Total Player Online

- Give a seek of how many players(or machines) is online with WorldLink on the client side
- Client side changes color when someone is recruiting
- Server side show online counts after a player joins or leaves
- Updated ReadMe files for developers

Author: Japerz12138

README.md

@@ -34,3 +34,104 @@ WorldLink maimai DX Online C2C Multiplayer Mod
 ## Running a Server
 
 If you want to self-host a server to play with your friends, read the [Self Host Guide](README.HOST.md).
+
+## Developer Guide
+
+This project consists of two main components:
+- **Server** (Kotlin/Ktor) - Handles multiplayer functionality
+- **Client Mod** (C#) - DLL for the MAI2 game
+
+### Prerequisites
+
+- **Java 17+** for building the server
+- **.NET Framework 4.7.2** for building the client mod
+- **MAI2 game DLLs** (see below)
+
+### Building the Server
+
+The server is a Kotlin application using Ktor framework.
+
+```bash
+# Build the server (excluding tests)
+./gradlew build -x test
+
+# The JAR file will be created at:
+# build/libs/worldlinkd.jar
+```
+
+### Building the Client Mod
+
+The client mod requires game-specific DLLs that are not included in the repository.
+
+#### 1. Required Game DLLs
+
+You need to obtain these DLLs from your MAI2 installation:
+- `mod/Libs/Assembly-CSharp.dll` - Main game assembly
+- `mod/Libs/Assembly-CSharp-firstpass.dll` - Game assembly (first pass)
+- `mod/Libs/AMDaemon.NET.dll` - AMDaemon library
+
+#### 2. Build the Mod
+
+```bash
+# Navigate to the mod directory
+cd mod
+
+# Build the mod
+dotnet build
+
+# The DLL will be created at:
+# bin/Debug/net472/WorldLink.dll
+```
+
+#### 3. Installation
+
+Copy the built `WorldLink.dll` to your MAI2 game's `Mods` folder.
+
+### Development Workflow
+
+1. **Server Development:**
+   - Modify server code in `src/main/kotlin/`
+   - Run `./gradlew build -x test` to rebuild
+   - Test with `java -jar build/libs/worldlinkd.jar`
+
+2. **Client Mod Development:**
+   - Modify mod code in `mod/WorldLink/`
+   - Run `dotnet build` from the `mod/` directory
+   - Copy the new DLL to your game's Mods folder
+   - Restart the game to test changes
+
+### Project Structure
+
+```
+worldlinkd/
+├── src/main/kotlin/          # Server source code
+│   ├── Application.kt        # Main server application
+│   ├── FutariLobby.kt       # Lobby server logic
+│   ├── FutariRelay.kt       # Relay server logic
+│   └── FutariTypes.kt       # Data structures
+├── mod/                     # Client mod source code
+│   ├── WorldLink/           # Main mod code
+│   │   ├── FutariPatch.cs   # Main patch logic
+│   │   ├── FutariClient.cs  # Client communication
+│   │   ├── FutariExt.cs     # Utility extensions
+│   │   └── FutariTypes.cs   # Data structures
+│   ├── Libs/                # Game DLLs (not included)
+│   └── WorldLink.csproj     # Mod project file
+└── build.gradle.kts         # Server build configuration
+```
+
+### Troubleshooting
+
+#### Build Errors
+
+- **Missing DLLs:** Ensure all required game DLLs are in `mod/Libs/`
+- **Java version:** Make sure you're using Java 17 or higher
+- **.NET Framework:** Ensure .NET Framework 4.7.2 is installed
+
+#### Runtime Issues
+
+- **Server won't start:** Check if port 20100 is available
+- **Mod not loading:** Verify the DLL is in the correct Mods folder and do not use dirty packs(脏脏包)
+- **Connection issues:** Check firewall settings and server configuration
+
+For more detailed information about the modding process, see the [Self Host Guide](README.HOST.md).

mod/WorldLink/FutariExt.cs

@@ -47,7 +47,8 @@ public static byte[] View(this byte[] buffer, int offset, int size)
 
     public static V? Get<K, V>(this ConcurrentDictionary<K, V> dict, K key) where V : class
     {
-        return dict.GetValueOrDefault(key);
+        dict.TryGetValue(key, out V value);
+        return value;
     }
 
     // Call a function using reflection

mod/WorldLink/FutariPatch.cs

@@ -37,6 +37,7 @@ public static class Futari
     private static bool checkAuthCalled = false;
     private static bool isInit = false;
     public static bool stopping = false;
+    private static int onlineUserCount = 0;
 
     private static MethodBase packetWriteUInt;
     private static System.Type StartUpStateType;
@@ -98,6 +99,12 @@ public static bool CheckAuth_Proc()
             client.keychip = keychip;
             client.ConnectAsync();
             isInit = true;
+            
+            // Fetch initial online user count
+            FetchOnlineUserCount();
+            
+            // Start periodic online user count fetching
+            30000.Interval(() => FetchOnlineUserCount());
         }).Start();
 
         return PrefixRet.RUN_ORIGINAL;
@@ -116,6 +123,23 @@ private static bool PreIsLanAvailable(ref bool __result)
         return false;
     }
 #endif
+
+    // Fetch online user count from server
+    private static void FetchOnlineUserCount()
+    {
+        try
+        {
+            var response = $"{FutariClient.LOBBY_BASE}/online".Get();
+            var onlineInfo = JsonUtility.FromJson<OnlineUserInfo>(response);
+            onlineUserCount = onlineInfo.totalUsers;
+        }
+        catch (Exception ex)
+        {
+            Log.Error($"Failed to fetch online user count: {ex.Message}");
+            onlineUserCount = 0;
+        }
+    }
+
     //Online Display
     [HarmonyPostfix]
     [HarmonyPatch(typeof(CommonMonitor), "ViewUpdate")]
@@ -138,8 +162,22 @@ public static void CommonMonitorViewUpdate(CommonMonitor __instance,TextMeshProU
                 ____buildVersionText.color = Color.yellow;
                 break;
             case 2:
-                ____buildVersionText.color = Color.cyan;
-                ____buildVersionText.text = PartyMan == null ? $"WorldLink Waiting" : $"WorldLink Recruiting: {PartyMan.GetRecruitList().Count}";
+                var recruitCount = PartyMan == null ? 0 : PartyMan.GetRecruitList().Count;
+                if (onlineUserCount > 0)
+                {
+                    ____buildVersionText.text = $"WorldLink Recruiting: {recruitCount}/{onlineUserCount}";
+                    ____buildVersionText.color = recruitCount > 0 ? Color.green : Color.cyan;
+                }
+                else if (onlineUserCount == 0)
+                {
+                    ____buildVersionText.text = $"No players online";
+                    ____buildVersionText.color = Color.gray;
+                }
+                else
+                {
+                    ____buildVersionText.text = $"WorldLink Recruiting: {recruitCount}";
+                    ____buildVersionText.color = Color.cyan;
+                }
                 break;
         }
     }

mod/WorldLink/FutariTypes.cs

@@ -41,6 +41,12 @@ public class ServerInfo
     public int relayPort;
 }
 
+public class OnlineUserInfo
+{
+    public int totalUsers;
+    public int activeRecruits;
+}
+
 public struct FutariMsg
 {
     public FutariCmd FutariCmd;

src/main/kotlin/FutariLobby.kt

@@ -87,6 +87,23 @@ fun Application.configureRouting() = routing {
         ).ok()
     }
 
+    get("/online") {
+        val time = millis()
+        // Clean up expired recruits
+        recruits.filterValues { time - it.Time > MAX_TTL }.keys.forEach { recruits.remove(it) }
+        
+        // Count actual connected clients from FutariRelay
+        val totalUsers = clients.size
+        
+        // Count active recruits (unique users)
+        val activeRecruits = recruits.size
+        
+        OnlineUserInfo(
+            totalUsers = totalUsers,
+            activeRecruits = activeRecruits
+        ).ok()
+    }
+
     get("/debug") {
         mapOf(
             "serverHost" to call.request.local.serverHost,

src/main/kotlin/FutariTypes.kt

@@ -96,3 +96,9 @@ data class RelayServerInfo(
     val port: Int = 20101,
     val official: Bool = true
 )
+
+@Serializable
+data class OnlineUserInfo(
+    val totalUsers: Int,
+    val activeRecruits: Int
+)