package updater

import (
	"bytes"
	"encoding/json"
	"net/http"

	"github.com/rs/zerolog/log"
	"github.com/traefik/traefik/v3/pkg/config/dynamic"
	"github.com/traefik/traefik/v3/pkg/config/static"
	"github.com/traefik/traefik/v3/pkg/safe"
)

type Updater struct {
	callbackUrls []string
}

func New(config *static.Configuration) *Updater {
	updater := &Updater{
		callbackUrls: config.Global.UpdaterCallbacks,
	}

	return updater
}

func (u *Updater) HandleConfigUpdate(cfg dynamic.Configuration) {
	body, err := json.Marshal(cfg)

	if err != nil {
		// should never happen?
		log.Error().Err(err).Msg("Error while marshalling dynamic configuration data to json")
		return
	}

	requestBody := bytes.NewBuffer(body)

	for _, url := range u.callbackUrls {
		safe.Go(func() {
			resp, err := http.Post(url, "application/json", requestBody)

			if err != nil {
				log.Error().Err(err).Str("url", url).Msg("Error while sending configuration data to callback")
			} else  {
				log.Debug().Str("url", url).Msg("Configuration data sent")
				resp.Body.Close()
			}
		})
	}
}