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import startOfWeek from '../startOfWeek/index.ts'import startOfWeekYear from '../startOfWeekYear/index.js'import toDate from '../toDate/index.ts'import requiredArgs from '../_lib/requiredArgs/index.ts'import { LocaleOptions, WeekStartOptions, FirstWeekContainsDateOptions } from '../types.ts'
const MILLISECONDS_IN_WEEK = 604800000
/** * @name getWeek * @category Week Helpers * @summary Get the local week index of the given date. * * @description * Get the local week index of the given date. * The exact calculation depends on the values of * `options.weekStartsOn` (which is the index of the first day of the week) * and `options.firstWeekContainsDate` (which is the day of January, which is always in * the first week of the week-numbering year) * * Week numbering: https://en.wikipedia.org/wiki/Week#Week_numbering * * ### v2.0.0 breaking changes: * * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes). * * @param {Date|Number} date - the given date * @param {Object} [options] - an object with options. * @param {Locale} [options.locale=defaultLocale] - the locale object. See [Locale]{@link https://date-fns.org/docs/Locale} * @param {0|1|2|3|4|5|6} [options.weekStartsOn=0] - the index of the first day of the week (0 - Sunday) * @param {1|2|3|4|5|6|7} [options.firstWeekContainsDate=1] - the day of January, which is always in the first week of the year * @returns {Number} the week * @throws {TypeError} 1 argument required * @throws {RangeError} `options.weekStartsOn` must be between 0 and 6 * @throws {RangeError} `options.firstWeekContainsDate` must be between 1 and 7 * * @example * // Which week of the local week numbering year is 2 January 2005 with default options? * const result = getISOWeek(new Date(2005, 0, 2)) * //=> 2 * * // Which week of the local week numbering year is 2 January 2005, * // if Monday is the first day of the week, * // and the first week of the year always contains 4 January? * const result = getISOWeek(new Date(2005, 0, 2), { *   weekStartsOn: 1, *   firstWeekContainsDate: 4 * }) * //=> 53 */
export default function getWeek(dirtyDate: Date | number, options?: LocaleOptions & WeekStartOptions & FirstWeekContainsDateOptions): number {  requiredArgs(1, arguments)
  const date = toDate(dirtyDate)  const diff =    startOfWeek(date, options).getTime() -    startOfWeekYear(date, options).getTime()
  // Round the number of days to the nearest integer  // because the number of milliseconds in a week is not constant  // (e.g. it's different in the week of the daylight saving time clock shift)  return Math.round(diff / MILLISECONDS_IN_WEEK) + 1}