ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/ping/ServerPingRecord.java

package com.comphenix.protocol.wrappers.ping;

import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.Semaphore;

import com.comphenix.protocol.events.InternalStructure;
import com.comphenix.protocol.reflect.EquivalentConverter;
import com.comphenix.protocol.reflect.StructureModifier;
import com.comphenix.protocol.reflect.accessors.Accessors;
import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
import com.comphenix.protocol.utility.MinecraftProtocolVersion;
import com.comphenix.protocol.utility.MinecraftReflection;
import com.comphenix.protocol.utility.MinecraftVersion;
import com.comphenix.protocol.wrappers.*;

import com.google.common.collect.ImmutableList;
import org.bukkit.Bukkit;

public final class ServerPingRecord implements ServerPingImpl {
	private static Class<?> SERVER_PING;
	private static Class<?> PLAYER_SAMPLE_CLASS;
	private static Class<?> SERVER_DATA_CLASS;

	private static WrappedChatComponent DEFAULT_DESCRIPTION;

	private static ConstructorAccessor PING_CTOR;

	private static EquivalentConverter<List<WrappedGameProfile>> PROFILE_LIST_CONVERTER;

	private static boolean initialized = false;
	private static final Object lock = new Object();

	private static void initialize() {
		if (initialized) {
			return;
		}

		synchronized (lock) {
			// may have been initialized while waiting for the lock
			if (initialized) {
				return;
			}

			try {
				SERVER_PING = MinecraftReflection.getServerPingClass();
				PLAYER_SAMPLE_CLASS = MinecraftReflection.getServerPingPlayerSampleClass();
				SERVER_DATA_CLASS = MinecraftReflection.getServerPingServerDataClass();

				PING_CTOR = Accessors.getConstructorAccessor(SERVER_PING.getConstructors()[0]);

				DATA_WRAPPER = AutoWrapper.wrap(ServerData.class, SERVER_DATA_CLASS);
				SAMPLE_WRAPPER = AutoWrapper.wrap(PlayerSample.class, PLAYER_SAMPLE_CLASS);
				FAVICON_WRAPPER = AutoWrapper.wrap(Favicon.class, MinecraftReflection.getMinecraftClass("network.protocol.status.ServerPing$a"));

				PROFILE_LIST_CONVERTER = BukkitConverters.getListConverter(BukkitConverters.getWrappedGameProfileConverter());

				DEFAULT_DESCRIPTION = WrappedChatComponent.fromLegacyText("A Minecraft Server");
			} catch (Exception ex) {
				throw new RuntimeException("Failed to initialize Server Ping", ex);
			} finally {
				initialized = true;
			}
		}
	}

	public static final class PlayerSample {
		public int max;
		public int online;
		public Object sample;

		public PlayerSample(int max, int online, Object sample) {
			this.max = max;
			this.online = online;
			this.sample = sample;
		}

		public PlayerSample() {
			this(0, 0, null);
		}
	}

	public static final class ServerData {
		public String name;
		public int protocol;

		public ServerData(String name, int protocol) {
			this.name = name;
			this.protocol = protocol;
		}

		public ServerData() {
			this("", 0);
		}
	}

	static final byte[] EMPTY_FAVICON = new byte[0];

	public static final class Favicon {
		public byte[] iconBytes;

		public Favicon(byte[] iconBytes) {
			this.iconBytes = iconBytes;
		}

		public Favicon() {
			this(EMPTY_FAVICON);
		}
	}

	private static AutoWrapper<PlayerSample> SAMPLE_WRAPPER;

	private static AutoWrapper<ServerData> DATA_WRAPPER;

	private static AutoWrapper<Favicon> FAVICON_WRAPPER;

	private WrappedChatComponent description;
	private PlayerSample playerSample;
	private ServerData serverData;
	private Favicon favicon;
	private boolean enforceSafeChat;
	private boolean playersVisible = true;

	private static ServerData defaultData() {
		String name = MinecraftVersion.getCurrentVersion().toString();
		int protocol = MinecraftProtocolVersion.getCurrentVersion();

		return new ServerData(name, protocol);
	}

	private static PlayerSample defaultSample() {
		int max = Bukkit.getMaxPlayers();
		int online = Bukkit.getOnlinePlayers().size();

		return new PlayerSample(max, online, null);
	}

	private static Favicon defaultFavicon() {
		return new Favicon();
	}

	public ServerPingRecord(Object handle) {
		initialize();

		StructureModifier<Object> modifier = new StructureModifier<>(handle.getClass()).withTarget(handle);
		InternalStructure structure = new InternalStructure(handle, modifier);

		this.description = structure.getChatComponents().readSafely(0);

		StructureModifier<Optional<Object>> optionals = structure.getOptionals(Converters.passthrough(Object.class));

		Optional<Object> sampleHandle = optionals.readSafely(0);
		this.playerSample = sampleHandle.isPresent() ? SAMPLE_WRAPPER.wrap(sampleHandle.get()) : defaultSample();

		Optional<Object> dataHandle = optionals.readSafely(1);
		this.serverData = dataHandle.isPresent() ? DATA_WRAPPER.wrap(dataHandle.get()) : defaultData();

		Optional<Object> faviconHandle = optionals.readSafely(2);
		this.favicon = faviconHandle.isPresent() ? FAVICON_WRAPPER.wrap(faviconHandle.get()) : defaultFavicon();

		this.enforceSafeChat = structure.getBooleans().readSafely(0);
	}

	public ServerPingRecord() {
		initialize();

		this.description = DEFAULT_DESCRIPTION;
		this.playerSample = defaultSample();
		this.serverData = defaultData();
		this.favicon = defaultFavicon();
	}

	@Override
	public WrappedChatComponent getMotD() {
		return description;
	}

	@Override
	public void setMotD(WrappedChatComponent description) {
		this.description = description;
	}

	@Override
	public int getPlayersMaximum() {
		return playerSample.max;
	}

	@Override
	public void setPlayersMaximum(int maxPlayers) {
		playerSample.max = maxPlayers;
	}

	@Override
	public int getPlayersOnline() {
		return playerSample.online;
	}

	@Override
	public void setPlayersOnline(int onlineCount) {
		playerSample.online = onlineCount;
	}

	@Override
	public ImmutableList<WrappedGameProfile> getPlayers() {
		if (playerSample.sample == null) {
			return ImmutableList.of();
		}

		List<WrappedGameProfile> list = PROFILE_LIST_CONVERTER.getSpecific(playerSample.sample);
		if (list == null) {
			return ImmutableList.of();
		}

		return ImmutableList.copyOf(list);
	}

	@Override
	public void setPlayers(Iterable<? extends WrappedGameProfile> playerSample) {
		if (playerSample == null) {
			this.playerSample.sample = null;
			return;
		}

		List<WrappedGameProfile> list = Converters.toList(playerSample);
		this.playerSample.sample = PROFILE_LIST_CONVERTER.getGeneric(list);
	}

	@Override
	public String getVersionName() {
		return serverData.name;
	}

	@Override
	public void setVersionName(String versionName) {
		serverData.name = versionName;
	}

	@Override
	public int getVersionProtocol() {
		return serverData.protocol;
	}

	@Override
	public void setVersionProtocol(int protocolVersion) {
		serverData.protocol = protocolVersion;
	}

	@Override
	public String getFavicon() {
		return new String(favicon.iconBytes, StandardCharsets.UTF_8);
	}

	@Override
	public void setFavicon(String favicon) {
		this.favicon.iconBytes = favicon.getBytes(StandardCharsets.UTF_8);
	}

	@Override
	public boolean isEnforceSecureChat() {
		return enforceSafeChat;
	}

	@Override
	public void setEnforceSecureChat(boolean safeChat) {
		this.enforceSafeChat = safeChat;
	}

	@Override
	public void resetPlayers() {
		this.playerSample = defaultSample();
	}

	@Override
	public void resetVersion() {
		this.serverData = defaultData();
	}

	@Override
	public boolean arePlayersVisible() {
		return playersVisible;
	}

	@Override
	public void setPlayersVisible(boolean visible) {
		this.playersVisible = visible;
	}

	@Override
	public Object getHandle() {
		WrappedChatComponent wrappedDescription = description != null ? description : DEFAULT_DESCRIPTION;
		Object descHandle = wrappedDescription.getHandle();

		Optional<Object> playersHandle = Optional.ofNullable(playerSample != null ? SAMPLE_WRAPPER.unwrap(playerSample) : null);
		Optional<Object> versionHandle = Optional.ofNullable(serverData != null ? DATA_WRAPPER.unwrap(serverData) : null);
		Optional<Object> favHandle = Optional.ofNullable(favicon != null ? FAVICON_WRAPPER.unwrap(favicon) : null);

		return PING_CTOR.invoke(descHandle, playersHandle, versionHandle, favHandle, enforceSafeChat);
	}
}