package util

import (
	"bytes"
	"errors"
	"net"
	"strconv"
)

// 获取本机网卡IP
func GetLocalIP(networkName string) (ipv4 string,mask string, err error) {
	interfaces, err := net.Interfaces()
	if err != nil {
		return "","", err
	}

	for _, i := range interfaces {
		byName, err := net.InterfaceByName(i.Name)
		if err != nil {
			return "","", err
		}
		addresses, err := byName.Addrs()
		for _, v := range addresses {
			if ipnet, ok:=v.(*net.IPNet);ok && !ipnet.IP.IsLoopback(){
				if ipnet.IP.To4() !=nil{
					if byName.Name == networkName{
						maskStr := ipnet.Mask.String()
						mask64, _ := strconv.ParseUint(maskStr, 16, 32)
						return ipnet.IP.String(),IpIntToString(int(mask64)),nil
					}
				}
			}
		}
	}
	return "","", errors.New("ipv4 not found")
}

func IpIntToString(ipInt int) string{
	ipSegs := make([]string, 4)
	var len int = len(ipSegs)
	buffer := bytes.NewBufferString("")
	for i := 0; i < len; i++ {
		tempInt := ipInt & 0xFF
		ipSegs[len-i-1] = strconv.Itoa(tempInt)

		ipInt = ipInt >> 8
	}
	for i := 0; i < len; i++ {
		buffer.WriteString(ipSegs[i])
		if i < len-1 {
			buffer.WriteString(".")
		}
	}
	return buffer.String()
}