/**
 * Sends a plugin message.
 *
 * Example usage using the "GetServers" bungee plugin message channel via an overload:
 * <code>
 *     Utils.sendPluginMessage("BungeeCord", r -> "GetServers".equals(r.readUTF()), "GetServers")
 *     			.thenAccept(response -> Bukkit.broadcastMessage(response.readUTF()) // comma delimited server broadcast
 *     			.exceptionally(ex -> {
 *     			 	Skript.warning("Failed to get servers because there are no players online");
 *     			 	return null;
 *     			});
 * </code>
 *
 * @param player the player to send the plugin message through
 * @param channel the channel for this plugin message
 * @param messageVerifier verifies that a plugin message is the response to the sent message
 * @param data the data to add to the outgoing message
 * @return a completable future for the message of the responding plugin message, if there is one.
 * this completable future will complete exceptionally if the player is null.
 */
public static CompletableFuture<ByteArrayDataInput> sendPluginMessage(Player player, String channel,
		Predicate<ByteArrayDataInput> messageVerifier, String... data) {
	CompletableFuture<ByteArrayDataInput> completableFuture = new CompletableFuture<>();

	if (player == null) {
		completableFuture.completeExceptionally(new IllegalStateException("Can't send plugin messages from a null player"));
		return completableFuture;
	}

	Skript skript = Skript.getInstance();
	Messenger messenger = Bukkit.getMessenger();

	messenger.registerOutgoingPluginChannel(skript, channel);

	PluginMessageListener listener = (sendingChannel, sendingPlayer, message) -> {
		ByteArrayDataInput input = ByteStreams.newDataInput(message);
		if (channel.equals(sendingChannel) && sendingPlayer == player && !completableFuture.isDone()
				&& !completableFuture.isCancelled() && messageVerifier.test(input)) {
			completableFuture.complete(input);
		}
	};

	messenger.registerIncomingPluginChannel(skript, channel, listener);

	completableFuture.whenComplete((r, ex) -> messenger.unregisterIncomingPluginChannel(skript, channel, listener));

	// if we haven't gotten a response after a minute, let's just assume there wil never be one
	Bukkit.getScheduler().scheduleSyncDelayedTask(skript, () -> {

		if (!completableFuture.isDone())
			completableFuture.cancel(true);

	}, 60 * 20);

	ByteArrayDataOutput out = ByteStreams.newDataOutput();
	Stream.of(data).forEach(out::writeUTF);
	player.sendPluginMessage(Skript.getInstance(), channel, out.toByteArray());

	return completableFuture;
}
 

/**
 * Registers the incoming channel for a certain {@link PluginMessageListener}
 */
public void registerIncomingChannel(final PluginMessageListener listener)
{
    Bukkit.getMessenger().registerIncomingPluginChannel(AACAdditionPro.getInstance(), this.getChannel(), listener);
}
 

/**
 * Unregisters the incoming channel for a certain {@link PluginMessageListener}
 */
public void unregisterIncomingChannel(final PluginMessageListener listener)
{
    Bukkit.getMessenger().unregisterIncomingPluginChannel(AACAdditionPro.getInstance(), this.getChannel(), listener);
}