Add utility AI (#806)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>
Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Content.Server/AI/Operators/Combat/Ranged/WaitForHitscanChargeOperator.cs

@@ -0,0 +1,41 @@
+using System;
+using Content.Server.GameObjects.Components.Weapon.Ranged.Hitscan;
+using Robust.Shared.Interfaces.GameObjects;
+
+namespace Content.Server.AI.Operators.Combat.Ranged
+{
+    public class WaitForHitscanChargeOperator : AiOperator
+    {
+        private float _lastCharge = 0.0f;
+        private float _lastFill = 0.0f;
+        private HitscanWeaponComponent _hitscan;
+
+        public WaitForHitscanChargeOperator(IEntity entity)
+        {
+            if (!entity.TryGetComponent(out HitscanWeaponComponent hitscanWeaponComponent))
+            {
+                throw new InvalidOperationException();
+            }
+
+            _hitscan = hitscanWeaponComponent;
+        }
+
+        public override Outcome Execute(float frameTime)
+        {
+            if (_hitscan.CapacitorComponent.Capacity - _hitscan.CapacitorComponent.Charge < 0.01f)
+            {
+                return Outcome.Success;
+            }
+
+            // If we're not charging then just stop
+            _lastFill = _hitscan.CapacitorComponent.Charge - _lastCharge;
+            _lastCharge = _hitscan.CapacitorComponent.Charge;
+
+            if (_lastFill == 0.0f)
+            {
+                return Outcome.Failed;
+            }
+            return Outcome.Continuing;
+        }
+    }
+}