New: Parsing of poorly named absolute number-only files in batches

Closes #5488

src/NzbDrone.Core.Test/ParserTests/AbsoluteEpisodeNumberParserFixture.cs

@@ -1,7 +1,9 @@
+using System.IO;
 using System.Linq;
 using FluentAssertions;
 using NUnit.Framework;
 using NzbDrone.Core.Test.Framework;
+using NzbDrone.Test.Common;
 
 namespace NzbDrone.Core.Test.ParserTests
 {
@@ -201,5 +203,17 @@ namespace NzbDrone.Core.Test.ParserTests
             result.SpecialAbsoluteEpisodeNumbers.Should().BeEquivalentTo(new[] { (decimal)specialEpisodeNumber });
             result.FullSeason.Should().BeFalse();
         }
+
+        [TestCase("Series Title 921-928 [English Dub][1080p][onepiecedubb]", "921.mkv", "Series Title", 921)]
+        public void should_handle_ambiguously_named_anime_files_in_batch_release(string releaseName, string filename, string title, int absoluteEpisodeNumber)
+        {
+            var result = Parser.Parser.ParsePath(Path.Combine(@"C:\Test".AsOsAgnostic(), releaseName, filename));
+            result.Should().NotBeNull();
+            result.AbsoluteEpisodeNumbers.Single().Should().Be(absoluteEpisodeNumber);
+            result.SeasonNumber.Should().Be(0);
+            result.EpisodeNumbers.Should().BeEmpty();
+            result.SeriesTitle.Should().Be(title);
+            result.FullSeason.Should().BeFalse();
+        }
     }
 }

src/NzbDrone.Core/Parser/Parser.cs

@@ -516,6 +516,31 @@ namespace NzbDrone.Core.Parser
 
             var result = ParseTitle(fileInfo.Name);
 
+            if (result == null && int.TryParse(Path.GetFileNameWithoutExtension(fileInfo.Name), out var number))
+            {
+                Logger.Debug("Attempting to parse episode info using directory and file names. {0}", fileInfo.Directory.Name);
+                result = ParseTitle(fileInfo.Directory.Name);
+
+                if (result != null && result.AbsoluteEpisodeNumbers.Contains(number))
+                {
+                    result.AbsoluteEpisodeNumbers = new[] { number };
+                }
+                else if (result != null && result.EpisodeNumbers.Contains(number))
+                {
+                    result.EpisodeNumbers = new[] { number };
+                }
+                else
+                {
+                    result = null;
+                }
+            }
+
+            if (result == null)
+            {
+                Logger.Debug("Attempting to parse episode info using combined directory and file names. {0}", fileInfo.Directory.Name);
+                result = ParseTitle(fileInfo.Directory.Name + " " + fileInfo.Name);
+            }
+
             if (result == null)
             {
                 Logger.Debug("Attempting to parse episode info using directory and file names. {0}", fileInfo.Directory.Name);