Don't let someone join a party they are already in

velocity/src/main/java/com/alttd/velocitychat/commands/partysubcommands/Join.java

@@ -10,6 +10,7 @@ import com.alttd.velocitychat.VelocityChat;
 import com.alttd.velocitychat.commands.SubCommand;
 import com.velocitypowered.api.command.CommandSource;
 import com.velocitypowered.api.proxy.Player;
+import net.kyori.adventure.text.minimessage.Template;
 import net.kyori.adventure.text.minimessage.placeholder.Placeholder;
 
 import java.util.ArrayList;
@@ -45,6 +46,10 @@ public class Join implements SubCommand {
 
 //      party.addUser(ChatUserManager.getChatUser(player.getUniqueId())); //Removed until we can get nicknames to translate to colors correctly
         ChatUser chatUser = ChatUserManager.getChatUser(player.getUniqueId());
+        if (chatUser.getPartyId() == party.getPartyId()) {
+            source.sendMessage(Utility.parseMiniMessage(Config.ALREADY_IN_THIS_PARTY, Placeholder.miniMessage("party", party.getPartyName())));
+            return;
+        }
         party.addUser(chatUser, player.getUsername());
         source.sendMessage(Utility.parseMiniMessage(Config.JOINED_PARTY, Placeholder.miniMessage("party_name", party.getPartyName())));
         VelocityChat.getPlugin().getChatHandler().sendPartyMessage(party,