package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"

	"github.com/robfig/cron"
)

type Configuration struct {
	Url       string `json:"url"`
	IsShowLog bool   `json:"show_log"`
	Cron      string `json:"cron"`
	Port      string `json:"port"`
}

func sayHello(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "自身服务返回")
}

func main() {
	conf := Configuration{"http://127.0.0.1:8092/timetask", true, "0 */1 * * * ?", ":8092"}
	isExit, err := PathExists("config.json")
	if err != nil || isExit == false {
		data, _ := json.Marshal(conf)

		ioutil.WriteFile("config.json", data, os.ModeAppend)
	}
	data, err := ioutil.ReadFile("config.json")
	if len(data) < 10 {
		data, _ := json.Marshal(conf)
		ioutil.WriteFile("config.json", data, os.ModeAppend)
	} else {
		err = json.Unmarshal(data, &conf)
		d, _ := json.Marshal(conf)
		log.Printf("载入配置：%s\n", string(d[:]))
	}

	c := cron.New()

	c.AddFunc(conf.Cron, func() {
		if conf.IsShowLog {
			log.Print("执行定时任务:\n")
		}
		resp, err := http.Get(conf.Url)
		if err != nil {
			log.Fatalf("请求失败:%s", conf.Url)
		}
		if conf.IsShowLog {
			result, _ := ioutil.ReadAll(resp.Body)
			resp.Body.Close()
			fmt.Println("    - " + string(result[:]))
		}
	})
	c.Start()

	http.HandleFunc("/timetask", sayHello)

	err = http.ListenAndServe(conf.Port, nil)

	if err != nil {
		log.Fatal("ListenAndServe:", err)
	}
}

func PathExists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return false, err
}