// Package hello
// @Author: Wang Feng
// @Description:
// @Version: 0.1.0
// @Date: 2022/7/14 22:01
// @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
//

package hello

import (
	common2 "minlib/common"
	"minlib/component"
	"minlib/packet"
	"mlsr/lsa"
	"time"
	"unsafe"
)

//
// @Description: 从管道读取并处理一个MIN包
// @receiver v
// @return error
//
func (v *HelloProtocol) dealWithRecvPkt(interest *packet.Interest) error {
	// 取出兴趣包倒数第二个组件，对其进行校验
	infoComponent, err := interest.GetName().Get(-2)
	if err != nil {
		common2.LogDebug("HelloProtocol deal with interest error, get(-2) err ", err)
		return err
	}
	if infoComponent.ToUri() != INFO_COMPONENT {
		common2.LogDebug("HelloProtocol deal with interest error, INFO_COMPONENT not found or interestName ", err)
		return err
	}
	// 取出兴趣包最后一个组件，其为该兴趣包所包含的RouterPrefix信息。
	prefixComponent, err := interest.GetName().Get(-1)
	if err != nil {
		common2.LogDebug("HelloProtocol deal with interest error, get(-1) err", err)
		return err
	}
	routerPrefix, err := GetRawPrefixForHelloProtocol(prefixComponent.ToUri())
	if err != nil {
		common2.LogDebug("HelloProtocol deal with interest error, GetRawPrefixForHelloProtocol err ", err)
		return err
	}
	routerIdentifier, err := component.CreateIdentifierByString(routerPrefix)
	if err != nil {
		common2.LogDebug("HelloProtocol deal with interest error, create identifier from prefix err ", err)
		return err
	}
	if v.m_adjacencyList.IsNeighbor(routerIdentifier) {
		// 构造Data，以向兴趣包做应答
		data := packet.NewData()
		// data name: /<neighbor>/NLSR/INFO/<router>/<version>
		dataName := interest.GetName()
		dataName.AppendVersionNumber(uint64(time.Now().UnixMilli()))
		data.SetName(dataName)
		data.SetFreshnessPeriod(10 * 1000)
		data.Payload.SetValue([]byte(INFO_COMPONENT))

		// todo 安全性：对该data包进行签名

		// 使用face对兴趣包进行响应
		err = v.m_face.SendData(data)
		if err != nil {
			common2.LogDebug("HelloProtocol deal with interest error, send data error ", err)
			return err
		}

		// 找到该邻接路由器的状态信息
		adjInfo := v.m_adjacencyList.FindAdjacencyByRouterIdentifier(routerIdentifier)
		// 如果该路由器状态在本机这里被记为未激活，则向其发送hello包，来确认其已激活
		if adjInfo.Status == lsa.STATUS_INACTIVE {
			// interest name: /<neighbor>/NLSR/INFO/<router>
			name, err := component.CreateIdentifierByString(routerPrefix +
				"/" + MLSR_COMPONENT + "/" + INFO_COMPONENT +
				"/" + GetSinglePrefixForHelloProtocol(v.mlsrConfig.GetRouterPrefix()))
			if err != nil {
				common2.LogDebug("HelloProtocol deal with interest error, hello name create wrong.")
				return err
			}
			// 将data发出去
			v.expressInterest(name, v.mlsrConfig.GetInterestResendTime())
		}
	}

	return nil
}

func stringToBytes(str string) []byte {
	return *(*[]byte)(unsafe.Pointer(&str))
}

func byteToString(bytes []byte) string {
	return *(*string)(unsafe.Pointer(&bytes))
}