package com.inspect.tcpserver.tcp;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import org.apache.commons.lang3.RandomStringUtils;
import org.apache.tomcat.util.buf.HexUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

public class MyDecoder extends ByteToMessageDecoder {

    private static final Logger log = LoggerFactory.getLogger(MyDecoder.class);
    private final String PACKET_FLAG = "EB90";

    private final int BASE_LENGTH = 2 + 8 + 8 + 1 + 4 + 2;

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        if (in.readableBytes() >= BASE_LENGTH) {
            try {
                //skip
                if (in.readableBytes() > 512 * 1024) {
                    in.skipBytes(in.readableBytes());
                }

                final String uuid = RandomStringUtils.randomAlphanumeric(32);
                ByteBuf forPrint = in.copy();
                log.info("################ 会话: {}, 客户: {}, 上行原始报文 ################ \n {}", uuid, ctx.channel().id().asShortText(), ByteBufUtil.hexDump(forPrint));

                int index;
                String flag;
                while (true) {
                    index = in.readerIndex();
                    in.markReaderIndex();
                    byte[] dst = new byte[2];
                    in.readBytes(dst, 0, 2);
                    flag = ByteUtils.byte2Hex(dst);
                    if (PACKET_FLAG.equalsIgnoreCase(flag)) {
                        break;
                    }
                    in.resetReaderIndex();
                    if (in.readableBytes() < BASE_LENGTH) {
                        return;
                    }
                }
                long sendIndex = in.readLongLE();
                long receiveIndex = in.readLongLE();
                byte sourceFlag = in.readByte();
                int xmlLength = in.readIntLE();
                if (in.readableBytes() < xmlLength) {
                    in.readerIndex(index);
                    return;
                }
                byte[] payload = new byte[xmlLength];
                in.readBytes(payload);
                in.readShortLE();
                BinaryModel binaryModel = new BinaryModel();
                binaryModel.receiveIndex = receiveIndex;
                binaryModel.sendIndex = sendIndex;
                binaryModel.sourceFlag = sourceFlag;
                binaryModel.dataLength = xmlLength;
                binaryModel.dataBuf = Unpooled.copiedBuffer(payload);
                binaryModel.uuid = uuid;
                out.add(binaryModel);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}