import { useState, useCallback, useMemo } from 'react';

/**
 * @name toDate
 * @category Common Helpers
 * @summary Convert the given argument to an instance of Date.
 *
 * @description
 * Convert the given argument to an instance of Date.
 *
 * If the argument is an instance of Date, the function returns its clone.
 *
 * If the argument is a number, it is treated as a timestamp.
 *
 * If the argument is none of the above, the function returns Invalid Date.
 *
 * **Note**: *all* Date arguments passed to any *date-fns* function is processed by `toDate`.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param argument - The value to convert
 *
 * @returns The parsed date in the local time zone
 *
 * @example
 * // Clone the date:
 * const result = toDate(new Date(2014, 1, 11, 11, 30, 30))
 * //=> Tue Feb 11 2014 11:30:30
 *
 * @example
 * // Convert the timestamp to date:
 * const result = toDate(1392098430000)
 * //=> Tue Feb 11 2014 11:30:30
 */
function toDate(argument) {
  const argStr = Object.prototype.toString.call(argument);

  // Clone the date
  if (
    argument instanceof Date ||
    (typeof argument === "object" && argStr === "[object Date]")
  ) {
    // Prevent the date to lose the milliseconds when passed to new Date() in IE10
    return new argument.constructor(+argument);
  } else if (
    typeof argument === "number" ||
    argStr === "[object Number]" ||
    typeof argument === "string" ||
    argStr === "[object String]"
  ) {
    // TODO: Can we get rid of as?
    return new Date(argument);
  } else {
    // TODO: Can we get rid of as?
    return new Date(NaN);
  }
}

/**
 * @name constructFrom
 * @category Generic Helpers
 * @summary Constructs a date using the reference date and the value
 *
 * @description
 * The function constructs a new date using the constructor from the reference
 * date and the given value. It helps to build generic functions that accept
 * date extensions.
 *
 * It defaults to `Date` if the passed reference date is a number or a string.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The reference date to take constructor from
 * @param value - The value to create the date
 *
 * @returns Date initialized using the given date and value
 *
 * @example
 * import { constructFrom } from 'date-fns'
 *
 * // A function that clones a date preserving the original type
 * function cloneDate<DateType extends Date(date: DateType): DateType {
 *   return constructFrom(
 *     date, // Use contrustor from the given date
 *     date.getTime() // Use the date value to create a new date
 *   )
 * }
 */
function constructFrom(date, value) {
  if (date instanceof Date) {
    return new date.constructor(value);
  } else {
    return new Date(value);
  }
}

/**
 * @name addDays
 * @category Day Helpers
 * @summary Add the specified number of days to the given date.
 *
 * @description
 * Add the specified number of days to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of days to be added.
 *
 * @returns The new date with the days added
 *
 * @example
 * // Add 10 days to 1 September 2014:
 * const result = addDays(new Date(2014, 8, 1), 10)
 * //=> Thu Sep 11 2014 00:00:00
 */
function addDays(date, amount) {
  const _date = toDate(date);
  if (isNaN(amount)) return constructFrom(date, NaN);
  if (!amount) {
    // If 0 days, no-op to avoid changing times in the hour before end of DST
    return _date;
  }
  _date.setDate(_date.getDate() + amount);
  return _date;
}

/**
 * @name addMonths
 * @category Month Helpers
 * @summary Add the specified number of months to the given date.
 *
 * @description
 * Add the specified number of months to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of months to be added.
 *
 * @returns The new date with the months added
 *
 * @example
 * // Add 5 months to 1 September 2014:
 * const result = addMonths(new Date(2014, 8, 1), 5)
 * //=> Sun Feb 01 2015 00:00:00
 *
 * // Add one month to 30 January 2023:
 * const result = addMonths(new Date(2023, 0, 30), 1)
 * //=> Tue Feb 28 2023 00:00:00
 */
function addMonths(date, amount) {
  const _date = toDate(date);
  if (isNaN(amount)) return constructFrom(date, NaN);
  if (!amount) {
    // If 0 months, no-op to avoid changing times in the hour before end of DST
    return _date;
  }
  const dayOfMonth = _date.getDate();

  // The JS Date object supports date math by accepting out-of-bounds values for
  // month, day, etc. For example, new Date(2020, 0, 0) returns 31 Dec 2019 and
  // new Date(2020, 13, 1) returns 1 Feb 2021.  This is *almost* the behavior we
  // want except that dates will wrap around the end of a month, meaning that
  // new Date(2020, 13, 31) will return 3 Mar 2021 not 28 Feb 2021 as desired. So
  // we'll default to the end of the desired month by adding 1 to the desired
  // month and using a date of 0 to back up one day to the end of the desired
  // month.
  const endOfDesiredMonth = constructFrom(date, _date.getTime());
  endOfDesiredMonth.setMonth(_date.getMonth() + amount + 1, 0);
  const daysInMonth = endOfDesiredMonth.getDate();
  if (dayOfMonth >= daysInMonth) {
    // If we're already at the end of the month, then this is the correct date
    // and we're done.
    return endOfDesiredMonth;
  } else {
    // Otherwise, we now know that setting the original day-of-month value won't
    // cause an overflow, so set the desired day-of-month. Note that we can't
    // just set the date of `endOfDesiredMonth` because that object may have had
    // its time changed in the unusual case where where a DST transition was on
    // the last day of the month and its local time was in the hour skipped or
    // repeated next to a DST transition.  So we use `date` instead which is
    // guaranteed to still have the original time.
    _date.setFullYear(
      endOfDesiredMonth.getFullYear(),
      endOfDesiredMonth.getMonth(),
      dayOfMonth,
    );
    return _date;
  }
}

let defaultOptions = {};

function getDefaultOptions() {
  return defaultOptions;
}

/**
 * The {@link startOfWeek} function options.
 */

/**
 * @name startOfWeek
 * @category Week Helpers
 * @summary Return the start of a week for the given date.
 *
 * @description
 * Return the start of a week for the given date.
 * The result will be in the local timezone.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The original date
 * @param options - An object with options
 *
 * @returns The start of a week
 *
 * @example
 * // The start of a week for 2 September 2014 11:55:00:
 * const result = startOfWeek(new Date(2014, 8, 2, 11, 55, 0))
 * //=> Sun Aug 31 2014 00:00:00
 *
 * @example
 * // If the week starts on Monday, the start of the week for 2 September 2014 11:55:00:
 * const result = startOfWeek(new Date(2014, 8, 2, 11, 55, 0), { weekStartsOn: 1 })
 * //=> Mon Sep 01 2014 00:00:00
 */
function startOfWeek(date, options) {
  const defaultOptions = getDefaultOptions();
  const weekStartsOn =
    options?.weekStartsOn ??
    options?.locale?.options?.weekStartsOn ??
    defaultOptions.weekStartsOn ??
    defaultOptions.locale?.options?.weekStartsOn ??
    0;

  const _date = toDate(date);
  const day = _date.getDay();
  const diff = (day < weekStartsOn ? 7 : 0) + day - weekStartsOn;

  _date.setDate(_date.getDate() - diff);
  _date.setHours(0, 0, 0, 0);
  return _date;
}

/**
 * @name startOfDay
 * @category Day Helpers
 * @summary Return the start of a day for the given date.
 *
 * @description
 * Return the start of a day for the given date.
 * The result will be in the local timezone.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The original date
 *
 * @returns The start of a day
 *
 * @example
 * // The start of a day for 2 September 2014 11:55:00:
 * const result = startOfDay(new Date(2014, 8, 2, 11, 55, 0))
 * //=> Tue Sep 02 2014 00:00:00
 */
function startOfDay(date) {
  const _date = toDate(date);
  _date.setHours(0, 0, 0, 0);
  return _date;
}

/**
 * @name addWeeks
 * @category Week Helpers
 * @summary Add the specified number of weeks to the given date.
 *
 * @description
 * Add the specified number of week to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of weeks to be added.
 *
 * @returns The new date with the weeks added
 *
 * @example
 * // Add 4 weeks to 1 September 2014:
 * const result = addWeeks(new Date(2014, 8, 1), 4)
 * //=> Mon Sep 29 2014 00:00:00
 */
function addWeeks(date, amount) {
  const days = amount * 7;
  return addDays(date, days);
}

/**
 * @name addYears
 * @category Year Helpers
 * @summary Add the specified number of years to the given date.
 *
 * @description
 * Add the specified number of years to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of years to be added.
 *
 * @returns The new date with the years added
 *
 * @example
 * // Add 5 years to 1 September 2014:
 * const result = addYears(new Date(2014, 8, 1), 5)
 * //=> Sun Sep 01 2019 00:00:00
 */
function addYears(date, amount) {
  return addMonths(date, amount * 12);
}

/**
 * @name endOfMonth
 * @category Month Helpers
 * @summary Return the end of a month for the given date.
 *
 * @description
 * Return the end of a month for the given date.
 * The result will be in the local timezone.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The original date
 *
 * @returns The end of a month
 *
 * @example
 * // The end of a month for 2 September 2014 11:55:00:
 * const result = endOfMonth(new Date(2014, 8, 2, 11, 55, 0))
 * //=> Tue Sep 30 2014 23:59:59.999
 */
function endOfMonth(date) {
  const _date = toDate(date);
  const month = _date.getMonth();
  _date.setFullYear(_date.getFullYear(), month + 1, 0);
  _date.setHours(23, 59, 59, 999);
  return _date;
}

/**
 * The {@link eachDayOfInterval} function options.
 */

/**
 * @name eachDayOfInterval
 * @category Interval Helpers
 * @summary Return the array of dates within the specified time interval.
 *
 * @description
 * Return the array of dates within the specified time interval.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param interval - The interval.
 * @param options - An object with options.
 *
 * @returns The array with starts of days from the day of the interval start to the day of the interval end
 *
 * @example
 * // Each day between 6 October 2014 and 10 October 2014:
 * const result = eachDayOfInterval({
 *   start: new Date(2014, 9, 6),
 *   end: new Date(2014, 9, 10)
 * })
 * //=> [
 * //   Mon Oct 06 2014 00:00:00,
 * //   Tue Oct 07 2014 00:00:00,
 * //   Wed Oct 08 2014 00:00:00,
 * //   Thu Oct 09 2014 00:00:00,
 * //   Fri Oct 10 2014 00:00:00
 * // ]
 */
function eachDayOfInterval(interval, options) {
  const startDate = toDate(interval.start);
  const endDate = toDate(interval.end);

  let reversed = +startDate > +endDate;
  const endTime = reversed ? +startDate : +endDate;
  const currentDate = reversed ? endDate : startDate;
  currentDate.setHours(0, 0, 0, 0);

  let step = options?.step ?? 1;
  if (!step) return [];
  if (step < 0) {
    step = -step;
    reversed = !reversed;
  }

  const dates = [];

  while (+currentDate <= endTime) {
    dates.push(toDate(currentDate));
    currentDate.setDate(currentDate.getDate() + step);
    currentDate.setHours(0, 0, 0, 0);
  }

  return reversed ? dates.reverse() : dates;
}

/**
 * The {@link eachMonthOfInterval} function options.
 */

/**
 * @name eachMonthOfInterval
 * @category Interval Helpers
 * @summary Return the array of months within the specified time interval.
 *
 * @description
 * Return the array of months within the specified time interval.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param interval - The interval
 *
 * @returns The array with starts of months from the month of the interval start to the month of the interval end
 *
 * @example
 * // Each month between 6 February 2014 and 10 August 2014:
 * const result = eachMonthOfInterval({
 *   start: new Date(2014, 1, 6),
 *   end: new Date(2014, 7, 10)
 * })
 * //=> [
 * //   Sat Feb 01 2014 00:00:00,
 * //   Sat Mar 01 2014 00:00:00,
 * //   Tue Apr 01 2014 00:00:00,
 * //   Thu May 01 2014 00:00:00,
 * //   Sun Jun 01 2014 00:00:00,
 * //   Tue Jul 01 2014 00:00:00,
 * //   Fri Aug 01 2014 00:00:00
 * // ]
 */
function eachMonthOfInterval(interval, options) {
  const startDate = toDate(interval.start);
  const endDate = toDate(interval.end);

  let reversed = +startDate > +endDate;
  const endTime = reversed ? +startDate : +endDate;
  const currentDate = reversed ? endDate : startDate;
  currentDate.setHours(0, 0, 0, 0);
  currentDate.setDate(1);

  let step = options?.step ?? 1;
  if (!step) return [];
  if (step < 0) {
    step = -step;
    reversed = !reversed;
  }

  const dates = [];

  while (+currentDate <= endTime) {
    dates.push(toDate(currentDate));
    currentDate.setMonth(currentDate.getMonth() + step);
  }

  return reversed ? dates.reverse() : dates;
}

/**
 * The {@link eachWeekOfInterval} function options.
 */

/**
 * @name eachWeekOfInterval
 * @category Interval Helpers
 * @summary Return the array of weeks within the specified time interval.
 *
 * @description
 * Return the array of weeks within the specified time interval.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param interval - The interval.
 * @param options - An object with options.
 *
 * @returns The array with starts of weeks from the week of the interval start to the week of the interval end
 *
 * @example
 * // Each week within interval 6 October 2014 - 23 November 2014:
 * const result = eachWeekOfInterval({
 *   start: new Date(2014, 9, 6),
 *   end: new Date(2014, 10, 23)
 * })
 * //=> [
 * //   Sun Oct 05 2014 00:00:00,
 * //   Sun Oct 12 2014 00:00:00,
 * //   Sun Oct 19 2014 00:00:00,
 * //   Sun Oct 26 2014 00:00:00,
 * //   Sun Nov 02 2014 00:00:00,
 * //   Sun Nov 09 2014 00:00:00,
 * //   Sun Nov 16 2014 00:00:00,
 * //   Sun Nov 23 2014 00:00:00
 * // ]
 */
function eachWeekOfInterval(interval, options) {
  const startDate = toDate(interval.start);
  const endDate = toDate(interval.end);

  let reversed = +startDate > +endDate;
  const startDateWeek = reversed
    ? startOfWeek(endDate, options)
    : startOfWeek(startDate, options);
  const endDateWeek = reversed
    ? startOfWeek(startDate, options)
    : startOfWeek(endDate, options);

  // Some timezones switch DST at midnight, making start of day unreliable in these timezones, 3pm is a safe bet
  startDateWeek.setHours(15);
  endDateWeek.setHours(15);

  const endTime = +endDateWeek.getTime();
  let currentDate = startDateWeek;

  let step = options?.step ?? 1;
  if (!step) return [];
  if (step < 0) {
    step = -step;
    reversed = !reversed;
  }

  const dates = [];

  while (+currentDate <= endTime) {
    currentDate.setHours(0);
    dates.push(toDate(currentDate));
    currentDate = addWeeks(currentDate, step);
    currentDate.setHours(15);
  }

  return reversed ? dates.reverse() : dates;
}

/**
 * @name startOfMonth
 * @category Month Helpers
 * @summary Return the start of a month for the given date.
 *
 * @description
 * Return the start of a month for the given date.
 * The result will be in the local timezone.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The original date
 *
 * @returns The start of a month
 *
 * @example
 * // The start of a month for 2 September 2014 11:55:00:
 * const result = startOfMonth(new Date(2014, 8, 2, 11, 55, 0))
 * //=> Mon Sep 01 2014 00:00:00
 */
function startOfMonth(date) {
  const _date = toDate(date);
  _date.setDate(1);
  _date.setHours(0, 0, 0, 0);
  return _date;
}

/**
 * The {@link endOfWeek} function options.
 */

/**
 * @name endOfWeek
 * @category Week Helpers
 * @summary Return the end of a week for the given date.
 *
 * @description
 * Return the end of a week for the given date.
 * The result will be in the local timezone.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The original date
 * @param options - An object with options
 *
 * @returns The end of a week
 *
 * @example
 * // The end of a week for 2 September 2014 11:55:00:
 * const result = endOfWeek(new Date(2014, 8, 2, 11, 55, 0))
 * //=> Sat Sep 06 2014 23:59:59.999
 *
 * @example
 * // If the week starts on Monday, the end of the week for 2 September 2014 11:55:00:
 * const result = endOfWeek(new Date(2014, 8, 2, 11, 55, 0), { weekStartsOn: 1 })
 * //=> Sun Sep 07 2014 23:59:59.999
 */
function endOfWeek(date, options) {
  const defaultOptions = getDefaultOptions();
  const weekStartsOn =
    options?.weekStartsOn ??
    options?.locale?.options?.weekStartsOn ??
    defaultOptions.weekStartsOn ??
    defaultOptions.locale?.options?.weekStartsOn ??
    0;

  const _date = toDate(date);
  const day = _date.getDay();
  const diff = (day < weekStartsOn ? -7 : 0) + 6 - (day - weekStartsOn);

  _date.setDate(_date.getDate() + diff);
  _date.setHours(23, 59, 59, 999);
  return _date;
}

/**
 * @name getDaysInMonth
 * @category Month Helpers
 * @summary Get the number of days in a month of the given date.
 *
 * @description
 * Get the number of days in a month of the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The given date
 *
 * @returns The number of days in a month
 *
 * @example
 * // How many days are in February 2000?
 * const result = getDaysInMonth(new Date(2000, 1))
 * //=> 29
 */
function getDaysInMonth(date) {
  const _date = toDate(date);
  const year = _date.getFullYear();
  const monthIndex = _date.getMonth();
  const lastDayOfMonth = constructFrom(date, 0);
  lastDayOfMonth.setFullYear(year, monthIndex + 1, 0);
  lastDayOfMonth.setHours(0, 0, 0, 0);
  return lastDayOfMonth.getDate();
}

/**
 * @name isAfter
 * @category Common Helpers
 * @summary Is the first date after the second one?
 *
 * @description
 * Is the first date after the second one?
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date that should be after the other one to return true
 * @param dateToCompare - The date to compare with
 *
 * @returns The first date is after the second date
 *
 * @example
 * // Is 10 July 1989 after 11 February 1987?
 * const result = isAfter(new Date(1989, 6, 10), new Date(1987, 1, 11))
 * //=> true
 */
function isAfter(date, dateToCompare) {
  const _date = toDate(date);
  const _dateToCompare = toDate(dateToCompare);
  return _date.getTime() > _dateToCompare.getTime();
}

/**
 * @name isBefore
 * @category Common Helpers
 * @summary Is the first date before the second one?
 *
 * @description
 * Is the first date before the second one?
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date that should be before the other one to return true
 * @param dateToCompare - The date to compare with
 *
 * @returns The first date is before the second date
 *
 * @example
 * // Is 10 July 1989 before 11 February 1987?
 * const result = isBefore(new Date(1989, 6, 10), new Date(1987, 1, 11))
 * //=> false
 */
function isBefore(date, dateToCompare) {
  const _date = toDate(date);
  const _dateToCompare = toDate(dateToCompare);
  return +_date < +_dateToCompare;
}

/**
 * @name isEqual
 * @category Common Helpers
 * @summary Are the given dates equal?
 *
 * @description
 * Are the given dates equal?
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param dateLeft - The first date to compare
 * @param dateRight - The second date to compare
 *
 * @returns The dates are equal
 *
 * @example
 * // Are 2 July 2014 06:30:45.000 and 2 July 2014 06:30:45.500 equal?
 * const result = isEqual(
 *   new Date(2014, 6, 2, 6, 30, 45, 0),
 *   new Date(2014, 6, 2, 6, 30, 45, 500)
 * )
 * //=> false
 */
function isEqual(leftDate, rightDate) {
  const _dateLeft = toDate(leftDate);
  const _dateRight = toDate(rightDate);
  return +_dateLeft === +_dateRight;
}

/**
 * @name setMonth
 * @category Month Helpers
 * @summary Set the month to the given date.
 *
 * @description
 * Set the month to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param month - The month index to set (0-11)
 *
 * @returns The new date with the month set
 *
 * @example
 * // Set February to 1 September 2014:
 * const result = setMonth(new Date(2014, 8, 1), 1)
 * //=> Sat Feb 01 2014 00:00:00
 */
function setMonth(date, month) {
  const _date = toDate(date);
  const year = _date.getFullYear();
  const day = _date.getDate();

  const dateWithDesiredMonth = constructFrom(date, 0);
  dateWithDesiredMonth.setFullYear(year, month, 15);
  dateWithDesiredMonth.setHours(0, 0, 0, 0);
  const daysInMonth = getDaysInMonth(dateWithDesiredMonth);
  // Set the last day of the new month
  // if the original date was the last day of the longer month
  _date.setMonth(month, Math.min(day, daysInMonth));
  return _date;
}

/**
 * @name set
 * @category Common Helpers
 * @summary Set date values to a given date.
 *
 * @description
 * Set date values to a given date.
 *
 * Sets time values to date from object `values`.
 * A value is not set if it is undefined or null or doesn't exist in `values`.
 *
 * Note about bundle size: `set` does not internally use `setX` functions from date-fns but instead opts
 * to use native `Date#setX` methods. If you use this function, you may not want to include the
 * other `setX` functions that date-fns provides if you are concerned about the bundle size.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param values - The date values to be set
 *
 * @returns The new date with options set
 *
 * @example
 * // Transform 1 September 2014 into 20 October 2015 in a single line:
 * const result = set(new Date(2014, 8, 20), { year: 2015, month: 9, date: 20 })
 * //=> Tue Oct 20 2015 00:00:00
 *
 * @example
 * // Set 12 PM to 1 September 2014 01:23:45 to 1 September 2014 12:00:00:
 * const result = set(new Date(2014, 8, 1, 1, 23, 45), { hours: 12 })
 * //=> Mon Sep 01 2014 12:23:45
 */

function set(date, values) {
  let _date = toDate(date);

  // Check if date is Invalid Date because Date.prototype.setFullYear ignores the value of Invalid Date
  if (isNaN(+_date)) {
    return constructFrom(date, NaN);
  }

  if (values.year != null) {
    _date.setFullYear(values.year);
  }

  if (values.month != null) {
    _date = setMonth(_date, values.month);
  }

  if (values.date != null) {
    _date.setDate(values.date);
  }

  if (values.hours != null) {
    _date.setHours(values.hours);
  }

  if (values.minutes != null) {
    _date.setMinutes(values.minutes);
  }

  if (values.seconds != null) {
    _date.setSeconds(values.seconds);
  }

  if (values.milliseconds != null) {
    _date.setMilliseconds(values.milliseconds);
  }

  return _date;
}

/**
 * @name setYear
 * @category Year Helpers
 * @summary Set the year to the given date.
 *
 * @description
 * Set the year to the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param year - The year of the new date
 *
 * @returns The new date with the year set
 *
 * @example
 * // Set year 2013 to 1 September 2014:
 * const result = setYear(new Date(2014, 8, 1), 2013)
 * //=> Sun Sep 01 2013 00:00:00
 */
function setYear(date, year) {
  const _date = toDate(date);

  // Check if date is Invalid Date because Date.prototype.setFullYear ignores the value of Invalid Date
  if (isNaN(+_date)) {
    return constructFrom(date, NaN);
  }

  _date.setFullYear(year);
  return _date;
}

/**
 * @name startOfToday
 * @category Day Helpers
 * @summary Return the start of today.
 * @pure false
 *
 * @description
 * Return the start of today.
 *
 * @returns The start of today
 *
 * @example
 * // If today is 6 October 2014:
 * const result = startOfToday()
 * //=> Mon Oct 6 2014 00:00:00
 */
function startOfToday() {
  return startOfDay(Date.now());
}

/**
 * @name subMonths
 * @category Month Helpers
 * @summary Subtract the specified number of months from the given date.
 *
 * @description
 * Subtract the specified number of months from the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of months to be subtracted.
 *
 * @returns The new date with the months subtracted
 *
 * @example
 * // Subtract 5 months from 1 February 2015:
 * const result = subMonths(new Date(2015, 1, 1), 5)
 * //=> Mon Sep 01 2014 00:00:00
 */
function subMonths(date, amount) {
  return addMonths(date, -amount);
}

/**
 * @name subYears
 * @category Year Helpers
 * @summary Subtract the specified number of years from the given date.
 *
 * @description
 * Subtract the specified number of years from the given date.
 *
 * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
 *
 * @param date - The date to be changed
 * @param amount - The amount of years to be subtracted.
 *
 * @returns The new date with the years subtracted
 *
 * @example
 * // Subtract 5 years from 1 September 2014:
 * const result = subYears(new Date(2014, 8, 1), 5)
 * //=> Tue Sep 01 2009 00:00:00
 */
function subYears(date, amount) {
  return addYears(date, -amount);
}

var Month;
(function (Month) {
    Month[Month["JANUARY"] = 0] = "JANUARY";
    Month[Month["FEBRUARY"] = 1] = "FEBRUARY";
    Month[Month["MARCH"] = 2] = "MARCH";
    Month[Month["APRIL"] = 3] = "APRIL";
    Month[Month["MAY"] = 4] = "MAY";
    Month[Month["JUNE"] = 5] = "JUNE";
    Month[Month["JULY"] = 6] = "JULY";
    Month[Month["AUGUST"] = 7] = "AUGUST";
    Month[Month["SEPTEMBER"] = 8] = "SEPTEMBER";
    Month[Month["OCTOBER"] = 9] = "OCTOBER";
    Month[Month["NOVEMBER"] = 10] = "NOVEMBER";
    Month[Month["DECEMBER"] = 11] = "DECEMBER";
})(Month || (Month = {}));
var Day;
(function (Day) {
    Day[Day["SUNDAY"] = 0] = "SUNDAY";
    Day[Day["MONDAY"] = 1] = "MONDAY";
    Day[Day["TUESDAY"] = 2] = "TUESDAY";
    Day[Day["WEDNESDAY"] = 3] = "WEDNESDAY";
    Day[Day["THURSDAY"] = 4] = "THURSDAY";
    Day[Day["FRIDAY"] = 5] = "FRIDAY";
    Day[Day["SATURDAY"] = 6] = "SATURDAY";
})(Day || (Day = {}));
var inRange = function (date, min, max) {
    return (isEqual(date, min) || isAfter(date, min)) && (isEqual(date, max) || isBefore(date, max));
};
var clearTime = function (date) { return set(date, { hours: 0, minutes: 0, seconds: 0, milliseconds: 0 }); };
var useLilius = function (_a) {
    var _b = _a === void 0 ? {} : _a, _c = _b.weekStartsOn, weekStartsOn = _c === void 0 ? Day.SUNDAY : _c, _d = _b.viewing, initialViewing = _d === void 0 ? new Date() : _d, _e = _b.selected, initialSelected = _e === void 0 ? [] : _e, _f = _b.numberOfMonths, numberOfMonths = _f === void 0 ? 1 : _f;
    var _g = useState(initialViewing), viewing = _g[0], setViewing = _g[1];
    var viewToday = useCallback(function () { return setViewing(startOfToday()); }, [setViewing]);
    var viewMonth = useCallback(function (month) { return setViewing(function (v) { return setMonth(v, month); }); }, []);
    var viewPreviousMonth = useCallback(function () { return setViewing(function (v) { return subMonths(v, 1); }); }, []);
    var viewNextMonth = useCallback(function () { return setViewing(function (v) { return addMonths(v, 1); }); }, []);
    var viewYear = useCallback(function (year) { return setViewing(function (v) { return setYear(v, year); }); }, []);
    var viewPreviousYear = useCallback(function () { return setViewing(function (v) { return subYears(v, 1); }); }, []);
    var viewNextYear = useCallback(function () { return setViewing(function (v) { return addYears(v, 1); }); }, []);
    var _h = useState(initialSelected.map(clearTime)), selected = _h[0], setSelected = _h[1];
    var clearSelected = function () { return setSelected([]); };
    var isSelected = useCallback(function (date) { return selected.findIndex(function (s) { return isEqual(s, date); }) > -1; }, [selected]);
    var select = useCallback(function (date, replaceExisting) {
        if (replaceExisting) {
            setSelected(Array.isArray(date) ? date : [date]);
        }
        else {
            setSelected(function (selectedItems) { return selectedItems.concat(Array.isArray(date) ? date : [date]); });
        }
    }, []);
    var deselect = useCallback(function (date) {
        return setSelected(function (selectedItems) {
            return Array.isArray(date)
                ? selectedItems.filter(function (s) { return !date.map(function (d) { return d.getTime(); }).includes(s.getTime()); })
                : selectedItems.filter(function (s) { return !isEqual(s, date); });
        });
    }, []);
    var toggle = useCallback(function (date, replaceExisting) { return (isSelected(date) ? deselect(date) : select(date, replaceExisting)); }, [deselect, isSelected, select]);
    var selectRange = useCallback(function (start, end, replaceExisting) {
        if (replaceExisting) {
            setSelected(eachDayOfInterval({ start: start, end: end }));
        }
        else {
            setSelected(function (selectedItems) { return selectedItems.concat(eachDayOfInterval({ start: start, end: end })); });
        }
    }, []);
    var deselectRange = useCallback(function (start, end) {
        setSelected(function (selectedItems) {
            return selectedItems.filter(function (s) {
                return !eachDayOfInterval({ start: start, end: end })
                    .map(function (d) { return d.getTime(); })
                    .includes(s.getTime());
            });
        });
    }, []);
    var calendar = useMemo(function () {
        return eachMonthOfInterval({
            start: startOfMonth(viewing),
            end: endOfMonth(addMonths(viewing, numberOfMonths - 1)),
        }).map(function (month) {
            return eachWeekOfInterval({
                start: startOfMonth(month),
                end: endOfMonth(month),
            }, { weekStartsOn: weekStartsOn }).map(function (week) {
                return eachDayOfInterval({
                    start: startOfWeek(week, { weekStartsOn: weekStartsOn }),
                    end: endOfWeek(week, { weekStartsOn: weekStartsOn }),
                });
            });
        });
    }, [viewing, weekStartsOn, numberOfMonths]);
    return {
        clearTime: clearTime,
        inRange: inRange,
        viewing: viewing,
        setViewing: setViewing,
        viewToday: viewToday,
        viewMonth: viewMonth,
        viewPreviousMonth: viewPreviousMonth,
        viewNextMonth: viewNextMonth,
        viewYear: viewYear,
        viewPreviousYear: viewPreviousYear,
        viewNextYear: viewNextYear,
        selected: selected,
        setSelected: setSelected,
        clearSelected: clearSelected,
        isSelected: isSelected,
        select: select,
        deselect: deselect,
        toggle: toggle,
        selectRange: selectRange,
        deselectRange: deselectRange,
        calendar: calendar,
    };
};

export { Day, Month, useLilius };
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