Conditional map support (#5868)

Co-authored-by: E F R <602406+Efruit@users.noreply.github.com>
Co-authored-by: Paul Ritter <ritter.paul1@googlemail.com>

Content.Server/Maps/Conditions/HolidayMapCondition.cs

@@ -0,0 +1,22 @@
+using System.Linq;
+using Content.Server.Holiday;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype.List;
+
+namespace Content.Server.Maps.Conditions;
+
+public class HolidayMapCondition : GameMapCondition
+{
+    [DataField("holidays")]
+    public string[] Holidays { get; } = default!;
+
+    public override bool Check(GameMapPrototype map)
+    {
+        var holidaySystem = EntitySystem.Get<HolidaySystem>();
+
+        return Holidays.Any(holiday => holidaySystem.IsCurrentlyHoliday(holiday)) ^ Inverted;
+    }
+}

Content.Server/Maps/GameMapCondition.cs

@@ -0,0 +1,11 @@
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Content.Server.Maps;
+
+[ImplicitDataDefinitionForInheritors]
+public abstract class GameMapCondition
+{
+    [DataField("inverted")]
+    public bool Inverted { get; }
+    public abstract bool Check(GameMapPrototype map);
+}

Content.Server/Maps/GameMapManager.cs

@@ -111,7 +111,9 @@ public class GameMapManager : IGameMapManager
 
     private bool IsMapEligible(GameMapPrototype map)
     {
-        return map.MaxPlayers >= _playerManager.PlayerCount && map.MinPlayers <= _playerManager.PlayerCount;
+        return map.MaxPlayers >= _playerManager.PlayerCount &&
+               map.MinPlayers <= _playerManager.PlayerCount &&
+               map.Conditions.All(x => x.Check(map));
     }
 
     private bool TryLookupMap(string gameMap, [NotNullWhen(true)] out GameMapPrototype? map)

Content.Server/Maps/GameMapPrototype.cs

@@ -66,6 +66,9 @@ public class GameMapPrototype : IPrototype
     [DataField("votable")]
     public bool Votable { get; } = true;
 
+    [DataField("conditions")]
+    public List<GameMapCondition> Conditions { get; } = new();
+
     /// <summary>
     /// Jobs used at round start should the station run out of job slots.
     /// Doesn't necessarily mean the station has infinite slots for the given jobs midround!