refactor: fix bugs and improve architecture

- Fix double-execution bug in LevelStateHandler (coins/skills were committed twice per level)
- Fix DamageComponent to track multiple targets via HashSet instead of single node
- Fix HealthComponent: update health immediately, decouple from PlayerController via signal wiring in PlayerController
- Remove dead loop in SkillManager.RemoveSkill; simplify O(n²) throw skill loop
- Replace GetNode<T>(path) with .Instance across managers; add Instance to StatisticsManager/SpeedRunManager
- GameManager.GetPlayer() now uses EventBus.PlayerSpawned instead of scanning all scene nodes
- UIManager.UiStack: remove [Export], use private List<Control>
- PlayerState: extract DefaultLives constant, simplify CreateDefault()

Autoloads/GameManager.cs

@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Godot;
 using Godot.Collections;
 using Mr.BrickAdventures.scripts.components;
@@ -21,7 +20,6 @@ public partial class GameManager : Node
         private set => _player = value;
     }
 
-    private List<Node> _sceneNodes = [];
     private PlayerController _player;
     private SpeedRunManager _speedRunManager;
 
@@ -32,38 +30,24 @@ public partial class GameManager : Node
 
     public static GameManager Instance { get; private set; }
 
-    public override void _EnterTree()
+    public override void _Ready()
     {
-        GetTree().NodeAdded += OnNodeAdded;
+        Instance = this;
-        GetTree().NodeRemoved += OnNodeRemoved;
+        _speedRunManager = SpeedRunManager.Instance;
+        EventBus.Instance.PlayerSpawned += OnPlayerSpawned;
     }
 
     public override void _ExitTree()
     {
         if (Instance == this) Instance = null;
-        GetTree().NodeAdded -= OnNodeAdded;
+        if (EventBus.Instance != null)
-        GetTree().NodeRemoved -= OnNodeRemoved;
+            EventBus.Instance.PlayerSpawned -= OnPlayerSpawned;
-        _sceneNodes.Clear();
     }
 
-    public override void _Ready()
+    private void OnPlayerSpawned(PlayerController player)
     {
-        Instance = this;
+        _player = player;
-        _speedRunManager = GetNode<SpeedRunManager>(Constants.SpeedRunManagerPath);
+        player.TreeExiting += () => { if (_player == player) _player = null; };
-    }
-
-    private void OnNodeAdded(Node node)
-    {
-        _sceneNodes.Add(node);
-    }
-
-    private void OnNodeRemoved(Node node)
-    {
-        _sceneNodes.Remove(node);
-        if (node == _player)
-        {
-            _player = null;
-        }
     }
 
     #region Coin Operations
@@ -187,7 +171,7 @@ public partial class GameManager : Node
     {
         Store?.ResetAll();
         GetTree().ChangeSceneToPacked(LevelScenes[0]);
-        GetNode<SaveSystem>(Constants.SaveSystemPath).SaveGame();
+        SaveSystem.Instance.SaveGame();
     }
 
     public void QuitGame() => GetTree().Quit();
@@ -209,13 +193,13 @@ public partial class GameManager : Node
         Store?.ResetAll();
         _speedRunManager?.StartTimer();
         GetTree().ChangeSceneToPacked(LevelScenes[0]);
-        GetNode<SaveSystem>(Constants.SaveSystemPath).SaveGame();
+        SaveSystem.Instance.SaveGame();
         EventBus.EmitGameStarted();
     }
 
     public void ContinueGame()
     {
-        var save = GetNode<SaveSystem>(Constants.SaveSystemPath);
+        var save = SaveSystem.Instance;
         if (!save.LoadGame())
         {
             GD.PrintErr("Failed to load game. Starting a new game instead.");
@@ -249,7 +233,7 @@ public partial class GameManager : Node
 
         Store.ResetSession();
         TryToGoToNextLevel();
-        GetNode<SaveSystem>(Constants.SaveSystemPath).SaveGame();
+        SaveSystem.Instance.SaveGame();
     }
 
     #endregion
@@ -259,18 +243,7 @@ public partial class GameManager : Node
     public PlayerController GetPlayer()
     {
         if (_player != null && IsInstanceValid(_player)) return _player;
-
         _player = null;
-
-        foreach (var node in _sceneNodes)
-        {
-            if (node is not PlayerController player) continue;
-
-            _player = player;
-            return _player;
-        }
-
-        GD.PrintErr("PlayerController not found in the scene tree.");
         return null;
     }
 

Autoloads/SkillManager.cs

@@ -2,7 +2,6 @@ using System.Collections.Generic;
 using System.Linq;
 using Godot;
 using Godot.Collections;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.scripts.components;
 using Mr.BrickAdventures.scripts.interfaces;
 using Mr.BrickAdventures.scripts.Resources;
@@ -11,8 +10,8 @@ namespace Mr.BrickAdventures.Autoloads;
 
 public partial class SkillManager : Node
 {
-    private GameManager _gameManager;
     private PlayerController _player;
+    private GameManager GameManager => GameManager.Instance;
 
     [Export] public Array<SkillData> AvailableSkills { get; set; } = [];
 
@@ -28,7 +27,6 @@ public partial class SkillManager : Node
     public override void _Ready()
     {
         Instance = this;
-        _gameManager = GetNode<GameManager>(Constants.GameManagerPath);
     }
 
     public override void _ExitTree()
@@ -85,21 +83,11 @@ public partial class SkillManager : Node
 
         if (skillData.Type == SkillType.Throw)
         {
-            var unlocked = _gameManager.GetUnlockedSkills();
+            // Remove any other active throw skill before adding the new one
-            foreach (var sd in unlocked)
+            foreach (var sd in AvailableSkills)
             {
-                SkillData data = null;
+                if (sd != skillData && sd.Type == SkillType.Throw)
-                foreach (var s in AvailableSkills)
+                    RemoveSkill(sd.Name);
-                {
-                    if (s == sd)
-                    {
-                        data = s;
-                        break;
-                    }
-                }
-                // Remove other throw skills if a new one is added
-                if (data is { Type: SkillType.Throw })
-                    RemoveSkill(data.Name);
             }
         }
 
@@ -146,14 +134,6 @@ public partial class SkillManager : Node
         if (IsInstanceValid(inst))
             inst.QueueFree();
 
-        var skills = _gameManager.GetUnlockedSkills();
-        foreach (var s in skills)
-        {
-            if (s.Name == skillName)
-            {
-                break;
-            }
-        }
         ActiveComponents.Remove(skillName);
         var sd = GetSkillByName(skillName);
         if (sd != null) EmitSignalSkillRemoved(sd);
@@ -174,10 +154,11 @@ public partial class SkillManager : Node
     public void ApplyUnlockedSkills()
     {
         if (_player == null || !IsInstanceValid(_player)) return;
+        if (GameManager == null) return;
 
         foreach (var sd in AvailableSkills)
         {
-            if (_gameManager.IsSkillUnlocked(sd))
+            if (GameManager.IsSkillUnlocked(sd))
             {
                 CallDeferred(MethodName.AddSkill, sd);
             }

Autoloads/SpeedRunManager.cs

@@ -5,6 +5,11 @@ namespace Mr.BrickAdventures.Autoloads;
 
 public partial class SpeedRunManager : Node
 {
+    public static SpeedRunManager Instance { get; private set; }
+
+    public override void _EnterTree() => Instance = this;
+    public override void _ExitTree() { if (Instance == this) Instance = null; }
+
     public bool IsRunning { get; private set; } = false;
     public bool IsVisible { get; private set; } = false;
     

Autoloads/StatisticsManager.cs

@@ -9,6 +9,10 @@ namespace Mr.BrickAdventures.Autoloads;
 /// </summary>
 public partial class StatisticsManager : Node
 {
+    public static StatisticsManager Instance { get; private set; }
+
+    public override void _Ready() => Instance = this;
+    public override void _ExitTree() { if (Instance == this) Instance = null; }
 
     /// <summary>
     /// Gets the statistics dictionary from the store.

Autoloads/UIManager.cs

@@ -1,11 +1,10 @@
 using Godot;
-using Godot.Collections;
 
 namespace Mr.BrickAdventures.Autoloads;
 
 public partial class UIManager : Node
 {
-    [Export] public Array<Control> UiStack { get; set; } = new();
+    private readonly System.Collections.Generic.List<Control> UiStack = new();
     
     [Signal] public delegate void ScreenPushedEventHandler(Control screen);
     [Signal] public delegate void ScreenPoppedEventHandler(Control screen);
@@ -34,19 +33,19 @@ public partial class UIManager : Node
             return;
         }
         
-        var top = (Control)UiStack[^1];
+        var top = UiStack[^1];
         UiStack.RemoveAt(UiStack.Count - 1);
         top.Hide();
         top.SetProcessInput(false);
         EmitSignalScreenPopped(top);
         top.AcceptEvent();
 
-        if (UiStack.Count > 0) ((Control)UiStack[^1]).GrabFocus();
+        if (UiStack.Count > 0) UiStack[^1].GrabFocus();
     }
     
-    public Control TopScreen() => UiStack.Count > 0 ? (Control)UiStack[^1] : null;
+    public Control TopScreen() => UiStack.Count > 0 ? UiStack[^1] : null;
 
-    public bool IsScreenOnTop(Control screen) => UiStack.Count > 0 && (Control)UiStack[^1] == screen;
+    public bool IsScreenOnTop(Control screen) => UiStack.Count > 0 && UiStack[^1] == screen;
     
     public bool IsVisibleOnStack(Control screen) => UiStack.Contains(screen) && screen.Visible;
     

scripts/Events/LevelStateHandler.cs

@@ -23,17 +23,7 @@ public partial class LevelStateHandler : Node
 
     private void OnLevelCompleted(int levelIndex, Node currentScene, double completionTime)
     {
-        var store = GameStateStore.Instance;
+        // State mutations (commit coins/skills, reset session) are handled by GameManager.OnLevelComplete
-        if (store == null) return;
+        // before this event fires. This handler is reserved for future level-specific side-effects.
-
-        // Mark level complete and unlock next
-        store.MarkLevelComplete(levelIndex);
-
-        // Commit session data to persistent state
-        store.CommitSessionCoins();
-        store.CommitSessionSkills();
-
-        // Reset session for next level
-        store.ResetSession();
     }
 }

scripts/Events/StatisticsEventHandler.cs

@@ -1,5 +1,4 @@
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 
 namespace Mr.BrickAdventures.scripts.Events;
@@ -14,7 +13,7 @@ public partial class StatisticsEventHandler : Node
 
     public override void _Ready()
     {
-        _statisticsManager = GetNode<StatisticsManager>(Constants.StatisticsManagerPath);
+        _statisticsManager = StatisticsManager.Instance;
 
         // Subscribe to events
         EventBus.Instance.CoinCollected += OnCoinCollected;

scripts/State/PlayerState.cs

@@ -9,6 +9,8 @@ namespace Mr.BrickAdventures.scripts.State;
 /// </summary>
 public class PlayerState
 {
+    private const int DefaultLives = 3;
+
     /// <summary>
     /// Saved coins (not including current session).
     /// </summary>
@@ -17,7 +19,7 @@ public class PlayerState
     /// <summary>
     /// Remaining lives.
     /// </summary>
-    public int Lives { get; set; } = 3;
+    public int Lives { get; set; } = DefaultLives;
 
     /// <summary>
     /// Indices of completed levels.
@@ -45,17 +47,9 @@ public class PlayerState
     public List<string> UnlockedAchievements { get; set; } = new();
 
     /// <summary>
-    /// Creates a fresh default player state.
+    /// Creates a fresh default player state (same as <c>new PlayerState()</c>).
     /// </summary>
-    public static PlayerState CreateDefault() => new()
+    public static PlayerState CreateDefault() => new();
-    {
-        Coins = 0,
-        Lives = 3,
-        CompletedLevels = new List<int>(),
-        UnlockedLevels = new List<int> { 0 },
-        UnlockedSkills = new List<SkillData>(),
-        Statistics = new Dictionary<string, int>()
-    };
 
     /// <summary>
     /// Resets this state to default values.
@@ -63,7 +57,7 @@ public class PlayerState
     public void Reset()
     {
         Coins = 0;
-        Lives = 3;
+        Lives = DefaultLives;
         CompletedLevels.Clear();
         UnlockedLevels.Clear();
         UnlockedLevels.Add(0);

scripts/components/DamageComponent.cs

@@ -11,7 +11,7 @@ public partial class DamageComponent : Node
     [Export] public StatusEffectDataResource StatusEffectData { get; set; }
     [Export] public Timer DamageTimer { get; set; }
     
-    private Node _currentTarget = null;
+    private readonly System.Collections.Generic.HashSet<Node> _currentTargets = new();
     private KnockbackComponent _knockbackComponent = null;
     
     [Signal] public delegate void EffectInflictedEventHandler(Node2D target, StatusEffectDataResource effect);
@@ -35,10 +35,11 @@ public partial class DamageComponent : Node
 
     public override void _Process(double delta)
     {
-        if (_currentTarget == null) return;
+        if (_currentTargets.Count == 0) return;
         if (DamageTimer != null) return;
 
-        ProcessEntityAndApplyDamage(_currentTarget as Node2D);
+        foreach (var target in _currentTargets)
+            ProcessEntityAndApplyDamage(target as Node2D);
     }
 
     public void DealDamage(HealthComponent target) => target.DecreaseHealth(Damage);
@@ -56,18 +57,19 @@ public partial class DamageComponent : Node
 
     private void OnAreaBodyExited(Node2D body)
     {
-        if (body != _currentTarget) return;
+        _currentTargets.Remove(body);
-        _currentTarget = null;
+        if (_currentTargets.Count == 0)
             DamageTimer?.Stop();
     }
 
     private void OnAreaBodyEntered(Node2D body)
     {
-        _currentTarget = body;
+        _currentTargets.Add(body);
 
         if (!CheckIfProcessingIsOn())
             return;
 
+        if (_currentTargets.Count == 1)
             DamageTimer?.Start();
 
         ProcessEntityAndApplyDamage(body);
@@ -75,9 +77,8 @@ public partial class DamageComponent : Node
 
     private void OnDamageTimerTimeout()
     {
-        if (_currentTarget == null) return;
+        foreach (var target in _currentTargets)
-        
+            ProcessEntityAndApplyDamage(target as Node2D);
-        ProcessEntityAndApplyDamage(_currentTarget as Node2D);
     }
     
     private void ProcessEntityAndApplyDamage(Node2D body)

scripts/components/HealthComponent.cs

@@ -1,6 +1,4 @@
-using System.Threading.Tasks;
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 
 namespace Mr.BrickAdventures.scripts.components;
@@ -20,27 +18,16 @@ public partial class HealthComponent : Node2D
 
     public override void _Ready()
     {
-        _floatingTextManager = GetNode<FloatingTextManager>(Constants.FloatingTextManagerPath);
+        _floatingTextManager = FloatingTextManager.Instance;
     }
 
-    public void SetHealth(float newValue)
+    public void SetHealth(float newValue) => ApplyHealthChange(newValue);
-    {
+    public void IncreaseHealth(float delta) => ApplyHealthChange(Health + delta);
-        _ = ApplyHealthChange(newValue);
+    public void DecreaseHealth(float delta) => ApplyHealthChange(Health - delta);
-    }
-
-    public void IncreaseHealth(float delta)
-    {
-        _ = ApplyHealthChange(Health + delta);
-    }
-
-    public void DecreaseHealth(float delta)
-    {
-        _ = ApplyHealthChange(Health - delta);
-    }
 
     public float GetDelta(float newValue) => newValue - Health;
 
-    private async Task ApplyHealthChange(float newHealth, bool playSfx = true)
+    private void ApplyHealthChange(float newHealth, bool playSfx = true)
     {
         newHealth = Mathf.Clamp(newHealth, 0.0f, MaxHealth);
         var delta = newHealth - Health;
@@ -53,39 +40,19 @@ public partial class HealthComponent : Node2D
         else
             _floatingTextManager?.ShowHeal(delta, GlobalPosition);
 
-        if (playSfx)
-        {
-            if (delta > 0f && HealSfx != null)
-            {
-                HealSfx.Play();
-            }
-            else if (delta < 0f && HurtSfx != null)
-            {
-                HurtSfx.Play();
-                await HurtSfx.ToSignal(HurtSfx, AudioStreamPlayer2D.SignalName.Finished);
-            }
-        }
-
         Health = newHealth;
 
+        if (playSfx)
+        {
+            if (delta > 0f)
+                HealSfx?.Play();
+            else
+                HurtSfx?.Play();
+        }
+
         if (Health <= 0f)
-        {
             EmitSignalDeath();
-            // Emit global event if this is the player
-            if (Owner is PlayerController)
-                EventBus.EmitPlayerDied(GlobalPosition);
-        }
         else
-        {
             EmitSignalHealthChanged(delta, Health);
-            // Emit global events if this is the player
-            if (Owner is PlayerController)
-            {
-                if (delta < 0f)
-                    EventBus.EmitPlayerDamaged(Mathf.Abs(delta), Health, GlobalPosition);
-                else
-                    EventBus.EmitPlayerHealed(delta, Health, GlobalPosition);
-            }
-        }
     }
 }

scripts/components/PlayerController.cs

@@ -2,7 +2,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 
 namespace Mr.BrickAdventures.scripts.components;
@@ -34,8 +33,19 @@ public partial class PlayerController : CharacterBody2D
 
     public override void _Ready()
     {
-        var skillManager = GetNodeOrNull<SkillManager>(Constants.SkillManagerPath);
+        SkillManager.Instance?.RegisterPlayer(this);
-        skillManager?.RegisterPlayer(this);
+
+        // Wire HealthComponent signals to global EventBus events
+        var health = GetNodeOrNull<HealthComponent>("HealthComponent");
+        if (health != null)
+        {
+            health.Death += () => EventBus.EmitPlayerDied(GlobalPosition);
+            health.HealthChanged += (delta, total) =>
+            {
+                if (delta < 0f) EventBus.EmitPlayerDamaged(Mathf.Abs(delta), total, GlobalPosition);
+                else EventBus.EmitPlayerHealed(delta, total, GlobalPosition);
+            };
+        }
 
         _inputHandler = GetNode<PlayerInputHandler>("PlayerInputHandler");
         foreach (var child in MovementAbilitiesContainer.GetChildren())
@@ -49,6 +59,7 @@ public partial class PlayerController : CharacterBody2D
 
         _ = ConnectJumpAndGravityAbilities();
         EmitSignalMovementAbilitiesChanged();
+        EventBus.EmitPlayerSpawned(this);
     }
 
     public override void _PhysicsProcess(double delta)