[U|F] More Customizations & Compatibility Fixes

[U] Now client side can use WorldLink.toml to customize RelayUrl with custom port. Just incase if server side is using other relay port instead of 20101. If user not defining RelayUrl or comment it out, it will use the LobbyUrl link with the default port 20101. (Modification has been made to WorldLink.toml, check it out! I wrote some comment in there)
[F] Fixed the issue where new clients could not join a room opened by an old client. This was caused by accidentally using different UserIDs types.

Author: Japerz12138

README.md

@@ -15,6 +15,8 @@ WorldLink maimai DX Online C2C Multiplayer Mod
 2. Download [WorldLink.dll](https://github.com/MewoLab/worldlinkd/releases/latest/download/WorldLink.dll), put it in Mods
 3. Download [WorldLink.toml](https://github.com/MewoLab/worldlinkd/blob/main/mod/WorldLink.toml)
 4. Edit `WorldLink.toml` to select a lobby server
+   - **LobbyUrl**: Required. Choose from `{asia, euro, usw, use, cn}.link.aquadx.net`
+   - **RelayUrl**: Optional. Custom relay server URL (e.g., `"myrelay.example.com:20101"`). If not specified, uses relay info from lobby server
 5. Start the game
 
 ### On KanadeDX

mod/Compat.cs

@@ -1,13 +1,16 @@
-
-
 using MelonLoader;
 using WorldLink;
 
 static class AquaMai
 {
     public static string ReadString(string key)
     {
-        return key == "Mods.WorldLink.LobbyUrl" ? Core.Config.LobbyUrl : null;
+        return key switch
+        {
+            "Mods.WorldLink.LobbyUrl" => Core.Config.LobbyUrl,
+            "Mods.WorldLink.RelayUrl" => Core.Config.RelayUrl,
+            _ => null
+        };
     }
 }
 

mod/Core.cs

@@ -9,6 +9,7 @@ namespace WorldLink;
 public class Config
 {
     public string LobbyUrl { get; set; }
+    public string RelayUrl { get; set; }
     public bool Debug { get; set; }
 }
 

mod/WorldLink.toml

@@ -1,4 +1,3 @@
-
 # WorldLink configuration file
 # 
 # The Lobby URL can be one of {asia, euro, usw, use, cn}.link.aquadx.net
@@ -12,6 +11,12 @@
 # NOTE: If you're playing with your friend, make sure you both use the same Lobby URL.
 LobbyUrl="https://euro.link.aquadx.net"
 
+# Optional: Custom relay server URL
+# If not specified or blank, the mod will use the relay server info from the lobby server
+# Format: "hostname:port" or "hostname" (defaults to port 20101)
+# Examples:
+# RelayUrl="relay.example.com:20101"
+
 # Show debug messages
 Debug=false
 

mod/WorldLink/FutariClient.cs

@@ -17,6 +17,7 @@
 public class FutariClient
 {
     public static string LOBBY_BASE => AquaMai.ReadString("Mods.WorldLink.LobbyUrl");
+    public static string RELAY_BASE => AquaMai.ReadString("Mods.WorldLink.RelayUrl");
     // public const string LOBBY_BASE = "https://aquadx.net/aqua/mai2-futari";
     public static FutariClient Instance { get; private set; }
 
@@ -165,6 +166,23 @@ private void HandleIncomingMessage(FutariMsg futariMsg)
 
         switch (futariMsg.FutariCmd)
         {
+            // Server registration response with version
+            case FutariCmd.CTL_START:
+                if (!string.IsNullOrEmpty(futariMsg.data))
+                {
+                    Log.Info($"Server registration response: {futariMsg.data}");
+                    // Parse version if present (format: "version=X")
+                    if (futariMsg.data.StartsWith("version="))
+                    {
+                        var versionStr = futariMsg.data.Substring("version=".Length);
+                        if (int.TryParse(versionStr, out var version))
+                        {
+                            Log.Info($"Server protocol version: {version}");
+                        }
+                    }
+                }
+                break;
+            
             // Heartbeat
             case FutariCmd.CTL_HEARTBEAT:
                 var delay = _heartbeat.ElapsedMilliseconds;

mod/WorldLink/FutariPatch.cs

@@ -64,19 +64,31 @@ public static void OnBeforePatch()
 
         // Send HTTP request to get the futari client address
         client = new FutariClient("A1234567890", "", 20101);
-        $"{FutariClient.LOBBY_BASE}/info".GetAsync((sender, e) =>
+        
+        // Check if RelayUrl is configured
+        if (!string.IsNullOrEmpty(FutariClient.RELAY_BASE))
         {
-            if (e.Error != null)
+            // Use configured RelayUrl directly
+            try
             {
-                Log.Error($"Failed to get WorldLink server address: {e.Error}");
-                return;
+                var relayUri = new Uri(FutariClient.RELAY_BASE);
+                client.host = relayUri.Host;
+                client.port = relayUri.Port != -1 ? relayUri.Port : 20101; // Default to 20101 if no port specified
+                Log.Info($"Using configured relay server: {client.host}:{client.port}");
             }
-            // Response Format: {"relayHost": "google.com", "relayPort": 20101}
-            var info = JsonUtility.FromJson<ServerInfo>(e.Result);
-            client.host = info.relayHost;
-            client.port = info.relayPort;
-            Log.Info($"WorldLink server address: {info.relayHost}:{info.relayPort}");
-        });
+            catch (Exception ex)
+            {
+                Log.Error($"Invalid RelayUrl format: {FutariClient.RELAY_BASE}. Error: {ex.Message}");
+                Log.Info("Falling back to lobby server relay info");
+                // Fall back to lobby server method
+                GetRelayInfoFromLobby();
+            }
+        }
+        else
+        {
+            // Fall back to getting relay info from lobby server
+            GetRelayInfoFromLobby();
+        }
     }
 
     // Entrypoint
@@ -855,4 +867,22 @@ public static bool RecvClientState(Packet packet)
 #endif
 
     #endregion
+
+    // Helper method to get relay info from lobby server
+    private static void GetRelayInfoFromLobby()
+    {
+        $"{FutariClient.LOBBY_BASE}/info".GetAsync((sender, e) =>
+        {
+            if (e.Error != null)
+            {
+                Log.Error($"Failed to get WorldLink server address: {e.Error}");
+                return;
+            }
+            // Response Format: {"relayHost": "google.com", "relayPort": 20101}
+            var info = JsonUtility.FromJson<ServerInfo>(e.Result);
+            client.host = info.relayHost;
+            client.port = info.relayPort;
+            Log.Info($"WorldLink server address: {info.relayHost}:{info.relayPort}");
+        });
+    }
 }

src/main/kotlin/Application.kt

@@ -16,8 +16,8 @@ fun main(args: Array<String>) {
     val relayPort = parsePort(args, "--relay-port", "RELAY_PORT", 20101)
 
     println("=== WorldLink Server Configuration ===")
-    println("Lobby Port (HTTP API): $lobbyPort")
-    println("Relay Port (Game Communication): $relayPort")
+    println("Lobby Port: $lobbyPort")
+    println("Relay Port: $relayPort")
     println("=====================================")
 
     embeddedServer(Netty, port = lobbyPort, module = Application::module).start()

src/main/kotlin/FutariLobby.kt

@@ -58,7 +58,16 @@ fun Application.configureRouting() = routing {
         recruits[d.ip] = d
 
         if (!exists) log(d, "StartRecruit")
-        d.RecruitInfo.MechaInfo.UserIDs = d.RecruitInfo.MechaInfo.UserIDs.map { it.str.hashToUInt().toLong() }
+        
+        // Backward compatibility: only hash UserIDs if they are strings (old clients)
+        // New clients already send hashed long values
+        d.RecruitInfo.MechaInfo.UserIDs = d.RecruitInfo.MechaInfo.UserIDs.map { userId ->
+            when (userId) {
+                is String -> userId.hashToUInt().toLong()
+                is Long -> userId
+                else -> userId.toString().hashToUInt().toLong()
+            }
+        }
     }
 
     post("/recruit/finish") {