package iface

import (
	"log"
	"net"
	"strings"

	"gitee.com/carlmax_my/console-core-go/pkg/net/ip_util"
	"github.com/pkg/errors"
)

// lo, eth
func FindIfaceByIp(ipaddr string) (ifaceName string, err error) {
	ifaces, err := net.Interfaces()
	if err != nil {
		return "", errors.Wrapf(err, "FindIfaceByIp[%s] err", ipaddr)
	}
	if len(ifaces) == 0 {
		return "", nil
	}

	for _, iface := range ifaces {
		if iface.Flags&net.FlagLoopback != 0 {
			continue
		}
		if iface.Flags&net.FlagUp == 0 {
			continue
		}

		addrs, err := iface.Addrs()
		if err != nil {
			log.Println("iface.Addrs err", err.Error())
		}
		if ip_util.IsIpInAddrs(addrs, ipaddr) {
			return iface.Name, nil
		}
	}

	return "", nil
}

func GetIfacesNameByPrefix(prefix string) ([]string, error) {
	ifaces, err := net.Interfaces()
	if err != nil {
		return nil, errors.Wrapf(err, "GetIfacesNameByPrefix(%s) error", prefix)
	}
	if len(ifaces) == 0 {
		return nil, nil
	}

	ret := []string{}
	for _, i := range ifaces {
		if strings.HasPrefix(i.Name, prefix) {
			ret = append(ret, i.Name)
		}
	}

	return ret, nil
}

// net.InterfaceByName(), err 会有 "no such network interface"
// if strings.Contains(err.Error(), "no such network interface") {
func FindIface(iface string) (*net.Interface, error) {
	list, err := net.Interfaces()
	if err != nil {
		return nil, errors.Wrapf(err, "FindIface(%s) error", iface)
	}

	if len(list) == 0 {
		return nil, nil
	}

	for _, v := range list {
		if v.Name == iface {
			return &v, nil
		}
	}

	return nil, nil
}

func IsIfaceExist(iface string) (bool, error) {
	i, err := FindIface(iface)
	if err != nil {
		return false, err
	}

	return i != nil, nil
}

func IsIfaceUp(iface string) (bool, error) {
	ifaceObj, err := FindIface(iface)
	if err != nil {
		return false, err
	}

	if ifaceObj == nil {
		return false, nil
	}

	up := ifaceObj.Flags & net.FlagUp
	return up != 0, nil
}