Syringe gun! (#32112)

* Init testing

* copyright

* oops

* Tracking the embed entity uid

* testing stuff for gradual injection

* work

* weh

* god save me

* bleh

* Yippee!

* Again

* Mini syringe ammo

* cleaning up

* mini syringes have a texture for fill amount

* -3 cool points :(

* hitboxes

* init cleanup

* much needed fixes

* Fixes

Content.Server/Chemistry/EntitySystems/SolutionInjectWhileEmbeddedSystem.cs

@@ -0,0 +1,60 @@
+using Content.Server.Body.Components;
+using Content.Server.Body.Systems;
+using Content.Server.Chemistry.Components;
+using Content.Shared.Chemistry.EntitySystems;
+using Content.Shared.Chemistry.Events;
+using Content.Shared.Inventory;
+using Content.Shared.Popups;
+using Content.Shared.Projectiles;
+using Content.Shared.Tag;
+using Content.Shared.Weapons.Melee.Events;
+using Robust.Shared.Collections;
+using Robust.Shared.Timing;
+
+namespace Content.Server.Chemistry.EntitySystems;
+
+/// <summary>
+/// System for handling injecting into an entity while a projectile is embedded.
+/// </summary>
+public sealed class SolutionInjectWhileEmbeddedSystem : EntitySystem
+{
+	[Dependency] private readonly IGameTiming _gameTiming = default!;
+    [Dependency] private readonly BloodstreamSystem _bloodstream = default!;
+    [Dependency] private readonly InventorySystem _inventory = default!;
+    [Dependency] private readonly SharedPopupSystem _popup = default!;
+    [Dependency] private readonly SharedSolutionContainerSystem _solutionContainer = default!;
+    [Dependency] private readonly TagSystem _tag = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        
+        SubscribeLocalEvent<SolutionInjectWhileEmbeddedComponent, MapInitEvent>(OnMapInit);
+    }
+
+    private void OnMapInit(Entity<SolutionInjectWhileEmbeddedComponent> ent, ref MapInitEvent args)
+    {
+        ent.Comp.NextUpdate = _gameTiming.CurTime + ent.Comp.UpdateInterval;
+    }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        var query = EntityQueryEnumerator<SolutionInjectWhileEmbeddedComponent, EmbeddableProjectileComponent>();
+        while (query.MoveNext(out var uid, out var injectComponent, out var projectileComponent))
+        {
+            if (_gameTiming.CurTime < injectComponent.NextUpdate)
+                continue;
+
+            injectComponent.NextUpdate += injectComponent.UpdateInterval;
+
+            if(projectileComponent.EmbeddedIntoUid == null)
+                continue;
+
+            var ev = new InjectOverTimeEvent(projectileComponent.EmbeddedIntoUid.Value);
+            RaiseLocalEvent(uid, ref ev);
+
+        }
+    }
+}