package sys

import (
	"errors"
	"os/exec"

	"fmt"
	"net"
	"strings"
	"time"
)

// 检查 root权限
func CheckRootPermissions() bool {
	showRootCMD := exec.Command("/bin/sh", "-c", "ls /root/")
	if _, err := showRootCMD.Output(); err != nil {
		return false
	}

	return true
}

// 配置时区
func TimeZone() (string, int64) {
	cmd := exec.Command("/bin/sh", "-c", "echo -n $TZ")
	tz, _ := cmd.Output()
	if tzstr := string(tz); tzstr != "" {
		return tzstr, time.Now().Unix()
	}

	zone, _ := time.Now().Zone()
	return zone, time.Now().Unix()
}

func NTPConfig() (bool, string, string) {
	status, server, interval := false, "", ""

	cmd := exec.Command("/bin/sh", "-c", "crontab -l | grep ntpdate | tr -d '\n'")
	cron, _ := cmd.Output()
	if task := string(cron); task != "" {
		status = true
		slice := strings.Split(task, " ")
		interval, server = slice[0][2:], slice[len(slice)-1]
	}

	return status, server, interval
}

// 设置时区
func SetTimeZone(tz string) bool {
	if _, err := time.LoadLocation(tz); err != nil {
		return false
	}

	// set env
	envCMD := exec.Command("/bin/sh", "-c", "TZ=%s", tz)
	envCMD.Run()
	// change permanent to the file '.profile'

	cleanTZ := exec.Command("/bin/sh", "-c", "sed -i '/^TZ=.*$/d' ~/.profile")
	cleanTZ.Run()

	TZ := "TZ='" + tz + "'; export TZ"
	appendTZCMD := fmt.Sprintf("echo \"%s\" >> ~/.profile;", TZ)
	appendTZ := exec.Command("/bin/sh", "-c", appendTZCMD)
	appendTZ.Run()

	return true
}

// 配置系统时间
func SetLocalTime(newTime string) bool {
	const TimeLayout = "2006-01-02 15:04:05"
	_, err := time.Parse(TimeLayout, newTime)
	if err != nil {
		return false
	}

	args := []string{"-s", newTime}
	exec.Command("date", args...).Run()
	stopNTPCron()

	return true
}

const NTPCRONTABFILE = "~/.webServer.crontab"

func EnableNTPCron(server string, interval int) bool {
	stopNTPCron()

	if ip := net.ParseIP(server); ip == nil {
		return false
	}

	addTask := fmt.Sprintf("echo \"*/%d * * * * /usr/sbin/ntpdate %s\" >> %s; crontab %s", interval, server, NTPCRONTABFILE, NTPCRONTABFILE)
	exec.Command("/bin/sh", "-c", addTask).Run()

	return true
}

func stopNTPCron() {
	cleanTask := fmt.Sprintf("crontab -l | grep -v /usr/sbin/ntpdate > %s; crontab %s", NTPCRONTABFILE, NTPCRONTABFILE)
	exec.Command("/bin/sh", "-c", cleanTask).Run()
}

func RunNTPDate(server string) (bool, error) {
	if ip := net.ParseIP(server); ip == nil {
		return false, errors.New("参数错误")
	}

	ntpdate := fmt.Sprintf("/usr/sbin/ntpdate %s", server)
	return true, exec.Command("/bin/sh", "-c", ntpdate).Run()
}