/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {Inject, Injectable, LOCALE_ID, Pipe, PipeTransform} from '@angular/core';
import {formatDate} from '../i18n/format_date';
import {invalidPipeArgumentError} from './invalid_pipe_argument_error';

// clang-format off
/**
 * @ngModule CommonModule
 * @description
 *
 * Formats a date value according to locale rules.
 *
 * Only the `en-US` locale data comes with Angular. To localize dates
 * in another language, you must import the corresponding locale data.
 * See the [I18n guide](guide/i18n#i18n-pipes) for more information.
 *
 * @see `formatDate()`
 *
 *
 * @usageNotes
 *
 * The result of this pipe is not reevaluated when the input is mutated. To avoid the need to
 * reformat the date on every change-detection cycle, treat the date as an immutable object
 * and change the reference when the pipe needs to run again.
 *
 * ### Pre-defined format options
 *
 * Examples are given in `en-US` locale.
 *
 * - `'short'`: equivalent to `'M/d/yy, h:mm a'` (`6/15/15, 9:03 AM`).
 * - `'medium'`: equivalent to `'MMM d, y, h:mm:ss a'` (`Jun 15, 2015, 9:03:01 AM`).
 * - `'long'`: equivalent to `'MMMM d, y, h:mm:ss a z'` (`June 15, 2015 at 9:03:01 AM
 * GMT+1`).
 * - `'full'`: equivalent to `'EEEE, MMMM d, y, h:mm:ss a zzzz'` (`Monday, June 15, 2015 at
 * 9:03:01 AM GMT+01:00`).
 * - `'shortDate'`: equivalent to `'M/d/yy'` (`6/15/15`).
 * - `'mediumDate'`: equivalent to `'MMM d, y'` (`Jun 15, 2015`).
 * - `'longDate'`: equivalent to `'MMMM d, y'` (`June 15, 2015`).
 * - `'fullDate'`: equivalent to `'EEEE, MMMM d, y'` (`Monday, June 15, 2015`).
 * - `'shortTime'`: equivalent to `'h:mm a'` (`9:03 AM`).
 * - `'mediumTime'`: equivalent to `'h:mm:ss a'` (`9:03:01 AM`).
 * - `'longTime'`: equivalent to `'h:mm:ss a z'` (`9:03:01 AM GMT+1`).
 * - `'fullTime'`: equivalent to `'h:mm:ss a zzzz'` (`9:03:01 AM GMT+01:00`).
 *
 * ### Custom format options
 *
 * You can construct a format string using symbols to specify the components
 * of a date-time value, as described in the following table.
 * Format details depend on the locale.
 * Fields marked with (*) are only available in the extra data set for the given locale.
 *
 *  | Field type         | Format      | Description                                                   | Example Value                                              |
 *  |--------------------|-------------|---------------------------------------------------------------|------------------------------------------------------------|
 *  | Era                | G, GG & GGG | Abbreviated                                                   | AD                                                         |
 *  |                    | GGGG        | Wide                                                          | Anno Domini                                                |
 *  |                    | GGGGG       | Narrow                                                        | A                                                          |
 *  | Year               | y           | Numeric: minimum digits                                       | 2, 20, 201, 2017, 20173                                    |
 *  |                    | yy          | Numeric: 2 digits + zero padded                               | 02, 20, 01, 17, 73                                         |
 *  |                    | yyy         | Numeric: 3 digits + zero padded                               | 002, 020, 201, 2017, 20173                                 |
 *  |                    | yyyy        | Numeric: 4 digits or more + zero padded                       | 0002, 0020, 0201, 2017, 20173                              |
 *  | Month              | M           | Numeric: 1 digit                                              | 9, 12                                                      |
 *  |                    | MM          | Numeric: 2 digits + zero padded                               | 09, 12                                                     |
 *  |                    | MMM         | Abbreviated                                                   | Sep                                                        |
 *  |                    | MMMM        | Wide                                                          | September                                                  |
 *  |                    | MMMMM       | Narrow                                                        | S                                                          |
 *  | Month standalone   | L           | Numeric: 1 digit                                              | 9, 12                                                      |
 *  |                    | LL          | Numeric: 2 digits + zero padded                               | 09, 12                                                     |
 *  |                    | LLL         | Abbreviated                                                   | Sep                                                        |
 *  |                    | LLLL        | Wide                                                          | September                                                  |
 *  |                    | LLLLL       | Narrow                                                        | S                                                          |
 *  | Week of year       | w           | Numeric: minimum digits                                       | 1... 53                                                    |
 *  |                    | ww          | Numeric: 2 digits + zero padded                               | 01... 53                                                   |
 *  | Week of month      | W           | Numeric: 1 digit                                              | 1... 5                                                     |
 *  | Day of month       | d           | Numeric: minimum digits                                       | 1                                                          |
 *  |                    | dd          | Numeric: 2 digits + zero padded                               | 01                                                          |
 *  | Week day           | E, EE & EEE | Abbreviated                                                   | Tue                                                        |
 *  |                    | EEEE        | Wide                                                          | Tuesday                                                    |
 *  |                    | EEEEE       | Narrow                                                        | T                                                          |
 *  |                    | EEEEEE      | Short                                                         | Tu                                                         |
 *  | Period             | a, aa & aaa | Abbreviated                                                   | am/pm or AM/PM                                             |
 *  |                    | aaaa        | Wide (fallback to `a` when missing)                           | ante meridiem/post meridiem                                |
 *  |                    | aaaaa       | Narrow                                                        | a/p                                                        |
 *  | Period*            | B, BB & BBB | Abbreviated                                                   | mid.                                                       |
 *  |                    | BBBB        | Wide                                                          | am, pm, midnight, noon, morning, afternoon, evening, night |
 *  |                    | BBBBB       | Narrow                                                        | md                                                         |
 *  | Period standalone* | b, bb & bbb | Abbreviated                                                   | mid.                                                       |
 *  |                    | bbbb        | Wide                                                          | am, pm, midnight, noon, morning, afternoon, evening, night |
 *  |                    | bbbbb       | Narrow                                                        | md                                                         |
 *  | Hour 1-12          | h           | Numeric: minimum digits                                       | 1, 12                                                      |
 *  |                    | hh          | Numeric: 2 digits + zero padded                               | 01, 12                                                     |
 *  | Hour 0-23          | H           | Numeric: minimum digits                                       | 0, 23                                                      |
 *  |                    | HH          | Numeric: 2 digits + zero padded                               | 00, 23                                                     |
 *  | Minute             | m           | Numeric: minimum digits                                       | 8, 59                                                      |
 *  |                    | mm          | Numeric: 2 digits + zero padded                               | 08, 59                                                     |
 *  | Second             | s           | Numeric: minimum digits                                       | 0... 59                                                    |
 *  |                    | ss          | Numeric: 2 digits + zero padded                               | 00... 59                                                   |
 *  | Fractional seconds | S           | Numeric: 1 digit                                              | 0... 9                                                     |
 *  |                    | SS          | Numeric: 2 digits + zero padded                               | 00... 99                                                   |
 *  |                    | SSS         | Numeric: 3 digits + zero padded (= milliseconds)              | 000... 999                                                 |
 *  | Zone               | z, zz & zzz | Short specific non location format (fallback to O)            | GMT-8                                                      |
 *  |                    | zzzz        | Long specific non location format (fallback to OOOO)          | GMT-08:00                                                  |
 *  |                    | Z, ZZ & ZZZ | ISO8601 basic format                                          | -0800                                                      |
 *  |                    | ZZZZ        | Long localized GMT format                                     | GMT-8:00                                                   |
 *  |                    | ZZZZZ       | ISO8601 extended format + Z indicator for offset 0 (= XXXXX)  | -08:00                                                     |
 *  |                    | O, OO & OOO | Short localized GMT format                                    | GMT-8                                                      |
 *  |                    | OOOO        | Long localized GMT format                                     | GMT-08:00                                                  |
 *
 * Note that timezone correction is not applied to an ISO string that has no time component, such as "2016-09-19"
 *
 * ### Format examples
 *
 * These examples transform a date into various formats,
 * assuming that `dateObj` is a JavaScript `Date` object for
 * year: 2015, month: 6, day: 15, hour: 21, minute: 43, second: 11,
 * given in the local time for the `en-US` locale.
 *
 * ```
 * {{ dateObj | date }}               // output is 'Jun 15, 2015'
 * {{ dateObj | date:'medium' }}      // output is 'Jun 15, 2015, 9:43:11 PM'
 * {{ dateObj | date:'shortTime' }}   // output is '9:43 PM'
 * {{ dateObj | date:'mm:ss' }}       // output is '43:11'
 * ```
 *
 * ### Usage example
 *
 * The following component uses a date pipe to display the current date in different formats.
 *
 * ```
 * @Component({
 *  selector: 'date-pipe',
 *  template: `<div>
 *    <p>Today is {{today | date}}</p>
 *    <p>Or if you prefer, {{today | date:'fullDate'}}</p>
 *    <p>The time is {{today | date:'h:mm a z'}}</p>
 *  </div>`
 * })
 * // Get the current date and time as a date-time value.
 * export class DatePipeComponent {
 *   today: number = Date.now();
 * }
 * ```
 *
 * @publicApi
 */
// clang-format on
@Injectable()
@Pipe({name: 'date', pure: true})
export class DatePipe implements PipeTransform {
  constructor(@Inject(LOCALE_ID) private locale: string) {}

  /**
   * @param value The date expression: a `Date` object,  a number
   * (milliseconds since UTC epoch), or an ISO string (https://www.w3.org/TR/NOTE-datetime).
   * @param format The date/time components to include, using predefined options or a
   * custom format string.
   * @param timezone A timezone offset (such as `'+0430'`), or a standard
   * UTC/GMT or continental US timezone abbreviation. Default is
   * the local system timezone of the end-user's machine.
   * @param locale A locale code for the locale format rules to use.
   * When not supplied, uses the value of `LOCALE_ID`, which is `en-US` by default.
   * See [Setting your app locale](guide/i18n#setting-up-the-locale-of-your-app).
   * @returns A date string in the desired format.
   */
  transform(value: any, format = 'mediumDate', timezone?: string, locale?: string): string|null {
    if (value == null || value === '' || value !== value) return null;

    try {
      return formatDate(value, format, locale || this.locale, timezone);
    } catch (error) {
      throw invalidPipeArgumentError(DatePipe, error.message);
    }
  }
}
