package util

import (
	"errors"
	"net"
	"os"
)

func AllIPV4() (ipv4s []string) {
	adders, err := net.InterfaceAddrs()
	if err != nil {
		return
	}

	for _, addr := range adders {
		if ipNet, ok := addr.(*net.IPNet); ok && !ipNet.IP.IsLoopback() {
			if ipNet.IP.To4() != nil {
				ipv4 := ipNet.IP.String()
				if ipv4 == "127.0.0.1" || ipv4 == "localhost" {
					continue
				}
				ipv4s = append(ipv4s, ipv4)
			}
		}
	}
	return
}

func GetLocalIP() (ip string, err error) {
	netInterfaces, err := net.Interfaces()
	if err != nil {
		return
	}
	for i := 0; i < len(netInterfaces); i++ {
		if ((netInterfaces[i].Flags & net.FlagUp) != 0) && ((netInterfaces[i].Flags & net.FlagLoopback) == 0) {
			addresses, _ := netInterfaces[i].Addrs()
			for _, address := range addresses {
				if ipNet, ok := address.(*net.IPNet); ok && !ipNet.IP.IsLoopback() && ipNet.IP.To4() != nil {
					ip = ipNet.IP.String()
					return
				}
			}
		}
	}
	return ip, errors.New("can not get local localIP")
}

func CurrentServerHostName() string {
	name, err := os.Hostname()
	if err != nil {
		Errorf("[CurrentServerHostName] get os.Hostnam err, err=%v\n", err.Error())
		localIP, ipErr := GetLocalIP()
		if ipErr != nil {
			Errorf("[CurrentServerHostName] get GetLocalIP err, err=%v\n", ipErr.Error())
			return "127.0.0.1"
		}
		return localIP
	}
	return name
}