import { Booking } from '@prisma/client';
import { google } from 'googleapis'
import { getBaseURL } from '../helpers/url'
import { getDays, getNextDay, dateFormatBackend } from '../helpers/date'
import { log } from '../helpers/log'

const calendarId = process.env.GOOGLE_CALENDAR_ID
let credentials: object

try {
  credentials = JSON.parse(process.env.GOOGLE_SERVICE_ACCOUNT_KEY_JSON)
} catch (error) {
  log.error(
    'Unable to parse process.env.GOOGLE_SERVICE_ACCOUNT_KEY_JSON - invalid JSON?'
  )
  throw error
}

const auth = new google.auth.GoogleAuth({
  credentials,
  scopes: ['https://www.googleapis.com/auth/calendar'],
})

const calendar = google.calendar({
  version: 'v3',
  auth,
})

export async function getBookedDays() {
  const { data } = await calendar.events.list({
    calendarId,
    timeMin: new Date().toISOString(),
    timeZone: 'utc',
  })

  return (
    data.items
      // ignore non all-day events
      .filter((event) => !!event.start.date)
      .flatMap((event) =>
        getDays({
          startDate: event.start.date,
          endDate: event.end.date,
          endDateExclusive: true,
        })
      )
  )
}

function getSummary(booking: Booking): string {
  let summary = ''

  if (booking.org) {
    summary += `${booking.org} - `
  }

  summary += booking.name

  return summary
}

function getDescription(booking: Booking) {
  const bookingUrl = `${getBaseURL()}/admin/booking/${booking.uuid}`

  return `Managelink ${bookingUrl}`
}

export async function createCalendarEvent(booking: Booking) {
  const exclusiveEndDate = dateFormatBackend(
    getNextDay(new Date(booking.endDate))
  )
  const data = {
    calendarId,
    requestBody: {
      summary: getSummary(booking),
      description: getDescription(booking),
      start: { date: booking.startDate },
      end: { date: exclusiveEndDate },
    },
  }
  const response = await calendar.events.insert(data, {})

  booking.calendarEventId = response.data.id

  return booking
}

export async function deleteCalendarEvent(booking: { calendarEventId: string }) {
  await calendar.events.delete({
    calendarId,
    eventId: booking.calendarEventId,
    // TODO: really useful?
    sendNotifications: true,
  })

  booking.calendarEventId = null
}

export async function patchCalendarEvent(booking: Booking ) {
  await calendar.events.patch({
    calendarId,
    eventId: booking.calendarEventId,
  });

  return booking;
}