Cleanup subdermal implant code (#39755)

Content.Shared/Implants/SharedSubdermalImplantSystem.Relays.cs

@@ -0,0 +1,50 @@
+using Content.Shared.Implants.Components;
+using Content.Shared.Interaction;
+using Content.Shared.Interaction.Events;
+using Content.Shared.Mobs;
+
+namespace Content.Shared.Implants;
+
+public abstract partial class SharedSubdermalImplantSystem
+{
+    public void InitializeRelay()
+    {
+        SubscribeLocalEvent<ImplantedComponent, MobStateChangedEvent>(RelayToImplantEvent);
+        SubscribeLocalEvent<ImplantedComponent, AfterInteractUsingEvent>(RelayToImplantEvent);
+        SubscribeLocalEvent<ImplantedComponent, SuicideEvent>(RelayToImplantEvent);
+    }
+
+    /// <summary>
+    /// Relays events from the implanted to the implant.
+    /// </summary>
+    private void RelayToImplantEvent<T>(EntityUid uid, ImplantedComponent component, T args) where T : notnull
+    {
+        if (!_container.TryGetContainer(uid, ImplanterComponent.ImplantSlotId, out var implantContainer))
+            return;
+
+        var relayEv = new ImplantRelayEvent<T>(args, uid);
+        foreach (var implant in implantContainer.ContainedEntities)
+        {
+            if (args is HandledEntityEventArgs { Handled: true })
+                return;
+
+            RaiseLocalEvent(implant, relayEv);
+        }
+    }
+}
+
+/// <summary>
+/// Wrapper for relaying events from an implanted entity to their implants.
+/// </summary>
+public sealed class ImplantRelayEvent<T> where T : notnull
+{
+    public readonly T Event;
+
+    public readonly EntityUid ImplantedEntity;
+
+    public ImplantRelayEvent(T ev, EntityUid implantedEntity)
+    {
+        Event = ev;
+        ImplantedEntity = implantedEntity;
+    }
+}