refactor: restructure interaction system into clean layers

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 Key;
+
+    [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(Key));
+        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

@@ -1,6 +1,9 @@
 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.Logging.Contracts;
 using Game.Features.Players.Contracts;
 using Game.Godot;
 using Game.Godot.Extensions;
@@ -11,39 +14,177 @@ namespace Game.Features.Interactions.Godot;
 
 public partial class PlayerInteractionController : Node, IItemSpawnPoint
 {
-    [Export] public Camera3D Camera;
-    [Export] public CharacterBody3D Body;
-    [Export] public InteractionRaycaster InteractionRaycaster;
-    [Export] public RayCast3D DropRaycaster;
-    [Export] public InteractionPromptController PromptController;
-    [Export] public Node3D LeftHandAnchor;
-    [Export] public Node3D RightHandAnchor;
+    [Export]
+    public Camera3D Camera;
 
+    [Export]
+    public CharacterBody3D Body;
+
+    [Export]
+    public InteractionRaycaster InteractionRaycaster;
+
+    [Export]
+    public RayCast3D DropRaycaster;
+
+    [Export]
+    public InteractionPromptController PromptController;
+
+    [Export]
+    public Node3D LeftHandAnchor;
+
+    [Export]
+    public Node3D RightHandAnchor;
+
+    private const string LogCategory = "PlayerInteraction";
     private IItemInteractionService _items;
-    private IInteractionService _interactions;
+    private IInteractionHandler _interactions;
+    private ILogger _logger;
     private PlayerId _playerId;
     private readonly HashSet<Hand> _dropActions = [];
-    private readonly Dictionary<Hand, InteractionTargetId?> _activeUseTargets = [];
+    private readonly ResolvePickupAvailability _resolvePickupAvailability = new();
+
+    private ItemUseRequest CreateUseRequest(Hand hand, ItemActionPhase phase)
+    {
+        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,
+        IInteractionHandler interactions,
+        ILogger logger
+    )
+    {
+        _playerId = playerId;
+        _items = items;
+        _interactions = interactions;
+        _logger = logger;
+    }
+
+    public Vector3 GetItemSpawnPosition() => CalculateDropPosition();
 
     public override void _Ready()
     {
         this.AssertRequiredExports();
     }
 
-    public void Initialize(
-        PlayerId playerId,
-        IItemInteractionService items,
-        IInteractionService interactions
-    )
-    {
-        _playerId = playerId;
-        _items = items;
-        _interactions = interactions;
-    }
-
     public override void _Process(double delta)
     {
-        if (_items is null || _interactions is null || GamePause.IsPaused || !MouseCapture.IsCaptured)
+        if (_items is null || _interactions is null)
+        {
+            _logger?.Warning(LogCategory, "Skipped frame: controller not yet initialized.");
+            PromptController.Clear();
+            return;
+        }
+
+        if (GamePause.IsPaused || !MouseCapture.IsCaptured)
         {
             PromptController.Clear();
             return;
@@ -54,7 +195,13 @@ 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)
+        {
+            _logger?.Warning(LogCategory, "Ignored input: controller not yet initialized.");
+            return;
+        }
+
+        if (GamePause.IsPaused || !MouseCapture.IsCaptured)
         {
             return;
         }
@@ -89,135 +236,15 @@ 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;
@@ -10,6 +12,8 @@ public sealed class ItemInteractionService(
     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);
@@ -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)

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

@@ -6,6 +6,7 @@ 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;
@@ -25,7 +26,7 @@ public partial class GameBootstrap : Node
     [Export] public PlayerInteractionController PlayerInteraction;
     [Export] public ItemWorldController ItemWorld;
     [Export] public ItemSpawnerController ItemSpawner;
-    [Export] public InteractionWorldController InteractionWorld;
+    [Export] public InteractionsRegistryController InteractionWorld;
     [Export] public MultiplayerController MultiplayerController;
 
     private FileLogger _fileLogger;
@@ -69,6 +70,9 @@ public partial class GameBootstrap : Node
     {
         ItemWorld.RegisterSceneItems();
         ItemSpawner.Initialize();
+
+        InteractionRegistry interactionRegistry = new();
+        InteractionWorld.UseRegistry(interactionRegistry);
         InteractionWorld.RegisterSceneTargets();
 
         PlayerHeldItemPresenter presenter = new(
@@ -77,8 +81,8 @@ public partial class GameBootstrap : Node
             PlayerInteraction.RightHandAnchor
         );
         ItemInteractionService itemInteractions = new(new HandsInventory(), ItemWorld, presenter);
-        InteractionService interactions = new(InteractionWorld);
-        PlayerInteraction.Initialize(new PlayerId(Guid.NewGuid()), itemInteractions, interactions);
+        Interact interactions = new(interactionRegistry);
+        PlayerInteraction.Initialize(new PlayerId(Guid.NewGuid()), itemInteractions, interactions, _logger);
     }
 
     public override void _Ready()

src/Godot/Scenes/GameWorld.tscn

@@ -9,7 +9,7 @@
 [ext_resource type="Script" uid="uid://f8n3b6w1k5r9m" path="res://src/Features/Items/Godot/ItemWorldController.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" 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")

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