package component;

import encoding.*;

/*
 * @Author: Wang Feng
 * @Description:
 * @Version: 1.0.0
 * @Date: 16:38 2021/3/9
 * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
 */
public class HopLimit implements TlvComponentBase,InitialAble, IEncodingAble {
    // 成员变量
    private long hopLimit;

    // 成员函数
    public long getHopLimit() {
        return hopLimit;
    }

    public void setHopLimit(long hopLimit) {
        this.hopLimit = hopLimit;
        this.doInitial();
    }

    // 接口实现-变量区
    private boolean initial=false;

    // 接口实现-方法区
    @Override
    public void doInitial() {
        initial=true;
    }

    @Override
    public boolean isInitial() {
        return initial;
    }

    /**
     *
     * @param encoder
     * @return
     */
    @Override
    public int wireEncode(Encoder encoder) throws EncoderException {
        int totalLength=0;

        // 编码 TLV-VALUE
        int tmplen=encoder.prependNonNegativeInteger(this.hopLimit);
        if(tmplen<=0){
            return -1;
        }
        totalLength+=tmplen;

        // 编码 TLV-LENGTH
        tmplen+=encoder.prependVarNumber(new VlInt(totalLength));
        if(tmplen<=0){
            return -1;
        }
        totalLength+=tmplen;

        // 编码 TLV-TYPE
        tmplen+=encoder.prependVarNumber(new VlInt(TLV.TlvHopLimit));
        if(tmplen<=0){
            return -1;
        }
        totalLength+=tmplen;

        return totalLength;
    }

    @Override
    public boolean wireDecode(Block block) throws VlIntException {
        // 检查 Type 是否正确
        if(!TLV.expectType(block.getType(),new VlInt(TLV.TlvHopLimit))){
            return false;
        }

        // 读取 HopLimit
        long value= 0;
        value = TLV.readNonNegativeInteger(block.getValue(),0,block.getLength().getVlIntValue2Int());
        if(value<0){
            return false;
        }
        this.setHopLimit(value);

        return true;
    }
}