Twitch OAuth Token Flow

oauth_token_flow.go

func main() {
  // local server to capture token
	go startSever()
	openBrowser(fmt.Sprintf("https://id.twitch.tv/oauth2/authorize?client_id=%s&redirect_uri=%s&response_type=token&scope=%s", clientID, redirectURI, scope))
	// TODO
	for{
	}
}

func startSever() {
	r := mux.NewRouter()
	r.HandleFunc("/twitch/", tokenHandler)
	r.HandleFunc("/twitch/toekn", getTokenHandler)
	log.Fatal(http.ListenAndServe(":8080", r))
}

// Redirect to capture the hash params
func tokenHandler(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(fmt.Sprintf(`<script>
		window.location.replace("http://127.0.0.1:8080/twitch/toekn" + document.location.hash.replace("#", "?"))
		</script>`)))
}

// Get query params
func getTokenHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Println(r.URL.Query())
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(`<script>
		close()
		</script>`))
}

func openBrowser(url string) bool {
	url = strings.Replace(url, "&", "^&", -1)
	var args []string
	switch runtime.GOOS {
	case "darwin":
		args = []string{"open"}
	case "windows":
		args = []string{"cmd", "/c", "start"}
	default:
		args = []string{"xdg-open"}
	}
	cmd := exec.Command(args[0], append(args[1:], url)...)
	return cmd.Start() == nil
}

verify_token.go

func main() {
	client := &http.Client{}
	req, _ := http.NewRequest("GET", "https://id.twitch.tv/oauth2/validate", nil)
	req.Header.Add("Authorization", fmt.Sprintf("OAuth %s", s))
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	res, _ := ioutil.ReadAll(resp.Body)

	// Print raw string of res
	fmt.Println(string(res))

	// Print json data of res
	var data map[string]interface{}
	err = json.Unmarshal([]byte(res), &data)
	if err != nil {
		panic(err)
	}
	fmt.Println(data)
}