Idle RPG checker

main.go

package main

import (
	"context"
	"crypto/tls"
	"encoding/xml"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"time"

	mailgun "github.com/mailgun/mailgun-go"
	log "github.com/sirupsen/logrus"
)

const (
	appVersion  = "1.0.0"
	infoURI     = "https://idlerpg.lolhosting.net/xml.php"
	msgTemplate = `Dear %s

You seem to be offline based on https://idlerpg.lolhosting.net/xml.php?player=%s`
)

var (
	domain   = os.Getenv("MG_DOMAIN")
	mgAPIKey = os.Getenv("MG_API_KEY")
)

type Player struct {
	XMLName  xml.Name `xml:"player"`
	Username string   `xml:"username"`
	Level    int      `xml:"level"`
	Online   bool     `xml:"online"`
}

func init() {
	log.SetFormatter(&log.JSONFormatter{})
}

func getUserInfo(username string) Player {
	client := &http.Client{}

	http.DefaultTransport.(*http.Transport).TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
	request, _ := http.NewRequest("GET", infoURI, nil)
	request.Header.Add("Accept", "text/xml")

	query := request.URL.Query()
	query.Add("player", username)
	request.URL.RawQuery = query.Encode()

	response, err := client.Do(request)
	if err != nil {
		panic(err.Error())
	}
	defer response.Body.Close()
	content, _ := ioutil.ReadAll(response.Body)

	var info Player
	xml.Unmarshal(content, &info)
	return info
}

func isOnline(username string) bool {
	return getUserInfo(username).Online
}

func sendEmailNotification(username string, email string) {
	mg := mailgun.NewMailgun(domain, mgAPIKey)

	sender := fmt.Sprintf("no-reply@%s", domain)
	subject := fmt.Sprintf("[%s] IdleRPG Notifier", time.Now().Format("2006-01-02"))
	body := fmt.Sprintf(msgTemplate, username, username)

	message := mg.NewMessage(sender, subject, body, email)
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
	defer cancel()
	mg.Send(ctx, message)
}

func main() {
	username := flag.String("username", "", "IdleRPG Username")
	email := flag.String("email", "", "Send notification if user is offline")
	flag.Parse()
	if *username == "" {
		panic("Username is not specified")
	}
	if *email != "" && !isOnline(*username) {
		log.Infoln("Notify user:", *username)
		sendEmailNotification(*username, *email)
	}
}