Clean Filenames for Windows

Fixes #391

API/Utils.cs

@@ -0,0 +1,42 @@
+using System.Text;
+
+namespace API;
+
+public static class Utils
+{
+    //https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file
+    //less than 32 is control *forbidden*
+    //34 is " *forbidden*
+    //42 is * *forbidden*
+    //47 is / *forbidden*
+    //58 is : *forbidden*
+    //60 is < *forbidden*
+    //62 is > *forbidden*
+    //63 is ? *forbidden*
+    //92 is \ *forbidden*
+    //124 is | *forbidden*
+    //127 is delete *forbidden*
+    //Below 127 all except *******
+    private static readonly int[] ForbiddenCharsBelow127 = [34, 42, 47, 58, 60, 62, 63, 92, 124, 127];
+    //Above 127 none except *******
+    private static readonly int[] IncludeCharsAbove127 = [128, 138, 142];
+    //128 is € include
+    //138 is Š include
+    //142 is Ž include
+    //152 through 255 looks fine except 157, 172, 173, 175 *******
+    private static readonly int[] ForbiddenCharsAbove152 = [157, 172, 173, 175];
+    public static string CleanNameForWindows(this string name)
+    {
+        StringBuilder sb = new ();
+        foreach (char c in name)
+        {
+            if (c >= 32 && c < 127 && ForbiddenCharsBelow127.Contains(c) == false)
+                sb.Append(c);
+            else if (c > 127 && c < 152 && IncludeCharsAbove127.Contains(c))
+                sb.Append(c);
+            else if(c >= 152 && c <= 255 && ForbiddenCharsAbove152.Contains(c) == false)
+                sb.Append(c);
+        }
+        return sb.ToString();
+    }
+}