Normalize renamed files' names

src/AudioTagger.Console/Operations/MediaFileRenamer.cs

@@ -60,12 +60,22 @@ public void Start(
             return;
         }
 
+        var normalizationForm = settings.Renaming.NormalizationForm.Trim() switch
+        {
+            "D" => NormalizationForm.FormD,
+            "KD" => NormalizationForm.FormKD,
+            "KC" => NormalizationForm.FormKC,
+            _ => NormalizationForm.FormC
+        };
+        printer.Print($"Filename normalization form is {normalizationForm}.");
+
         RenameFiles(
             eligibleMediaFiles,
             workingDirectory,
             printer,
             settings.Renaming.Patterns,
-            settings.Renaming.UseAlbumDirectories);
+            settings.Renaming.UseAlbumDirectories,
+            normalizationForm);
 
         var deletedDirs = DeleteEmptySubDirectories(workingDirectory.FullName, printer);
         PrintDeletedDirectories(deletedDirs, printer);
@@ -96,7 +106,8 @@ private static void RenameFiles(
         DirectoryInfo workingDirectory,
         IPrinter printer,
         IEnumerable<string> renamePatterns,
-        bool useAlbumDirectories)
+        bool useAlbumDirectories,
+        NormalizationForm normalizationForm)
     {
         var isCancelRequested = false;
         var doConfirm = true;
@@ -106,7 +117,7 @@ private static void RenameFiles(
 
         for (int i = 0; i < mediaFiles.Count; i++)
         {
-            MediaFile file = mediaFiles.ElementAt(i);
+            var file = mediaFiles.ElementAt(i);
 
             if (file.Title.Length == 0)
             {
@@ -131,6 +142,7 @@ private static void RenameFiles(
                     workingDirectory.FullName,
                     useArtistDirectory,
                     useAlbumDirectories,
+                    normalizationForm,
                     ref doConfirm,
                     renamePatterns);
             }
@@ -181,6 +193,7 @@ private static bool RenameSingleFile(
         string workingPath,
         bool useArtistDirectory,
         bool useAlbumDirectory,
+        NormalizationForm normalizationForm,
         ref bool doConfirm,
         IEnumerable<string> renamePatterns)
     {
@@ -207,16 +220,17 @@ private static bool RenameSingleFile(
             return false;
         }
 
-        MediaFilePathInfo oldPathInfo = new(workingPath, file.FileInfo.FullName);
+        var oldPathInfo = new MediaFilePathInfo(workingPath, file.FileInfo.FullName);
 
         string newArtistDir = useArtistDirectory
-            ? GenerateSafeDirectoryName(file)
+            ? GenerateSafeDirectoryName(file).Normalize(normalizationForm)
             : string.Empty;
         string newAlbumDir = useAlbumDirectory && useArtistDirectory && file.Album.HasText()
-            ? IoUtilities.SanitizePath(file.Album)
+            ? IoUtilities.SanitizePath(file.Album).Normalize(normalizationForm)
             : string.Empty;
-        string newFileName = GenerateFileNameUsingPattern(file, populatedTagNames, matchedRenamePattern);
-        MediaFilePathInfo newPathInfo = new(workingPath, [newArtistDir, newAlbumDir], newFileName);
+        string newFileName = GenerateFileName(file, populatedTagNames, matchedRenamePattern)
+                                .Normalize(normalizationForm);
+        var newPathInfo = new MediaFilePathInfo(workingPath, [newArtistDir, newAlbumDir], newFileName);
 
         if (oldPathInfo.FullFilePath(true) == newPathInfo.FullFilePath(true))
         {
@@ -271,7 +285,7 @@ private static bool RenameSingleFile(
         /// Generates and returns a new filename by replacing placeholders within the rename
         /// pattern (e.g., `%ALBUM%`) with actual tag data from the `MediaFile`.
         /// </summary>
-        static string GenerateFileNameUsingPattern(
+        static string GenerateFileName(
             MediaFile file,
             ICollection<string> fileTagNames,
             string renamePattern)

src/AudioTagger.Library/UserSettings/Settings.cs

@@ -99,6 +99,17 @@ public sealed record Renaming
     [JsonPropertyName("useAlbumDirectories")]
     public bool UseAlbumDirectories { get; init; } = false;
 
+    /// <summary>
+    /// The Unicode normalization form to use for renamed filenames.
+    /// Valid values are `C`, `D`, `KC`, and `KD`.
+    /// `C` is used by default is no valid value is provided.
+    ///
+    /// Reference: https://unicode.org/reports/tr15/
+    /// Reference: https://en.wikipedia.org/wiki/Unicode_equivalence
+    /// </summary>
+    [JsonPropertyName("normalizationForm")]
+    public string NormalizationForm { get; init; } = "C";
+
     [JsonPropertyName("ignoredDirectories")]
     public ImmutableList<string>? IgnoredDirectories { get; init; }
 }