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/Inventory/CloseStorageOperator.cs

@@ -0,0 +1,73 @@
+using Content.Server.AI.Utility;
+using Content.Server.AI.WorldState.States.Inventory;
+using Content.Server.GameObjects.Components;
+using Content.Server.GameObjects.EntitySystems;
+using Content.Server.Utility;
+using Robust.Shared.Interfaces.GameObjects;
+
+namespace Content.Server.AI.Operators.Inventory
+{
+    /// <summary>
+    /// Close the last EntityStorage we opened
+    /// This will also update the State for it (which a regular InteractWith won't do)
+    /// </summary>
+    public sealed class CloseLastStorageOperator : AiOperator
+    {
+        private readonly IEntity _owner;
+        private IEntity _target;
+
+        public CloseLastStorageOperator(IEntity owner)
+        {
+            _owner = owner;
+        }
+
+        public override bool TryStartup()
+        {
+            if (!base.TryStartup())
+            {
+                return true;
+            }
+            
+            var blackboard = UtilityAiHelpers.GetBlackboard(_owner);
+
+            if (blackboard == null)
+            {
+                return false;
+            }
+
+            _target = blackboard.GetState<LastOpenedStorageState>().GetValue();
+            
+            return _target != null;
+        }
+
+        public override void Shutdown(Outcome outcome)
+        {
+            base.Shutdown(outcome);
+            var blackboard = UtilityAiHelpers.GetBlackboard(_owner);
+
+            blackboard?.GetState<LastOpenedStorageState>().SetValue(null);
+        }
+
+        public override Outcome Execute(float frameTime)
+        {
+            if (!InteractionChecks.InRangeUnobstructed(_owner, _target.Transform.MapPosition))
+            {
+                return Outcome.Failed;
+            }
+
+            if (!_target.TryGetComponent(out EntityStorageComponent storageComponent) || 
+                storageComponent.IsWeldedShut)
+            {
+                return Outcome.Failed;
+            }
+            
+            if (storageComponent.Open)
+            {
+                var activateArgs = new ActivateEventArgs {User = _owner, Target = _target};
+                storageComponent.Activate(activateArgs);
+            }
+
+            return Outcome.Success;
+        }
+    }
+}