Add ability to control online players along with max players

src/main/java/me/crypnotic/neutron/module/serverlist/ServerListConfig.java

@@ -48,6 +48,10 @@ public class ServerListConfig {
     @Setting("server-preview")
     private ServerPreview serverPreview = new ServerPreview();
 
+    @Getter
+    @Setting("online-player-count")
+    private OnlinePlayerCount onlinePlayerCount = new OnlinePlayerCount();
+
     @ConfigSerializable
     public static class PlayerCount {
 
@@ -92,4 +96,27 @@ public class ServerListConfig {
             PLAYERS;
         }
     }
+
+    @ConfigSerializable
+    public static class OnlinePlayerCount {
+
+        @Getter
+        @Setting(value = "action", comment = "      # The online player count has three different actions:\r\n" + "        # \r\n"
+                + "        # STATIC - online players will always be the value of `online-player-count`\r\n"
+                + "        # PING - online player count shows the sum of all backend servers' online player counts. Cached every 5 minutes\r\n"
+                + "        # CURRENT - online players matches number of players connected to the proxy\r\n" + "        #\r\n"
+                + "        # `online-player-count` is only used with the STATIC action")
+
+        private OnlinePlayerCountAction action = OnlinePlayerCountAction.CURRENT;
+
+        @Getter
+        @Setting("online-player-count")
+        private int onlinePlayerCount = 32;
+
+        public static enum OnlinePlayerCountAction {
+            STATIC,
+            PING,
+            CURRENT;
+        }
+    }
 }

src/main/java/me/crypnotic/neutron/module/serverlist/ServerListHandler.java

@@ -50,12 +50,23 @@ public class ServerListHandler {
         Builder builder = ServerPing.builder();
 
         builder.version(original.getVersion());
-        builder.onlinePlayers(playerCount);
 
         original.getFavicon().ifPresent(builder::favicon);
 
         builder.description(config.getMotd());
 
+        switch (config.getOnlinePlayerCount().getAction()) {
+            case STATIC:
+                builder.onlinePlayers(playerCount);
+                break;
+            case PING:
+                builder.onlinePlayers(module.getOnlinePlayerPing());
+                break;
+            case CURRENT:
+                builder.onlinePlayers(module.getNeutron().getProxy().getPlayerCount());
+                break;
+        }
+
         switch (config.getPlayerCount().getAction()) {
         case CURRENT:
             builder.maximumPlayers(playerCount);

src/main/java/me/crypnotic/neutron/module/serverlist/ServerListModule.java

@@ -47,6 +47,8 @@ public class ServerListModule extends Module {
     private ServerListHandler handler;
     @Getter
     private int maxPlayerPing;
+    @Getter
+    private int onlinePlayerPing;
 
     @Override
     public StateResult init() {
@@ -90,6 +92,7 @@ public class ServerListModule extends Module {
     public class PingTask implements Runnable {
 
         int buffer = 0;
+        int onlineBuffer = 0;
 
         @Override
         public void run() {
@@ -100,6 +103,7 @@ public class ServerListModule extends Module {
 
                     if (players.isPresent()) {
                         buffer += players.get().getMax();
+                        onlineBuffer += players.get().getOnline();
                     }
                 } catch (InterruptedException | ExecutionException exception) {
                     /* Catch silently */
@@ -108,7 +112,9 @@ public class ServerListModule extends Module {
             }
 
             maxPlayerPing = buffer;
+            onlinePlayerPing = onlineBuffer;
             buffer = 0;
+            onlineBuffer = 0;
         }
     }
 }