitle)
         {
             // TODO: can replace this search mechanism with something smarter/faster/better
-            var normalizedReleaseTitle = Parser.Parser.NormalizeEpisodeTitle(releaseTitle).Replace(".", " ");
+            var normalizedReleaseTitle = Parser.Parser.NormalizeTrackTitle(releaseTitle).Replace(".", " ");
             var tracks = _trackRepository.GetTracksByMedium(albumId, mediumNumber);
 
-            var matches = tracks.Select(
-                track => new
+            var matches = from track in tracks
+                //if we have a trackNumber use it
+                let trackNumCheck = (trackNumber == 0 || track.AbsoluteTrackNumber == trackNumber)
+                //if release title is longer than track title
+                let posReleaseTitle = normalizedReleaseTitle.IndexOf(Parser.Parser.NormalizeTrackTitle(track.Title), StringComparison.CurrentCultureIgnoreCase)
+                //if track title is longer than release title 
+                let posTrackTitle = Parser.Parser.NormalizeTrackTitle(track.Title).IndexOf(normalizedReleaseTitle, StringComparison.CurrentCultureIgnoreCase)
+                where track.Title.Length > 0 && trackNumCheck && (posReleaseTitle >= 0 || posTrackTitle >= 0)
+                orderby posReleaseTitle, posTrackTitle
+                select new
                 {
-                    Position = normalizedReleaseTitle.IndexOf(Parser.Parser.NormalizeEpisodeTitle(track.Title), StringComparison.CurrentCultureIgnoreCase),
-                    Length = Parser.Parser.NormalizeEpisodeTitle(track.Title).Length,
+                    NormalizedLength = Parser.Parser.NormalizeTrackTitle(track.Title).Length,
                     Track = track
-                });
+                };
 
-            if (trackNumber == 0)
-            {
-                matches =  matches.Where(e => e.Track.Title.Length > 0 && e.Position >= 0);
-            } else
-            {
-                matches = matches.Where(e => e.Track.Title.Length > 0 && e.Position >= 0 && e.Track.AbsoluteTrackNumber == trackNumber);
-            }
- 
-            matches.OrderBy(e => e.Position)
-                    .ThenByDescending(e => e.Length)
-                    .ToList();
-
-            if (matches.Any())
-            {
-                return matches.First().Track;
-            }
-
-            return null;
+            return matches.OrderByDescending(e => e.NormalizedLength).FirstOrDefault()?.Track;
         }
 
         public List<Track> TracksWithFiles(int artistId)

src/NzbDrone.Core/Parser/Parser.cs

@@ -529,7 +529,7 @@ namespace NzbDrone.Core.Parser
             return NormalizeRegex.Replace(name, string.Empty).ToLower().RemoveAccent();
         }
 
-        public static string NormalizeEpisodeTitle(string title)
+        public static string NormalizeTrackTitle(string title)
         {
             title = SpecialEpisodeWordRegex.Replace(title, string.Empty);
             title = PunctuationRegex.Replace(title, " ");