feat: Add ElympicsLobby to "Add GameObject" context menu

Editor/ElympicsMouseActions.cs

@@ -1,22 +1,58 @@
 using UnityEditor;
 using UnityEngine;
+using UnityEngine.SceneManagement;
 
 namespace Elympics
 {
     public static class ElympicsMouseActions
     {
         private const string PathToElympicsSystem = "Elympics";
+        private const string PathToElympicsLobby = "ElympicsLobby";
 
-        [MenuItem(ElympicsEditorMenuPaths.MOUSE_ACTION_CREATE_ELYMPICS_SYSTEM, priority = 11)]
+        [MenuItem(ElympicsEditorMenuPaths.MOUSE_ACTION_CREATE_ELYMPICS_SYSTEM)]
         private static void AddElympicsSystemToScene()
         {
-            var elympicsSystemPrefabReference = Resources.Load<GameObject>(PathToElympicsSystem);
+            const string name = "Elympics System";
+            if (HasActiveSceneAnyObjectOfType<ElympicsLobbyClient>())
+            {
+                Debug.LogError($"{name} cannot be placed in the menu scene. Use a separate game scene.");
+                return;
+            }
+            AddUniquePrefabToScene<GameSceneManager>(PathToElympicsSystem, name);
+        }
+
+        [MenuItem(ElympicsEditorMenuPaths.MOUSE_ACTION_CREATE_ELYMPICS_LOBBY)]
+        private static void AddElympicsLobbyToScene()
+        {
+            const string name = "Elympics Lobby";
+            if (HasActiveSceneAnyObjectOfType<GameSceneManager>())
+            {
+                Debug.LogError($"{name} cannot be placed in the game scene. Use a separate menu scene.");
+                return;
+            }
+            AddUniquePrefabToScene<ElympicsLobbyClient>(PathToElympicsLobby, name);
+        }
 
-            if (elympicsSystemPrefabReference != null)
-                _ = PrefabUtility.InstantiatePrefab(elympicsSystemPrefabReference);
-            else
-                Debug.LogError("Cannot instantiate elympics system - prefab reference is null!");
+        private static void AddUniquePrefabToScene<T>(string path, string name)
+            where T : Component
+        {
+            if (HasActiveSceneAnyObjectOfType<T>())
+            {
+                Debug.LogError($"{name} is already present in the current scene.");
+                return;
+            }
+            var prefabReference = Resources.Load<T>(path);
+            if (prefabReference == null)
+            {
+                Debug.LogError($"Cannot instantiate {name} - prefab reference is null!");
+                return;
+            }
+            var instance = PrefabUtility.InstantiatePrefab(prefabReference.gameObject);
+            Undo.RegisterCreatedObjectUndo(instance, $"Instantiate {name}");
         }
+
+        private static bool HasActiveSceneAnyObjectOfType<T>() where T : Object =>
+            SceneObjectsFinder.FindObjectsOfType<T>(SceneManager.GetActiveScene(), true).Count > 0;
     }
 }
 

Runtime/ElympicsSystems/ElympicsLobbyClient.cs

@@ -13,6 +13,7 @@
 
 namespace Elympics
 {
+    [RequireComponent(typeof(AsyncEventsDispatcher))]
     public class ElympicsLobbyClient : MonoBehaviour
     {
         public static ElympicsLobbyClient Instance { get; private set; }

Runtime/Tools/ElympicsEditorMenuPaths.cs

@@ -2,14 +2,16 @@ namespace Elympics
 {
     public static class ElympicsEditorMenuPaths
     {
-        public const string TOOLS_MENU_PATH = "Tools/Elympics/";
+        private const string TOOLS_MENU_PATH = "Tools/Elympics/";
         public const string RESET_IDS_MENU_PATH = TOOLS_MENU_PATH + "Reset Network Ids";
         public const string SETUP_MENU_PATH = TOOLS_MENU_PATH + "Select or Create Config";
         public const string BUILD_WINDOWS_SERVER = TOOLS_MENU_PATH + "Build Windows Server";
         public const string BUILD_LINUX_SERVER = TOOLS_MENU_PATH + "Build Linux Server";
         public const string BUILD_AND_UPLOAD_SERVER = TOOLS_MENU_PATH + "Build and Upload Server";
         public const string MANAGE_GAMES_IN_ELYMPICS = TOOLS_MENU_PATH + "Manage games in Elympics";
 
-        public const string MOUSE_ACTION_CREATE_ELYMPICS_SYSTEM = "GameObject/ElympicsSystem";
+        private const string GAMEOBJECT_MENU_PATH = "GameObject/Elympics/";
+        public const string MOUSE_ACTION_CREATE_ELYMPICS_SYSTEM = GAMEOBJECT_MENU_PATH + "ElympicsSystem";
+        public const string MOUSE_ACTION_CREATE_ELYMPICS_LOBBY = GAMEOBJECT_MENU_PATH + "ElympicsLobby";
     }
 }