package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"time"

	"golang.org/x/oauth2/google"
	"google.golang.org/api/calendar/v3"
)

var calName = flag.String("calendar", "", "name of calendar")

var students = []string{
	"oliver.park@heliosns.org",
}

var classes = []Class {
	Class{
		Summary: "Test 2",
		Start: "22:00",
		End: "22:30",
		Days: []time.Weekday{time.Monday, time.Tuesday, time.Wednesday, time.Thursday},
		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
	},
}

type Class struct {
	Summary string
	Start string
	End string
	Students []string
	Days []time.Weekday
	Zoom string
}

func main() {
	flag.Parse()

	b, err := ioutil.ReadFile("credentials.json")
	if err != nil {
		log.Fatal(err)
	}

	// If modifying these scopes, delete your previously saved token.json.
	config, err := google.ConfigFromJSON(b, calendar.CalendarScope)
	if err != nil {
		log.Fatal(err)
	}
	client, err := getClient(config)
	if err != nil {
		log.Fatal(err)
	}

	srv, err := calendar.New(client)
	if err != nil {
		log.Fatal(err)
	}

	calendars, err := srv.CalendarList.List().Do()
	if err != nil {
		log.Fatal(err)
	}
	var myCal *calendar.CalendarListEntry
	for _, item := range calendars.Items {
		if item.Summary == *calName {
			myCal = item
			break
		}
	}
	if myCal == nil {
		log.Fatalf("calendar '%s' not found", *calName)
	}

	loc, err := time.LoadLocation("US/Pacific")
	if err != nil {
		log.Fatal(err)
	}

	now := time.Now().In(loc)

	dateStr := now.Format("2006-01-02")

	// TOOD: loop through days

	for _, class := range classes {
		found := false
		for _, day := range class.Days {
			if day == now.Weekday() {
				found = true
				break
			}
		}
		if !found {
			continue
		}

		ev := &calendar.Event{
			Summary: class.Summary,
			Start: &calendar.EventDateTime{
				DateTime: fmt.Sprintf("%sT%s:00", dateStr, class.Start),
				TimeZone: "US/Pacific",
			},
			End: &calendar.EventDateTime{
				DateTime: fmt.Sprintf("%sT%s:00", dateStr, class.End),
				TimeZone: "US/Pacific",
			},
			Attendees: []*calendar.EventAttendee{},
		}

		attendees := class.Students
		if len(attendees) == 0 {
			attendees = students
		}

		for _, student := range attendees {
			ev.Attendees = append(
				ev.Attendees,
				&calendar.EventAttendee{
					Email: student,
				},
			)
		}

		if class.Zoom != "" {
			ev.Description = fmt.Sprintf(`Zoom: %s`, class.Zoom)
		}

		_, err := srv.Events.Insert(myCal.Id, ev).Do()
		if err != nil {
			log.Fatal(err)
		}
	}


	/*
	ev := &calendar.Event{
		Summary: "Test event",
		Start: &calendar.EventDateTime{
			DateTime: "2020-09-09T16:00:00",
			TimeZone: "US/Pacific",
		},
		End: &calendar.EventDateTime{
			DateTime: "2020-09-09T17:00:00",
			TimeZone: "US/Pacific",
		},
		Attendees: []*calendar.EventAttendee{
			&calendar.EventAttendee{
				Email: "oliver.park@heliosns.org",
			},
		},
	}

	res, err := srv.Events.Insert(myCal.Id, ev).Do()
	if err != nil {
		log.Fatal(err)
	}

	log.Printf("%#v", res)
	*/

	/*
	t := time.Now().Format(time.RFC3339)
	events, err := srv.Events.List(myCal.Id).ShowDeleted(false).
		SingleEvents(true).TimeMin(t).MaxResults(250).OrderBy("startTime").Do()
	if err != nil {
		log.Fatal(err)
	}

	for _, item := range events.Items {
		date := item.Start.DateTime
		if date == "" {
			date = item.Start.Date
		}
		log.Printf("%v (%v)", item.Summary, date)
	}
	*/
}