HandshakeDecoder.java

package net.scapeemulator.game.net.handshake;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundByteHandlerAdapter;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;

import java.io.IOException;
import java.nio.charset.StandardCharsets;

import net.scapeemulator.game.net.auto.AutoLoginDecoder;
import net.scapeemulator.game.net.jaggrab.JaggrabDecoder;
import net.scapeemulator.game.net.jaggrab.JaggrabEncoder;
import net.scapeemulator.game.net.login.LoginDecoder;
import net.scapeemulator.game.net.login.LoginEncoder;
import net.scapeemulator.game.net.register.RegisterDecoder;
import net.scapeemulator.game.net.register.RegisterEncoder;
import net.scapeemulator.game.net.update.FileResponseEncoder;
import net.scapeemulator.game.net.update.UpdateDecoder;
import net.scapeemulator.game.net.update.UpdateStatusMessageEncoder;
import net.scapeemulator.game.net.update.XorEncoder;
import net.scapeemulator.game.net.world.WorldListDecoder;
import net.scapeemulator.game.net.world.WorldListEncoder;

public final class HandshakeDecoder extends ChannelInboundByteHandlerAdapter {

    @Override
    public void inboundBufferUpdated(ChannelHandlerContext ctx, ByteBuf buf) throws IOException {
        if (!buf.isReadable())
            return;

        int service = buf.readUnsignedByte();

        ByteBuf additionalBuf = null;
        if (buf.isReadable()) {
            additionalBuf = buf.readBytes(buf.readableBytes());
        }

        ChannelPipeline pipeline = ctx.pipeline();
        pipeline.remove(HandshakeDecoder.class);

        switch (service) {
        case HandshakeMessage.SERVICE_LOGIN:
            pipeline.addFirst(
                    new LoginEncoder(),
                    new LoginDecoder());
            break;

        case HandshakeMessage.SERVICE_UPDATE:
            pipeline.addFirst(
                    new FileResponseEncoder(),
                    new UpdateStatusMessageEncoder(),
                    new XorEncoder(),
                    new UpdateDecoder());
            break;

        case HandshakeMessage.SERVICE_JAGGRAB:
            pipeline.addFirst(
                    new JaggrabEncoder(), // Dummy encoder here because it wasn't working for some reason without it
                    new DelimiterBasedFrameDecoder(1024, Delimiters.lineDelimiter()),
                    new StringDecoder(StandardCharsets.US_ASCII),
                    new JaggrabDecoder());
            break;

        case HandshakeMessage.SERVICE_REGISTER_PERSONAL_DETAILS:
        case HandshakeMessage.SERVICE_REGISTER_USERNAME:
        case HandshakeMessage.SERVICE_REGISTER_COMMIT:
            pipeline.addFirst(
                    new RegisterEncoder(),
                    new RegisterDecoder(service));
            break;

        case HandshakeMessage.SERVICE_AUTO_LOGIN:
            pipeline.addFirst(
                    new LoginEncoder(),
                    new AutoLoginDecoder());
            break;

        case HandshakeMessage.SERVICE_WORLD_LIST:
            pipeline.addFirst(
                    new WorldListEncoder(),
                    new WorldListDecoder());
            break;

        default:
            throw new IOException("Invalid service id: " + service + ".");
        }

        ctx.nextInboundMessageBuffer().add(new HandshakeMessage(service));
        ctx.fireInboundBufferUpdated();

        if (additionalBuf != null) {
            ChannelHandlerContext head = ctx.pipeline().firstContext();
            head.nextInboundByteBuffer().writeBytes(additionalBuf);
            head.fireInboundBufferUpdated();
        }
    }

}