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node_modules/@internationalized/date/src/conversion.ts

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+/*
+ * Copyright 2020 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+
+// Portions of the code in this file are based on code from the TC39 Temporal proposal.
+// Original licensing can be found in the NOTICE file in the root directory of this source tree.
+
+import {AnyCalendarDate, AnyDateTime, AnyTime, Calendar, DateFields, Disambiguation, TimeFields} from './types';
+import {CalendarDate, CalendarDateTime, Time, ZonedDateTime} from './CalendarDate';
+import {constrain} from './manipulation';
+import {getExtendedYear, GregorianCalendar} from './calendars/GregorianCalendar';
+import {getLocalTimeZone, isEqualCalendar} from './queries';
+import {Mutable} from './utils';
+
+export function epochFromDate(date: AnyDateTime): number {
+  date = toCalendar(date, new GregorianCalendar());
+  let year = getExtendedYear(date.era, date.year);
+  return epochFromParts(year, date.month, date.day, date.hour, date.minute, date.second, date.millisecond);
+}
+
+function epochFromParts(year: number, month: number, day: number, hour: number, minute: number, second: number, millisecond: number): number {
+  // Note: Date.UTC() interprets one and two-digit years as being in the
+  // 20th century, so don't use it
+  let date = new Date();
+  date.setUTCHours(hour, minute, second, millisecond);
+  date.setUTCFullYear(year, month - 1, day);
+  return date.getTime();
+}
+
+export function getTimeZoneOffset(ms: number, timeZone: string): number {
+  // Fast path for UTC.
+  if (timeZone === 'UTC') {
+    return 0;
+  }
+
+  // Fast path: for local timezone after 1970, use native Date.
+  if (ms > 0 && timeZone === getLocalTimeZone()) {
+    return new Date(ms).getTimezoneOffset() * -60 * 1000;
+  }
+
+  let {year, month, day, hour, minute, second} = getTimeZoneParts(ms, timeZone);
+  let utc = epochFromParts(year, month, day, hour, minute, second, 0);
+  return utc - Math.floor(ms / 1000) * 1000;
+}
+
+const formattersByTimeZone = new Map<string, Intl.DateTimeFormat>();
+
+function getTimeZoneParts(ms: number, timeZone: string) {
+  let formatter = formattersByTimeZone.get(timeZone);
+  if (!formatter) {
+    formatter = new Intl.DateTimeFormat('en-US', {
+      timeZone,
+      hour12: false,
+      era: 'short',
+      year: 'numeric',
+      month: 'numeric',
+      day: 'numeric',
+      hour: 'numeric',
+      minute: 'numeric',
+      second: 'numeric'
+    });
+
+    formattersByTimeZone.set(timeZone, formatter);
+  }
+
+  let parts = formatter.formatToParts(new Date(ms));
+  let namedParts: {[name: string]: string} = {};
+  for (let part of parts) {
+    if (part.type !== 'literal') {
+      namedParts[part.type] = part.value;
+    }
+  }
+
+
+  return {
+    // Firefox returns B instead of BC... https://bugzilla.mozilla.org/show_bug.cgi?id=1752253
+    year: namedParts.era === 'BC' || namedParts.era === 'B' ? -namedParts.year + 1 : +namedParts.year,
+    month: +namedParts.month,
+    day: +namedParts.day,
+    hour: namedParts.hour === '24' ? 0 : +namedParts.hour, // bugs.chromium.org/p/chromium/issues/detail?id=1045791
+    minute: +namedParts.minute,
+    second: +namedParts.second
+  };
+}
+
+const DAYMILLIS = 86400000;
+
+export function possibleAbsolutes(date: CalendarDateTime, timeZone: string): number[] {
+  let ms = epochFromDate(date);
+  let earlier = ms - getTimeZoneOffset(ms - DAYMILLIS, timeZone);
+  let later = ms - getTimeZoneOffset(ms + DAYMILLIS, timeZone);
+  return getValidWallTimes(date, timeZone, earlier, later);
+}
+
+function getValidWallTimes(date: CalendarDateTime, timeZone: string, earlier: number, later: number): number[] {
+  let found = earlier === later ? [earlier] : [earlier, later];
+  return found.filter(absolute => isValidWallTime(date, timeZone, absolute));
+}
+
+function isValidWallTime(date: CalendarDateTime, timeZone: string, absolute: number) {
+  let parts = getTimeZoneParts(absolute, timeZone);
+  return date.year === parts.year
+    && date.month === parts.month
+    && date.day === parts.day
+    && date.hour === parts.hour
+    && date.minute === parts.minute
+    && date.second === parts.second;
+}
+
+export function toAbsolute(date: CalendarDate | CalendarDateTime, timeZone: string, disambiguation: Disambiguation = 'compatible'): number {
+  let dateTime = toCalendarDateTime(date);
+
+  // Fast path: if the time zone is UTC, use native Date.
+  if (timeZone === 'UTC') {
+    return epochFromDate(dateTime);
+  }
+
+  // Fast path: if the time zone is the local timezone and disambiguation is compatible, use native Date.
+  if (timeZone === getLocalTimeZone() && disambiguation === 'compatible') {
+    dateTime = toCalendar(dateTime, new GregorianCalendar());
+
+    // Don't use Date constructor here because two-digit years are interpreted in the 20th century.
+    let date = new Date();
+    let year = getExtendedYear(dateTime.era, dateTime.year);
+    date.setFullYear(year, dateTime.month - 1, dateTime.day);
+    date.setHours(dateTime.hour, dateTime.minute, dateTime.second, dateTime.millisecond);
+    return date.getTime();
+  }
+
+  let ms = epochFromDate(dateTime);
+  let offsetBefore = getTimeZoneOffset(ms - DAYMILLIS, timeZone);
+  let offsetAfter = getTimeZoneOffset(ms + DAYMILLIS, timeZone);
+  let valid = getValidWallTimes(dateTime, timeZone, ms - offsetBefore, ms - offsetAfter);
+
+  if (valid.length === 1) {
+    return valid[0];
+  }
+
+  if (valid.length > 1) {
+    switch (disambiguation) {
+      // 'compatible' means 'earlier' for "fall back" transitions
+      case 'compatible':
+      case 'earlier':
+        return valid[0];
+      case 'later':
+        return valid[valid.length - 1];
+      case 'reject':
+        throw new RangeError('Multiple possible absolute times found');
+    }
+  }
+
+  switch (disambiguation) {
+    case 'earlier':
+      return Math.min(ms - offsetBefore, ms - offsetAfter);
+    // 'compatible' means 'later' for "spring forward" transitions
+    case 'compatible':
+    case 'later':
+      return Math.max(ms - offsetBefore, ms - offsetAfter);
+    case 'reject':
+      throw new RangeError('No such absolute time found');
+  }
+}
+
+export function toDate(dateTime: CalendarDate | CalendarDateTime, timeZone: string, disambiguation: Disambiguation = 'compatible'): Date {
+  return new Date(toAbsolute(dateTime, timeZone, disambiguation));
+}
+
+/**
+ * Takes a Unix epoch (milliseconds since 1970) and converts it to the provided time zone.
+ */
+export function fromAbsolute(ms: number, timeZone: string): ZonedDateTime {
+  let offset = getTimeZoneOffset(ms, timeZone);
+  let date = new Date(ms + offset);
+  let year = date.getUTCFullYear();
+  let month = date.getUTCMonth() + 1;
+  let day = date.getUTCDate();
+  let hour = date.getUTCHours();
+  let minute = date.getUTCMinutes();
+  let second = date.getUTCSeconds();
+  let millisecond = date.getUTCMilliseconds();
+
+  return new ZonedDateTime(year < 1 ? 'BC' : 'AD', year < 1 ? -year + 1 : year, month, day, timeZone, offset, hour, minute, second, millisecond);
+}
+
+/**
+ * Takes a `Date` object and converts it to the provided time zone.
+ */
+export function fromDate(date: Date, timeZone: string): ZonedDateTime {
+  return fromAbsolute(date.getTime(), timeZone);
+}
+
+export function fromDateToLocal(date: Date): ZonedDateTime {
+  return fromDate(date, getLocalTimeZone());
+}
+
+/** Converts a value with date components such as a `CalendarDateTime` or `ZonedDateTime` into a `CalendarDate`. */
+export function toCalendarDate(dateTime: AnyCalendarDate): CalendarDate {
+  return new CalendarDate(dateTime.calendar, dateTime.era, dateTime.year, dateTime.month, dateTime.day);
+}
+
+export function toDateFields(date: AnyCalendarDate): DateFields {
+  return {
+    era: date.era,
+    year: date.year,
+    month: date.month,
+    day: date.day
+  };
+}
+
+export function toTimeFields(date: AnyTime): TimeFields {
+  return {
+    hour: date.hour,
+    minute: date.minute,
+    second: date.second,
+    millisecond: date.millisecond
+  };
+}
+
+/**
+ * Converts a date value to a `CalendarDateTime`. An optional `Time` value can be passed to set the time
+ * of the resulting value, otherwise it will default to midnight.
+ */
+export function toCalendarDateTime(date: CalendarDate | CalendarDateTime | ZonedDateTime, time?: AnyTime): CalendarDateTime {
+  let hour = 0, minute = 0, second = 0, millisecond = 0;
+  if ('timeZone' in date) {
+    ({hour, minute, second, millisecond} = date);
+  } else if ('hour' in date && !time) {
+    return date;
+  }
+
+  if (time) {
+    ({hour, minute, second, millisecond} = time);
+  }
+
+  return new CalendarDateTime(
+    date.calendar,
+    date.era,
+    date.year,
+    date.month,
+    date.day,
+    hour,
+    minute,
+    second,
+    millisecond
+  );
+}
+
+/** Extracts the time components from a value containing a date and time. */
+export function toTime(dateTime: CalendarDateTime | ZonedDateTime): Time {
+  return new Time(dateTime.hour, dateTime.minute, dateTime.second, dateTime.millisecond);
+}
+
+/** Converts a date from one calendar system to another. */
+export function toCalendar<T extends AnyCalendarDate>(date: T, calendar: Calendar): T {
+  if (isEqualCalendar(date.calendar, calendar)) {
+    return date;
+  }
+
+  let calendarDate = calendar.fromJulianDay(date.calendar.toJulianDay(date));
+  let copy: Mutable<T> = date.copy();
+  copy.calendar = calendar;
+  copy.era = calendarDate.era;
+  copy.year = calendarDate.year;
+  copy.month = calendarDate.month;
+  copy.day = calendarDate.day;
+  constrain(copy);
+  return copy;
+}
+
+/**
+ * Converts a date value to a `ZonedDateTime` in the provided time zone. The `disambiguation` option can be set
+ * to control how values that fall on daylight saving time changes are interpreted.
+ */
+export function toZoned(date: CalendarDate | CalendarDateTime | ZonedDateTime, timeZone: string, disambiguation?: Disambiguation): ZonedDateTime {
+  if (date instanceof ZonedDateTime) {
+    if (date.timeZone === timeZone) {
+      return date;
+    }
+
+    return toTimeZone(date, timeZone);
+  }
+
+  let ms = toAbsolute(date, timeZone, disambiguation);
+  return fromAbsolute(ms, timeZone);
+}
+
+export function zonedToDate(date: ZonedDateTime): Date {
+  let ms = epochFromDate(date) - date.offset;
+  return new Date(ms);
+}
+
+/** Converts a `ZonedDateTime` from one time zone to another. */
+export function toTimeZone(date: ZonedDateTime, timeZone: string): ZonedDateTime {
+  let ms = epochFromDate(date) - date.offset;
+  return toCalendar(fromAbsolute(ms, timeZone), date.calendar);
+}
+
+/** Converts the given `ZonedDateTime` into the user's local time zone. */
+export function toLocalTimeZone(date: ZonedDateTime): ZonedDateTime {
+  return toTimeZone(date, getLocalTimeZone());
+}