#region Copyright & License Information
/*
 * Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
 * This file is part of OpenRA, which is free software. It is made
 * available to you under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version. For more
 * information, see COPYING.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using OpenRA.Graphics;
using OpenRA.Mods.Common.Traits;
using OpenRA.Network;
using OpenRA.Server;
using OpenRA.Traits;
using S = OpenRA.Server.Server;

namespace OpenRA.Mods.Common.Server
{
	public class LobbyCommands : ServerTrait, IInterpretCommand, INotifyServerStart, INotifyServerEmpty, IClientJoined
	{
		static bool ValidateSlotCommand(S server, Connection conn, Session.Client client, string arg, bool requiresHost)
		{
			if (!server.LobbyInfo.Slots.ContainsKey(arg))
			{
				Log.Write("server", "Invalid slot: {0}", arg);
				return false;
			}

			if (requiresHost && !client.IsAdmin)
			{
				server.SendOrderTo(conn, "Message", "Only the host can do that.");
				return false;
			}

			return true;
		}

		public static bool ValidateCommand(S server, Connection conn, Session.Client client, string cmd)
		{
			if (server.State == ServerState.GameStarted)
			{
				server.SendOrderTo(conn, "Message", "Cannot change state when game started. ({0})".F(cmd));
				return false;
			}
			else if (client.State == Session.ClientState.Ready && !(cmd.StartsWith("state") || cmd == "startgame"))
			{
				server.SendOrderTo(conn, "Message", "Cannot change state when marked as ready.");
				return false;
			}

			return true;
		}

		static void CheckAutoStart(S server)
		{
			// A spectating admin is included for checking these rules
			var playerClients = server.LobbyInfo.Clients.Where(c => (c.Bot == null && c.Slot != null) || c.IsAdmin);

			// Are all players ready?
			if (!playerClients.Any() || playerClients.Any(c => c.State != Session.ClientState.Ready))
				return;

			// Are the map conditions satisfied?
			if (server.LobbyInfo.Slots.Any(sl => sl.Value.Required && server.LobbyInfo.ClientInSlot(sl.Key) == null))
				return;

			// Does server have only one player?
			if (!server.LobbyInfo.GlobalSettings.EnableSingleplayer && playerClients.Count() == 1)
				return;

			server.StartGame();
		}

		public bool InterpretCommand(S server, Connection conn, Session.Client client, string cmd)
		{
			if (server == null || conn == null || client == null || !ValidateCommand(server, conn, client, cmd))
				return false;

			var dict = new Dictionary<string, Func<string, bool>>
			{
				{ "state",
					s =>
					{
						var state = Session.ClientState.Invalid;
						if (!Enum<Session.ClientState>.TryParse(s, false, out state))
						{
							server.SendOrderTo(conn, "Message", "Malformed state command");
							return true;
						}

						client.State = state;

						Log.Write("server", "Player @{0} is {1}",
							conn.Socket.RemoteEndPoint, client.State);

						server.SyncLobbyClients();

						CheckAutoStart(server);

						return true;
					}
				},
				{ "startgame",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can start the game.");
							return true;
						}

						if (server.LobbyInfo.Slots.Any(sl => sl.Value.Required &&
							server.LobbyInfo.ClientInSlot(sl.Key) == null))
						{
							server.SendOrderTo(conn, "Message", "Unable to start the game until required slots are full.");
							return true;
						}

						if (!server.LobbyInfo.GlobalSettings.EnableSingleplayer &&
							server.LobbyInfo.Clients.Where(c => c.Bot == null && c.Slot != null).Count() == 1)
						{
							server.SendOrderTo(conn, "Message", server.TwoHumansRequiredText);
							return true;
						}

						server.StartGame();
						return true;
					}
				},
				{ "slot",
					s =>
					{
						if (!server.LobbyInfo.Slots.ContainsKey(s))
						{
							Log.Write("server", "Invalid slot: {0}", s);
							return false;
						}

						var slot = server.LobbyInfo.Slots[s];

						if (slot.Closed || server.LobbyInfo.ClientInSlot(s) != null)
							return false;

						// If the previous slot had a locked spawn then we must not carry that to the new slot
						var oldSlot = client.Slot != null ? server.LobbyInfo.Slots[client.Slot] : null;
						if (oldSlot != null && oldSlot.LockSpawn)
							client.SpawnPoint = 0;

						client.Slot = s;
						S.SyncClientToPlayerReference(client, server.Map.Players.Players[s]);

						if (!slot.LockColor)
							client.PreferredColor = client.Color = SanitizePlayerColor(server, client.Color, client.Index, conn);

						server.SyncLobbyClients();
						CheckAutoStart(server);

						return true;
					}
				},
				{ "allow_spectators",
					s =>
					{
						if (bool.TryParse(s, out server.LobbyInfo.GlobalSettings.AllowSpectators))
						{
							server.SyncLobbyGlobalSettings();
							return true;
						}
						else
						{
							server.SendOrderTo(conn, "Message", "Malformed allow_spectate command");
							return true;
						}
					}
				},
				{ "spectate",
					s =>
					{
						if (server.LobbyInfo.GlobalSettings.AllowSpectators || client.IsAdmin)
						{
							client.Slot = null;
							client.SpawnPoint = 0;
							client.Color = HSLColor.FromRGB(255, 255, 255);
							server.SyncLobbyClients();
							CheckAutoStart(server);
							return true;
						}
						else
							return false;
					}
				},
				{ "slot_close",
					s =>
					{
						if (!ValidateSlotCommand(server, conn, client, s, true))
							return false;

						// kick any player that's in the slot
						var occupant = server.LobbyInfo.ClientInSlot(s);
						if (occupant != null)
						{
							if (occupant.Bot != null)
							{
								server.LobbyInfo.Clients.Remove(occupant);
								server.SyncLobbyClients();
								var ping = server.LobbyInfo.PingFromClient(occupant);
								if (ping != null)
								{
									server.LobbyInfo.ClientPings.Remove(ping);
									server.SyncClientPing();
								}
							}
							else
							{
								var occupantConn = server.Conns.FirstOrDefault(c => c.PlayerIndex == occupant.Index);
								if (occupantConn != null)
								{
									server.SendOrderTo(occupantConn, "ServerError", "Your slot was closed by the host.");
									server.DropClient(occupantConn);
								}
							}
						}

						server.LobbyInfo.Slots[s].Closed = true;
						server.SyncLobbySlots();
						return true;
					}
				},
				{ "slot_open",
					s =>
					{
						if (!ValidateSlotCommand(server, conn, client, s, true))
							return false;

						var slot = server.LobbyInfo.Slots[s];
						slot.Closed = false;
						server.SyncLobbySlots();

						// Slot may have a bot in it
						var occupant = server.LobbyInfo.ClientInSlot(s);
						if (occupant != null && occupant.Bot != null)
						{
							server.LobbyInfo.Clients.Remove(occupant);
							var ping = server.LobbyInfo.PingFromClient(occupant);
							if (ping != null)
							{
								server.LobbyInfo.ClientPings.Remove(ping);
								server.SyncClientPing();
							}
						}

						server.SyncLobbyClients();
						return true;
					}
				},
				{ "slot_bot",
					s =>
					{
						var parts = s.Split(' ');

						if (parts.Length < 3)
						{
							server.SendOrderTo(conn, "Message", "Malformed slot_bot command");
							return true;
						}

						if (!ValidateSlotCommand(server, conn, client, parts[0], true))
							return false;

						var slot = server.LobbyInfo.Slots[parts[0]];
						var bot = server.LobbyInfo.ClientInSlot(parts[0]);
						int controllerClientIndex;
						if (!Exts.TryParseIntegerInvariant(parts[1], out controllerClientIndex))
						{
							Log.Write("server", "Invalid bot controller client index: {0}", parts[1]);
							return false;
						}

						var botType = parts.Skip(2).JoinWith(" ");

						// Invalid slot
						if (bot != null && bot.Bot == null)
						{
							server.SendOrderTo(conn, "Message", "Can't add bots to a slot with another client.");
							return true;
						}

						slot.Closed = false;
						if (bot == null)
						{
							// Create a new bot
							bot = new Session.Client()
							{
								Index = server.ChooseFreePlayerIndex(),
								Name = botType,
								Bot = botType,
								Slot = parts[0],
								Faction = "Random",
								SpawnPoint = 0,
								Team = 0,
								State = Session.ClientState.NotReady,
								BotControllerClientIndex = controllerClientIndex
							};

							// Pick a random color for the bot
							var validator = server.ModData.Manifest.Get<ColorValidator>();
							var tileset = server.Map.Rules.TileSet;
							var terrainColors = tileset.TerrainInfo.Where(ti => ti.RestrictPlayerColor).Select(ti => ti.Color);
							var playerColors = server.LobbyInfo.Clients.Select(c => c.Color.RGB)
								.Concat(server.Map.Players.Players.Values.Select(p => p.Color.RGB));
							bot.Color = bot.PreferredColor = validator.RandomValidColor(server.Random, terrainColors, playerColors);

							server.LobbyInfo.Clients.Add(bot);
						}
						else
						{
							// Change the type of the existing bot
							bot.Name = botType;
							bot.Bot = botType;
						}

						S.SyncClientToPlayerReference(bot, server.Map.Players.Players[parts[0]]);
						server.SyncLobbyClients();
						server.SyncLobbySlots();
						return true;
					}
				},
				{ "map",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can change the map.");
							return true;
						}

						var lastMap = server.LobbyInfo.GlobalSettings.Map;
						Action<MapPreview> selectMap = map =>
						{
							// Make sure the map hasn't changed in the meantime
							if (server.LobbyInfo.GlobalSettings.Map != lastMap)
								return;

							server.LobbyInfo.GlobalSettings.Map = map.Uid;

							var oldSlots = server.LobbyInfo.Slots.Keys.ToArray();
							server.Map = server.ModData.MapCache[server.LobbyInfo.GlobalSettings.Map];

							server.LobbyInfo.Slots = server.Map.Players.Players
								.Select(p => MakeSlotFromPlayerReference(p.Value))
								.Where(ss => ss != null)
								.ToDictionary(ss => ss.PlayerReference, ss => ss);

							LoadMapSettings(server, server.LobbyInfo.GlobalSettings, server.Map.Rules);

							// Reset client states
							foreach (var c in server.LobbyInfo.Clients)
								c.State = Session.ClientState.Invalid;

							// Reassign players into new slots based on their old slots:
							//  - Observers remain as observers
							//  - Players who now lack a slot are made observers
							//  - Bots who now lack a slot are dropped
							//  - Bots who are not defined in the map rules are dropped
							var botNames = server.Map.Rules.Actors["player"].TraitInfos<IBotInfo>().Select(t => t.Name);
							var slots = server.LobbyInfo.Slots.Keys.ToArray();
							var i = 0;
							foreach (var os in oldSlots)
							{
								var c = server.LobbyInfo.ClientInSlot(os);
								if (c == null)
									continue;

								c.SpawnPoint = 0;
								c.Slot = i < slots.Length ? slots[i++] : null;
								if (c.Slot != null)
								{
									// Remove Bot from slot if slot forbids bots
									if (c.Bot != null && (!server.Map.Players.Players[c.Slot].AllowBots || !botNames.Contains(c.Bot)))
										server.LobbyInfo.Clients.Remove(c);
									S.SyncClientToPlayerReference(c, server.Map.Players.Players[c.Slot]);
								}
								else if (c.Bot != null)
									server.LobbyInfo.Clients.Remove(c);
							}

							// Validate if color is allowed and get an alternative if it isn't
							foreach (var c in server.LobbyInfo.Clients)
								if (c.Slot == null || (c.Slot != null && !server.LobbyInfo.Slots[c.Slot].LockColor))
									c.Color = c.PreferredColor = SanitizePlayerColor(server, c.Color, c.Index, conn);

							server.SyncLobbyInfo();

							server.SendMessage("{0} changed the map to {1}.".F(client.Name, server.Map.Title));

							if (server.Map.DefinesUnsafeCustomRules)
								server.SendMessage("This map contains custom rules. Game experience may change.");

							if (!server.LobbyInfo.GlobalSettings.EnableSingleplayer)
								server.SendMessage(server.TwoHumansRequiredText);
							else if (server.Map.Players.Players.Where(p => p.Value.Playable).All(p => !p.Value.AllowBots))
								server.SendMessage("Bots have been disabled on this map.");

							var briefing = MissionBriefingOrDefault(server);
							if (briefing != null)
								server.SendMessage(briefing);
						};

						Action queryFailed = () =>
							server.SendOrderTo(conn, "Message", "Map was not found on server.");

						var m = server.ModData.MapCache[s];
						if (m.Status == MapStatus.Available || m.Status == MapStatus.DownloadAvailable)
							selectMap(m);
						else if (server.Settings.QueryMapRepository)
						{
							server.SendOrderTo(conn, "Message", "Searching for map on the Resource Center...");
							server.ModData.MapCache.QueryRemoteMapDetails(new[] { s }, selectMap, queryFailed);
						}
						else
							queryFailed();

						return true;
					}
				},
				{ "option",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can change the configuration.");
							return true;
						}

						var allOptions = server.Map.Rules.Actors["player"].TraitInfos<ILobbyOptions>()
							.Concat(server.Map.Rules.Actors["world"].TraitInfos<ILobbyOptions>())
							.SelectMany(t => t.LobbyOptions(server.Map.Rules));

						// Overwrite keys with duplicate ids
						var options = new Dictionary<string, LobbyOption>();
						foreach (var o in allOptions)
							options[o.Id] = o;

						var split = s.Split(' ');
						LobbyOption option;
						if (split.Length < 2 || !options.TryGetValue(split[0], out option) ||
							!option.Values.ContainsKey(split[1]))
						{
							server.SendOrderTo(conn, "Message", "Invalid configuration command.");
							return true;
						}

						if (option.Locked)
						{
							server.SendOrderTo(conn, "Message", "{0} cannot be changed.".F(option.Name));
							return true;
						}

						var oo = server.LobbyInfo.GlobalSettings.LobbyOptions[option.Id];
						if (oo.Value == split[1])
							return true;

						oo.Value = oo.PreferredValue = split[1];

						if (option.Id == "gamespeed")
						{
							var speed = server.ModData.Manifest.Get<GameSpeeds>().Speeds[oo.Value];
							server.LobbyInfo.GlobalSettings.Timestep = speed.Timestep;
							server.LobbyInfo.GlobalSettings.OrderLatency = speed.OrderLatency;
						}

						server.SyncLobbyGlobalSettings();
						server.SendMessage(option.ValueChangedMessage(client.Name, split[1]));

						return true;
					}
				},
				{ "assignteams",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can set that option.");
							return true;
						}

						int teamCount;
						if (!Exts.TryParseIntegerInvariant(s, out teamCount))
						{
							server.SendOrderTo(conn, "Message", "Number of teams could not be parsed: {0}".F(s));
							return true;
						}

						var maxTeams = (server.LobbyInfo.Clients.Count(c => c.Slot != null) + 1) / 2;
						teamCount = teamCount.Clamp(0, maxTeams);
						var clients = server.LobbyInfo.Slots
							.Select(slot => server.LobbyInfo.ClientInSlot(slot.Key))
							.Where(c => c != null && !server.LobbyInfo.Slots[c.Slot].LockTeam);

						var assigned = 0;
						var clientCount = clients.Count();
						foreach (var player in clients)
						{
							// Free for all
							if (teamCount == 0)
								player.Team = 0;

							// Humans vs Bots
							else if (teamCount == 1)
								player.Team = player.Bot == null ? 1 : 2;
							else
								player.Team = assigned++ * teamCount / clientCount + 1;
						}

						server.SyncLobbyClients();
						return true;
					}
				},
				{ "kick",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can kick players.");
							return true;
						}

						var split = s.Split(' ');
						if (split.Length < 2)
						{
							server.SendOrderTo(conn, "Message", "Malformed kick command");
							return true;
						}

						int kickClientID;
						Exts.TryParseIntegerInvariant(split[0], out kickClientID);

						var kickConn = server.Conns.SingleOrDefault(c => server.GetClient(c) != null && server.GetClient(c).Index == kickClientID);
						if (kickConn == null)
						{
							server.SendOrderTo(conn, "Message", "No-one in that slot.");
							return true;
						}

						var kickClient = server.GetClient(kickConn);

						Log.Write("server", "Kicking client {0}.", kickClientID);
						server.SendMessage("{0} kicked {1} from the server.".F(client.Name, kickClient.Name));
						server.SendOrderTo(kickConn, "ServerError", "You have been kicked from the server.");
						server.DropClient(kickConn);

						bool tempBan;
						bool.TryParse(split[1], out tempBan);

						if (tempBan)
						{
							Log.Write("server", "Temporarily banning client {0} ({1}).", kickClientID, kickClient.IpAddress);
							server.SendMessage("{0} temporarily banned {1} from the server.".F(client.Name, kickClient.Name));
							server.TempBans.Add(kickClient.IpAddress);
						}

						server.SyncLobbyClients();
						server.SyncLobbySlots();

						return true;
					}
				},
				{ "name",
					s =>
					{
						var sanitizedName = Settings.SanitizedPlayerName(s);
						if (sanitizedName == client.Name)
							return true;

						Log.Write("server", "Player@{0} is now known as {1}.", conn.Socket.RemoteEndPoint, sanitizedName);
						server.SendMessage("{0} is now known as {1}.".F(client.Name, sanitizedName));
						client.Name = sanitizedName;
						server.SyncLobbyClients();
						return true;
					}
				},
				{ "faction",
					s =>
					{
						var parts = s.Split(' ');
						var targetClient = server.LobbyInfo.ClientWithIndex(Exts.ParseIntegerInvariant(parts[0]));

						// Only the host can change other client's info
						if (targetClient.Index != client.Index && !client.IsAdmin)
							return true;

						// Map has disabled faction changes
						if (server.LobbyInfo.Slots[targetClient.Slot].LockFaction)
							return true;

						var factions = server.Map.Rules.Actors["world"].TraitInfos<FactionInfo>()
							.Where(f => f.Selectable).Select(f => f.InternalName);

						if (!factions.Contains(parts[1]))
						{
							server.SendOrderTo(conn, "Message", "Invalid faction selected: {0}".F(parts[1]));
							server.SendOrderTo(conn, "Message", "Supported values: {0}".F(factions.JoinWith(", ")));
							return true;
						}

						targetClient.Faction = parts[1];
						server.SyncLobbyClients();
						return true;
					}
				},
				{ "team",
					s =>
					{
						var parts = s.Split(' ');
						var targetClient = server.LobbyInfo.ClientWithIndex(Exts.ParseIntegerInvariant(parts[0]));

						// Only the host can change other client's info
						if (targetClient.Index != client.Index && !client.IsAdmin)
							return true;

						// Map has disabled team changes
						if (server.LobbyInfo.Slots[targetClient.Slot].LockTeam)
							return true;

						int team;
						if (!Exts.TryParseIntegerInvariant(parts[1], out team))
						{
							Log.Write("server", "Invalid team: {0}", s);
							return false;
						}

						targetClient.Team = team;
						server.SyncLobbyClients();
						return true;
					}
				},
				{ "spawn",
					s =>
					{
						var parts = s.Split(' ');
						var targetClient = server.LobbyInfo.ClientWithIndex(Exts.ParseIntegerInvariant(parts[0]));

						// Only the host can change other client's info
						if (targetClient.Index != client.Index && !client.IsAdmin)
							return true;

						// Spectators don't need a spawnpoint
						if (targetClient.Slot == null)
							return true;

						// Map has disabled spawn changes
						if (server.LobbyInfo.Slots[targetClient.Slot].LockSpawn)
							return true;

						int spawnPoint;
						if (!Exts.TryParseIntegerInvariant(parts[1], out spawnPoint)
							|| spawnPoint < 0 || spawnPoint > server.Map.SpawnPoints.Length)
						{
							Log.Write("server", "Invalid spawn point: {0}", parts[1]);
							return true;
						}

						if (server.LobbyInfo.Clients.Where(cc => cc != client).Any(cc => (cc.SpawnPoint == spawnPoint) && (cc.SpawnPoint != 0)))
						{
							server.SendOrderTo(conn, "Message", "You cannot occupy the same spawn point as another player.");
							return true;
						}

						// Check if any other slot has locked the requested spawn
						if (spawnPoint > 0)
						{
							var spawnLockedByAnotherSlot = server.LobbyInfo.Slots.Where(ss => ss.Value.LockSpawn).Any(ss =>
							{
								var pr = PlayerReferenceForSlot(server, ss.Value);
								return pr != null && pr.Spawn == spawnPoint;
							});

							if (spawnLockedByAnotherSlot)
							{
								server.SendOrderTo(conn, "Message", "The spawn point is locked to another player slot.");
								return true;
							}
						}

						targetClient.SpawnPoint = spawnPoint;
						server.SyncLobbyClients();
						return true;
					}
				},
				{ "color",
					s =>
					{
						var parts = s.Split(' ');
						var targetClient = server.LobbyInfo.ClientWithIndex(Exts.ParseIntegerInvariant(parts[0]));

						// Only the host can change other client's info
						if (targetClient.Index != client.Index && !client.IsAdmin)
							return true;

						// Spectator or map has disabled color changes
						if (targetClient.Slot == null || server.LobbyInfo.Slots[targetClient.Slot].LockColor)
							return true;

						// Validate if color is allowed and get an alternative it isn't
						var newColor = FieldLoader.GetValue<HSLColor>("(value)", parts[1]);
						targetClient.Color = SanitizePlayerColor(server, newColor, targetClient.Index, conn);

						// Only update player's preferred color if new color is valid
						if (newColor == targetClient.Color)
							targetClient.PreferredColor = targetClient.Color;

						server.SyncLobbyClients();
						return true;
					}
				},
				{ "sync_lobby",
					s =>
					{
						if (!client.IsAdmin)
						{
							server.SendOrderTo(conn, "Message", "Only the host can set lobby info");
							return true;
						}

						var lobbyInfo = Session.Deserialize(s);
						if (lobbyInfo == null)
						{
							server.SendOrderTo(conn, "Message", "Invalid Lobby Info Sent");
							return true;
						}

						server.LobbyInfo = lobbyInfo;

						server.SyncLobbyInfo();
						return true;
					}
				}
			};

			var cmdName = cmd.Split(' ').First();
			var cmdValue = cmd.Split(' ').Skip(1).JoinWith(" ");

			Func<string, bool> a;
			if (!dict.TryGetValue(cmdName, out a))
				return false;

			return a(cmdValue);
		}

		public void ServerStarted(S server)
		{
			// 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 {0} not found".F(uid));

			server.LobbyInfo.Slots = server.Map.Players.Players
				.Select(p => MakeSlotFromPlayerReference(p.Value))
				.Where(s => s != null)
				.ToDictionary(s => s.PlayerReference, s => s);

			LoadMapSettings(server, server.LobbyInfo.GlobalSettings, server.Map.Rules);
		}

		static Session.Slot MakeSlotFromPlayerReference(PlayerReference pr)
		{
			if (!pr.Playable) return null;
			return new Session.Slot
			{
				PlayerReference = pr.Name,
				Closed = false,
				AllowBots = pr.AllowBots,
				LockFaction = pr.LockFaction,
				LockColor = pr.LockColor,
				LockTeam = pr.LockTeam,
				LockSpawn = pr.LockSpawn,
				Required = pr.Required,
			};
		}

		public static void LoadMapSettings(S server, Session.Global gs, Ruleset rules)
		{
			var options = rules.Actors["player"].TraitInfos<ILobbyOptions>()
				.Concat(rules.Actors["world"].TraitInfos<ILobbyOptions>())
				.SelectMany(t => t.LobbyOptions(rules));

			foreach (var o in options)
			{
				var value = o.DefaultValue;
				var preferredValue = o.DefaultValue;
				Session.LobbyOptionState state;
				if (gs.LobbyOptions.TryGetValue(o.Id, out state))
				{
					// Propagate old state on map change
					if (!o.Locked)
					{
						if (o.Values.Keys.Contains(state.PreferredValue))
							value = state.PreferredValue;
						else if (o.Values.Keys.Contains(state.Value))
							value = state.Value;
					}

					preferredValue = state.PreferredValue;
				}
				else
					state = new Session.LobbyOptionState();

				state.Locked = o.Locked;
				state.Value = value;
				state.PreferredValue = preferredValue;
				gs.LobbyOptions[o.Id] = state;

				if (o.Id == "gamespeed")
				{
					var speed = server.ModData.Manifest.Get<GameSpeeds>().Speeds[value];
					gs.Timestep = speed.Timestep;
					gs.OrderLatency = speed.OrderLatency;
				}
			}
		}

		static HSLColor SanitizePlayerColor(S server, HSLColor askedColor, int playerIndex, Connection connectionToEcho = null)
		{
			var validator = server.ModData.Manifest.Get<ColorValidator>();
			var askColor = askedColor;

			Action<string> onError = message =>
			{
				if (connectionToEcho != null)
					server.SendOrderTo(connectionToEcho, "Message", message);
			};

			var tileset = server.Map.Rules.TileSet;
			var terrainColors = tileset.TerrainInfo.Where(ti => ti.RestrictPlayerColor).Select(ti => ti.Color).ToList();
			var playerColors = server.LobbyInfo.Clients.Where(c => c.Index != playerIndex).Select(c => c.Color.RGB)
				.Concat(server.Map.Players.Players.Values.Select(p => p.Color.RGB)).ToList();

			return validator.MakeValid(askColor.RGB, server.Random, terrainColors, playerColors, onError);
		}

		static string MissionBriefingOrDefault(S server)
		{
			var missionData = server.Map.Rules.Actors["world"].TraitInfoOrDefault<MissionDataInfo>();
			if (missionData != null && !string.IsNullOrEmpty(missionData.Briefing))
				return missionData.Briefing.Replace("\\n", "\n");

			return null;
		}

		public void ClientJoined(S server, Connection conn)
		{
			var client = server.GetClient(conn);

			// Validate whether color is allowed and get an alternative if it isn't
			if (client.Slot == null || !server.LobbyInfo.Slots[client.Slot].LockColor)
				client.Color = SanitizePlayerColor(server, client.Color, client.Index);

			// Report any custom map details
			// HACK: this isn't the best place for this to live, but if we move it somewhere else
			// then we need a larger hack to hook the map change event.
			var briefing = MissionBriefingOrDefault(server);
			if (briefing != null)
				server.SendOrderTo(conn, "Message", briefing);
		}

		void INotifyServerEmpty.ServerEmpty(S server)
		{
			// Expire any temporary bans
			server.TempBans.Clear();

			// Re-enable spectators
			server.LobbyInfo.GlobalSettings.AllowSpectators = true;

			// Reset player slots
			server.LobbyInfo.Slots = server.Map.Players.Players
				.Select(p => MakeSlotFromPlayerReference(p.Value))
				.Where(ss => ss != null)
				.ToDictionary(ss => ss.PlayerReference, ss => ss);
		}

		public PlayerReference PlayerReferenceForSlot(S server, Session.Slot slot)
		{
			if (slot == null)
				return null;

			return server.Map.Players.Players[slot.PlayerReference];
		}
	}
}
