Fix Unix having lower and uppercase files for songs

AM2RLauncher/AM2RLauncherLib/CrossPlatformOperations.cs

@@ -217,6 +217,7 @@ public static class CrossPlatformOperations
     {
         const string process = "xdelta3";
         const string arguments = "-V";
+        // TODO: for mac, we need to embed two xdelta binaries, for x64 and arm
 
         ProcessStartInfo xdeltaStart = new ProcessStartInfo
         {

AM2RLauncher/AM2RLauncherLib/HelperMethods.cs

@@ -87,6 +87,36 @@ public static class HelperMethods
 
         Directory.Delete(targetDir, false);
     }
+    
+    /// <summary>
+    /// Recursively lowercases all files and folders from a specified directory.
+    /// </summary>
+    /// <param name="directory">The path to the directory whose contents should be lowercased.</param>
+    public static void LowercaseFolder(string directory)
+    {
+        DirectoryInfo dir = new DirectoryInfo(directory);
+
+        foreach(var file in dir.GetFiles())
+        {
+            if (file.Name == file.Name.ToLower()) continue;
+            // Windows is dumb, thus we need to move in two trips
+            file.MoveTo(file.DirectoryName + "/" + file.Name.ToLower() + "_");
+            string newPath = file.FullName.Substring(0, file.FullName.Length - 1);
+            File.Delete(newPath);
+            file.MoveTo(newPath);
+        }
+
+        foreach(var subDir in dir.GetDirectories())
+        {
+            if (subDir.Name == subDir.Name.ToLower()) continue;
+            // ReSharper disable once PossibleNullReferenceException - since this is a subdirectory, it always has a parent
+            // Windows is dumb, thus we need to move in two trips
+            subDir.MoveTo(subDir.Parent.FullName + "/" + subDir.Name.ToLower() + "_");
+            // -2 because after a moving operation, DirInfo already appends a / 
+            subDir.MoveTo(subDir.FullName.Substring(0, subDir.FullName.Length-2));
+            LowercaseFolder(subDir.FullName);
+        }
+    }
 
     /// <summary>
     /// Calculates an MD5 hash from a given file.

AM2RLauncher/AM2RLauncherLib/Profile.cs

@@ -12,6 +12,8 @@ using AM2RLauncherLib.XML;
 
 namespace AM2RLauncherLib;
 
+// TODO: grey out create desktop shortcut on download mode
+
 /// <summary>
 /// An enum, that has possible return codes for <see cref="Profile.CheckIfZipIsAM2R11"/>.
 /// </summary>
@@ -50,6 +52,7 @@ public static class Profile
     /// </summary>
     /// <param name="invalidateCache">Determines if the AM2R_11 Cache should be invalidated.</param>
     /// <returns></returns>
+    // TODO: returns ^
     public static bool Is11Installed(bool invalidateCache = false)
     {
         // Only invalidate if we need to
@@ -458,6 +461,10 @@ public static class Profile
         if (!profile.UsesCustomMusic && useHqMusic)
             HelperMethods.DirectoryCopy($"{Core.PatchDataPath}/data/HDR_HQ_in-game_music", tempPath);
 
+        // On Unix, everything needs to be lowercased, so we need to fix the AM2R_11 files / HQ songs
+        if (OS.IsUnix)
+            HelperMethods.LowercaseFolder(tempPath);
+        
         // Linux post-process
         if (OS.IsLinux)
         {