package main

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net"
	"net/http"
	"time"
)

const (
	watchInterval = 10
	base64Table   = "ABNOPqrceQRSTklmUDEFGXYZabnopfghHVWdijstuvwCIJKLMxyz0123456789+/"
)

var (
	coder = base64.NewEncoding(base64Table)
)

// reloadProxies 重新加载代理池
func reloadProxies() {
	fmt.Print("请求远程proxy service")
	resp, err := http.Get("http://proxy.spdata.jianyu360.com/proxy/getallip")
	if err != nil {
		fmt.Print(err.Error())
		return
	}
	bs, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		fmt.Print(err.Error())
		return
	}
	resp.Body.Close()
	data := make([]*IpItem, 0, 0)
	newPool := make([]*IpItem, 0, 0)
	err = json.Unmarshal(bs, &data)
	if err != nil {
		fmt.Print(err.Error())
		return
	}
	index := 0
	//5分钟以内过期的都不要
	lifeTimieout := time.Now().Unix() + 5*60
	for _, v := range data {
		fmt.Print(">")
		if v.LifeTime <= lifeTimieout {
			fmt.Print("O")
			continue
		}
		rawIp, err := coder.DecodeString(v.Ip)
		if err != nil {
			continue
		}
		ipStr := string(rawIp)
		v.Ip = ipStr
		for _, p := range v.Ports {
			addr := ipStr + ":" + p
			if checkDial(addr) {
				fmt.Print("+")
				v.Raw = addr
				break
			} else {
				fmt.Print("?")
			}
		}
		if v.Raw != "" {
			v.Index = index
			index += 1
			newPool = append(newPool, v)
		}
	}
	if len(newPool) > 0 {
		roulette.Init(newPool)
		fmt.Printf("--{proxy size %d}--", roulette.Length)
	} else {
		fmt.Print("远程服务没有返回有效proxy")
	}
}

// checkDial 检查是否能tcp连接通
func checkDial(addr string) bool {
	conn, err := net.DialTimeout("tcp", addr, 1*time.Second)
	if err == nil {
		conn.Close()
	}
	return err == nil
}

func watch() {
	for {
		time.Sleep(time.Duration(int64(watchInterval)) * time.Minute)
		reloadProxies()
	}
}