package main

import (
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"os"
	"strings"
	"time"
)

var (
	port string
	host string

	showVer bool
)

var name string

var Version = "v0.1.0"
var Build = "v0.1.0"

func init() {
	name, _ = os.Hostname()
	flag.BoolVar(&showVer, "v", false, "show version")
	flag.StringVar(&host, "u", "kumoly.io", "hostname to ask for")
	flag.StringVar(&port, "p", "5080", "port to listen|connect")

	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "Usage: myip-basic [options]\n")
		flag.PrintDefaults()
	}
}

func main() {
	flag.Parse()
	if showVer {
		fmt.Println(Version + "-" + Build)
		return
	}

	fmt.Printf("%s ", GetPublicIP())
	for _, v := range GetLocalIP() {
		fmt.Printf("%s ", v)
	}
	fmt.Printf("\n")
}

func GetLocalIP() []string {
	ret := []string{}
	ifaces, err := net.Interfaces()
	if err != nil {
		log.Println(err)
		return ret
	}
	for _, i := range ifaces {
		addrs, err := i.Addrs()
		if err != nil {
			log.Println(err)
			return ret
		}
		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
				if ip.IsLoopback() {
					continue
				}
				if ip.To4() == nil {
					continue
				}
			default:
				continue
			}
			ret = append(ret, ip.String())
			break
		}
	}
	return ret
}

func GetPublicIP() string {
	protocol := "http://"
	req, _ := http.NewRequest("GET", protocol+host+":"+port+"?name="+name, nil)
	client := &http.Client{
		Timeout: time.Second * 10,
	}
	res, err := client.Do(req)
	if err != nil {
		log.Println(err)
		return ""
	}
	if res.StatusCode != 200 {
		err = errors.New("http status error: " + res.Status)
		log.Println(err)
		return ""
	}
	defer res.Body.Close()
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		log.Println(err)
		return ""
	}
	return strings.TrimRight(string(body), "\r\n")
}