Patch Jester destructor to reset the light show

It is needed to despawn Jester via Imperium's Object Explorer.

MuzikaGromche/Plugin.cs

@@ -528,7 +528,9 @@ namespace MuzikaGromche
                 }
                 Config = new Config(base.Config);
                 DiscoBallManager.Initialize();
-                new Harmony(PluginInfo.PLUGIN_NAME).PatchAll(typeof(JesterPatch));
+                var harmony = new Harmony(PluginInfo.PLUGIN_NAME);
+                harmony.PatchAll(typeof(JesterPatch));
+                harmony.PatchAll(typeof(EnemyAIPatch));
             }
             else
             {
@@ -1875,6 +1877,26 @@ namespace MuzikaGromche
         }
     }
 
+    [HarmonyPatch(typeof(EnemyAI))]
+    internal class EnemyAIPatch
+    {
+        // JesterAI class does not override abstract method OnDestroy,
+        // so we have to patch its superclass directly.
+        [HarmonyPatch(nameof(EnemyAI.OnDestroy))]
+        [HarmonyPrefix]
+        public static void CleanUpOnDestroy(EnemyAI __instance)
+        {
+            if (__instance is JesterAI)
+            {
+                Plugin.ResetLightColor();
+                DiscoBallManager.Disable();
+                // Just in case if players have spawned multiple Jesters,
+                // Don't reset Plugin.CurrentTrack and Plugin.BeatTimeState to null,
+                // so that the code wouldn't crash without extra null checks.
+            }
+        }
+    }
+
     internal class State
     {
         public AudioSource farAudio;