From 7db56d7605e2386e82b09619b5a71ed1b8270168 Mon Sep 17 00:00:00 2001
From: Rohan Chandi <masterxroh@gmail.com>
Date: Tue, 5 Mar 2024 13:29:41 +0100
Subject: [PATCH] fix: swap trailing determiners at the end of titles

fixes #9815.\n\n Some files have their , A or , The at the end of the file to prevent alphabetical sorting clustering these titles together. This stops working when searching for files inside radarr as a cleaned title will have 'prestigethe' instead of 'theprestige'.
---
 src/NzbDrone.Common/Extensions/StringExtensions.cs | 14 ++++++++++++++
 .../ParserTests/NormalizeTitleFixture.cs           | 12 ++++++++++++
 src/NzbDrone.Core/Parser/Parser.cs                 |  2 +-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/NzbDrone.Common/Extensions/StringExtensions.cs b/src/NzbDrone.Common/Extensions/StringExtensions.cs
index 8e327cd88..9cdd5bd63 100644
--- a/src/NzbDrone.Common/Extensions/StringExtensions.cs
+++ b/src/NzbDrone.Common/Extensions/StringExtensions.cs
@@ -12,6 +12,7 @@ namespace NzbDrone.Common.Extensions
     public static class StringExtensions
     {
         private static readonly Regex CamelCaseRegex = new Regex("(?<!^)[A-Z]", RegexOptions.Compiled);
+        private static readonly Regex TrailingDeterminerRegex = new Regex("(, The)$|(, A)$", RegexOptions.Compiled);
 
         public static string NullSafe(this string target)
         {
@@ -228,5 +229,18 @@ namespace NzbDrone.Common.Extensions
 
             return new string(array);
         }
+
+        // Some files have their determiner (The, A) at the end of the title to help sorting, flip them back to prevent searching errors.
+        public static string SwapTrailingDeterminers(this string input)
+        {
+            var match = TrailingDeterminerRegex.Match(input);
+            if (match.Success)
+            {
+                input = TrailingDeterminerRegex.Replace(input, string.Empty);
+                input = match.Value.Replace(", ", string.Empty) + " " + input;
+            }
+
+            return input;
+        }
     }
 }
diff --git a/src/NzbDrone.Core.Test/ParserTests/NormalizeTitleFixture.cs b/src/NzbDrone.Core.Test/ParserTests/NormalizeTitleFixture.cs
index 23631b51d..f5192358b 100644
--- a/src/NzbDrone.Core.Test/ParserTests/NormalizeTitleFixture.cs
+++ b/src/NzbDrone.Core.Test/ParserTests/NormalizeTitleFixture.cs
@@ -186,5 +186,17 @@ namespace NzbDrone.Core.Test.ParserTests
         {
             "Tokyo Ghoul A".CleanMovieTitle().Should().Be("tokyoghoula");
         }
+
+        [TestCase("Prestige, The", "theprestige")]
+        [TestCase("Prestige, A", "aprestige")]
+        [TestCase("Crow, The", "thecrow")]
+        [TestCase("Crow, A", "acrow")]
+        [TestCase("Beautiful Romance, The", "thebeautifulromance")]
+        [TestCase("Beautiful Romance, A", "abeautifulromance")]
+        public void should_swap_determiner(string parsedSeriesName, string seriesName)
+        {
+            var result = parsedSeriesName.CleanMovieTitle();
+            result.Should().Be(seriesName);
+        }
     }
 }
diff --git a/src/NzbDrone.Core/Parser/Parser.cs b/src/NzbDrone.Core/Parser/Parser.cs
index 54c1a1e2f..6d02edff6 100644
--- a/src/NzbDrone.Core/Parser/Parser.cs
+++ b/src/NzbDrone.Core/Parser/Parser.cs
@@ -466,7 +466,7 @@ namespace NzbDrone.Core.Parser
                 return title;
             }
 
-            return ReplaceGermanUmlauts(NormalizeRegex.Replace(title, string.Empty).ToLower()).RemoveAccent();
+            return ReplaceGermanUmlauts(NormalizeRegex.Replace(title.SwapTrailingDeterminers(), string.Empty).ToLower()).RemoveAccent();
         }
 
         public static string NormalizeEpisodeTitle(this string title)