refactor: refactor stuff

docs/02_architecture.md

@@ -247,6 +247,27 @@ Loot      -> Enemies.Application                ŹLE
 Combat    -> Enemies.Godot                      ŹLE
 ```
 
+### Wyjątek: `Godot` -> `Godot`
+
+`Domain` i `Application` trzymają się reguły bez wyjątków - tam kontrakt broni czegoś realnego (można podmienić implementację, przetestować logikę bez silnika, nie ma przypadkowego sprzężenia).
+
+`Godot` tego wsparcia nie potrzebuje - kontrolery są celowo "głupie" i nie są objęte testami automatycznymi, więc kontrakt istniałby tam wyłącznie po to, żeby ominąć ograniczenie edytora Godota (`[Export]` nie umie wskazywać na typ-interfejs). Dlatego `Godot` jednego feature'a może importować `Godot` innego feature'a bezpośrednio, najczęściej po to, żeby zawrzeć w scenie węzeł z innego feature'a (`[Export]` na konkretną klasę) i wywołać na nim kilka metod.
+
+```text
+Players.Godot        -> Interactions.Godot      DOBRZE (kontener sceny, wywołanie metod kontrolera)
+Players.Application  -> Interactions.Godot      ŹLE    (logika feature'a nadal tylko przez Contracts)
+Players.Domain       -> Interactions.Godot      ŹLE
+```
+
+`GetNode`/`GetNodeOrNull` po ścieżce w scenie między feature'ami dalej jest niepożądane - zależność ma być jawna (typowane pole `[Export]` albo parametr metody `Initialize`/`Use...`), nie odnajdywana w drzewie sceny w runtime.
+
+Ten wyjątek nie zwalnia z Prawa Demeter. Rozmawiamy tylko z bezpośrednim sąsiadem - jeśli feature trzyma w sobie kontroler innego feature'a, woła na nim metody sam, zamiast wystawiać go dalej do przechodzenia przez łańcuch (`node.Inner.Other.Method()`). Kod spoza feature'a nie powinien wiedzieć, że dany kontroler w ogóle zawiera w sobie coś z innego feature'a.
+
+```text
+player.SetMovementMode(mode)              DOBRZE (PlayerController sam woła w środku Interaction/Body)
+player.Interaction.SetActive(isActive)    ŹLE    (wywołujący łańcuje się przez Playera do Interaction)
+```
+
 ### Eventy między feature'ami
 
 Gdy jedno zdarzenie interesuje wiele feature'ów, feature źródłowy publikuje event i nie wie, kto go słucha:

src/Features/Console/Application/Commands/SpawnItemCommand.cs

@@ -15,12 +15,12 @@ public sealed class SpawnItemCommand : ICommand
     public string Description => "Spawns an item in front of the player.";
     public IReadOnlyList<CommandArgSpec> Args { get; }
 
-    public SpawnItemCommand(IItemSpawner spawner, IItemSpawnPoint spawnPoint)
+    public SpawnItemCommand(IItemSpawner spawner, IItemDefinitionRegistry registry, IItemSpawnPoint spawnPoint)
     {
         _spawner = spawner;
         _spawnPoint = spawnPoint;
 
-        string[] definitions = spawner.DefinitionIds
+        string[] definitions = registry.DefinitionIds
             .Select(id => id.Value)
             .OrderBy(id => id, StringComparer.Ordinal)
             .ToArray();

src/Features/Interactions/Application/Interact.cs

@@ -0,0 +1,21 @@
+using Game.Features.Interactions.Contracts;
+
+namespace Game.Features.Interactions.Application;
+
+public sealed class Interact(IInteractionRegistry registry) : IInteractionHandler
+{
+    public InteractionResult TryInteract(InteractionRequest request)
+    {
+        if (!registry.TryGetTarget(request.TargetId, out IInteractionTarget target))
+        {
+            return InteractionResult.Fail(InteractionStatus.TargetNotFound, $"Target {request.TargetId} was not found.");
+        }
+
+        if (!target.CanInteract)
+        {
+            return InteractionResult.Fail(InteractionStatus.Unavailable, "The target is not currently available.");
+        }
+
+        return target.Execute(request.PlayerId);
+    }
+}

src/Features/Interactions/Application/InteractionService.cs

@@ -1,8 +0,0 @@
-using Game.Features.Interactions.Contracts;
-
-namespace Game.Features.Interactions.Application;
-
-public sealed class InteractionService(IInteractionWorld world) : IInteractionService
-{
-    public InteractionResult TryInteract(InteractionRequest request) => world.TryInteract(request);
-}

src/Features/Interactions/Application/ResolvePickupAvailability.cs

@@ -0,0 +1,19 @@
+using Game.Features.Items.Contracts;
+
+namespace Game.Features.Interactions.Application;
+
+public readonly record struct PickupAvailability(bool LeftHand, bool RightHand, bool RequiresBoth);
+
+public sealed class ResolvePickupAvailability
+{
+    public PickupAvailability Resolve(HandRequirement requirement, bool leftHandFree, bool rightHandFree)
+    {
+        if (requirement == HandRequirement.Both)
+        {
+            bool canUseBoth = leftHandFree && rightHandFree;
+            return new PickupAvailability(canUseBoth, canUseBoth, true);
+        }
+
+        return new PickupAvailability(leftHandFree, rightHandFree, false);
+    }
+}

src/Features/Interactions/Application/ResolvePickupAvailability.cs.uid

@@ -0,0 +1 @@
+uid://c6mhpn06a47qu

src/Features/Interactions/Contracts/IInteractionHandler.cs

@@ -1,6 +1,6 @@
 namespace Game.Features.Interactions.Contracts;
 
-public interface IInteractionService
+public interface IInteractionHandler
 {
     InteractionResult TryInteract(InteractionRequest request);
 }

src/Features/Interactions/Contracts/IInteractionRegistry.cs

@@ -0,0 +1,8 @@
+namespace Game.Features.Interactions.Contracts;
+
+public interface IInteractionRegistry
+{
+    void Register(IInteractionTarget target);
+    void Unregister(InteractionTargetId targetId);
+    bool TryGetTarget(InteractionTargetId targetId, out IInteractionTarget target);
+}

src/Features/Interactions/Contracts/IInteractionRegistry.cs.uid

@@ -0,0 +1 @@
+uid://baejppnflmpnn

src/Features/Interactions/Contracts/IInteractionTarget.cs

@@ -1,8 +1,12 @@
+using Game.Features.Players.Contracts;
+
 namespace Game.Features.Interactions.Contracts;
 
 public interface IInteractionTarget
 {
-    InteractionTargetId Id { get; }
+    InteractionTargetId InteractionTargetId { get; }
     bool CanInteract { get; }
     InteractionPrompt Prompt { get; }
+
+    InteractionResult Execute(PlayerId playerId);
 }

src/Features/Interactions/Contracts/IInteractionWorld.cs

@@ -1,6 +0,0 @@
-namespace Game.Features.Interactions.Contracts;
-
-public interface IInteractionWorld
-{
-    InteractionResult TryInteract(InteractionRequest request);
-}

src/Features/Interactions/Contracts/IInteractionWorld.cs.uid

@@ -1 +0,0 @@
-uid://d7k1x6m4v9q2b

src/Features/Interactions/Contracts/InteractionTargetId.cs

@@ -1,8 +1,10 @@
-using System;
+using Game.Shared.Domain;
 
 namespace Game.Features.Interactions.Contracts;
 
-public readonly record struct InteractionTargetId(Guid Value)
+public readonly record struct InteractionTargetId(InstanceId Value)
 {
+    public static InteractionTargetId From(InstanceId value) => new(value);
+
     public override string ToString() => Value.ToString();
 }

src/Features/Interactions/Domain/DropPosition.cs

@@ -0,0 +1,26 @@
+using Godot;
+
+namespace Game.Features.Interactions.Domain;
+
+public readonly record struct DropRayHit(
+    Vector3 Origin,
+    Vector3 Direction,
+    float RayLength,
+    bool IsBlocked,
+    Vector3 BlockPoint
+);
+
+public static class DropPosition
+{
+    public static Vector3 CalculateFrom(DropRayHit hit)
+    {
+        float distance = hit.RayLength;
+
+        if (hit.IsBlocked)
+        {
+            distance = Mathf.Max(0.25f, hit.Origin.DistanceTo(hit.BlockPoint) - 0.2f);
+        }
+
+        return hit.Origin + hit.Direction * distance;
+    }
+}

src/Features/Interactions/Domain/DropPosition.cs.uid

@@ -0,0 +1 @@
+uid://derjakse05m3d

src/Features/Interactions/Godot/InteractableController.cs

@@ -0,0 +1,58 @@
+using Game.Features.Interactions.Contracts;
+using Game.Features.Players.Contracts;
+using Game.Godot.Extensions;
+using Godot;
+using Godot.Collections;
+
+namespace Game.Features.Interactions.Godot;
+
+public abstract partial class InteractableController : Node3D, IInteractionTarget
+{
+    public const string InteractionGroup = "interactions";
+
+    [Export]
+    public string InstanceKey;
+
+    [Export]
+    public string PromptText = "Wejdź w interakcję";
+
+    public InteractionTargetId InteractionTargetId { get; private set; }
+    public virtual bool CanInteract => true;
+    public InteractionPrompt Prompt => new(PromptText);
+
+    private InteractionsRegistryController _registry;
+
+    private void RegisterWithAvailableRegistry()
+    {
+        Array<Node> availableRegistries = GetTree()
+            .GetNodesInGroup(InteractionsRegistryController.RegistryGroup);
+
+        foreach (Node node in availableRegistries)
+        {
+            if (node is InteractionsRegistryController registry)
+            {
+                registry.Register(this);
+                return;
+            }
+        }
+    }
+
+    public void UseRegistry(InteractionsRegistryController registry)
+    {
+        _registry = registry;
+    }
+
+    public abstract InteractionResult Execute(PlayerId playerId);
+
+    public override void _ExitTree()
+    {
+        _registry?.Unregister(InteractionTargetId);
+    }
+
+    public override void _Ready()
+    {
+        InteractionTargetId = InteractionTargetId.From(this.GetStableInstanceIdFrom(InstanceKey));
+        AddToGroup(InteractionGroup);
+        RegisterWithAvailableRegistry();
+    }
+}

src/Features/Interactions/Godot/InteractableController.cs.uid

@@ -0,0 +1 @@
+uid://bh0e1kwa1i4r

src/Features/Interactions/Godot/InteractionRaycaster.cs

@@ -4,7 +4,7 @@ namespace Game.Features.Interactions.Godot;
 
 public partial class InteractionRaycaster : RayCast3D
 {
-    public T GetTarget<T>() where T : class
+    public T GetTargetOrNull<T>() where T : class
     {
         if (!IsColliding() || GetCollider() is not Node node)
         {

src/Features/Interactions/Godot/InteractionWorldController.cs

@@ -1,65 +0,0 @@
-using System;
-using System.Collections.Generic;
-using Game.Features.Interactions.Contracts;
-using Godot;
-
-namespace Game.Features.Interactions.Godot;
-
-public partial class InteractionWorldController : Node, IInteractionWorld
-{
-    public const string RegistryGroup = "interaction_world_registry";
-
-    private readonly Dictionary<InteractionTargetId, WorldInteractionController> _targets = [];
-
-    public override void _EnterTree()
-    {
-        AddToGroup(RegistryGroup);
-    }
-
-    public void RegisterSceneTargets()
-    {
-        foreach (Node node in GetTree().GetNodesInGroup(WorldInteractionController.InteractionGroup))
-        {
-            if (node is WorldInteractionController target)
-            {
-                Register(target);
-            }
-        }
-    }
-
-    public void Register(WorldInteractionController target)
-    {
-        if (_targets.TryGetValue(target.Id, out WorldInteractionController existing))
-        {
-            if (ReferenceEquals(existing, target))
-            {
-                return;
-            }
-
-            throw new InvalidOperationException($"Duplicate interaction target id: {target.Id}.");
-        }
-
-        _targets.Add(target.Id, target);
-        target.RegisterWith(this);
-    }
-
-    public void Unregister(InteractionTargetId targetId)
-    {
-        _targets.Remove(targetId);
-    }
-
-    public InteractionResult TryInteract(InteractionRequest request)
-    {
-        if (!_targets.TryGetValue(request.TargetId, out WorldInteractionController target))
-        {
-            return InteractionResult.Fail(InteractionStatus.TargetNotFound, $"Target {request.TargetId} was not found.");
-        }
-
-        if (!target.CanInteract)
-        {
-            return InteractionResult.Fail(InteractionStatus.Unavailable, "The target is not currently available.");
-        }
-
-        return target.Execute(request.PlayerId);
-    }
-}

src/Features/Interactions/Godot/InteractionsRegistryController.cs

@@ -0,0 +1,47 @@
+using Game.Features.Interactions.Contracts;
+using Godot;
+using GodotNodeArray = Godot.Collections.Array<Godot.Node>;
+
+namespace Game.Features.Interactions.Godot;
+
+public partial class InteractionsRegistryController : Node
+{
+    public const string RegistryGroup = "interactions_registry";
+
+    private IInteractionRegistry _registry;
+
+    private GodotNodeArray GetInteractionTargetNodesInScene() =>
+        GetTree().GetNodesInGroup(InteractableController.InteractionGroup);
+
+    public override void _EnterTree()
+    {
+        AddToGroup(RegistryGroup);
+    }
+
+    public void UseRegistry(IInteractionRegistry registry)
+    {
+        _registry = registry;
+    }
+
+    public void RegisterSceneTargets()
+    {
+        foreach (Node node in GetInteractionTargetNodesInScene())
+        {
+            if (node is InteractableController target)
+            {
+                Register(target);
+            }
+        }
+    }
+
+    public void Register(InteractableController target)
+    {
+        _registry.Register(target);
+        target.UseRegistry(this);
+    }
+
+    public void Unregister(InteractionTargetId targetId)
+    {
+        _registry.Unregister(targetId);
+    }
+}

src/Features/Interactions/Godot/PlayerInteractionController.cs

@@ -1,8 +1,11 @@
 using System.Collections.Generic;
+using Game.Features.Interactions.Application;
 using Game.Features.Interactions.Contracts;
+using Game.Features.Interactions.Domain;
 using Game.Features.Items.Contracts;
 using Game.Features.Players.Contracts;
 using Game.Godot;
+using Game.Godot.Exceptions;
 using Game.Godot.Extensions;
 using Game.Godot.Mappings;
 using Godot;
@@ -11,29 +14,149 @@ namespace Game.Features.Interactions.Godot;
 
 public partial class PlayerInteractionController : Node, IItemSpawnPoint
 {
-    [Export] public Camera3D Camera;
+    [Export]
-    [Export] public CharacterBody3D Body;
+    public Camera3D Camera;
-    [Export] public InteractionRaycaster InteractionRaycaster;
+
-    [Export] public RayCast3D DropRaycaster;
+    [Export]
-    [Export] public InteractionPromptController PromptController;
+    public CharacterBody3D Body;
-    [Export] public Node3D LeftHandAnchor;
+
-    [Export] public Node3D RightHandAnchor;
+    [Export]
+    public InteractionRaycaster InteractionRaycaster;
+
+    [Export]
+    public RayCast3D DropRaycaster;
+
+    [Export]
+    public InteractionPromptController PromptController;
+
+    [Export]
+    public Node3D LeftHandAnchor;
+
+    [Export]
+    public Node3D RightHandAnchor;
 
     private IItemInteractionService _items;
-    private IInteractionService _interactions;
+    private IInteractionHandler _interactions;
     private PlayerId _playerId;
     private readonly HashSet<Hand> _dropActions = [];
-    private readonly Dictionary<Hand, InteractionTargetId?> _activeUseTargets = [];
+    private readonly ResolvePickupAvailability _resolvePickupAvailability = new();
 
-    public override void _Ready()
+    private ItemUseRequest CreateUseRequest(Hand hand, ItemActionPhase phase)
     {
-        this.AssertRequiredExports();
+        InteractionTargetId? targetId = InteractionRaycaster
+            .GetTargetOrNull<IInteractionTarget>()
+            ?.InteractionTargetId;
+
+        return new ItemUseRequest(_playerId, hand, phase, targetId);
+    }
+
+    private void ProcessHandActionStarted(Hand hand)
+    {
+        if (Input.IsActionPressed(InputAction.DropModifier.ActionName()))
+        {
+            _items.TryUse(new ItemUseRequest(_playerId, hand, ItemActionPhase.Cancelled));
+            _items.TryDrop(hand, CalculateDropPosition());
+            _dropActions.Add(hand);
+            return;
+        }
+
+        if (!_items.IsHandFree(hand))
+        {
+            _items.TryUse(CreateUseRequest(hand, ItemActionPhase.Started));
+            return;
+        }
+
+        IPickupTarget target = InteractionRaycaster.GetTargetOrNull<IPickupTarget>();
+        if (target is not null)
+        {
+            _items.TryPickup(target.ItemInfo.Id, hand);
+        }
+    }
+
+    private void ProcessHandActionCompleted(Hand hand)
+    {
+        if (_dropActions.Remove(hand))
+        {
+            return;
+        }
+
+        _items.TryUse(new ItemUseRequest(_playerId, hand, ItemActionPhase.Completed));
+    }
+
+    private Vector3 CalculateDropPosition()
+    {
+        DropRaycaster.ForceRaycastUpdate();
+
+        bool isBlocked = DropRaycaster.IsColliding();
+        DropRayHit hit = new(
+            Camera.GlobalPosition,
+            -Camera.GlobalBasis.Z.Normalized(),
+            DropRaycaster.TargetPosition.Length(),
+            isBlocked,
+            isBlocked ? DropRaycaster.GetCollisionPoint() : default
+        );
+
+        return DropPosition.CalculateFrom(hit);
+    }
+
+    private void UpdatePrompt()
+    {
+        IPickupTarget pickupTarget = InteractionRaycaster.GetTargetOrNull<IPickupTarget>();
+        if (pickupTarget is not null)
+        {
+            ShowPickupPrompt(pickupTarget.ItemInfo);
+            return;
+        }
+
+        IInteractionTarget interactionTarget = InteractionRaycaster.GetTargetOrNull<IInteractionTarget>();
+        if (interactionTarget?.CanInteract == true)
+        {
+            PromptController.ShowPrompt($"[E] {interactionTarget.Prompt.Text}");
+            return;
+        }
+
+        PromptController.Clear();
+    }
+
+    private void ShowPickupPrompt(ItemInfo itemInfo)
+    {
+        PickupAvailability availability = _resolvePickupAvailability.Resolve(
+            itemInfo.HandRequirement,
+            _items.IsHandFree(Hand.Left),
+            _items.IsHandFree(Hand.Right)
+        );
+
+        if (availability.RequiresBoth)
+        {
+            PromptController.ShowPrompt(
+                availability.LeftHand
+                    ? $"[LPM lub PPM] Podnieś {itemInfo.DisplayName} — obie ręce"
+                    : "Potrzebujesz obu wolnych rąk"
+            );
+            return;
+        }
+
+        List<string> actions = [];
+
+        if (availability.LeftHand)
+        {
+            actions.Add($"[LPM] Podnieś {itemInfo.DisplayName} — lewa ręka");
+        }
+
+        if (availability.RightHand)
+        {
+            actions.Add($"[PPM] Podnieś {itemInfo.DisplayName} — prawa ręka");
+        }
+
+        PromptController.ShowPrompt(
+            actions.Count > 0 ? string.Join("\n", actions) : "Brak wolnej ręki"
+        );
     }
 
     public void Initialize(
         PlayerId playerId,
         IItemInteractionService items,
-        IInteractionService interactions
+        IInteractionHandler interactions
     )
     {
         _playerId = playerId;
@@ -41,9 +164,21 @@ public partial class PlayerInteractionController : Node, IItemSpawnPoint
         _interactions = interactions;
     }
 
+    public Vector3 GetItemSpawnPosition() => CalculateDropPosition();
+
+    public override void _Ready()
+    {
+        this.AssertRequiredExports();
+    }
+
     public override void _Process(double delta)
     {
-        if (_items is null || _interactions is null || GamePause.IsPaused || !MouseCapture.IsCaptured)
+        if (_items is null || _interactions is null)
+        {
+            throw new ControllerNotInitializedException(Name);
+        }
+
+        if (GamePause.IsPaused || !MouseCapture.IsCaptured)
         {
             PromptController.Clear();
             return;
@@ -54,7 +189,12 @@ public partial class PlayerInteractionController : Node, IItemSpawnPoint
 
     public override void _UnhandledInput(InputEvent @event)
     {
-        if (_items is null || _interactions is null || GamePause.IsPaused || !MouseCapture.IsCaptured)
+        if (_items is null || _interactions is null)
+        {
+            throw new ControllerNotInitializedException(Name);
+        }
+
+        if (GamePause.IsPaused || !MouseCapture.IsCaptured)
         {
             return;
         }
@@ -89,135 +229,15 @@ public partial class PlayerInteractionController : Node, IItemSpawnPoint
 
         if (@event.IsActionPressed(InputAction.Interact.ActionName()))
         {
-            IInteractionTarget target = InteractionRaycaster.GetTarget<IInteractionTarget>();
+            IInteractionTarget target = InteractionRaycaster.GetTargetOrNull<IInteractionTarget>();
             if (target?.CanInteract == true)
             {
-                _interactions.TryInteract(new InteractionRequest(_playerId, target.Id));
+                _interactions.TryInteract(
+                    new InteractionRequest(_playerId, target.InteractionTargetId)
+                );
             }
 
             GetViewport().SetInputAsHandled();
         }
     }
-
-    public Vector3 GetItemSpawnPosition() => CalculateDropPosition();
-
-    private void ProcessHandActionStarted(Hand hand)
-    {
-        if (Input.IsActionPressed(InputAction.DropModifier.ActionName()))
-        {
-            if (_activeUseTargets.Remove(hand, out InteractionTargetId? activeTargetId))
-            {
-                _items.TryUse(new ItemUseRequest(
-                    _playerId,
-                    hand,
-                    ItemActionPhase.Cancelled,
-                    activeTargetId
-                ));
-            }
-
-            _items.TryDrop(hand, CalculateDropPosition());
-            _dropActions.Add(hand);
-            return;
-        }
-
-        if (!_items.IsHandFree(hand))
-        {
-            ItemUseRequest request = CreateUseRequest(hand, ItemActionPhase.Started);
-            ItemActionResult result = _items.TryUse(request);
-            if (result.Success)
-            {
-                _activeUseTargets[hand] = request.TargetId;
-            }
-
-            return;
-        }
-
-        IPickupTarget target = InteractionRaycaster.GetTarget<IPickupTarget>();
-        if (target is not null)
-        {
-            _items.TryPickup(target.ItemInfo.Id, hand);
-        }
-    }
-
-    private void ProcessHandActionCompleted(Hand hand)
-    {
-        if (_dropActions.Remove(hand))
-        {
-            return;
-        }
-
-        if (_activeUseTargets.Remove(hand, out InteractionTargetId? targetId))
-        {
-            _items.TryUse(new ItemUseRequest(_playerId, hand, ItemActionPhase.Completed, targetId));
-        }
-    }
-
-    private ItemUseRequest CreateUseRequest(Hand hand, ItemActionPhase phase)
-    {
-        InteractionTargetId? targetId = InteractionRaycaster.GetTarget<IInteractionTarget>()?.Id;
-        return new ItemUseRequest(_playerId, hand, phase, targetId);
-    }
-
-    private Vector3 CalculateDropPosition()
-    {
-        DropRaycaster.ForceRaycastUpdate();
-
-        Vector3 origin = Camera.GlobalPosition;
-        Vector3 direction = -Camera.GlobalBasis.Z.Normalized();
-        float distance = DropRaycaster.TargetPosition.Length();
-
-        if (DropRaycaster.IsColliding())
-        {
-            distance = Mathf.Max(0.25f, origin.DistanceTo(DropRaycaster.GetCollisionPoint()) - 0.2f);
-        }
-
-        return origin + direction * distance;
-    }
-
-    private void UpdatePrompt()
-    {
-        IPickupTarget pickupTarget = InteractionRaycaster.GetTarget<IPickupTarget>();
-        if (pickupTarget is not null)
-        {
-            ShowPickupPrompt(pickupTarget.ItemInfo);
-            return;
-        }
-
-        IInteractionTarget interactionTarget = InteractionRaycaster.GetTarget<IInteractionTarget>();
-        if (interactionTarget?.CanInteract == true)
-        {
-            PromptController.ShowPrompt($"[E] {interactionTarget.Prompt.Text}");
-            return;
-        }
-
-        PromptController.Clear();
-    }
-
-    private void ShowPickupPrompt(ItemInfo itemInfo)
-    {
-        if (itemInfo.HandRequirement == HandRequirement.Both)
-        {
-            bool bothHandsFree = _items.IsHandFree(Hand.Left) && _items.IsHandFree(Hand.Right);
-            PromptController.ShowPrompt(bothHandsFree
-                ? $"[LPM lub PPM] Podnieś {itemInfo.DisplayName} — obie ręce"
-                : "Potrzebujesz obu wolnych rąk");
-            return;
-        }
-
-        List<string> actions = [];
-
-        if (_items.IsHandFree(Hand.Left))
-        {
-            actions.Add($"[LPM] Podnieś {itemInfo.DisplayName} — lewa ręka");
-        }
-
-        if (_items.IsHandFree(Hand.Right))
-        {
-            actions.Add($"[PPM] Podnieś {itemInfo.DisplayName} — prawa ręka");
-        }
-
-        PromptController.ShowPrompt(actions.Count > 0
-            ? string.Join("\n", actions)
-            : "Brak wolnej ręki");
-    }
 }

src/Features/Interactions/Godot/WorldInteractionController.cs

@@ -1,52 +0,0 @@
-using System;
-using Game.Features.Interactions.Contracts;
-using Game.Features.Players.Contracts;
-using Godot;
-
-namespace Game.Features.Interactions.Godot;
-
-public abstract partial class WorldInteractionController : Node3D, IInteractionTarget
-{
-    public const string InteractionGroup = "world_interactions";
-
-    [Export] public string InstanceId;
-    [Export] public string PromptText = "Wejdź w interakcję";
-
-    public InteractionTargetId Id { get; private set; }
-    public virtual bool CanInteract => true;
-    public InteractionPrompt Prompt => new(PromptText);
-
-    private InteractionWorldController _registry;
-
-    public override void _Ready()
-    {
-        Guid id = string.IsNullOrWhiteSpace(InstanceId) ? Guid.NewGuid() : Guid.Parse(InstanceId);
-        Id = new InteractionTargetId(id);
-        AddToGroup(InteractionGroup);
-        RegisterWithAvailableWorld();
-    }
-
-    public override void _ExitTree()
-    {
-        _registry?.Unregister(Id);
-    }
-
-    public void RegisterWith(InteractionWorldController registry)
-    {
-        _registry = registry;
-    }
-
-    public abstract InteractionResult Execute(PlayerId playerId);
-
-    private void RegisterWithAvailableWorld()
-    {
-        foreach (Node node in GetTree().GetNodesInGroup(InteractionWorldController.RegistryGroup))
-        {
-            if (node is InteractionWorldController registry)
-            {
-                registry.Register(this);
-                return;
-            }
-        }
-    }
-}

src/Features/Interactions/Godot/WorldInteractionController.cs.uid

@@ -1 +0,0 @@
-uid://d2r8m5v1q9k4x

src/Features/Interactions/Infrastructure/InteractionRegistry.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using Game.Features.Interactions.Contracts;
+
+namespace Game.Features.Interactions.Infrastructure;
+
+public sealed class InteractionRegistry : IInteractionRegistry
+{
+    private readonly Dictionary<InteractionTargetId, IInteractionTarget> _interactionTargetsById =
+    [];
+
+    public void Register(IInteractionTarget target)
+    {
+        if (
+            _interactionTargetsById.TryGetValue(
+                target.InteractionTargetId,
+                out IInteractionTarget existing
+            )
+        )
+        {
+            if (ReferenceEquals(existing, target))
+            {
+                return;
+            }
+
+            throw new InvalidOperationException(
+                $"Duplicate interaction target id: {target.InteractionTargetId}."
+            );
+        }
+
+        _interactionTargetsById.Add(target.InteractionTargetId, target);
+    }
+
+    public void Unregister(InteractionTargetId targetId)
+    {
+        _interactionTargetsById.Remove(targetId);
+    }
+
+    public bool TryGetTarget(InteractionTargetId targetId, out IInteractionTarget target) =>
+        _interactionTargetsById.TryGetValue(targetId, out target);
+}

src/Features/Interactions/Infrastructure/InteractionRegistry.cs.uid

@@ -0,0 +1 @@
+uid://dtnwqalxdu6n2

src/Features/Items/Application/ItemInteractionService.cs

@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+using Game.Features.Interactions.Contracts;
 using Game.Features.Items.Contracts;
 using Game.Features.Items.Domain;
 using Godot;
@@ -6,17 +8,19 @@ namespace Game.Features.Items.Application;
 
 public sealed class ItemInteractionService(
     HandsInventory hands,
-    IItemRepository itemRepository,
+    IItemInstanceRegistry itemRegistry,
     IHeldItemPresenter presenter
 ) : IItemInteractionService
 {
+    private readonly Dictionary<Hand, InteractionTargetId?> _activeUseTargets = [];
+
     public bool IsHandFree(Hand hand) => hands.IsFree(hand);
 
     public ItemInstanceId? GetHeldItem(Hand hand) => hands.Get(hand);
 
     public ItemActionResult TryPickup(ItemInstanceId itemId, Hand hand)
     {
-        if (!itemRepository.TryGet(itemId, out IItemInstance item))
+        if (!itemRegistry.TryGet(itemId, out IItemInstance item))
         {
             return ItemActionResult.Fail(ItemActionStatus.ItemNotFound, $"Item {itemId} was not found.");
         }
@@ -36,6 +40,27 @@ public sealed class ItemInteractionService(
     }
 
     public ItemActionResult TryUse(ItemUseRequest request)
+    {
+        if (request.Phase == ItemActionPhase.Started)
+        {
+            ItemActionResult startResult = ExecuteUse(request);
+            if (startResult.Success)
+            {
+                _activeUseTargets[request.Hand] = request.TargetId;
+            }
+
+            return startResult;
+        }
+
+        if (!_activeUseTargets.Remove(request.Hand, out InteractionTargetId? activeTargetId))
+        {
+            return ItemActionResult.Ok();
+        }
+
+        return ExecuteUse(request with { TargetId = activeTargetId });
+    }
+
+    private ItemActionResult ExecuteUse(ItemUseRequest request)
     {
         ItemInstanceId? itemId = hands.Get(request.Hand);
         if (itemId is null)
@@ -43,7 +68,7 @@ public sealed class ItemInteractionService(
             return ItemActionResult.Fail(ItemActionStatus.HandEmpty, "The requested hand is empty.");
         }
 
-        if (!itemRepository.TryGet(itemId.Value, out IItemInstance item))
+        if (!itemRegistry.TryGet(itemId.Value, out IItemInstance item))
         {
             return ItemActionResult.Fail(ItemActionStatus.ItemNotFound, $"Item {itemId} was not found.");
         }
@@ -65,7 +90,7 @@ public sealed class ItemInteractionService(
             return ItemActionResult.Fail(ItemActionStatus.HandEmpty, "The requested hand is empty.");
         }
 
-        if (!itemRepository.TryGet(itemId.Value, out IItemInstance item))
+        if (!itemRegistry.TryGet(itemId.Value, out IItemInstance item))
         {
             return ItemActionResult.Fail(ItemActionStatus.ItemNotFound, $"Item {itemId} was not found.");
         }

src/Features/Items/Contracts/IItemDefinitionRegistry.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace Game.Features.Items.Contracts;
+
+public interface IItemDefinitionRegistry
+{
+    IReadOnlyCollection<ItemDefinitionId> DefinitionIds { get; }
+    bool TryRegister(ItemDefinitionId definitionId, ItemDefinition definition);
+    bool TryGetDefinition(ItemDefinitionId definitionId, out ItemDefinition definition);
+}

src/Features/Items/Contracts/IItemDefinitionRegistry.cs.uid

@@ -0,0 +1 @@
+uid://kjka28plyqeo

src/Features/Items/Contracts/IItemInstanceRegistry.cs

@@ -0,0 +1,8 @@
+namespace Game.Features.Items.Contracts;
+
+public interface IItemInstanceRegistry
+{
+    void Register(ItemInstanceId itemId, IItemInstance item);
+    void Unregister(ItemInstanceId itemId);
+    bool TryGet(ItemInstanceId itemId, out IItemInstance item);
+}

src/Features/Items/Contracts/IItemInstanceRegistry.cs.uid

@@ -0,0 +1 @@
+uid://s83yytevpj52

src/Features/Items/Contracts/IItemRepository.cs

@@ -1,6 +0,0 @@
-namespace Game.Features.Items.Contracts;
-
-public interface IItemRepository
-{
-    bool TryGet(ItemInstanceId itemId, out IItemInstance item);
-}

src/Features/Items/Contracts/IItemRepository.cs.uid

@@ -1 +0,0 @@
-uid://e7n1m6v4k9r3q

src/Features/Items/Contracts/IItemSpawner.cs

@@ -1,10 +1,12 @@
-using System.Collections.Generic;
 using Godot;
 
 namespace Game.Features.Items.Contracts;
 
 public interface IItemSpawner
 {
-    IReadOnlyCollection<ItemDefinitionId> DefinitionIds { get; }
+    ItemActionResult TrySpawn(
-    ItemActionResult TrySpawn(ItemDefinitionId definitionId, Vector3 worldPosition, out ItemInstanceId itemId);
+        ItemDefinitionId definitionId,
+        Vector3 worldPosition,
+        out ItemInstanceId itemId
+    );
 }

src/Features/Items/Contracts/ItemInstanceId.cs

@@ -1,8 +1,10 @@
-using System;
+using Game.Shared.Domain;
 
 namespace Game.Features.Items.Contracts;
 
-public readonly record struct ItemInstanceId(Guid Value)
+public readonly record struct ItemInstanceId(InstanceId Value)
 {
+    public static ItemInstanceId From(InstanceId value) => new(value);
+
     public override string ToString() => Value.ToString();
 }

src/Features/Items/Godot/Flashlight/FlashlightItemController.cs

@@ -5,7 +5,7 @@ using Godot;
 
 namespace Game.Features.Items.Godot.Flashlight;
 
-public partial class FlashlightItemController : WorldItemController
+public partial class FlashlightItemController : ItemController
 {
     [Export] public SpotLight3D WorldLight;
 

src/Features/Items/Godot/HeldItemPresenter.cs

@@ -3,15 +3,15 @@ using Godot;
 
 namespace Game.Features.Items.Godot;
 
-public sealed class PlayerHeldItemPresenter(
+public sealed class HeldItemPresenter(
-    ItemWorldController itemWorld,
+    ItemControllerRegistryController itemWorld,
     Node3D leftHandAnchor,
     Node3D rightHandAnchor
 ) : IHeldItemPresenter
 {
     public bool TryShowHeld(IItemInstance item, Hand hand)
     {
-        if (!itemWorld.TryGetController(item.Info.Id, out WorldItemController controller))
+        if (!itemWorld.TryGetController(item.Info.Id, out ItemController controller))
         {
             return false;
         }
@@ -23,7 +23,7 @@ public sealed class PlayerHeldItemPresenter(
 
     public bool TryShowDropped(IItemInstance item, Vector3 worldPosition)
     {
-        if (!itemWorld.TryGetController(item.Info.Id, out WorldItemController controller))
+        if (!itemWorld.TryGetController(item.Info.Id, out ItemController controller))
         {
             return false;
         }
@@ -34,7 +34,7 @@ public sealed class PlayerHeldItemPresenter(
 
     public void Refresh(IItemInstance item)
     {
-        if (itemWorld.TryGetController(item.Info.Id, out WorldItemController controller))
+        if (itemWorld.TryGetController(item.Info.Id, out ItemController controller))
         {
             controller.ApplyState(item);
         }

src/Features/Items/Godot/ItemController.cs

@@ -6,17 +6,30 @@ using Godot;
 
 namespace Game.Features.Items.Godot;
 
-public partial class WorldItemController : RigidBody3D, IPickupTarget
+public partial class ItemController : RigidBody3D, IPickupTarget
 {
     public const string ItemGroup = "world_items";
 
-    [Export] public string InstanceId;
+    [Export]
-    [Export] public string DefinitionId = "item";
+    public string InstanceKey;
-    [Export] public string DisplayName = "Item";
+
-    [Export] public HandRequirement HandRequirement = HandRequirement.One;
+    [Export]
-    [Export] public CollisionShape3D Collision;
+    public string DefinitionId = "item";
-    [Export] public Node3D WorldVisual;
+
-    [Export] public PackedScene HeldViewScene;
+    [Export]
+    public string DisplayName = "Item";
+
+    [Export]
+    public HandRequirement HandRequirement = HandRequirement.One;
+
+    [Export]
+    public CollisionShape3D Collision;
+
+    [Export]
+    public Node3D WorldVisual;
+
+    [Export]
+    public PackedScene HeldViewScene;
 
     protected Node3D HeldView { get; private set; }
     protected bool IsHeld => HeldView is not null;
@@ -25,7 +38,7 @@ public partial class WorldItemController : RigidBody3D, IPickupTarget
     public ItemDefinition Definition { get; private set; }
     public IItemInstance Item { get; private set; }
 
-    private ItemWorldController _registry;
+    private ItemControllerRegistryController _registry;
 
     public override void _Ready()
     {
@@ -41,20 +54,19 @@ public partial class WorldItemController : RigidBody3D, IPickupTarget
             throw new InvalidOperationException($"{Name}: held view scene is not assigned.");
         }
 
-        Guid id = string.IsNullOrWhiteSpace(InstanceId)
+        Definition = new ItemDefinition(
-            ? Guid.NewGuid()
+            new ItemDefinitionId(DefinitionId),
-            : Guid.Parse(InstanceId);
+            DisplayName,
-
+            HandRequirement
-        Definition = new ItemDefinition(new ItemDefinitionId(DefinitionId), DisplayName, HandRequirement);
+        );
         ItemInfo = new ItemInfo(
-            new ItemInstanceId(id),
+            ItemInstanceId.From(this.GetStableInstanceIdFrom(InstanceKey)),
             Definition.Id,
             Definition.DisplayName,
             Definition.HandRequirement
         );
         Item = CreateItemInstance(ItemInfo);
         AddToGroup(ItemGroup);
-        RegisterWithAvailableWorld();
         ApplyState(Item);
     }
 
@@ -63,7 +75,7 @@ public partial class WorldItemController : RigidBody3D, IPickupTarget
         _registry?.Unregister(ItemInfo.Id);
     }
 
-    public void RegisterWith(ItemWorldController registry)
+    public void RegisterWith(ItemControllerRegistryController registry)
     {
         _registry = registry;
     }
@@ -113,29 +125,12 @@ public partial class WorldItemController : RigidBody3D, IPickupTarget
         OnPresentationChanged(item);
     }
 
-    protected virtual IItemInstance CreateItemInstance(ItemInfo itemInfo) => new PassiveItemInstance(itemInfo);
+    protected virtual IItemInstance CreateItemInstance(ItemInfo itemInfo) =>
+        new PassiveItemInstance(itemInfo);
 
-    protected virtual void OnHeldViewCreated(Node3D heldView)
+    protected virtual void OnHeldViewCreated(Node3D heldView) { }
-    {
-    }
 
-    protected virtual void OnHeldViewRemoving(Node3D heldView)
+    protected virtual void OnHeldViewRemoving(Node3D heldView) { }
-    {
-    }
 
-    protected virtual void OnPresentationChanged(IItemInstance item)
+    protected virtual void OnPresentationChanged(IItemInstance item) { }
-    {
-    }
-
-    private void RegisterWithAvailableWorld()
-    {
-        foreach (Node node in GetTree().GetNodesInGroup(ItemWorldController.RegistryGroup))
-        {
-            if (node is ItemWorldController registry)
-            {
-                registry.Register(this);
-                return;
-            }
-        }
-    }
 }

src/Features/Items/Godot/ItemControllerRegistryController.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using Game.Features.Items.Contracts;
+using Godot;
+
+namespace Game.Features.Items.Godot;
+
+public partial class ItemControllerRegistryController : Node
+{
+    private IItemInstanceRegistry _registry;
+    private readonly Dictionary<ItemInstanceId, ItemController> _items = [];
+
+    public IReadOnlyCollection<ItemController> Items => _items.Values;
+
+    public void UseRegistry(IItemInstanceRegistry registry)
+    {
+        _registry = registry;
+    }
+
+    public void RegisterSceneItems()
+    {
+        foreach (Node node in GetTree().GetNodesInGroup(ItemController.ItemGroup))
+        {
+            if (node is ItemController item)
+            {
+                Register(item);
+            }
+        }
+    }
+
+    public void Register(ItemController item)
+    {
+        if (_items.TryGetValue(item.ItemInfo.Id, out ItemController existing))
+        {
+            if (ReferenceEquals(existing, item))
+            {
+                return;
+            }
+
+            throw new InvalidOperationException($"Duplicate item instance id: {item.ItemInfo.Id}.");
+        }
+
+        _items.Add(item.ItemInfo.Id, item);
+        _registry.Register(item.ItemInfo.Id, item.Item);
+        item.RegisterWith(this);
+    }
+
+    public void Unregister(ItemInstanceId itemId)
+    {
+        _items.Remove(itemId);
+        _registry.Unregister(itemId);
+    }
+
+    public bool TryGetController(ItemInstanceId itemId, out ItemController controller)
+    {
+        return _items.TryGetValue(itemId, out controller);
+    }
+}

src/Features/Items/Godot/ItemSceneRegistryController.cs

@@ -0,0 +1,112 @@
+using System;
+using System.Collections.Generic;
+using Game.Features.Items.Contracts;
+using Game.Godot.Extensions;
+using Godot;
+
+namespace Game.Features.Items.Godot;
+
+public partial class ItemSceneRegistryController : Node
+{
+    [Export]
+    public ItemControllerRegistryController ItemWorld;
+
+    [Export]
+    public global::Godot.Collections.Array<PackedScene> ItemScenes = [];
+
+    private readonly Dictionary<ItemDefinitionId, PackedScene> _scenes = [];
+
+    private IItemDefinitionRegistry _definitions;
+
+    public void UseRegistry(IItemDefinitionRegistry registry)
+    {
+        _definitions = registry;
+    }
+
+    public override void _Ready()
+    {
+        this.AssertRequiredExports();
+    }
+
+    public void Initialize()
+    {
+        _scenes.Clear();
+
+        foreach (PackedScene scene in ItemScenes)
+        {
+            RegisterItem(scene, throwOnDuplicate: true);
+        }
+
+        foreach (ItemController item in ItemWorld.Items)
+        {
+            string scenePath = item.SceneFilePath;
+            if (string.IsNullOrWhiteSpace(scenePath))
+            {
+                continue;
+            }
+
+            RegisterItem(ResourceLoader.Load<PackedScene>(scenePath), throwOnDuplicate: false);
+        }
+
+        if (_scenes.Count == 0)
+        {
+            throw new InvalidOperationException("The item spawn catalog is empty.");
+        }
+
+        foreach (ItemController item in ItemWorld.Items)
+        {
+            ValidateAgainstCatalog(item);
+        }
+    }
+
+    public bool TryGetScene(ItemDefinitionId definitionId, out PackedScene scene)
+    {
+        return _scenes.TryGetValue(definitionId, out scene);
+    }
+
+    private void RegisterItem(PackedScene itemScene, bool throwOnDuplicate)
+    {
+        if (itemScene is null)
+        {
+            return;
+        }
+
+        ItemController prototype = itemScene.Instantiate<ItemController>();
+        ItemDefinitionId definitionId = new(prototype.DefinitionId);
+        ItemDefinition definition = new(
+            definitionId,
+            prototype.DisplayName,
+            prototype.HandRequirement
+        );
+        prototype.Free();
+
+        if (!_definitions.TryRegister(definitionId, definition))
+        {
+            if (throwOnDuplicate)
+            {
+                throw new InvalidOperationException(
+                    $"Duplicate item spawn definition: {definitionId}."
+                );
+            }
+
+            return;
+        }
+
+        _scenes.Add(definitionId, itemScene);
+    }
+
+    private void ValidateAgainstCatalog(ItemController item)
+    {
+        if (!_definitions.TryGetDefinition(item.Definition.Id, out ItemDefinition canonical))
+        {
+            return;
+        }
+
+        if (!item.Definition.Equals(canonical))
+        {
+            throw new InvalidOperationException(
+                $"{item.Name}: item definition drifted from the catalog for '{item.Definition.Id}'."
+            );
+        }
+    }
+}

src/Features/Items/Godot/ItemSceneRegistryController.cs.uid

@@ -0,0 +1 @@
+uid://cft7r2j1f0sav

src/Features/Items/Godot/ItemSpawnerController.cs

@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Game.Features.Items.Contracts;
 using Game.Godot.Extensions;
 using Godot;
@@ -9,57 +6,29 @@ namespace Game.Features.Items.Godot;
 
 public partial class ItemSpawnerController : Node, IItemSpawner
 {
-    [Export] public Node3D ItemsRoot;
+    [Export]
-    [Export] public ItemWorldController ItemWorld;
+    public Node3D ItemsRoot;
-    [Export] public global::Godot.Collections.Array<PackedScene> ItemScenes = [];
 
-    private readonly Dictionary<ItemDefinitionId, PackedScene> _scenes = [];
+    [Export]
+    public ItemControllerRegistryController ItemWorld;
 
-    public IReadOnlyCollection<ItemDefinitionId> DefinitionIds => _scenes.Keys.ToArray();
+    [Export]
+    public ItemSceneRegistryController Scenes;
 
     public override void _Ready()
     {
         this.AssertRequiredExports();
     }
 
-    public void Initialize()
-    {
-        _scenes.Clear();
-
-        foreach (PackedScene scene in ItemScenes)
-        {
-            RegisterScene(scene);
-        }
-
-        foreach (WorldItemController item in ItemWorld.Items)
-        {
-            string scenePath = item.SceneFilePath;
-            if (string.IsNullOrWhiteSpace(scenePath))
-            {
-                continue;
-            }
-
-            PackedScene scene = ResourceLoader.Load<PackedScene>(scenePath);
-            if (scene is not null)
-            {
-                _scenes.TryAdd(item.ItemInfo.DefinitionId, scene);
-            }
-        }
-
-        if (_scenes.Count == 0)
-        {
-            throw new InvalidOperationException("The item spawn catalog is empty.");
-        }
-    }
-
     public ItemActionResult TrySpawn(
         ItemDefinitionId definitionId,
         Vector3 worldPosition,
         out ItemInstanceId itemId
-    ) {
+    )
+    {
         itemId = default;
 
-        if (!_scenes.TryGetValue(definitionId, out PackedScene scene))
+        if (!Scenes.TryGetScene(definitionId, out PackedScene scene))
         {
             return ItemActionResult.Fail(
                 ItemActionStatus.UnknownDefinition,
@@ -67,29 +36,11 @@ public partial class ItemSpawnerController : Node, IItemSpawner
             );
         }
 
-        WorldItemController item = scene.Instantiate<WorldItemController>();
+        ItemController item = scene.Instantiate<ItemController>();
-        item.InstanceId = Guid.NewGuid().ToString();
         ItemsRoot.AddChild(item);
         item.GlobalPosition = worldPosition;
         ItemWorld.Register(item);
         itemId = item.ItemInfo.Id;
         return ItemActionResult.Ok();
     }
-
-    private void RegisterScene(PackedScene scene)
-    {
-        if (scene is null)
-        {
-            return;
-        }
-
-        WorldItemController prototype = scene.Instantiate<WorldItemController>();
-        ItemDefinitionId definitionId = new(prototype.DefinitionId);
-        prototype.Free();
-
-        if (!_scenes.TryAdd(definitionId, scene))
-        {
-            throw new InvalidOperationException($"Duplicate item spawn definition: {definitionId}.");
-        }
-    }
 }

src/Features/Items/Godot/ItemWorldController.cs

@@ -1,69 +0,0 @@
-using System;
-using System.Collections.Generic;
-using Game.Features.Items.Contracts;
-using Godot;
-
-namespace Game.Features.Items.Godot;
-
-public partial class ItemWorldController : Node, IItemRepository
-{
-    public const string RegistryGroup = "item_world_registry";
-
-    private readonly Dictionary<ItemInstanceId, WorldItemController> _items = [];
-
-    public IReadOnlyCollection<WorldItemController> Items => _items.Values;
-
-    public override void _EnterTree()
-    {
-        AddToGroup(RegistryGroup);
-    }
-
-    public void RegisterSceneItems()
-    {
-        foreach (Node node in GetTree().GetNodesInGroup(WorldItemController.ItemGroup))
-        {
-            if (node is WorldItemController item)
-            {
-                Register(item);
-            }
-        }
-    }
-
-    public void Register(WorldItemController item)
-    {
-        if (_items.TryGetValue(item.ItemInfo.Id, out WorldItemController existing))
-        {
-            if (ReferenceEquals(existing, item))
-            {
-                return;
-            }
-
-            throw new InvalidOperationException($"Duplicate item instance id: {item.ItemInfo.Id}.");
-        }
-
-        _items.Add(item.ItemInfo.Id, item);
-        item.RegisterWith(this);
-    }
-
-    public void Unregister(ItemInstanceId itemId)
-    {
-        _items.Remove(itemId);
-    }
-
-    public bool TryGet(ItemInstanceId itemId, out IItemInstance item)
-    {
-        if (_items.TryGetValue(itemId, out WorldItemController controller))
-        {
-            item = controller.Item;
-            return true;
-        }
-
-        item = null;
-        return false;
-    }
-
-    public bool TryGetController(ItemInstanceId itemId, out WorldItemController controller)
-    {
-        return _items.TryGetValue(itemId, out controller);
-    }
-}

src/Features/Items/Infrastructure/ItemDefinitionRegistry.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Linq;
+using Game.Features.Items.Contracts;
+
+namespace Game.Features.Items.Infrastructure;
+
+public sealed class ItemDefinitionRegistry : IItemDefinitionRegistry
+{
+    private readonly Dictionary<ItemDefinitionId, ItemDefinition> _definitionsById = [];
+
+    public IReadOnlyCollection<ItemDefinitionId> DefinitionIds => _definitionsById.Keys.ToArray();
+
+    public bool TryRegister(ItemDefinitionId definitionId, ItemDefinition definition) =>
+        _definitionsById.TryAdd(definitionId, definition);
+
+    public bool TryGetDefinition(ItemDefinitionId definitionId, out ItemDefinition definition) =>
+        _definitionsById.TryGetValue(definitionId, out definition);
+}

src/Features/Items/Infrastructure/ItemDefinitionRegistry.cs.uid

@@ -0,0 +1 @@
+uid://72g8eg0lvlui

src/Features/Items/Infrastructure/ItemInstanceRegistry.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using Game.Features.Items.Contracts;
+
+namespace Game.Features.Items.Infrastructure;
+
+public sealed class ItemInstanceRegistry : IItemInstanceRegistry
+{
+    private readonly Dictionary<ItemInstanceId, IItemInstance> _itemsById = [];
+
+    public void Register(ItemInstanceId itemId, IItemInstance item)
+    {
+        if (_itemsById.TryGetValue(itemId, out IItemInstance existing))
+        {
+            if (ReferenceEquals(existing, item))
+            {
+                return;
+            }
+
+            throw new InvalidOperationException($"Duplicate item instance id: {itemId}.");
+        }
+
+        _itemsById.Add(itemId, item);
+    }
+
+    public void Unregister(ItemInstanceId itemId)
+    {
+        _itemsById.Remove(itemId);
+    }
+
+    public bool TryGet(ItemInstanceId itemId, out IItemInstance item) =>
+        _itemsById.TryGetValue(itemId, out item);
+}

src/Features/Items/Infrastructure/ItemInstanceRegistry.cs.uid

@@ -0,0 +1 @@
+uid://dfbylp383il2v

src/Godot/Exceptions/ControllerNotInitializedException.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Game.Godot.Exceptions;
+
+/// <summary>
+/// Thrown when a controller is used before it has been initialized.
+/// </summary>
+public sealed class ControllerNotInitializedException(string nodeName)
+    : Exception(BuildMessage(nodeName))
+{
+    public string NodeName { get; } = nodeName;
+
+    private static string BuildMessage(string nodeName)
+        => $"{nodeName}: controller was used before it was initialized.";
+}

src/Godot/Exceptions/ControllerNotInitializedException.cs.uid

@@ -0,0 +1 @@
+uid://dj8kxrwjoyfvi

src/Godot/Extensions/NodeInstanceIdExtensions.cs

@@ -0,0 +1,15 @@
+using Game.Shared.Domain;
+using Godot;
+
+namespace Game.Godot.Extensions;
+
+public static class NodeInstanceIdExtensions
+{
+    private static string GetKeyFrom(Node node) => node.GetPath().ToString();
+
+    public static InstanceId GetStableInstanceId(this Node node) =>
+        InstanceId.FromKey(GetKeyFrom(node));
+
+    public static InstanceId GetStableInstanceIdFrom(this Node node, string key) =>
+        string.IsNullOrWhiteSpace(key) ? node.GetStableInstanceId() : InstanceId.FromKey(key);
+}

src/Godot/Extensions/NodeInstanceIdExtensions.cs.uid

@@ -0,0 +1 @@
+uid://csng1pjcgsh80

src/Godot/GameBootstrap.cs

@@ -2,13 +2,15 @@ using System;
 using Game.Features.Console.Application.Commands;
 using Game.Features.Console.Godot;
 using Game.Features.Console.Infrastructure;
-using Game.Features.Logging.Godot;
-using Game.Features.Logging.Infrastructure;
 using Game.Features.Interactions.Application;
 using Game.Features.Interactions.Godot;
+using Game.Features.Interactions.Infrastructure;
 using Game.Features.Items.Application;
 using Game.Features.Items.Domain;
 using Game.Features.Items.Godot;
+using Game.Features.Items.Infrastructure;
+using Game.Features.Logging.Godot;
+using Game.Features.Logging.Infrastructure;
 using Game.Features.Multiplayer.Godot;
 using Game.Features.Players.Contracts;
 using Game.Features.Players.Godot;
@@ -20,16 +22,33 @@ namespace Game.Godot;
 
 public partial class GameBootstrap : Node
 {
-    [Export] public ConsoleController Console;
+    [Export]
-    [Export] public PlayerController Player;
+    public ConsoleController Console;
-    [Export] public PlayerInteractionController PlayerInteraction;
+
-    [Export] public ItemWorldController ItemWorld;
+    [Export]
-    [Export] public ItemSpawnerController ItemSpawner;
+    public PlayerController Player;
-    [Export] public InteractionWorldController InteractionWorld;
+
-    [Export] public MultiplayerController MultiplayerController;
+    [Export]
+    public PlayerInteractionController PlayerInteraction;
+
+    [Export]
+    public ItemControllerRegistryController ItemWorld;
+
+    [Export]
+    public ItemSceneRegistryController ItemScenes;
+
+    [Export]
+    public ItemSpawnerController ItemSpawner;
+
+    [Export]
+    public InteractionsRegistryController InteractionWorld;
+
+    [Export]
+    public MultiplayerController MultiplayerController;
 
     private FileLogger _fileLogger;
     private CompositeLogger _logger;
+    private ItemDefinitionRegistry _itemDefinitions;
 
     private void InitializeLogging()
     {
@@ -37,7 +56,7 @@ public partial class GameBootstrap : Node
         _logger = new CompositeLogger([
             new GodotConsoleLogger(),
             new LogTargetLogger(Console),
-            _fileLogger
+            _fileLogger,
         ]);
     }
 
@@ -48,7 +67,7 @@ public partial class GameBootstrap : Node
         registry.Register(new EchoCommand());
         registry.Register(new ClearCommand());
         registry.Register(new NoclipCommand(Player));
-        registry.Register(new SpawnItemCommand(ItemSpawner, PlayerInteraction));
+        registry.Register(new SpawnItemCommand(ItemSpawner, _itemDefinitions, PlayerInteraction));
         registry.Register(new HostCommand(MultiplayerController));
         registry.Register(new JoinCommand(MultiplayerController));
 
@@ -58,26 +77,41 @@ public partial class GameBootstrap : Node
     private void InitializeMultiplayer()
     {
         MultiplayerController.UsePeerFactory(new EnetMultiplayerPeerFactory());
-        MultiplayerController.Connected += () => _logger.Info("Multiplayer", "Connected successfully.");
+        MultiplayerController.Connected += () =>
-        MultiplayerController.ConnectionFailed += () => _logger.Warning("Multiplayer", "Connection failed.");
+            _logger.Info("Multiplayer", "Connected successfully.");
-        MultiplayerController.Disconnected += () => _logger.Warning("Multiplayer", "Server disconnected.");
+        MultiplayerController.ConnectionFailed += () =>
+            _logger.Warning("Multiplayer", "Connection failed.");
+        MultiplayerController.Disconnected += () =>
+            _logger.Warning("Multiplayer", "Server disconnected.");
         MultiplayerController.PeerJoined += id => _logger.Info("Multiplayer", $"Peer {id} joined.");
         MultiplayerController.PeerLeft += id => _logger.Info("Multiplayer", $"Peer {id} left.");
     }
 
     private void InitializeItems()
     {
+        ItemInstanceRegistry itemInstanceRegistry = new();
+        ItemWorld.UseRegistry(itemInstanceRegistry);
         ItemWorld.RegisterSceneItems();
-        ItemSpawner.Initialize();
+
+        _itemDefinitions = new ItemDefinitionRegistry();
+        ItemScenes.UseRegistry(_itemDefinitions);
+        ItemScenes.Initialize();
+
+        InteractionRegistry interactionRegistry = new();
+        InteractionWorld.UseRegistry(interactionRegistry);
         InteractionWorld.RegisterSceneTargets();
 
-        PlayerHeldItemPresenter presenter = new(
+        HeldItemPresenter presenter = new(
             ItemWorld,
             PlayerInteraction.LeftHandAnchor,
             PlayerInteraction.RightHandAnchor
         );
-        ItemInteractionService itemInteractions = new(new HandsInventory(), ItemWorld, presenter);
+        ItemInteractionService itemInteractions = new(
-        InteractionService interactions = new(InteractionWorld);
+            new HandsInventory(),
+            itemInstanceRegistry,
+            presenter
+        );
+        Interact interactions = new(interactionRegistry);
         PlayerInteraction.Initialize(new PlayerId(Guid.NewGuid()), itemInteractions, interactions);
     }
 
@@ -86,7 +120,7 @@ public partial class GameBootstrap : Node
         this.AssertRequiredExports();
 
         MouseCapture.Capture();
-        
+
         InitializeLogging();
         InitializeItems();
         InitializeMultiplayer();

src/Godot/Scenes/GameWorld.tscn

@@ -6,10 +6,11 @@
 [ext_resource type="Script" uid="uid://drctu5y21ey2y" path="res://src/Godot/GameBootstrap.cs" id="3_bootstrap"]
 [ext_resource type="PackedScene" uid="uid://bk0771dvonxh8" path="res://src/Features/Console/Godot/ConsoleController.tscn" id="4_console"]
 [ext_resource type="Script" uid="uid://drqx0wiw0sbj1" path="res://src/Features/Multiplayer/Godot/MultiplayerController.cs" id="5_multiplayer"]
-[ext_resource type="Script" uid="uid://f8n3b6w1k5r9m" path="res://src/Features/Items/Godot/ItemWorldController.cs" id="6_items"]
+[ext_resource type="Script" uid="uid://f8n3b6w1k5r9m" path="res://src/Features/Items/Godot/ItemControllerRegistryController.cs" id="6_items"]
 [ext_resource type="PackedScene" uid="uid://cv8m3q1y6r4nf" path="res://src/Features/Items/Godot/Flashlight/FlashlightItem.tscn" id="7_flashlight"]
 [ext_resource type="Script" uid="uid://c3x9m6w2q8r1b" path="res://src/Features/Items/Godot/ItemSpawnerController.cs" id="8_spawner"]
-[ext_resource type="Script" uid="uid://f6q1c9m4w7v2n" path="res://src/Features/Interactions/Godot/InteractionWorldController.cs" id="9_interactions"]
+[ext_resource type="Script" path="res://src/Features/Items/Godot/ItemSceneRegistryController.cs" id="8b_catalog"]
+[ext_resource type="Script" uid="uid://f6q1c9m4w7v2n" path="res://src/Features/Interactions/Godot/InteractionsRegistryController.cs" id="9_interactions"]
 
 [sub_resource type="PanoramaSkyMaterial" id="PanoramaSkyMaterial_epykj"]
 panorama = ExtResource("1_g4n7o")
@@ -22,12 +23,13 @@ background_mode = 2
 sky = SubResource("Sky_1kpcd")
 glow_enabled = true
 
-[node name="GameWorld" type="Node" unique_id=222644234 node_paths=PackedStringArray("Console", "Player", "PlayerInteraction", "ItemWorld", "ItemSpawner", "InteractionWorld", "MultiplayerController")]
+[node name="GameWorld" type="Node" unique_id=222644234 node_paths=PackedStringArray("Console", "Player", "PlayerInteraction", "ItemWorld", "ItemScenes", "ItemSpawner", "InteractionWorld", "MultiplayerController")]
 script = ExtResource("3_bootstrap")
 Console = NodePath("Console")
 Player = NodePath("Player")
 PlayerInteraction = NodePath("Player/PlayerInteraction")
 ItemWorld = NodePath("ItemWorld")
+ItemScenes = NodePath("ItemScenesRegistry")
 ItemSpawner = NodePath("ItemSpawner")
 InteractionWorld = NodePath("InteractionWorld")
 MultiplayerController = NodePath("Multiplayer")
@@ -50,11 +52,16 @@ script = ExtResource("5_multiplayer")
 [node name="ItemWorld" type="Node" parent="."]
 script = ExtResource("6_items")
 
-[node name="ItemSpawner" type="Node" parent="." node_paths=PackedStringArray("ItemsRoot", "ItemWorld")]
+[node name="ItemScenesRegistry" type="Node" parent="." node_paths=PackedStringArray("ItemWorld")]
+script = ExtResource("8b_catalog")
+ItemWorld = NodePath("../ItemWorld")
+ItemScenes = Array[PackedScene]([ExtResource("7_flashlight")])
+
+[node name="ItemSpawner" type="Node" parent="." node_paths=PackedStringArray("ItemsRoot", "ItemWorld", "Scenes")]
 script = ExtResource("8_spawner")
 ItemsRoot = NodePath("../Entities")
 ItemWorld = NodePath("../ItemWorld")
-ItemScenes = Array[PackedScene]([ExtResource("7_flashlight")])
+Scenes = NodePath("../ItemScenesRegistry")
 
 [node name="InteractionWorld" type="Node" parent="."]
 script = ExtResource("9_interactions")
@@ -89,8 +96,6 @@ transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -4, 0, 0)
 
 [node name="FlashlightLeft" parent="Entities" instance=ExtResource("7_flashlight")]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -0.25, 0.65, -0.7)
-InstanceId = "c08790de-b2de-44e6-a73c-a7502ca27e34"
 
 [node name="FlashlightRight" parent="Entities" instance=ExtResource("7_flashlight")]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0.25, 0.65, -0.7)
-InstanceId = "f71e67cb-786b-49eb-bd56-cb42ad19a754"

src/Shared/Domain/InstanceId.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Game.Shared.Domain;
+
+public readonly record struct InstanceId(Guid Value)
+{
+    private static Guid CreateDeterministicId(string source) =>
+        new(MD5.HashData(Encoding.UTF8.GetBytes(source)));
+
+    public static InstanceId FromKey(string key) => new(CreateDeterministicId(key));
+
+    public override string ToString() => Value.ToString();
+}

src/Shared/Domain/InstanceId.cs.uid

@@ -0,0 +1 @@
+uid://cpikg7xirrc1g