feat: extras messaging !!! (unused for now)

src/main/java/me/chayapak1/chomens_bot/Bot.java

@@ -79,6 +79,7 @@ public class Bot extends SessionAdapter {
     public ServerPluginsManagerPlugin serverPluginsManager;
     public SelfCarePlugin selfCare;
     public QueryPlugin query;
+    public ExtrasMessengerPlugin extrasMessenger;
     public CorePlugin core;
     public TeamPlugin team;
     public PlayersPlugin players;
@@ -130,6 +131,7 @@ public class Bot extends SessionAdapter {
         this.serverPluginsManager = new ServerPluginsManagerPlugin(this);
         this.selfCare = new SelfCarePlugin(this);
         this.query = new QueryPlugin(this);
+        this.extrasMessenger = new ExtrasMessengerPlugin(this);
         this.core = new CorePlugin(this);
         this.team = new TeamPlugin(this);
         this.players = new PlayersPlugin(this);

src/main/java/me/chayapak1/chomens_bot/plugins/ExtrasMessengerPlugin.java

@@ -0,0 +1,145 @@
+package me.chayapak1.chomens_bot.plugins;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import me.chayapak1.chomens_bot.Bot;
+import net.kyori.adventure.key.Key;
+import org.geysermc.mcprotocollib.network.Session;
+import org.geysermc.mcprotocollib.network.event.session.ConnectedEvent;
+import org.geysermc.mcprotocollib.network.packet.Packet;
+import org.geysermc.mcprotocollib.protocol.packet.common.clientbound.ClientboundCustomPayloadPacket;
+import org.geysermc.mcprotocollib.protocol.packet.common.serverbound.ServerboundCustomPayloadPacket;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class ExtrasMessengerPlugin extends Bot.Listener {
+    private static final Key EXTRAS_REGISTER_KEY = Key.key("extras", "register");
+    private static final Key EXTRAS_UNREGISTER_KEY = Key.key("extras", "unregister");
+    private static final Key EXTRAS_MESSAGE_KEY = Key.key("extras", "message");
+
+    private final List<Listener> listeners = new ArrayList<>();
+
+    private final Bot bot;
+
+    private final String chomens_namespace;
+
+    public ExtrasMessengerPlugin (Bot bot) {
+        this.bot = bot;
+        this.chomens_namespace = bot.config.namespace + "_"; // Ex. chomens_bot_ (then it will be appended by channel)
+
+        bot.addListener(this);
+    }
+
+    @Override
+    public void connected (ConnectedEvent event) {
+        // TODO: don't register these things on connected but on the
+        //       custom payload packet instead so it only registers
+        //       for servers that support this
+        final List<String> channels = new ArrayList<>();
+
+        channels.add(EXTRAS_REGISTER_KEY.asString());
+        channels.add(EXTRAS_UNREGISTER_KEY.asString());
+        channels.add(EXTRAS_MESSAGE_KEY.asString());
+
+        bot.session.send(
+                new ServerboundCustomPayloadPacket(
+                        Key.key("minecraft", "register"),
+                        String.join("\u0000", channels).getBytes(StandardCharsets.UTF_8)
+                )
+        );
+    }
+
+    @Override
+    public void packetReceived (Session session, Packet packet) {
+        if (packet instanceof ClientboundCustomPayloadPacket t_packet) packetReceived(t_packet);
+    }
+
+    public void packetReceived (ClientboundCustomPayloadPacket packet) {
+        final Key packetChannel = packet.getChannel();
+
+        if (!packetChannel.equals(EXTRAS_MESSAGE_KEY)) return;
+
+        final ByteBuf buf = Unpooled.wrappedBuffer(packet.getData());
+
+        final String channelName = readString(buf);
+
+        if (!channelName.startsWith(chomens_namespace)) return;
+
+        final UUID uuid = readUUID(buf);
+
+        final byte[] data = readByteArrayToEnd(buf);
+
+        for (Listener listener : listeners) listener.onMessage(uuid, data);
+    }
+
+    public void sendPayload (String name, byte[] data) {
+        final ByteBuf buf = Unpooled.buffer();
+
+        writeString(buf, chomens_namespace + name);
+        buf.writeBytes(data);
+
+        final byte[] byteArray = readByteArrayToEnd(buf);
+
+        bot.session.send(
+                new ServerboundCustomPayloadPacket(
+                        EXTRAS_MESSAGE_KEY,
+                        byteArray
+                )
+        );
+    }
+
+    // TODO: automatically register the already registered channels on reconnect
+    public void registerChannel (String channel) {
+        final ByteBuf buf = Unpooled.buffer();
+
+        writeString(buf, chomens_namespace + channel);
+
+        bot.session.send(
+                new ServerboundCustomPayloadPacket(
+                        EXTRAS_REGISTER_KEY,
+                        readByteArrayToEnd(buf)
+                )
+        );
+    }
+
+    private void writeString (ByteBuf input, String string) {
+        final byte[] bytesString = string.getBytes(StandardCharsets.US_ASCII);
+
+        input.writeByte(bytesString.length);
+        input.writeBytes(bytesString);
+    }
+
+    private String readString (ByteBuf input) {
+        final int length = input.readUnsignedByte();
+
+        final byte[] buf = new byte[length];
+
+        input.readBytes(buf);
+
+        return new String(buf, StandardCharsets.US_ASCII);
+    }
+
+    private UUID readUUID (ByteBuf input) {
+        final long mostSignificant = input.readLong();
+        final long leastSignificant = input.readLong();
+
+        return new UUID(mostSignificant, leastSignificant);
+    }
+
+    private byte[] readByteArrayToEnd (ByteBuf input) {
+        final byte[] bytes = new byte[input.readableBytes()];
+
+        input.readBytes(bytes);
+
+        return bytes;
+    }
+
+    public void addListener (Listener listener) { listeners.add(listener); }
+
+    public static class Listener {
+        public void onMessage (UUID sender, byte[] message) {}
+    }
+}