add http status request and display html (Melledy#86)

* add http status request

* add maxplayer value

* add http status request

* add http status request

* maxPlayers limit

* maxPlayers limit

src/main/java/emu/lunarcore/Config.java

@@ -131,7 +131,7 @@ public static class ServerOptions {
         public boolean autoUpgradeWorldLevel = true; // Automatically upgrades world level when the player reaches a certain TB level
         public String language = "EN";
         public Set<String> defaultPermissions = Set.of("*");
-
+        public int maxPlayers = -1;
         public ServerProfile serverFriendInfo = new ServerProfile();
         public WelcomeMail welcomeMail = new WelcomeMail();
 

src/main/java/emu/lunarcore/server/http/HttpServer.java

@@ -135,6 +135,7 @@ private void addRoutes() {
 
         // Fallback handler
         getApp().error(404, this::notFoundHandler);
+        getApp().get("/status/server", new StatusServerHandler()::handle);
     }
 
     private void addDispatchRoutes() {
@@ -199,9 +200,9 @@ private void addGateServerRoutes() {
         this.modes.add("GATESERVER");
     }
 
-    private void notFoundHandler(Context ctx) {
+ private void notFoundHandler(Context ctx) {
         ctx.status(404);
         ctx.contentType(ContentType.TEXT_PLAIN);
         ctx.result("not found");
     }
-}
+}

src/main/java/emu/lunarcore/server/http/handlers/StatusServerHandler.java

@@ -0,0 +1,26 @@
+package emu.lunarcore.server.http.handlers;
+
+import org.jetbrains.annotations.NotNull;
+
+import emu.lunarcore.GameConstants;
+import emu.lunarcore.LunarCore;
+
+import io.javalin.http.Context;
+import io.javalin.http.Handler;
+
+public class StatusServerHandler implements Handler {
+
+    @Override
+    public void handle(@NotNull Context ctx) throws Exception {
+        int playerCount = LunarCore.getGameServer().getPlayerCount();
+        int maxPlayers = LunarCore.getConfig().getServerOptions().maxPlayers;
+        String version = GameConstants.VERSION;
+        String responseJson = String.format(
+                "{\"retcode\":0,\"status\":{\"playerCount\":%d,\"maxPlayers\":%d,\"version\":\"%s\"}}",
+                playerCount, maxPlayers, version
+        );
+        ctx.status(200);
+        ctx.contentType("application/json");
+        ctx.result(responseJson);
+    }
+}

src/main/java/emu/lunarcore/server/packet/recv/HandlerPlayerGetTokenCsReq.java

@@ -28,6 +28,14 @@ public void handle(GameSession session, byte[] data) throws Exception {
         // Set account object for session
         session.setAccount(account);
 
+        // If playerCount reach the set maxPlayers, newly logged-in players will be kicked out
+        int maxPlayers = LunarCore.getConfig().getServerOptions().maxPlayers;
+        int playerCount = LunarCore.getGameServer().getPlayerCount();
+        if (maxPlayers > -1 &&  playerCount >= maxPlayers) {
+            session.close();
+            return;
+        }
+
         // Get player from database, if it doesnt exist, we create it
         Player player = LunarCore.getGameDatabase().getObjectByField(Player.class, "accountUid", account.getUid());