VIAaaS/src/main/kotlin/com/viaversion/aas/handler/ViaCodec.kt

package com.viaversion.aas.handler

import com.viaversion.viaversion.api.connection.UserConnection
import com.viaversion.viaversion.exception.CancelDecoderException
import com.viaversion.viaversion.exception.CancelEncoderException
import io.netty.buffer.ByteBuf
import io.netty.channel.ChannelHandlerContext
import io.netty.handler.codec.MessageToMessageCodec

class ViaCodec(val info: UserConnection) : MessageToMessageCodec<ByteBuf, ByteBuf>() {
    override fun decode(ctx: ChannelHandlerContext, bytebuf: ByteBuf, out: MutableList<Any>) {
        if (!ctx.channel().isActive) return
        if (!info.checkClientboundPacket()) throw CancelDecoderException.generate(null)
        if (!info.shouldTransformPacket()) {
            out.add(bytebuf.retain())
            return
        }
        val transformedBuf: ByteBuf = ctx.alloc().buffer().writeBytes(bytebuf)
        try {
            info.transformClientbound(transformedBuf, CancelDecoderException::generate)
            out.add(transformedBuf.retain())
        } finally {
            transformedBuf.release()
        }
    }

    override fun encode(ctx: ChannelHandlerContext, bytebuf: ByteBuf, out: MutableList<Any>) {
        if (!ctx.channel().isActive) throw CancelEncoderException.CACHED
        if (!info.checkServerboundPacket()) throw CancelEncoderException.generate(null)
        if (!info.shouldTransformPacket()) {
            out.add(bytebuf.retain())
            return
        }
        val transformedBuf: ByteBuf = ctx.alloc().buffer().writeBytes(bytebuf)
        try {
            info.transformServerbound(transformedBuf, CancelEncoderException::generate)
            out.add(transformedBuf.retain())
        } finally {
            transformedBuf.release()
        }
    }
}