package main

import (
	"log"
	"net"
	"os/exec"
	"strings"
	"sync/atomic"
	"time"
)

// DutiesNet 保证PPPoe可行
type DutiesNet struct {
	PW *PingWorker

	NetProtectTime int64 // 当前时间大于保护时间,才能进行重启的计算操作(pppoe最大重启保护时间, 保证重启后不会重复接受重启命令而造成不停重启 )
	MaxProtectTime int64 // NetProtectTime保护时间的最大值
	CmdRestart     int64 // 只要大于MaxRestart就重启
	MaxRestart     int64 // 达到这个值就重启
}

// Default 设置默认值
func (duties *DutiesNet) Default(pw *PingWorker) {
	duties.PW = pw
	atomic.StoreInt64(&duties.MaxProtectTime, 15)
	atomic.StoreInt64(&duties.CmdRestart, 0)
	duties.MaxRestart = 4
	go duties.Duties()
}

// IsPPP0Up Pppoe是否是UP的状态
func (duties *DutiesNet) IsPPP0Up() bool {
	ifaces, err := net.Interfaces()
	if ErrorLog(err) {
		return false
	}

	for _, i := range ifaces {
		if i.Name == "ppp0" {
			flags := strings.Split(i.Flags.String(), "|")
			if len(flags) > 0 {
				log.Println(flags)
				if flags[0] != "up" {
					return false
				}
			}
		}
	}
	return true
}

// IsPPP1Exist ppp1是否是UP的状态
func (duties *DutiesNet) IsPPP1Exist() bool {
	ifaces, err := net.Interfaces()
	if ErrorLog(err) {
		return false
	}

	for _, i := range ifaces {
		if i.Name == "ppp1" {
			return true
		}
	}
	return false
}

// PPP0Restart ppp0 重启
func (duties *DutiesNet) PPP0Restart() {
	log.Println("PPP0Restart")
	_, err := exec.Command("ifdown", "ppp1").Output()
	ErrorLog(err)
	_, err = exec.Command("ifdown", "ppp0").Output()
	ErrorLog(err)
	time.Sleep(time.Second * 1)
	_, err = exec.Command("ifdown", "ppp0").Output()
	ErrorLog(err)
	time.Sleep(time.Second * 1)
	_, err = exec.Command("ifup", "ppp0").Output()
	ErrorLog(err)
	time.Sleep(time.Second * 5)
	_, err = exec.Command("ip", "route", "replace", "default", "dev", "ppp0").CombinedOutput()
	ErrorLog(err)

	atomic.StoreInt64(&duties.NetProtectTime, time.Now().Unix()+duties.MaxProtectTime)
	atomic.StoreInt64(&duties.CmdRestart, 0)
}

// SetRestart 设置重启 异步
func (duties *DutiesNet) SetRestart() {
	log.Println("SetRestart")
	now := time.Now().Unix()
	// 当前时间大于保护时间,才能进行重启的计算操作
	if now >= duties.NetProtectTime {
		log.Println("SetRestart Success")
		atomic.AddInt64(&duties.CmdRestart, duties.MaxRestart+20) // 设置超过最大的值的20, 保证重启.
	}
}

func (duties *DutiesNet) checkError1() bool {
	if duties.IsPPP1Exist() {
		log.Println("IsPPP1Exist not")
		duties.PPP0Restart()
		return true
	}
	return false // 检测错误才返回true 否则 false
}

func (duties *DutiesNet) checkError2() bool {
	// 检测3次ppp0是否处于Up的状态(pppoe有可能存在Down的状态, 这种错误. 但是判断为已经成功拨号)
	for i := 0; i < 4; i++ {
		if duties.IsPPP0Up() {
			return false
		}
		if i == 3 {
			log.Println("IsPPP0Up not")
			duties.PPP0Restart() // 强制重启, 不受最大值的限制
			return true
		}
		time.Sleep(time.Second * 1)
	}

	return false
}

//Duties 核心循环过程, 保证pppoe的网络可行
func (duties *DutiesNet) Duties() {
	for {
		// 如果超过MaxRestart也会重启
		if atomic.LoadInt64(&duties.CmdRestart) > duties.MaxRestart {
			log.Println("CmdRestart ", atomic.LoadInt64(&duties.CmdRestart))
			duties.PPP0Restart()
		}

		time.Sleep(time.Second * 2)

		// 如果网络不能ping通 执行下面的处理
		if !duties.PW.PingNet() {
			time.Sleep(time.Second * 1)
			atomic.AddInt64(&duties.CmdRestart, 1) // 重启因素的积累, 出一次错误就积累一次. 达到最大值后重启

			if duties.checkError1() {
				continue
			}

			if duties.checkError2() {
				continue
			}

		} else {
			if atomic.LoadInt64(&duties.CmdRestart) > 0 {
				atomic.AddInt64(&duties.CmdRestart, -1) // 如果Ping成功就减少重启因素积累. 0为最低限制值
			}
		}

	}
}