add server welcome message feature

src/Patches/PlayersManager_Patch.cs

@@ -0,0 +1,149 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Game;
+using Game.Messages;
+using Game.State;
+using HarmonyLib;
+using Network;
+using Network.Client;
+using Serilog;
+
+namespace tostilities.Patches;
+
+[HarmonyPatch(typeof(PlayersManager))]
+[HarmonyPatch(nameof(PlayersManager.NotifyOfNewPlayers))]
+public class PlayersManager_NotifyOfNewPlayers_Patch
+{
+	private static bool Prefix(ref PlayersManager __instance, Dictionary<string, Snapshot.Player> players)
+	{
+		if (!Main.MySettings.EnableWelcomeMessage && !Main.MySettings.ConsoleTimeStamps)
+		{
+			return true; //execute original function
+		}
+
+		// ============= unchanged =============
+
+		HashSet<PlayerId> playerIdSet = new HashSet<PlayerId>(__instance._remotePlayers.Keys);
+		HashSet<Snapshot.Player> playerSet = new HashSet<Snapshot.Player>();
+		foreach (KeyValuePair<string, Snapshot.Player> player1 in players)
+		{
+			PlayerId key = new PlayerId(player1.Key);
+			playerIdSet.Remove(key);
+			if (!__instance._remotePlayers.ContainsKey(key) && key != PlayersManager.PlayerId)
+			{
+				Snapshot.Player player2 = player1.Value;
+				playerSet.Add(player2);
+			}
+		}
+		if (playerSet.Any())
+		{
+			Log.Information("Connected: {players}", playerSet);
+			string playerNames = string.Join(", ", playerSet.OrderBy(p => p.Name).Select(p => p.Name));
+			bool flag = playerSet.Count != 1;
+			if (__instance._hasNotifiedOfPlayers)
+			{
+				// ============= changed =============
+
+				var timeString = Main.MySettings.ConsoleTimeStamps ? "" : DateTime.Now.ToString("HH:mm")+" ";
+				Console.Log($"{timeString}{playerNames} has connected.");
+
+				if (Main.MySettings.EnableWelcomeMessage)
+				{
+					var message = Main.MySettings.WelcomeMessage.Replace(Settings.playername_replaceo, playerNames);
+					Multiplayer.Broadcast(message);
+				}
+
+				// ============= unchanged =============
+			}
+			else
+			{
+				Console.Log(playerNames + " " + (flag ? "are" : "is") + " connected.");
+			}
+
+			__instance._hasNotifiedOfPlayers = true;
+		}
+		foreach (PlayerId playerId in playerIdSet)
+		{
+			RemotePlayer remotePlayer;
+			if (!__instance._remotePlayers.TryGetValue(playerId, out remotePlayer))
+			{
+				Log.Error("Couldn't find name of disconnected player {playerId}", playerId);
+			}
+			else
+			{
+				Log.Information("{name} {playerId} has disconnected", remotePlayer.playerName, remotePlayer.playerId);
+
+				// ============= changed =============
+
+				var timeString = Main.MySettings.ConsoleTimeStamps ? "" : DateTime.Now.ToString("HH:mm")+" ";
+				Console.Log($"{timeString}{remotePlayer.playerName} has disconnected.");
+
+				// ============= unchanged =============
+			}
+		}
+
+		return false; //skip original function
+	}
+}
+
+/*
+
+[HarmonyPatch(typeof(PlayersManager))]
+[HarmonyPatch(nameof(PlayersManager.NotifyOfNewPlayers))]
+public class PlayersManager_NotifyOfNewPlayers_Patch
+{
+	private static void Prefix(out List<PlayerId> __state, PlayersManager __instance)
+	{
+		__state = __instance._remotePlayers.Keys.ToList();
+
+		foreach (var aaa in __instance._remotePlayers)
+		{
+			Console.Log("old:"+aaa.Value.Name);
+		}
+	}
+
+	private static void Postfix(List<PlayerId> __state, PlayersManager __instance)
+	{
+		// _hasNotifiedOfPlayers is false at server startup
+		if (!Main.MySettings.EnableWelcomeMessage || !__instance._hasNotifiedOfPlayers)
+		{
+			return;
+		}
+
+		foreach (var aaa in __instance._remotePlayers)
+		{
+			Console.Log("new:"+aaa.Value.Name);
+		}
+
+		if (__instance._remotePlayers.Keys.ToList() != __state)
+		{
+			Console.Log("player list changed!");
+		}
+
+		List<string> newPlayerNames = new();
+
+		foreach (var aPlayerNow in __instance._remotePlayers)
+		{
+			Console.Log(aPlayerNow.Value.Name);
+			if (!__state.Contains(aPlayerNow.Key))
+			{
+				Console.Log("new");
+				//new player
+				newPlayerNames.Add(aPlayerNow.Value.Name);
+			}
+			else
+			{
+				Console.Log("newn't");
+			}
+		}
+
+		foreach (var playerName in newPlayerNames)
+		{
+			var message = Main.MySettings.WelcomeMessage.Replace(Settings.playername_replaceo, playerName);
+			Multiplayer.Broadcast(message);
+		}
+	}
+}
+
+*/

src/Settings.cs

@@ -6,6 +6,7 @@ namespace tostilities
 {
 	public class Settings : UnityModManager.ModSettings
 	{
+		public const string playername_replaceo = "<playername>";
 		private const int SPACE = 15;
 
 		public float PushForceMultiplier = 10;
@@ -16,6 +17,9 @@ public class Settings : UnityModManager.ModSettings
 		public bool EnableBunnyHopping = false;
 		public bool ReportDamage = false;
 		public bool ConsoleTimeStamps = false;
+
+		public bool EnableWelcomeMessage = false;
+		public string WelcomeMessage = "<playername>, welcome to the server!";
 
 		public void Setup()
 		{
@@ -39,6 +43,14 @@ public void Draw(UnityModManager.ModEntry modEntry)
 			DisableDerailing = GUILayout.Toggle(DisableDerailing, "Disable derailing");
 			DisableDamage = GUILayout.Toggle(DisableDamage, "Disable damage to rolling stock");
 			ReportDamage = GUILayout.Toggle(ReportDamage, "Report damage to rolling stock and derailments in the console");
+
+			EnableWelcomeMessage = GUILayout.Toggle(EnableWelcomeMessage, "Show a customizable message in the console when a new player joins");
+
+			if (EnableWelcomeMessage)
+			{
+				GUILayout.Label($"Welcome message text. {playername_replaceo} will be replaced with the name of the player.");
+				WelcomeMessage = GUILayout.TextArea(WelcomeMessage);
+			}
 		}
 
 		private void DrawFloatInput(string descriptionText, ref string fieldText, ref float number)