package webhook

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

	"maunium.net/go/mautrix/event"
)

const (
	messageTemplate = `@room Alerts for group "{{ .GroupKey }}":{{ range .Alerts }}
* {{ .Annotations.Description }}{{ end }}`
)

func (s Server) handleWebhook(w http.ResponseWriter, r *http.Request) {
	if r.Header.Get("Content-Type") != "application/json" {
		writeStatus(w, http.StatusBadRequest)
		return
	}

	decoder := json.NewDecoder(r.Body)

	var payload Payload
	err := decoder.Decode(&payload)
	if err != nil {
		writeStatus(w, http.StatusBadRequest)
		return
	}

	if payload.Version != "4" {
		writeStatus(w, http.StatusBadRequest)
		return
	}

	if payload.Status != StatusFiring {
		writeStatus(w, http.StatusOK)
		return
	}

	var message bytes.Buffer
	err = s.tmpl.Execute(&message, payload)
	if err != nil {
		log.Print(err)
		writeStatus(w, http.StatusInternalServerError)
		return
	}

	evt := event.MessageEventContent{
		MsgType:	event.MsgText,
		Body:		message.String(),
	}

	success := s.matrix.Broadcast(&evt)
	if !success {
		writeStatus(w, http.StatusInternalServerError)
	}
}