discordBots/cmd/domaincheckbot/main.go

package main

import (
	"context"
	"errors"
	"fmt"
	"github.com/dgraph-io/badger/v4"
	"github.com/disgoorg/disgo"
	"github.com/disgoorg/disgo/discord"
	"github.com/disgoorg/disgo/rest"
	"github.com/disgoorg/disgo/webhook"
	"github.com/disgoorg/snowflake/v2"
	"grow.rievo.dev/discordBots/cmd/domaincheckbot/config"
	"grow.rievo.dev/discordBots/cmd/domaincheckbot/dns"
	"grow.rievo.dev/discordBots/cmd/domaincheckbot/repository"
	"log/slog"
	"os"
	"os/signal"
	"reflect"
	"syscall"
	"time"
)

var (
	webhookID    = snowflake.GetEnv("webhook_id")
	webhookToken = os.Getenv("webhook_token")
)

var logger = slog.New(slog.NewJSONHandler(os.Stdout, nil))

// TODO: clear db from domains removed from json

var release string

func main() {

	logger.Info("starting domainCheck...", slog.String("disgo version", disgo.Version))

	client := webhook.New(webhookID, webhookToken)
	defer client.Close(context.TODO())

	repo := repository.InitDb()
	defer repo.Close()

	ticker := time.NewTicker(10 * time.Minute)
	tickerGC := time.NewTicker(15 * time.Minute)
	quit := make(chan struct{})

	go func() {
		for {
			select {
			case <-ticker.C:
				for _, d := range config.Domains {
					go checkDomain(0, d, repo, client)
				}

			case <-tickerGC.C:
				err := repo.RunGC()
				if err != nil && !errors.Is(err, badger.ErrNoRewrite) {
					logger.Error("GC failed", slog.Any("error", err))
				} else {
					logger.Debug("GC successful")
				}

			case <-quit:
				ticker.Stop()
				tickerGC.Stop()
				return
			}
		}
	}()

	logger.Info("domaincheckbot is now running. Press CTRL-C to exit.", slog.String("version", release))

	s := make(chan os.Signal, 1)
	signal.Notify(s, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
	<-s
}

func checkDomain(counter int, d string, repo *repository.DomainRepository, client webhook.Client) {
	domain := dns.CheckDomain(d)
	retrievedDomain, _ := repo.GetValue(d)
	if reflect.DeepEqual(domain, retrievedDomain) {
		logger.Debug("domain did not change", slog.String("domain", d))
		return
	}
	logger.Info("domain changed changed", slog.String("domain", d))
	counter += 1
	if counter >= 2 {
		go sendWebhook(client, domain, retrievedDomain)
		repo.SetValue(domain)
		return
	}
	time.Sleep(1 * time.Minute)
	checkDomain(counter, d, repo, client)
}

func sendWebhook(client webhook.Client, domain repository.Domain, oldDomain repository.Domain) {
	var status string

	status = fmt.Sprintf("```md\n# %v", domain.Name)
	status = fmt.Sprintf("%v\n - %v", status, oldDomain.NS)
	status = fmt.Sprintf("%v\n + %v", status, domain.NS)
	status = fmt.Sprintf("%v```\n", status)

	if _, err := client.CreateMessage(discord.NewWebhookMessageCreateBuilder().
		SetContent(status).Build(),
		rest.WithDelay(2*time.Second),
	); err != nil {
		logger.Error("sending message failed", slog.Any("error", err))
	}
}