Ghost Roles (#3106)

* Add files for Ghost Roles.

* Work on Ghost Roles

* Improvements

* GHOST ROLES IS DONE

* mmm yes

* auto-update when setting rolename/roledescription

* well

* command graceful error

* Makes UI have a scrollbar when it has too many entries

* fix command fuckup

* Apply suggestions from code review

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Server/GameObjects/EntitySystems/GhostRoleSystem.cs

@@ -0,0 +1,144 @@
+using System.Collections.Generic;
+using System.Drawing;
+using Content.Server.Administration;
+using Content.Server.Eui;
+using Content.Server.GameObjects.Components.Observer;
+using Content.Shared.GameObjects.Components.Observer;
+using Content.Shared.GameObjects.EntitySystemMessages;
+using Content.Shared.GameTicking;
+using JetBrains.Annotations;
+using Robust.Server.GameObjects;
+using Robust.Server.Interfaces.Player;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.IoC;
+using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    [UsedImplicitly]
+    public class GhostRoleSystem : EntitySystem, IResettingEntitySystem
+    {
+        [Dependency] private readonly EuiManager _euiManager = default!;
+
+        private uint _nextRoleIdentifier = 0;
+        private readonly Dictionary<uint, GhostRoleComponent> _ghostRoles = new();
+        private readonly Dictionary<IPlayerSession, GhostRolesEui> _openUis = new();
+
+        [ViewVariables]
+        public IReadOnlyCollection<GhostRoleComponent> GhostRoles => _ghostRoles.Values;
+
+        public override void Initialize()
+        {
+            SubscribeLocalEvent<PlayerAttachSystemMessage>(OnPlayerAttached);
+        }
+
+        private uint GetNextRoleIdentifier()
+        {
+            return unchecked(_nextRoleIdentifier++);
+        }
+
+        public void OpenEui(IPlayerSession session)
+        {
+            if (session.AttachedEntity == null || !session.AttachedEntity.HasComponent<GhostComponent>())
+                return;
+
+            if(_openUis.ContainsKey(session))
+                CloseEui(session);
+
+            var eui = _openUis[session] = new GhostRolesEui();
+            _euiManager.OpenEui(eui, session);
+            eui.StateDirty();
+        }
+
+        public void CloseEui(IPlayerSession session)
+        {
+            if (!_openUis.ContainsKey(session)) return;
+
+            _openUis.Remove(session, out var eui);
+
+            eui?.Close();
+        }
+
+        public void UpdateAllEui()
+        {
+            foreach (var eui in _openUis.Values)
+            {
+                eui.StateDirty();
+            }
+        }
+
+        public void RegisterGhostRole(GhostRoleComponent role)
+        {
+            if (_ghostRoles.ContainsValue(role)) return;
+            _ghostRoles[role.Identifier = GetNextRoleIdentifier()] = role;
+            UpdateAllEui();
+
+        }
+
+        public void UnregisterGhostRole(GhostRoleComponent role)
+        {
+            if (!_ghostRoles.ContainsKey(role.Identifier) || _ghostRoles[role.Identifier] != role) return;
+            _ghostRoles.Remove(role.Identifier);
+            UpdateAllEui();
+        }
+
+        public void Takeover(IPlayerSession player, uint identifier)
+        {
+            if (!_ghostRoles.TryGetValue(identifier, out var role)) return;
+            if (!role.Take(player)) return;
+            CloseEui(player);
+        }
+
+        public GhostRoleInfo[] GetGhostRolesInfo()
+        {
+            var roles = new GhostRoleInfo[_ghostRoles.Count];
+
+            var i = 0;
+
+            foreach (var (id, role) in _ghostRoles)
+            {
+                roles[i] = new GhostRoleInfo(){Identifier = id, Name = role.RoleName, Description = role.RoleDescription};
+                i++;
+            }
+
+            return roles;
+        }
+
+        private void OnPlayerAttached(PlayerAttachSystemMessage message)
+        {
+            // Close the session of any player that has a ghost roles window open and isn't a ghost anymore.
+            if (!_openUis.ContainsKey(message.NewPlayer)) return;
+            if (message.Entity.HasComponent<GhostComponent>()) return;
+            CloseEui(message.NewPlayer);
+        }
+
+        public void Reset()
+        {
+            foreach (var session in _openUis.Keys)
+            {
+                CloseEui(session);
+            }
+
+            _openUis.Clear();
+            _ghostRoles.Clear();
+            _nextRoleIdentifier = 0;
+        }
+    }
+
+    [AnyCommand]
+    public class GhostRoles : IConsoleCommand
+    {
+        public string Command => "ghostroles";
+        public string Description => "Opens the ghost role request window.";
+        public string Help => $"{Command}";
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if(shell.Player != null)
+                EntitySystem.Get<GhostRoleSystem>().OpenEui((IPlayerSession)shell.Player);
+            else
+                shell.WriteLine("You can only open the ghost roles UI on a client.");
+        }
+    }
+}