GH-939 Fix /tprp command often teleports to the same player repeatedly (#941)

* GH-939 Fix `/tprp` command often teleports to the same player repeatedly

* Code review

* Code review

* Follow review.

* Fix

---------

Co-authored-by: Rollczi <[email protected]>

Author: vLuckyyy

eternalcore-core/src/main/java/com/eternalcode/core/feature/teleport/command/TeleportToRandomPlayerCommand.java

@@ -0,0 +1,54 @@
+package com.eternalcode.core.feature.teleportrandomplayer;
+
+import com.eternalcode.core.configuration.implementation.PluginConfiguration;
+import com.eternalcode.core.injector.annotations.Inject;
+import com.eternalcode.core.injector.annotations.component.Service;
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import java.util.concurrent.TimeUnit;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+
+import java.time.Instant;
+import java.util.Comparator;
+import java.util.UUID;
+import org.jetbrains.annotations.Nullable;
+
+@Service
+public class TeleportRandomPlayerService {
+
+    private final Server server;
+    private final PluginConfiguration pluginConfiguration;
+
+    private final Cache<HistoryKey, Instant> teleportationHistory = Caffeine.newBuilder()
+        .expireAfterWrite(30, TimeUnit.MINUTES)
+        .build();
+
+    @Inject
+    public TeleportRandomPlayerService(Server server, PluginConfiguration pluginConfiguration) {
+        this.server = server;
+        this.pluginConfiguration = pluginConfiguration;
+    }
+
+    @Nullable
+    public Player findLeastRecentlyTeleportedPlayer(Player sender) {
+        UUID senderId = sender.getUniqueId();
+        return this.server.getOnlinePlayers().stream()
+            .filter(target -> !target.equals(sender))
+            .filter(target -> this.pluginConfiguration.teleport.includeOpPlayersInRandomTeleport || !target.isOp())
+            .min(Comparator.comparing(target -> this.getTeleportationHistory(target, senderId)))
+            .orElse(null);
+    }
+
+    private Instant getTeleportationHistory(Player target, UUID senderId) {
+        return this.teleportationHistory.get(new HistoryKey(senderId, target.getUniqueId()), key -> Instant.EPOCH);
+    }
+
+    public void updateTeleportationHistory(Player sender, Player target) {
+        this.teleportationHistory.put(new HistoryKey(sender.getUniqueId(), target.getUniqueId()), Instant.now());
+    }
+
+    private record HistoryKey(UUID sender, UUID target) {
+    }
+
+} 

eternalcore-core/src/main/java/com/eternalcode/core/feature/teleportrandomplayer/TeleportRandomPlayerService.java

@@ -0,0 +1,59 @@
+package com.eternalcode.core.feature.teleportrandomplayer;
+
+import com.eternalcode.annotations.scan.command.DescriptionDocs;
+import com.eternalcode.core.injector.annotations.Inject;
+import com.eternalcode.core.notice.NoticeService;
+import dev.rollczi.litecommands.annotations.command.Command;
+import dev.rollczi.litecommands.annotations.context.Context;
+import dev.rollczi.litecommands.annotations.execute.Execute;
+import dev.rollczi.litecommands.annotations.permission.Permission;
+import org.bukkit.entity.Player;
+
+@Command(name = "teleportorandomplayer", aliases = {"tprp"})
+@Permission("eternalcode.tprp")
+public class TeleportToRandomPlayerCommand {
+
+    private final TeleportRandomPlayerService teleportRandomPlayerService;
+    private final NoticeService noticeService;
+
+    @Inject
+    public TeleportToRandomPlayerCommand(
+        TeleportRandomPlayerService teleportRandomPlayerService,
+        NoticeService noticeService
+    ) {
+        this.teleportRandomPlayerService = teleportRandomPlayerService;
+        this.noticeService = noticeService;
+    }
+
+    @Execute
+    @DescriptionDocs(description = "Teleport to a player who hasn't been teleported to recently, ensuring fair distribution")
+    void execute(@Context Player player) {
+        Player targetPlayer = this.teleportRandomPlayerService.findLeastRecentlyTeleportedPlayer(player);
+
+        if (targetPlayer != null && targetPlayer.equals(player)) {
+            this.noticeService.create()
+                .player(player.getUniqueId())
+                .notice(translation -> translation.teleport().randomPlayerNotFound())
+                .send();
+            return;
+        }
+
+        if (targetPlayer == null) {
+            this.noticeService.create()
+                .player(player.getUniqueId())
+                .notice(translation -> translation.teleport().randomPlayerNotFound())
+                .send();
+            return;
+        }
+
+        this.teleportRandomPlayerService.updateTeleportationHistory(targetPlayer, player);
+
+        player.teleport(targetPlayer);
+
+        this.noticeService.create()
+            .player(player.getUniqueId())
+            .notice(translation -> translation.teleport().teleportedToRandomPlayer())
+            .placeholder("{PLAYER}", targetPlayer.getName())
+            .send();
+    }
+}