package fetch

import (
	"net/http"
	"strings"
	"time"

	"git.newty.dev/uofgsync/auth"
	ics "github.com/arran4/golang-ical"
	"github.com/charmbracelet/log"
	cron "github.com/go-co-op/gocron/v2"
	"golang.org/x/oauth2/google"
	"google.golang.org/api/calendar/v3"
)

const calendar_url = "https://frontdoor.spa.gla.ac.uk/spacett/download/uogtimetable.ics"

var Scheduler *cron.Scheduler

func StartScheduler() {
	// fetch credentials
	config, err := google.ConfigFromJSON(auth.GoogleOAuthCreds, calendar.CalendarReadonlyScope)
	if err != nil {
		log.Fatal(err)
	}
	credentials, err := auth.GetCredentials(config)
	if err != nil {
		log.Fatal(err)
	}

	// create scheduler
	Scheduler, err := cron.NewScheduler()
	if err != nil {
		log.Fatal(err)
	}

	j, err := Scheduler.NewJob(
		// every 24 hours
		cron.DurationJob(
			24*time.Hour,
		),

		// update the calendar
		cron.NewTask(
			update_calendar,
			auth.GetHeader(credentials.GUID, credentials.UofgPass),
			auth.GetGoogleClient(config, credentials.GoogleToken),
		),
	)
	if err != nil {
		log.Fatal(err)
	}

	// run job and start scheduler
	go j.RunNow()
	Scheduler.Start()
}

func update_calendar(authorization string, google *http.Client) {
	// create request
	req, err := http.NewRequest("GET", calendar_url, nil)
	if err != nil {
		log.Fatal(err)
	}
	req.Header.Set("Authorization", authorization)

	// send request
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	// check if authentication failed
	if resp.StatusCode == 401 {
		log.Fatal("authentication failed")
	}

	// parse ics file
	calendar, err := ics.ParseCalendar(resp.Body)
	if err != nil {
		log.Fatal(err)
	}

	for _, event := range calendar.Events() {
		name := event.GetProperty(ics.ComponentPropertySummary).Value
		location := strings.TrimSpace(strings.Replace(event.GetProperty(ics.ComponentPropertyLocation).Value, "ON CAMPUS:", "", 1))
		log.Infof("%s: %s", name, location)
	}
}