HandsSystem Refactor (#38438)

* checkpoint

* pt 2

* pt... i forgot

* pt 4

* patch

* More test fixes

* optimization!!!

* the REAL hand system

* fix RetractableItemActionSystem.cs oversight

* the review

* test

* remove test usage of body prototype

* Update Content.IntegrationTests/Tests/Interaction/InteractionTest.cs

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

* hellcode

* hellcode 2

* Minor cleanup

* test

* Chasing the last of the bugs

* changes

---------

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

Content.Shared/Hands/Components/HandsComponent.cs

@@ -1,6 +1,5 @@
 using Content.Shared.DisplacementMap;
 using Content.Shared.Hands.EntitySystems;
-using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
 using Robust.Shared.Serialization;
 
@@ -13,50 +12,50 @@ public sealed partial class HandsComponent : Component
     /// <summary>
     ///     The currently active hand.
     /// </summary>
-    [ViewVariables]
-    public Hand? ActiveHand;
+    [DataField]
+    public string? ActiveHandId;
 
     /// <summary>
-    ///     The item currently held in the active hand.
+    /// Dictionary relating a unique hand ID corresponding to a container slot on the attached entity to a class containing information about the Hand itself.
     /// </summary>
-    [ViewVariables]
-    public EntityUid? ActiveHandEntity => ActiveHand?.HeldEntity;
-
-    [ViewVariables]
+    [DataField]
     public Dictionary<string, Hand> Hands = new();
 
+    /// <summary>
+    /// The number of hands
+    /// </summary>
+    [ViewVariables]
     public int Count => Hands.Count;
 
     /// <summary>
     ///     List of hand-names. These are keys for <see cref="Hands"/>. The order of this list determines the order in which hands are iterated over.
     /// </summary>
+    [DataField]
     public List<string> SortedHands = new();
 
     /// <summary>
     ///     If true, the items in the hands won't be affected by explosions.
     /// </summary>
     [DataField]
-    public bool DisableExplosionRecursion = false;
+    public bool DisableExplosionRecursion;
 
     /// <summary>
     ///     Modifies the speed at which items are thrown.
     /// </summary>
     [DataField]
-    [ViewVariables(VVAccess.ReadWrite)]
-    public float BaseThrowspeed { get; set; } = 11f;
+    public float BaseThrowspeed = 11f;
 
     /// <summary>
     ///     Distance after which longer throw targets stop increasing throw impulse.
     /// </summary>
-    [DataField("throwRange")]
-    [ViewVariables(VVAccess.ReadWrite)]
-    public float ThrowRange { get; set; } = 8f;
+    [DataField]
+    public float ThrowRange = 8f;
 
     /// <summary>
     ///     Whether or not to add in-hand sprites for held items. Some entities (e.g., drones) don't want these.
     ///     Used by the client.
     /// </summary>
-    [DataField("showInHands")]
+    [DataField]
     public bool ShowInHands = true;
 
     /// <summary>
@@ -68,14 +67,13 @@ public sealed partial class HandsComponent : Component
     /// <summary>
     ///     The time at which throws will be allowed again.
     /// </summary>
-    [DataField, ViewVariables(VVAccess.ReadWrite)]
-    [AutoPausedField]
+    [DataField, AutoPausedField]
     public TimeSpan NextThrowTime;
 
     /// <summary>
     ///     The minimum time inbetween throws.
     /// </summary>
-    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    [DataField]
     public TimeSpan ThrowCooldown = TimeSpan.FromSeconds(0.5f);
 
     /// <summary>
@@ -103,48 +101,37 @@ public sealed partial class HandsComponent : Component
     public bool CanBeStripped = true;
 }
 
+[DataDefinition]
 [Serializable, NetSerializable]
-public sealed class Hand //TODO: This should definitely be a struct - Jezi
+public partial record struct Hand
 {
-    [ViewVariables]
-    public string Name { get; }
+    [DataField]
+    public HandLocation Location = HandLocation.Right;
 
-    [ViewVariables]
-    public HandLocation Location { get; }
-
-    /// <summary>
-    ///     The container used to hold the contents of this hand. Nullable because the client must get the containers via <see cref="ContainerManagerComponent"/>,
-    ///     which may not be synced with the server when the client hands are created.
-    /// </summary>
-    [ViewVariables, NonSerialized]
-    public ContainerSlot? Container;
-
-    [ViewVariables]
-    public EntityUid? HeldEntity => Container?.ContainedEntity;
-
-    public bool IsEmpty => HeldEntity == null;
-
-    public Hand(string name, HandLocation location, ContainerSlot? container = null)
+    public Hand()
+    {
+
+    }
+
+    public Hand(HandLocation location)
     {
-        Name = name;
         Location = location;
-        Container = container;
     }
 }
 
 [Serializable, NetSerializable]
 public sealed class HandsComponentState : ComponentState
 {
-    public readonly List<Hand> Hands;
-    public readonly List<string> HandNames;
-    public readonly string? ActiveHand;
+    public readonly Dictionary<string, Hand> Hands;
+    public readonly List<string> SortedHands;
+    public readonly string? ActiveHandId;
 
     public HandsComponentState(HandsComponent handComp)
     {
         // cloning lists because of test networking.
-        Hands = new(handComp.Hands.Values);
-        HandNames = new(handComp.SortedHands);
-        ActiveHand = handComp.ActiveHand?.Name;
+        Hands = new(handComp.Hands);
+        SortedHands = new(handComp.SortedHands);
+        ActiveHandId = handComp.ActiveHandId;
     }
 }