Add custom map pool support for dedicated servers

OpenRA.Game/Map/MapCache.cs

@@ -233,7 +233,7 @@ public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids
 				.ToList();
 
 			foreach (var uid in queryUids)
-				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null);
+				previews[uid].UpdateRemoteSearch(MapStatus.Searching, null, null);
 
 			Task.Run(async () =>
 			{
@@ -251,13 +251,13 @@ public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids
 
 						var yaml = MiniYaml.FromStream(result);
 						foreach (var kv in yaml)
-							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, mapDetailsReceived);
+							previews[kv.Key].UpdateRemoteSearch(MapStatus.DownloadAvailable, kv.Value, modData.Manifest.MapCompatibility, mapDetailsReceived);
 
 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
 							if (p.Status != MapStatus.DownloadAvailable)
-								p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+								p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
 						}
 					}
 					catch (Exception e)
@@ -269,7 +269,7 @@ public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids
 						foreach (var uid in batchUids)
 						{
 							var p = previews[uid];
-							p.UpdateRemoteSearch(MapStatus.Unavailable, null);
+							p.UpdateRemoteSearch(MapStatus.Unavailable, null, null);
 							mapQueryFailed?.Invoke(p);
 						}
 					}

OpenRA.Game/Map/MapPreview.cs

@@ -59,6 +59,7 @@ public class RemoteMapData
 		public readonly string rules;
 		public readonly string players_block;
 		public readonly int mapformat;
+		public readonly string game_mod;
 	}
 
 	public sealed class MapPreview : IDisposable, IReadOnlyFileSystem
@@ -427,7 +428,7 @@ public void UpdateFromMap(IReadOnlyPackage p, IReadOnlyPackage parent, MapClassi
 			innerData = newData;
 		}
 
-		public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, Action<MapPreview> parseMetadata = null)
+		public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, string[] mapCompatibility, Action<MapPreview> parseMetadata = null)
 		{
 			var newData = innerData.Clone();
 			newData.Status = status;
@@ -479,6 +480,12 @@ public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, Action<MapPrevie
 					var rulesString = Encoding.UTF8.GetString(Convert.FromBase64String(r.rules));
 					var rulesYaml = new MiniYaml("", MiniYaml.FromString(rulesString)).ToDictionary();
 					newData.SetCustomRules(modData, this, rulesYaml, null);
+
+					// Map is for a different mod: update its information so it can be displayed
+					// in the cross-mod server browser UI, but mark it as unavailable so it can't
+					// be selected in a server for the current mod.
+					if (!mapCompatibility.Contains(r.game_mod))
+						newData.Status = MapStatus.Unavailable;
 				}
 				catch (Exception e)
 				{

OpenRA.Game/Network/OrderManager.cs

@@ -39,6 +39,9 @@ public sealed class OrderManager : IDisposable
 		public string ServerError = null;
 		public bool AuthenticationFailed = false;
 
+		// The default null means "no map restriction" while an empty set means "all maps restricted"
+		public HashSet<string> ServerMapPool = null;
+
 		public int NetFrameNumber { get; private set; }
 		public int LocalFrameNumber;
 

OpenRA.Game/Network/UnitOrders.cs

@@ -383,6 +383,12 @@ internal static void ProcessOrder(OrderManager orderManager, World world, int cl
 						break;
 					}
 
+				case "SyncMapPool":
+					{
+						orderManager.ServerMapPool = FieldLoader.GetValue<HashSet<string>>("SyncMapPool", order.TargetString);
+						break;
+					}
+
 				default:
 					{
 						if (world == null)

OpenRA.Game/Server/Server.cs

@@ -128,7 +128,8 @@ public sealed class Server
 		// Managed by LobbyCommands
 		public MapPreview Map;
 		public readonly MapStatusCache MapStatusCache;
-		public GameSave GameSave = null;
+		public GameSave GameSave;
+		public HashSet<string> MapPool;
 
 		// Default to the next frame for ServerType.Local - MP servers take the value from the selected GameSpeed.
 		public int OrderLatency = 1;
@@ -316,7 +317,6 @@ public Server(List<IPEndPoint> endpoints, ServerSettings settings, ModData modDa
 
 			serverTraits.TrimExcess();
 
-			Map = ModData.MapCache[settings.Map];
 			MapStatusCache = new MapStatusCache(modData, MapStatusChanged, type == ServerType.Dedicated && settings.EnableLintChecks);
 
 			playerMessageTracker = new PlayerMessageTracker(this, DispatchOrdersToClient, SendLocalizedMessageTo);
@@ -327,8 +327,6 @@ public Server(List<IPEndPoint> endpoints, ServerSettings settings, ModData modDa
 				GlobalSettings =
 				{
 					RandomSeed = randomSeed,
-					Map = Map.Uid,
-					MapStatus = Session.MapStatus.Unknown,
 					ServerName = settings.Name,
 					EnableSingleplayer = settings.EnableSingleplayer || Type != ServerType.Dedicated,
 					EnableSyncReports = settings.EnableSyncReports,
@@ -348,8 +346,7 @@ public Server(List<IPEndPoint> endpoints, ServerSettings settings, ModData modDa
 
 			new Thread(_ =>
 			{
-				// Initial status is set off the main thread to avoid triggering a load screen when joining a skirmish game
-				LobbyInfo.GlobalSettings.MapStatus = MapStatusCache[Map];
+				// Note: at least one of these is required to set the initial LobbyInfo.Map and MapStatus
 				foreach (var t in serverTraits.WithInterface<INotifyServerStart>())
 					t.ServerStarted(this);
 
@@ -1434,6 +1431,27 @@ public ConnectionTarget GetEndpointForLocalConnection()
 			return new ConnectionTarget(endpoints);
 		}
 
+		public bool MapIsUnknown(string uid)
+		{
+			if (string.IsNullOrEmpty(uid))
+				return true;
+
+			var status = ModData.MapCache[uid].Status;
+			return status != MapStatus.Available && status != MapStatus.DownloadAvailable;
+		}
+
+		public bool MapIsKnown(string uid)
+		{
+			if (string.IsNullOrEmpty(uid))
+				return false;
+
+			if (MapPool != null && !MapPool.Contains(uid))
+				return false;
+
+			var status = ModData.MapCache[uid].Status;
+			return status == MapStatus.Available || status == MapStatus.DownloadAvailable;
+		}
+
 		interface IServerEvent { void Invoke(Server server); }
 
 		sealed class ConnectionConnectEvent : IServerEvent

OpenRA.Game/Settings.cs

@@ -102,6 +102,9 @@ public class ServerSettings
 		[Desc("For dedicated servers only, treat maps that fail the lint checks as invalid.")]
 		public bool EnableLintChecks = true;
 
+		[Desc("For dedicated servers only, a comma separated list of map uids that are allowed to be used.")]
+		public string[] MapPool = Array.Empty<string>();
+
 		[Desc("Delay in milliseconds before newly joined players can send chat messages.")]
 		public int FloodLimitJoinCooldown = 5000;
 

OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs

@@ -11,12 +11,15 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
+using System.Threading;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Mods.Common.Widgets.Logic;
 using OpenRA.Network;
 using OpenRA.Primitives;
 using OpenRA.Server;
+using OpenRA.Support;
 using OpenRA.Traits;
 using S = OpenRA.Server.Server;
 
@@ -570,6 +573,12 @@ static bool Map(S server, Connection conn, Session.Client client, string s)
 					return true;
 				}
 
+				if (server.MapPool != null && !server.MapPool.Contains(s))
+				{
+					QueryFailed();
+					return true;
+				}
+
 				var lastMap = server.LobbyInfo.GlobalSettings.Map;
 				void SelectMap(MapPreview map)
 				{
@@ -659,8 +668,6 @@ void SelectMap(MapPreview map)
 					}
 				}
 
-				void QueryFailed() => server.SendLocalizedMessageTo(conn, UnknownMap);
-
 				var m = server.ModData.MapCache[s];
 				if (m.Status == MapStatus.Available || m.Status == MapStatus.DownloadAvailable)
 					SelectMap(m);
@@ -682,6 +689,8 @@ void SelectMap(MapPreview map)
 
 				return true;
 			}
+
+			void QueryFailed() => server.SendLocalizedMessageTo(conn, UnknownMap);
 		}
 
 		static bool Option(S server, Connection conn, Session.Client client, string s)
@@ -1227,16 +1236,68 @@ static bool SyncLobby(S server, Connection conn, Session.Client client, string s
 			}
 		}
 
+		static void InitializeMapPool(S server)
+		{
+			if (server.Type != ServerType.Dedicated)
+				return;
+
+			var mapCache = server.ModData.MapCache;
+			if (server.Settings.MapPool.Length > 0)
+				server.MapPool = server.Settings.MapPool.ToHashSet();
+			else if (!server.Settings.QueryMapRepository)
+				server.MapPool = mapCache
+					.Where(p => p.Status == MapStatus.Available && p.Visibility.HasFlag(MapVisibility.Lobby))
+					.Select(p => p.Uid)
+					.ToHashSet();
+			else
+				return;
+
+			var unknownMaps = server.MapPool.Where(server.MapIsUnknown);
+			if (server.Settings.QueryMapRepository && unknownMaps.Any())
+			{
+				Log.Write("server", $"Querying Resource Center for information on {unknownMaps.Count()} maps...");
+
+				// Query any missing maps and wait up to 10 seconds for a response
+				// Maps that have not resolved will not be valid for the initial map choice
+				var mapRepository = server.ModData.Manifest.Get<WebServices>().MapRepository;
+				mapCache.QueryRemoteMapDetails(mapRepository, unknownMaps);
+
+				var searchingMaps = server.MapPool.Where(uid => mapCache[uid].Status == MapStatus.Searching);
+				var stopwatch = Stopwatch.StartNew();
+				while (searchingMaps.Any() && stopwatch.ElapsedMilliseconds < 10000)
+					Thread.Sleep(100);
+			}
+
+			if (unknownMaps.Any())
+				Log.Write("server", "Failed to resolve maps: " + unknownMaps.JoinWith(", "));
+		}
+
+		static string ChooseInitialMap(S server)
+		{
+			if (server.MapIsKnown(server.Settings.Map))
+				return server.Settings.Map;
+
+			if (server.MapPool == null)
+				return server.ModData.MapCache.ChooseInitialMap(server.Settings.Map, new MersenneTwister());
+
+			return server.MapPool
+				.Where(server.MapIsKnown)
+				.RandomOrDefault(new MersenneTwister());
+		}
+
 		public void ServerStarted(S server)
 		{
 			lock (server.LobbyInfo)
 			{
-				// Remote maps are not supported for the initial map
-				var uid = server.LobbyInfo.GlobalSettings.Map;
-				server.Map = server.ModData.MapCache[uid];
-				if (server.Map.Status != MapStatus.Available)
-					throw new InvalidOperationException($"Map {uid} not found");
+				InitializeMapPool(server);
 
+				var uid = ChooseInitialMap(server);
+				if (string.IsNullOrEmpty(uid))
+					throw new InvalidOperationException("Unable to resolve a valid initial map");
+
+				server.LobbyInfo.GlobalSettings.Map = server.Settings.Map = uid;
+				server.Map = server.ModData.MapCache[uid];
+				server.LobbyInfo.GlobalSettings.MapStatus = server.MapStatusCache[server.Map];
 				server.LobbyInfo.Slots = server.Map.Players.Players
 					.Select(p => MakeSlotFromPlayerReference(p.Value))
 					.Where(s => s != null)
@@ -1335,6 +1396,9 @@ public void ClientJoined(S server, Connection conn)
 		{
 			lock (server.LobbyInfo)
 			{
+				if (server.MapPool != null)
+					server.SendOrderTo(conn, "SyncMapPool", FieldSaver.FormatValue(server.MapPool));
+
 				var client = server.GetClient(conn);
 
 				// Validate whether color is allowed and get an alternative if it isn't

OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs

@@ -236,7 +236,8 @@ void OnConnect()
 					var onSelect = new Action<string>(uid =>
 					{
 						// Don't select the same map again, and handle map becoming unavailable
-						if (uid == map.Uid || modData.MapCache[uid].Status != MapStatus.Available)
+						var status = modData.MapCache[uid].Status;
+						if (uid == map.Uid || (status != MapStatus.Available && status != MapStatus.DownloadAvailable))
 							return;
 
 						orderManager.IssueOrder(Order.Command("map " + uid));
@@ -250,6 +251,7 @@ void OnConnect()
 					Ui.OpenWindow("MAPCHOOSER_PANEL", new WidgetArgs()
 					{
 						{ "initialMap", modData.MapCache.PickLastModifiedMap(MapVisibility.Lobby) ?? map.Uid },
+						{ "remoteMapPool", orderManager.ServerMapPool },
 						{ "initialTab", MapClassification.System },
 						{ "onExit", modData.MapCache.UpdateMaps },
 						{ "onSelect", Game.IsHost ? onSelect : null },

OpenRA.Mods.Common/Widgets/Logic/MainMenuLogic.cs

@@ -204,6 +204,7 @@ public MainMenuLogic(Widget widget, World world, ModData modData)
 				Game.OpenWindow("MAPCHOOSER_PANEL", new WidgetArgs()
 				{
 					{ "initialMap", null },
+					{ "remoteMapPool", null },
 					{ "initialTab", MapClassification.User },
 					{ "onExit", () => SwitchMenu(MenuType.MapEditor) },
 					{ "onSelect", onSelect },