Access groups + aghost all access (#6671)

Content.Shared/Access/Systems/AccessSystem.cs

@@ -1,11 +1,33 @@
 using Content.Shared.Access.Components;
 using Robust.Shared.GameObjects;
 using System.Collections.Generic;
+using Robust.Shared.Prototypes;
 
 namespace Content.Shared.Access.Systems
 {
-    public class AccessSystem : EntitySystem
+    public sealed class AccessSystem : EntitySystem
     {
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<AccessComponent, ComponentInit>(OnAccessInit);
+        }
+
+        private void OnAccessInit(EntityUid uid, AccessComponent component, ComponentInit args)
+        {
+            // Add all tags in groups to the list of tags.
+            foreach (var group in component.Groups)
+            {
+                if (!_prototypeManager.TryIndex<AccessGroupPrototype>(group, out var proto))
+                    continue;
+
+                component.Tags.UnionWith(proto.Tags);
+            }
+        }
+
         /// <summary>
         ///     Replaces the set of access tags we have with the provided set.
         /// </summary>
@@ -20,5 +42,21 @@ namespace Content.Shared.Access.Systems
 
             return true;
         }
+
+        public bool TryAddGroups(EntityUid uid, IEnumerable<string> newGroups, AccessComponent? access = null)
+        {
+            if (!Resolve(uid, ref access))
+                return false;
+
+            foreach (var group in newGroups)
+            {
+                if (!_prototypeManager.TryIndex<AccessGroupPrototype>(group, out var proto))
+                    continue;
+
+                access.Tags.UnionWith(proto.Tags);
+            }
+
+            return true;
+        }
     }
 }