Added a way to track how often players relog within 30 seconds of being afk kicked

src/main/java/com/alttd/afkdectector/AFKDetector.java

@@ -5,8 +5,14 @@ import com.alttd.afkdectector.command.AFKCheckCommand;
 import com.alttd.afkdectector.command.AFKListCommand;
 import com.alttd.afkdectector.command.ReloadCommand;
 import com.alttd.afkdectector.config.Config;
+import com.alttd.afkdectector.config.Messages;
 import com.alttd.afkdectector.config.MessagesConfig;
+import com.alttd.afkdectector.trackers.AutoJoinTracker;
+import com.alttd.afkdectector.trackers.SuspiciousKickTracker;
+import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.minimessage.MiniMessage;
+import net.kyori.adventure.text.minimessage.tag.resolver.Placeholder;
+import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
 import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
@@ -22,8 +28,10 @@ import org.bukkit.scoreboard.Scoreboard;
 import org.bukkit.scoreboard.ScoreboardManager;
 import org.bukkit.scoreboard.Team;
 
+import java.util.Date;
 import java.util.HashMap;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 
 public class AFKDetector extends JavaPlugin implements Listener{
 
@@ -117,11 +125,25 @@ public class AFKDetector extends JavaPlugin implements Listener{
     @EventHandler
     public void onJoin(PlayerJoinEvent event) {
         Player player = event.getPlayer();
-        PlayerAfkTime.put(player.getUniqueId(), getPlayerAfktime(player));
+        UUID uuid = player.getUniqueId();
-        players.put(player.getUniqueId(), new AFKPlayer(player, this));
+        PlayerAfkTime.put(uuid, getPlayerAfktime(player));
+        players.put(uuid, new AFKPlayer(player, this));
         if(Bukkit.getOnlinePlayers().size() >= Config.PLAYERLIMIT && !Config.SERVERFULL) {
         	fulloverride = true;
         }
+
+        long lastKick = AutoJoinTracker.getInstance().getLastKick(uuid);
+        if (lastKick + TimeUnit.SECONDS.toMicros(Config.MAXREJOINFORTRACKING) > new Date().getTime()) {
+            SuspiciousKickTracker skt = SuspiciousKickTracker.getInstance();
+            skt.addSuspiciousKick(uuid);
+            int suspiciousKickCount = skt.getSuspiciousKickCount(uuid);
+            TagResolver placeholders = TagResolver.resolver(
+                    Placeholder.component("player", player.name()),
+                    Placeholder.parsed("count", "" + suspiciousKickCount)
+            );
+            Component component = MiniMessage.miniMessage().deserialize(Messages.SUSPICIOUSKICKCOUNT.getMessage(), placeholders);
+            Bukkit.broadcast(component, "afkdetector.notify");
+        }
     }
     
     @EventHandler

src/main/java/com/alttd/afkdectector/MessageTimer.java

@@ -1,10 +1,12 @@
 package com.alttd.afkdectector;
 
+import java.util.Date;
 import java.util.UUID;
 
 import com.alttd.afkdectector.afkplayer.AFKPlayer;
 import com.alttd.afkdectector.config.Config;
 import com.alttd.afkdectector.config.Messages;
+import com.alttd.afkdectector.trackers.AutoJoinTracker;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.minimessage.MiniMessage;
 import net.kyori.adventure.text.minimessage.tag.resolver.Placeholder;
@@ -66,6 +68,7 @@ public class MessageTimer extends BukkitRunnable {
 	        	//Bukkit.dispatchCommand(Bukkit.getConsoleSender(), plugin.kickCommand.replace("%player%", player.getName()));
 	        	plugin.messageTimers.remove(player.getUniqueId());
 	        	Bukkit.dispatchCommand(Bukkit.getConsoleSender(), return_placeholders(Config.KICKCOMMAND, player));
+				AutoJoinTracker.getInstance().addKick(player.getUniqueId(), new Date().getTime());
 				TagResolver templates = TagResolver.resolver(
 						Placeholder.unparsed("player", player.getName()),
 						Placeholder.unparsed("afk_time", "" + afkPlayer.getafkTime())

src/main/java/com/alttd/afkdectector/config/Config.java

@@ -39,6 +39,7 @@ public class Config extends AbstractConfiguration {
     public static int COMMANDCOOLDOWWN = 60;
     public static boolean AFKTOGGLEMESSAGES = true;
     public static boolean NOTIFYSTAFFONAFKKIC = true;
+    public static int MAXREJOINFORTRACKING = 30;
     private static void playerSettings() {
         SLEEPIGNORE = config.getBoolean("player.sleep", SLEEPIGNORE);
         RADIUS = config.getInt("player.radius", RADIUS);
@@ -49,6 +50,7 @@ public class Config extends AbstractConfiguration {
         COMMANDCOOLDOWWN = config.getInt("player.commandcooldown", COMMANDCOOLDOWWN);
         AFKTOGGLEMESSAGES = config.getBoolean("player.afk-toggle-messages", AFKTOGGLEMESSAGES);
         NOTIFYSTAFFONAFKKIC = config.getBoolean("player.notify-staff-on-afk-kick", NOTIFYSTAFFONAFKKIC);
+        MAXREJOINFORTRACKING = config.getInt("tracking.max-seconds-for-tracking", MAXREJOINFORTRACKING);
     }
 
     public static boolean COUNTDOWNENABLED = false;

src/main/java/com/alttd/afkdectector/config/Messages.java

@@ -19,7 +19,8 @@ public enum Messages {
     AFKCHECKTITLE("afkcheck-title", "AFK CHECK"),
     AFKCHECKSUBTITLE("afkcheck-subtitle", "Please respond to the dm from staff!"),
     AFKCHECKMESSAGE("afkcheck-message", "Hey, since you're near a farm and not moving. I'm making sure you aren't afk. Please respond to me if you're not AFK."),
-    AFKICKSTAFFMESSAGE("afkkick-staff-messsge", "<gold><player> got afk kicked after being marked as afk for <afk_time> minutes.");
+    AFKICKSTAFFMESSAGE("afkkick-staff-messsge", "<gold><player> got afk kicked after being marked as afk for <afk_time> minutes."),
+    SUSPICIOUSKICKCOUNT("afkkick-suspicious-message", "<gold><player> has had <count> suspicious AFK kicks since last reboot.");
 
     public final String key;
     public String message;

src/main/java/com/alttd/afkdectector/trackers/AutoJoinTracker.java

@@ -0,0 +1,26 @@
+package com.alttd.afkdectector.trackers;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public class AutoJoinTracker {
+    private static AutoJoinTracker instance = null;
+
+    public static AutoJoinTracker getInstance() {
+        if (instance == null)
+            instance = new AutoJoinTracker();
+        return instance;
+    }
+
+    Map<UUID, Long> lastKickedMap = new HashMap<>();
+
+    synchronized public void addKick(UUID uuid, long time) {
+        lastKickedMap.put(uuid, time);
+    }
+
+    synchronized public long getLastKick(UUID uuid) {
+        return lastKickedMap.get(uuid);
+    }
+
+}

src/main/java/com/alttd/afkdectector/trackers/SuspiciousKickTracker.java

@@ -0,0 +1,29 @@
+package com.alttd.afkdectector.trackers;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public class SuspiciousKickTracker {
+
+    private static SuspiciousKickTracker instance = null;
+
+    public static SuspiciousKickTracker getInstance() {
+        if (instance == null)
+            instance = new SuspiciousKickTracker();
+        return instance;
+    }
+
+    Map<UUID, Integer> suspiciousKicksCount = new HashMap<>();
+
+    public synchronized void addSuspiciousKick(UUID uuid) {
+        if (suspiciousKicksCount.containsKey(uuid))
+            suspiciousKicksCount.put(uuid, suspiciousKicksCount.get(uuid) + 1);
+        else
+            suspiciousKicksCount.put(uuid, 1);
+    }
+
+    public synchronized int getSuspiciousKickCount(UUID uuid) {
+        return suspiciousKicksCount.getOrDefault(uuid, 0);
+    }
+}