package main

import (
	"encoding/json"
	"flag"
	"github.com/athurg/go-qcloud-cns-sdk"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"strconv"
	"strings"
	"time"
)

var gSecretId = *flag.String("secretId", "111123123", "腾讯云秘钥id")
var gSecretKey = *flag.String("secretKey", "222222", "腾讯云秘钥key")
var gDomain = *flag.String("domain", "dszgame.cn", "域名")
var gSubName = *flag.String("subname", "home", "二级域名")
var gInterval = 120 // 间隔时间
// 获取当前网络环境的公网IP
func GetIP() string {
	resp, err := http.Get("http://ip.cip.cc")
	if err != nil {
		return ""
	}
	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	return string(body)
}

// unicode转中文
func u2s(form string) string {
	str, err := strconv.Unquote(strings.Replace(strconv.Quote(string(form)), `\\u`, `\u`, -1))
	if err != nil {
		return ""
	}
	return str
}

// 检测域名是否需要修改解析
func checkDomain(secretId, secretKey, sDomain, sSubName string){
	url := sSubName +"." + sDomain
	oldips, err := net.LookupHost(url)
	if err != nil {
		log.Println(err.Error())
	}
	oldip := strings.ReplaceAll(oldips[0], "\n", "")
	curip := strings.ReplaceAll(GetIP(), "\n", "")
	if oldip == curip {
		log.Println("解析出来的IP本来就是当前公网IP：", url, curip)
		return
	}
	log.Println("开始检测 url:" + url + " ip:", GetIP(), " host:", oldip)

	cli := cns.New( secretId, secretKey)
	lists, err := cli.RecordList(sDomain)

	for _, rec := range lists {
		if rec.Name == sSubName && rec.Type == "A" { // 找到要修改的解析
			log.Println("record:", rec)
			if oldip != rec.Value || curip != oldip {
				rec.Value = curip
				err1 := cli.RecordModify(sDomain, rec)
				if err1 != nil {
					log.Println("RecordModify error:", err1.Error())
				}else{
					log.Println("RecordModify succeded:", url, rec.Value)
				}
			}

		}
	}
}

func main() {

	bytes, err := ioutil.ReadFile("./config.json")
	if err == nil {
		log.Println("读取json文件成功")

		configjson := map[string]string{}
		json.Unmarshal(bytes, &configjson)

		gSecretId = configjson["secretId"]
		gSecretKey = configjson["secretKey"]
		gDomain = configjson["domain"]
		gSubName = configjson["subname"]
		gInterval, _ = strconv.Atoi(configjson["interval"])

	}

	log.Println("start:", gSecretId, gSecretKey, gDomain, gSubName, gInterval)


	// 默认启动执行一次检测
	checkDomain(gSecretId, gSecretKey, gDomain, gSubName)

	go func() {
		for {
			ticker := time.NewTicker(time.Duration(gInterval)  * time.Second)
			select {
			case <-ticker.C:
				log.Println("当前时间为:", time.Now())
				checkDomain(gSecretId, gSecretKey, gDomain, gSubName)
			}
		}
	}()

	for {
		time.Sleep(time.Second * 1)
	}
}