Dumb mutex stuff

main.go

package main

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

type WorldTimeAPIResponse struct {
	UTCDateTime string `json:"utc_datetime"`
	DateTime    string `json:"datetime"`
	TimeZone    string `json:"timezone"`
}

type WorldTimeAPIFetcher struct {
	state *WorldTimeAPIResponse
	mutex *sync.Mutex
}

func NewWorldTimeAPIFetcher() *WorldTimeAPIFetcher {
	return &WorldTimeAPIFetcher{
		mutex: &sync.Mutex{},
	}
}

func (w *WorldTimeAPIFetcher) Fetch() {
	resp, err := http.Get("http://worldtimeapi.org/api/timezone/Europe/Paris")
	if err != nil {
		fmt.Println("An error occured " + err.Error())
		return
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		fmt.Println("An error occured " + err.Error())
		return
	}

	worldTimeAPIResponse := new(WorldTimeAPIResponse)
	err = json.Unmarshal(body, worldTimeAPIResponse)
	if err != nil {
		fmt.Println("An error occured " + err.Error())
		return
	}

	w.mutex.Lock()
	w.state = worldTimeAPIResponse
	w.mutex.Unlock()
}

func (w *WorldTimeAPIFetcher) Print() {
	w.mutex.Lock()
	if w.state != nil {
		fmt.Println(w.state.DateTime)
	}
	w.mutex.Unlock()
}

func FetchLoop(w *WorldTimeAPIFetcher) {
	for true {
		w.Fetch()
		time.Sleep(time.Duration(1000000000))
	}
}

func PrintLoop(w *WorldTimeAPIFetcher) {
	for true {
		w.Print()
		time.Sleep(time.Duration(1000000))
	}
}

func main() {
	w := NewWorldTimeAPIFetcher()
	go FetchLoop(w)
	PrintLoop(w)
}