From 1545291942a169cfc55dc0e18ad58ab952d9dbfa Mon Sep 17 00:00:00 2001
From: Syntriax <syntriax@gmail.com>
Date: Sun, 10 Nov 2024 20:21:53 +0300
Subject: [PATCH] fix: Issues With Behaviours Entering / Leaving the Hierarchy
 Callbacks Not Firing

---
 Engine.Core/Abstract/IBehaviourController.cs |  2 +-
 Engine.Core/BehaviourController.cs           | 54 ++++++++++++++++++--
 Engine.Core/GameManager.cs                   |  6 +--
 Engine.Core/GameObject.cs                    |  7 ++-
 4 files changed, 60 insertions(+), 9 deletions(-)

diff --git a/Engine.Core/Abstract/IBehaviourController.cs b/Engine.Core/Abstract/IBehaviourController.cs
index 9c4bc1f..c5ba6da 100644
--- a/Engine.Core/Abstract/IBehaviourController.cs
+++ b/Engine.Core/Abstract/IBehaviourController.cs
@@ -6,7 +6,7 @@ namespace Syntriax.Engine.Core.Abstract;
 /// <summary>
 /// Represents a controller for managing <see cref="IBehaviour"/>s and notify them accordingly about the engine's updates. Connected to an <see cref="IGameObject"/>.
 /// </summary>
-public interface IBehaviourController : IAssignableGameObject, IEnumerable<IBehaviour>
+public interface IBehaviourController : IInitialize, IAssignableGameObject, IEnumerable<IBehaviour>
 {
     /// <summary>
     /// Event triggered before the update of <see cref="IBehaviour"/>s.
diff --git a/Engine.Core/BehaviourController.cs b/Engine.Core/BehaviourController.cs
index 0f36423..44e1969 100644
--- a/Engine.Core/BehaviourController.cs
+++ b/Engine.Core/BehaviourController.cs
@@ -5,6 +5,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 
 using Syntriax.Engine.Core.Abstract;
+using Syntriax.Engine.Core.Exceptions;
 
 namespace Syntriax.Engine.Core;
 
@@ -17,17 +18,37 @@ public class BehaviourController : IBehaviourController
 
     public event IBehaviourController.OnBehaviourAddedDelegate? OnBehaviourAdded = null;
     public event IBehaviourController.OnBehaviourRemovedDelegate? OnBehaviourRemoved = null;
-    public event IAssignable.OnUnassignedDelegate? OnUnassigned;
     public event IAssignableGameObject.OnGameObjectAssignedDelegate? OnGameObjectAssigned = null;
 
+    public event IInitialize.OnInitializedDelegate? OnInitialized = null;
+    public event IInitialize.OnFinalizedDelegate? OnFinalized = null;
+
+    public event IAssignable.OnUnassignedDelegate? OnUnassigned = null;
 
     private readonly IList<IBehaviour> behaviours = new List<IBehaviour>(Constants.BEHAVIOURS_SIZE_INITIAL);
 
     private IGameObject _gameObject = null!;
-
+    private bool _initialized = false;
 
     public IGameObject GameObject => _gameObject;
 
+
+    public bool IsInitialized
+    {
+        get => _initialized;
+        private set
+        {
+            if (value == _initialized)
+                return;
+
+            _initialized = value;
+            if (value)
+                OnInitialized?.Invoke(this);
+            else
+                OnFinalized?.Invoke(this);
+        }
+    }
+
     public T AddBehaviour<T>(T behaviour) where T : class, IBehaviour
     {
         InsertBehaviourByPriority(behaviour);
@@ -121,9 +142,36 @@ public class BehaviourController : IBehaviourController
         return true;
     }
 
+
+    public bool Initialize()
+    {
+        if (IsInitialized)
+            return false;
+
+        NotAssignedException.Check(this, _gameObject);
+
+        foreach (IBehaviour behaviour in behaviours)
+            behaviour.Initialize();
+
+        IsInitialized = true;
+        return true;
+    }
+
+    public bool Finalize()
+    {
+        if (!IsInitialized)
+            return false;
+
+        foreach (IBehaviour behaviour in behaviours)
+            behaviour.Finalize();
+
+        IsInitialized = false;
+        return true;
+    }
+
     public bool Unassign()
     {
-        if (GameObject is not null && GameObject.IsInitialized)
+        if (IsInitialized)
             return false;
 
         _gameObject = null!;
diff --git a/Engine.Core/GameManager.cs b/Engine.Core/GameManager.cs
index 8fe4591..56f2e10 100644
--- a/Engine.Core/GameManager.cs
+++ b/Engine.Core/GameManager.cs
@@ -140,12 +140,12 @@ public class GameManager : BaseEntity, IGameManager
         gameObject.OnFinalized += OnGameObjectFinalize;
         gameObject.OnExitedHierarchy += OnGameObjectExitedHierarchy;
 
-        foreach (ITransform child in gameObject.Transform.Children)
-            Register(child.GameObject);
-
         if (!gameObject.Initialize())
             throw new Exception($"{nameof(gameObject)} can't be initialized");
 
+        foreach (ITransform child in gameObject.Transform.Children)
+            Register(child.GameObject);
+
         _gameObjects.Add(gameObject);
         _hierarchyObjects.Add(gameObject);
 
diff --git a/Engine.Core/GameObject.cs b/Engine.Core/GameObject.cs
index c952724..942ed15 100644
--- a/Engine.Core/GameObject.cs
+++ b/Engine.Core/GameObject.cs
@@ -46,6 +46,9 @@ public class GameObject : BaseEntity, IGameObject
 
         NotAssignedException.Check(this, _transform);
         NotAssignedException.Check(this, _behaviourController);
+
+        if (!_behaviourController.Initialize())
+            throw new System.Exception($"Failed to Initialize {BehaviourController.GetType().Name} on {Transform.GameObject.Name}");
     }
 
     public void Update()
@@ -60,8 +63,8 @@ public class GameObject : BaseEntity, IGameObject
     {
         base.FinalizeInternal();
 
-        foreach (IBehaviour behaviour in _behaviourController.GetBehaviours<IBehaviour>())
-            behaviour.Finalize();
+        if (!_behaviourController.Finalize())
+            throw new System.Exception($"Failed to Finalize {BehaviourController.GetType().Name} on {Transform.GameObject.Name}");
     }
 
     public bool Assign(ITransform transform)