import { randomId } from 'lib/id'
import ApiError from './errors/seamly-api-error'

export function buildPayload(command, payload) {
  if (command !== 'message') {
    return payload
  }

  const { type, body } = payload
  let { transactionId } = payload

  if (!transactionId) {
    transactionId = randomId()
  }

  return { type, body, transactionId }
}

export const fetchApi = async (
  input: string,
  init: RequestInit,
): Promise<Response> => {
  const url = new URL(input)

  const response = await fetch(url.href, { mode: 'cors', ...init })

  if (!response.ok) {
    throw new ApiError(
      response.statusText || `Request failed with status: ${response.status}`,
      { status: response.status },
    )
  }

  return response
}

/**
 * Tries to get the time zone key directly from the operating system for those
 * environments that support the ECMAScript Internationalization API.
 *
 * Based on https://github.com/pellepim/jstimezonedetect/blob/master/jstz.main.js
 */
export function getTimeZone() {
  if (
    !Intl ||
    typeof Intl === 'undefined' ||
    typeof Intl.DateTimeFormat === 'undefined'
  ) {
    return undefined
  }

  const format = Intl.DateTimeFormat()

  if (
    typeof format === 'undefined' ||
    typeof format.resolvedOptions === 'undefined'
  ) {
    return undefined
  }

  const timezone = format.resolvedOptions().timeZone

  // Ensure we get a valid timezone
  if (timezone && (timezone.indexOf('/') > -1 || timezone === 'UTC')) {
    return timezone
  } else {
    return undefined
  }
}