Add support for setting the genre of the song.

This also contains a workaround for JeevanJames/Id3#2

Id3Genre.cs

@@ -0,0 +1,194 @@
+/*
+ * Part of the ID3-AutoGen project
+ * Copyright (c) 2012-2022 Michael Bemmerl
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+// ReSharper disable UnusedMember.Global
+// ReSharper disable InconsistentNaming
+namespace ID3_AutoGen
+{
+	/// <summary>
+	/// Represents the available genres.
+	/// </summary>
+	public enum Id3Genre : byte
+	{
+		Blues = 0,
+		ClassicRock = 1,
+		Country = 2,
+		Dance = 3,
+		Disco = 4,
+		Funk = 5,
+		Grunge = 6,
+		HipHop = 7,
+		Jazz = 8,
+		Metal = 9,
+		NewAge = 10,
+		Oldies = 11,
+		Other = 12,
+		Pop = 13,
+		RnB = 14,
+		Rap = 15,
+		Reggae = 16,
+		Rock = 17,
+		Techno = 18,
+		Industrial = 19,
+		Alternative = 20,
+		Ska = 21,
+		DeathMetal = 22,
+		Pranks = 23,
+		Soundtrack = 24,
+		EuroTechno = 25,
+		Ambient = 26,
+		TripHop = 27,
+		Vocal = 28,
+		JazzFunk = 29,
+		Fusion = 30,
+		Trance = 31,
+		Classical = 32,
+		Instrumental = 33,
+		Acid = 34,
+		House = 35,
+		Game = 36,
+		SoundClip = 37,
+		Gospel = 38,
+		Noise = 39,
+		AlternativeRock = 40,
+		Bass = 41,
+		Soul = 42,
+		Punk = 43,
+		Space = 44,
+		Meditative = 45,
+		InstrumentalPop = 46,
+		InstrumentalRock = 47,
+		Ethnic = 48,
+		Gothic = 49,
+		Darkwave = 50,
+		TechnoIndustrial = 51,
+		Electronic = 52,
+		PopFolk = 53,
+		Eurodance = 54,
+		Dream = 55,
+		SouthernRock = 56,
+		Comedy = 57,
+		Cult = 58,
+		Gangsta = 59,
+		Top40 = 60,
+		ChristianRap = 61,
+		PopFunk = 62,
+		Jungle = 63,
+		NativeAmerican = 64,
+		Cabaret = 65,
+		NewWave = 66,
+		Psychadelic = 67,
+		Rave = 68,
+		Showtunes = 69,
+		Trailer = 70,
+		LoFi = 71,
+		Tribal = 72,
+		AcidPunk = 73,
+		AcidJazz = 74,
+		Polka = 75,
+		Retro = 76,
+		Musical = 77,
+		RocknRoll = 78,
+		HardRock = 79,
+		Folk = 80,
+		FolkRock = 81,
+		NationalFolk = 82,
+		Swing = 83,
+		FastFusion = 84,
+		Bebob = 85,
+		Latin = 86,
+		Revival = 87,
+		Celtic = 88,
+		Bluegrass = 89,
+		Avantgarde = 90,
+		GothicRock = 91,
+		ProgressiveRock = 92,
+		PsychedelicRock = 93,
+		SymphonicRock = 94,
+		SlowRock = 95,
+		BigBand = 96,
+		Chorus = 97,
+		EasyListening = 98,
+		Acoustic = 99,
+		Humour = 100,
+		Speech = 101,
+		Chanson = 102,
+		Opera = 103,
+		ChamberMusic = 104,
+		Sonata = 105,
+		Symphony = 106,
+		BootyBrass = 107,
+		Primus = 108,
+		PornGroove = 109,
+		Satire = 110,
+		SlowJam = 111,
+		Club = 112,
+		Tango = 113,
+		Samba = 114,
+		Folklore = 115,
+		Ballad = 116,
+		PoweerBallad = 117,
+		RhytmicSoul = 118,
+		Freestyle = 119,
+		Duet = 120,
+		PunkRock = 121,
+		DrumSolo = 122,
+		ACapela = 123,
+		EuroHouse = 124,
+		DanceHall = 125,
+		Merengue = 142,
+		Salsa = 143,
+		ThrashMetal = 144,
+		Anime = 145,
+		Jpop = 146,
+		Synthpop = 147,
+		Abstract = 148,
+		ArtRock = 149,
+		Baroque = 150,
+		Bhangra = 151,
+		Bigbeat = 152,
+		Breakbeat = 153,
+		Chillout = 154,
+		Downtempo = 155,
+		Dub = 156,
+		EBM = 157,
+		Eclectic = 158,
+		Electro = 159,
+		Electroclash = 160,
+		Emo = 161,
+		Experimental = 162,
+		Garage = 163,
+		Global = 164,
+		IDM = 165,
+		Illbient = 166,
+		IndustroGoth = 167,
+		JamBand = 168,
+		Krautrock = 169,
+		Leftfield = 170,
+		Lounge = 171,
+		MathRock = 172,
+		NewRomantic = 173,
+		NuBreakz = 174,
+		PostPunk = 175,
+		PostRock = 176,
+		Psytrance = 177,
+		Shoegaze = 178,
+		SpaceRock = 179,
+		TropRock = 180,
+		WorldMusic = 181,
+		Neoclassical = 182,
+		Audiobook = 183,
+		AudioTheatre = 184,
+		NeueDeutscheWelle = 185,
+		Podcast = 186,
+		IndieRock = 187,
+		GFunk = 188,
+		Dubstep = 189,
+		GarageRock = 190,
+		Psybient = 191,
+	}
+}

Id3Tag.cs

@@ -57,6 +57,12 @@ public string Artist
 		public string Title
 		{ get; set; }
 
+		/// <summary>
+		/// Genre tag
+		/// </summary>
+		public Id3Genre? Genre
+		{ get; set; }
+
 		/// <summary>
 		/// Creates a new object that is a copy of the current instance.
 		/// </summary>
@@ -69,6 +75,7 @@ public object Clone()
 			newTag.Year = this.Year;
 			newTag.Artist = this.Artist;
 			newTag.Title = this.Title;
+			newTag.Genre = this.Genre;
 
 			return newTag;
 		}

Program.cs

@@ -25,7 +25,7 @@ static void Main(string[] args)
 			if (result is NotParsed<Options>)
 			{
 				// Special case for showing license info
-				if (args.Contains("--license"))
+				if (args.Select(y => y.ToLower()).Contains("--license"))
 				{
 					Console.Write(Properties.Resources.licenses);
 					return;
@@ -45,6 +45,7 @@ static void Main(string[] args)
 				tag.Artist = opt.Artist;
 				tag.Comment = opt.Comment;
 				tag.Year = opt.Year;
+				tag.Genre = opt.Genre;
 
 				Tagger tagger = new Tagger(tag);
 				tagger.DryRun = opt.DryRun;
@@ -92,6 +93,7 @@ static void processFile(Tagger tagger, FileInfo file, bool verbose)
 				Console.WriteLine("\tAlbum: {0}", writtenTag.Album);
 				Console.WriteLine("\tYear: {0}", writtenTag.Year);
 				Console.WriteLine("\tComment: {0}", writtenTag.Comment);
+				Console.WriteLine("\tGenre: {0}", writtenTag.Genre.HasValue ? writtenTag.Genre.Value.ToString() : "None");
 			}
 		}
 
@@ -127,6 +129,10 @@ public string Album
 			public ushort? Year
 			{ get; set; }
 
+			[Option('g', "genre", HelpText = "Genre of the song.")]
+			public Id3Genre? Genre
+			{ get; set; }
+
 			[Option('p', "pattern", HelpText = "Process only files matching this pattern.")]
 			public string Pattern
 			{ get; set; }

Tagger.cs

@@ -14,6 +14,7 @@ namespace ID3_AutoGen
 	using System.Collections.Generic;
 	using System.IO;
 	using System.Text.RegularExpressions;
+	using CommandLine;
 
 	/// <summary>
 	/// Provides methods for tagging MP3 files while automatically detecting ID3 data from the filename.
@@ -121,35 +122,60 @@ private bool writeTag(FileInfo file, ref Id3Tag tag)
 		{
 			Guard.IsNotNull(file);
 			Guard.IsNotNull(tag);
+			bool success = false;
 
 			tag.Artist = tag.Artist.Trim();
 			tag.Title = tag.Title.Trim();
 
-			using Mp3 mp3 = new Mp3(file, Mp3Permissions.ReadWrite);
+			using (Mp3 mp3 = new Mp3(file, Mp3Permissions.ReadWrite))
+			{
+				Id3.Id3Tag fileTag = new Id3.Id3Tag();
 
-			Id3.Id3Tag fileTag = new Id3.Id3Tag();
+				fileTag.Artists = new ArtistsFrame();
+				fileTag.Artists.Value.Add(tag.Artist);
+				fileTag.Title = new TitleFrame(tag.Title);
 
-			fileTag.Artists = new ArtistsFrame();
-			fileTag.Artists.Value.Add(tag.Artist);
-			fileTag.Title = new TitleFrame(tag.Title);
+				if (tag.Year.HasValue)
+					fileTag.Year = new YearFrame(tag.Year.Value);
 
-			if (tag.Year.HasValue)
-				fileTag.Year = new YearFrame(tag.Year.Value);
+				if (tag.Comment != null)
+				{
+					tag.Comment = tag.Comment.Trim();
+					fileTag.Comments.Add(tag.Comment);
+				}
 
-			if (tag.Comment != null)
-			{
-				tag.Comment = tag.Comment.Trim();
-				fileTag.Comments.Add(tag.Comment);
+				if (tag.Album != null)
+				{
+					tag.Album = tag.Album.Trim();
+					fileTag.Album = new AlbumFrame(tag.Album);
+				}
+
+				// Don't write changes to the file if DryRun is active.
+				success = DryRun || mp3.WriteTag(fileTag, Id3Version.V1X);
 			}
 
-			if (tag.Album != null)
+			// The library used for writing the ID3 tags to the MP3 file lacks support for writing a genre tag.
+			// (See https://github.com/JeevanJames/Id3/issues/2)
+			// We're lucky here: The genre tag is in ID3v1 actually the very last byte of the segment and thus the file.
+			// So open the file for writing, jump to the last byte and set it accordingly.
+			// But only if DryRun is not active and writing of the other tags was successful.
+			if (success && !DryRun)
 			{
-				tag.Album = tag.Album.Trim();
-				fileTag.Album = new AlbumFrame(tag.Album);
+				using FileStream stream = file.OpenWrite();
+				Guard.CanWrite(stream);
+
+				stream.Position = stream.Length - 1;
+
+				// The specification has no information what value means "genre not set", but Winamp uses 0xFF, so we do so too.
+				byte genre = 0xFF;
+
+				if (tag.Genre.HasValue)
+					genre = (byte)tag.Genre.Value;
+
+				stream.WriteByte(genre);
 			}
 
-			// Don't write changes to the file if DryRun is active.
-			return DryRun || mp3.WriteTag(fileTag, Id3Version.V1X);
+			return success;
 		}
-	}
+}
 }