package net.minecraft.server.network;

import com.mojang.logging.LogUtils;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.net.SocketAddress;
import java.util.Locale;
import net.minecraft.server.ServerInfo;
import org.slf4j.Logger;

public class LegacyQueryHandler extends ChannelInboundHandlerAdapter {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final ServerInfo server;

	public LegacyQueryHandler(final ServerInfo server) {
		this.server = server;
	}

	@Override
	public void channelRead(final ChannelHandlerContext ctx, final Object msg) {
		ByteBuf in = (ByteBuf)msg;
		in.markReaderIndex();
		boolean connectNormally = true;

		try {
			try {
				if (in.readUnsignedByte() != 254) {
					return;
				}

				SocketAddress socket = ctx.channel().remoteAddress();
				int length = in.readableBytes();
				if (length == 0) {
					LOGGER.debug("Ping: (<1.3.x) from {}", socket);
					String body = createVersion0Response(this.server);
					sendFlushAndClose(ctx, createLegacyDisconnectPacket(ctx.alloc(), body));
				} else {
					if (in.readUnsignedByte() != 1) {
						return;
					}

					if (in.isReadable()) {
						if (!readCustomPayloadPacket(in)) {
							return;
						}

						LOGGER.debug("Ping: (1.6) from {}", socket);
					} else {
						LOGGER.debug("Ping: (1.4-1.5.x) from {}", socket);
					}

					String body = createVersion1Response(this.server);
					sendFlushAndClose(ctx, createLegacyDisconnectPacket(ctx.alloc(), body));
				}

				in.release();
				connectNormally = false;
			} catch (RuntimeException var11) {
			}
		} finally {
			if (connectNormally) {
				in.resetReaderIndex();
				ctx.channel().pipeline().remove(this);
				ctx.fireChannelRead(msg);
			}
		}
	}

	private static boolean readCustomPayloadPacket(final ByteBuf in) {
		short packetId = in.readUnsignedByte();
		if (packetId != 250) {
			return false;
		} else {
			String channelId = LegacyProtocolUtils.readLegacyString(in);
			if (!"MC|PingHost".equals(channelId)) {
				return false;
			} else {
				int payloadSize = in.readUnsignedShort();
				if (in.readableBytes() != payloadSize) {
					return false;
				} else {
					short protocolVersion = in.readUnsignedByte();
					if (protocolVersion < 73) {
						return false;
					} else {
						String host = LegacyProtocolUtils.readLegacyString(in);
						int port = in.readInt();
						return port <= 65535;
					}
				}
			}
		}
	}

	private static String createVersion0Response(final ServerInfo server) {
		return String.format(Locale.ROOT, "%s§%d§%d", server.getMotd(), server.getPlayerCount(), server.getMaxPlayers());
	}

	private static String createVersion1Response(final ServerInfo server) {
		return String.format(
			Locale.ROOT, "§1\u0000%d\u0000%s\u0000%s\u0000%d\u0000%d", 127, server.getServerVersion(), server.getMotd(), server.getPlayerCount(), server.getMaxPlayers()
		);
	}

	private static void sendFlushAndClose(final ChannelHandlerContext ctx, final ByteBuf out) {
		ctx.pipeline().firstContext().writeAndFlush(out).addListener(ChannelFutureListener.CLOSE);
	}

	private static ByteBuf createLegacyDisconnectPacket(final ByteBufAllocator alloc, final String reason) {
		ByteBuf out = alloc.buffer();
		out.writeByte(255);
		LegacyProtocolUtils.writeLegacyString(out, reason);
		return out;
	}
}