Add gamerule to restart the round after a max time (#2681)

* Add gamerule to restart the round after a max time

* Add test

* Set default max time to 5 minutes

Content.Server/GameTicking/GameRules/RuleMaxTimeRestart.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Threading;
+using Content.Server.Interfaces.Chat;
+using Content.Server.Interfaces.GameTicking;
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Timer = Robust.Shared.Timers.Timer;
+
+namespace Content.Server.GameTicking.GameRules
+{
+    public sealed class RuleMaxTimeRestart : GameRule
+    {
+        [Dependency] private readonly IGameTicker _gameTicker = default!;
+        [Dependency] private readonly IChatManager _chatManager = default!;
+
+        private CancellationTokenSource _timerCancel = new();
+
+        public TimeSpan RoundMaxTime { get; set; } = TimeSpan.FromMinutes(5);
+        public TimeSpan RoundEndDelay { get; set; } = TimeSpan.FromSeconds(10);
+
+        public override void Added()
+        {
+            base.Added();
+
+            _gameTicker.OnRunLevelChanged += RunLevelChanged;
+        }
+
+        public override void Removed()
+        {
+            base.Removed();
+
+            _gameTicker.OnRunLevelChanged -= RunLevelChanged;
+            StopTimer();
+        }
+
+        public void RestartTimer()
+        {
+            _timerCancel.Cancel();
+            _timerCancel = new CancellationTokenSource();
+            Timer.Spawn(RoundMaxTime, TimerFired, _timerCancel.Token);
+        }
+
+        public void StopTimer()
+        {
+            _timerCancel.Cancel();
+        }
+
+        private void TimerFired()
+        {
+            _gameTicker.EndRound("Time has run out!");
+
+            _chatManager.DispatchServerAnnouncement(Loc.GetString("Restarting in {0} seconds.", (int) RoundEndDelay.TotalSeconds));
+
+            Timer.Spawn(RoundEndDelay, () => _gameTicker.RestartRound());
+        }
+
+        private void RunLevelChanged(GameRunLevelChangedEventArgs args)
+        {
+            switch (args.NewRunLevel)
+            {
+                case GameRunLevel.InRound:
+                    RestartTimer();
+                    break;
+                case GameRunLevel.PreRoundLobby:
+                case GameRunLevel.PostRound:
+                    StopTimer();
+                    break;
+            }
+        }
+    }
+}