refactoring enums

App/Types/ThemeMode.cs

@@ -0,0 +1,27 @@
+using System;
+using System.ComponentModel;
+using ModernWpf;
+
+namespace ModernWpfPlayground.Types
+{
+    public enum ThemeMode
+    {
+        [Description("Light")] Light,
+        [Description("Dark")] Dark,
+        [Description("Use system setting")] UseSystemSetting
+    }
+
+    public static class ThemeModeExtension
+    {
+        public static ApplicationTheme? ToApplicationTheme(this ThemeMode themeMode)
+        {
+            return themeMode switch
+            {
+                ThemeMode.Light => ApplicationTheme.Light,
+                ThemeMode.Dark => ApplicationTheme.Dark,
+                ThemeMode.UseSystemSetting => default,
+                _ => throw new ArgumentOutOfRangeException(nameof(themeMode), themeMode, null)
+            };
+        } 
+    }
+}