// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// Tests the DateFormat library in dart. This file contains core tests that are
/// run regardless of where the locale data is found, so it doesn't expect to be
/// run on its own, but rather to be imported and run from another test file.

library date_time_format_tests;

import 'package:clock/clock.dart';
import 'package:intl/intl.dart';
import 'package:test/test.dart';
import 'date_time_format_test_data.dart';

var formatsToTest = const [
  DateFormat.DAY,
  DateFormat.ABBR_WEEKDAY,
  DateFormat.WEEKDAY,
  DateFormat.ABBR_STANDALONE_MONTH,
  DateFormat.STANDALONE_MONTH,
  DateFormat.NUM_MONTH,
  DateFormat.NUM_MONTH_DAY,
  DateFormat.NUM_MONTH_WEEKDAY_DAY,
  DateFormat.ABBR_MONTH,
  DateFormat.ABBR_MONTH_DAY,
  DateFormat.ABBR_MONTH_WEEKDAY_DAY,
  DateFormat.MONTH,
  DateFormat.MONTH_DAY,
  DateFormat.MONTH_WEEKDAY_DAY,
  DateFormat.ABBR_QUARTER,
  DateFormat.QUARTER,
  DateFormat.YEAR,
  DateFormat.YEAR_NUM_MONTH,
  DateFormat.YEAR_NUM_MONTH_DAY,
  DateFormat.YEAR_NUM_MONTH_WEEKDAY_DAY,
  DateFormat.YEAR_ABBR_MONTH,
  DateFormat.YEAR_ABBR_MONTH_DAY,
  DateFormat.YEAR_ABBR_MONTH_WEEKDAY_DAY,
  DateFormat.YEAR_MONTH,
  DateFormat.YEAR_MONTH_DAY,
  DateFormat.YEAR_MONTH_WEEKDAY_DAY,
  // TODO(alanknight): CLDR and ICU appear to disagree on these for Japanese
  //    DateFormat.YEAR_ABBR_QUARTER,
  //    DateFormat.YEAR_QUARTER,
  DateFormat.HOUR24,
  DateFormat.HOUR24_MINUTE,
  DateFormat.HOUR24_MINUTE_SECOND,
  DateFormat.HOUR,
  DateFormat.HOUR_MINUTE,
  DateFormat.HOUR_MINUTE_SECOND,
  // TODO(alanknight): Time zone support
  //    DateFormat.HOUR_MINUTE_GENERIC_TZ,
  //    DateFormat.HOUR_MINUTE_TZ,
  //    DateFormat.HOUR_GENERIC_TZ,
  //    DateFormat.HOUR_TZ,
  DateFormat.MINUTE,
  DateFormat.MINUTE_SECOND,
  DateFormat.SECOND
  // ABBR_GENERIC_TZ,
  // GENERIC_TZ,
  // ABBR_SPECIFIC_TZ,
  // SPECIFIC_TZ,
  // ABBR_UTC_TZ
];

var icuFormatNamesToTest = const [
  // It would be really nice to not have to duplicate this and just be able
  // to use the names to get reflective access.
  'DAY',
  'ABBR_WEEKDAY',
  'WEEKDAY',
  'ABBR_STANDALONE_MONTH',
  'STANDALONE_MONTH',
  'NUM_MONTH',
  'NUM_MONTH_DAY',
  'NUM_MONTH_WEEKDAY_DAY',
  'ABBR_MONTH',
  'ABBR_MONTH_DAY',
  'ABBR_MONTH_WEEKDAY_DAY',
  'MONTH',
  'MONTH_DAY',
  'MONTH_WEEKDAY_DAY',
  'ABBR_QUARTER',
  'QUARTER',
  'YEAR',
  'YEAR_NUM_MONTH',
  'YEAR_NUM_MONTH_DAY',
  'YEAR_NUM_MONTH_WEEKDAY_DAY',
  'YEAR_ABBR_MONTH',
  'YEAR_ABBR_MONTH_DAY',
  'YEAR_ABBR_MONTH_WEEKDAY_DAY',
  'YEAR_MONTH',
  'YEAR_MONTH_DAY',
  'YEAR_MONTH_WEEKDAY_DAY',
  // TODO(alanknight): CLDR and ICU appear to disagree on these for Japanese.
  // omit for the time being
  //    'YEAR_ABBR_QUARTER',
  //    'YEAR_QUARTER',
  'HOUR24',
  'HOUR24_MINUTE',
  'HOUR24_MINUTE_SECOND',
  'HOUR',
  'HOUR_MINUTE',
  'HOUR_MINUTE_SECOND',
  // TODO(alanknight): Time zone support
  //    'HOUR_MINUTE_GENERIC_TZ',
  //    'HOUR_MINUTE_TZ',
  //    'HOUR_GENERIC_TZ',
  //    'HOUR_TZ',
  'MINUTE',
  'MINUTE_SECOND',
  'SECOND'
  // ABBR_GENERIC_TZ,
  // GENERIC_TZ,
  // ABBR_SPECIFIC_TZ,
  // SPECIFIC_TZ,
  // ABBR_UTC_TZ
];

/// Exercise all of the formats we have explicitly defined on a particular
/// locale. [expectedResults] is a map from ICU format names to the
/// expected result of formatting [date] according to that format in
/// [localeName].
void testLocale(
    String localeName, Map<String, String> expectedResults, DateTime date) {
  var intl = Intl(localeName);
  for (var i = 0; i < formatsToTest.length; i++) {
    var skeleton = formatsToTest[i];
    var format = intl.date(skeleton);
    var icuName = icuFormatNamesToTest[i];
    var actualResult = format.format(date);
    expect(expectedResults[icuName], equals(actualResult),
        reason: 'Mismatch in $localeName, testing skeleton "$skeleton"');
  }
}

void testRoundTripParsing(String localeName, DateTime date,
    [bool forceAscii = false]) {
  // In order to test parsing, we can't just read back the date, because
  // printing in most formats loses information. But we can test that
  // what we parsed back prints the same as what we originally printed.
  // At least in most cases. In some cases, we can't even do that. e.g.
  // the skeleton WEEKDAY can't be reconstructed at all, and YEAR_MONTH
  // formats don't give us enough information to construct a valid date.
  var badSkeletons = const [
    DateFormat.ABBR_WEEKDAY,
    DateFormat.WEEKDAY,
    DateFormat.QUARTER,
    DateFormat.ABBR_QUARTER,
    DateFormat.YEAR,
    DateFormat.YEAR_NUM_MONTH,
    DateFormat.YEAR_ABBR_MONTH,
    DateFormat.YEAR_MONTH,
    DateFormat.MONTH_WEEKDAY_DAY,
    DateFormat.NUM_MONTH_WEEKDAY_DAY,
    DateFormat.ABBR_MONTH_WEEKDAY_DAY
  ];
  for (var i = 0; i < formatsToTest.length; i++) {
    var skeleton = formatsToTest[i];
    if (!badSkeletons.any((x) => x == skeleton)) {
      var format = DateFormat(skeleton, localeName);
      if (forceAscii) format.useNativeDigits = false;
      var actualResult = format.format(date);
      var parsed = format.parseStrict(actualResult);
      var thenPrintAgain = format.format(parsed);
      expect(thenPrintAgain, equals(actualResult));
    }
  }
}

/// A shortcut for returning all the locales we have available.
List<String> allLocales() => DateFormat.allLocalesWithSymbols();

typedef SubsetFuncType = List<String> Function();
SubsetFuncType _subsetFunc;

List<String> _subsetValue;

List<String> get subset {
  return _subsetValue ??= _subsetFunc();
}

// TODO(alanknight): Run specific tests for the en_ISO locale which isn't
// included in CLDR, and check that our patterns for it are correct (they
// very likely aren't).
void runDateTests(SubsetFuncType subsetFunc) {
  assert(subsetFunc != null);
  _subsetFunc = subsetFunc;

  test('Multiple patterns', () {
    var date = DateTime.now();
    var multiple1 = DateFormat.yMd().add_jms();
    var multiple2 = DateFormat('yMd').add_jms();
    var separate1 = DateFormat.yMd();
    var separate2 = DateFormat.jms();
    var separateFormat = '${separate1.format(date)} ${separate2.format(date)}';
    expect(multiple1.format(date), equals(multiple2.format(date)));
    expect(multiple1.format(date), equals(separateFormat));
    var customPunctuation = DateFormat('yMd').addPattern('jms', ':::');
    var custom = '${separate1.format(date)}:::${separate2.format(date)}';
    expect(customPunctuation.format(date), equals(custom));
  });

  test('Basic date format parsing', () {
    var dateFormat = DateFormat('d');
    expect(dateFormat.parsePattern('hh:mm:ss').map((x) => x.pattern).toList(),
        orderedEquals(['hh', ':', 'mm', ':', 'ss']));
    expect(dateFormat.parsePattern('hh:mm:ss').map((x) => x.pattern).toList(),
        orderedEquals(['hh', ':', 'mm', ':', 'ss']));
  });

  test('Two-digit years', () {
    withClock(Clock.fixed(DateTime(2000, 1, 1)), () {
      var dateFormat = DateFormat('yy');
      expect(dateFormat.parse('99'), DateTime(1999));
      expect(dateFormat.parse('00'), DateTime(2000));
      expect(dateFormat.parse('19'), DateTime(2019));
      expect(dateFormat.parse('20'), DateTime(2020));
      expect(dateFormat.parse('21'), DateTime(1921));

      expect(dateFormat.parse('2000'), DateTime(2000));

      dateFormat = DateFormat('MM-dd-yy');
      expect(dateFormat.parse('12-31-19'), DateTime(2019, 12, 31));
      expect(dateFormat.parse('1-1-20'), DateTime(2020, 1, 1));
      expect(dateFormat.parse('1-2-20'), DateTime(1920, 1, 2));

      expect(DateFormat('y').parse('99'), DateTime(99));
      expect(DateFormat('yyy').parse('99'), DateTime(99));
      expect(DateFormat('yyyy').parse('99'), DateTime(99));
    });
  });

  test('Test ALL the supported formats on representative locales', () {
    var aDate = DateTime(2012, 1, 27, 20, 58, 59, 0);
    testLocale('en_US', english, aDate);
    if (subset.length > 1) {
      // Don't run if we have just one locale, so some of these won't be there.
      testLocale('de_DE', german, aDate);
      testLocale('fr_FR', french, aDate);
      testLocale('ja_JP', japanese, aDate);
      testLocale('el_GR', greek, aDate);
      testLocale('de_AT', austrian, aDate);
    }
  });

  test('Test round-trip parsing of dates', () {
    var hours = [0, 1, 11, 12, 13, 23];
    var months = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
    // For locales that use non-ascii digits, e.g. 'ar', also test
    // forcing ascii digits.
    for (var locale in subset) {
      var alsoForceAscii = DateFormat.d(locale).usesNativeDigits;
      for (var month in months) {
        var aDate = DateTime(2012, month, 27, 13, 58, 59, 012);
        testRoundTripParsing(locale, aDate);
        if (alsoForceAscii) {
          testRoundTripParsing(locale, aDate, true);
        }
      }
      for (var hour in hours) {
        var aDate = DateTime(2012, 1, 27, hour, 58, 59, 123);
        testRoundTripParsing(locale, aDate);
        if (alsoForceAscii) {
          testRoundTripParsing(locale, aDate, true);
        }
      }
    }
  });

  // TODO(alanknight): The coverage for patterns and symbols differs
  // at the source, in CLDR 25, so we can't guarantee that all patterns
  // have symbols or vice versa. Wish we could.

  test('Test malformed locales', () {
    // Don't run if we have just one locale, which may not include these.
    if (subset.length <= 1) return;
    var aDate = DateTime(2012, 1, 27, 20, 58, 59, 0);
    // Austrian is a useful test locale here because it differs slightly
    // from the generic 'de' locale so we can tell the difference between
    // correcting to 'de_AT' and falling back to just 'de'.
    testLocale('de-AT', austrian, aDate);
    testLocale('de_at', austrian, aDate);
    testLocale('de-at', austrian, aDate);
  });

  test('Test format creation via Intl', () {
    // Don't run if we have just one locale, which may not include these.
    if (subset.length <= 1) return;
    var intl = Intl('ja_JP');
    var instanceJP = intl.date('jms');
    var instanceUS = intl.date('jms', 'en_US');
    var blank = intl.date('jms');
    var date = DateTime(2012, 1, 27, 20, 58, 59, 0);
    expect(instanceJP.format(date), equals('20:58:59'));
    expect(instanceUS.format(date), equals('8:58:59 PM'));
    expect(blank.format(date), equals('20:58:59'));
  });

  test('Test explicit format string', () {
    // Don't run if we have just one locale, which may not include these.
    if (subset.length <= 1) return;
    var aDate = DateTime(2012, 1, 27, 20, 58, 59, 0);
    // An explicit format that doesn't conform to any skeleton
    var us = DateFormat(r'yy //// :W \\\\ dd:ss ^&@ M');
    expect(us.format(aDate), equals(r'12 //// :W \\\\ 27:59 ^&@ 1'));
    // The result won't change with locale unless we use fields that are words.
    var greek = DateFormat(r'yy //// :W \\\\ dd:ss ^&@ M', 'el_GR');
    expect(greek.format(aDate), equals(r'12 //// :W \\\\ 27:59 ^&@ 1'));
    var usWithWords = DateFormat('yy / :W \\ dd:ss ^&@ MMM', 'en_US');
    var greekWithWords = DateFormat('yy / :W \\ dd:ss ^&@ MMM', 'el_GR');
    expect(usWithWords.format(aDate), equals(r'12 / :W \ 27:59 ^&@ Jan'));
    expect(greekWithWords.format(aDate), equals(r'12 / :W \ 27:59 ^&@ Ιαν'));
    var escaped = DateFormat(r"hh 'o''clock'");
    expect(escaped.format(aDate), equals(r"08 o'clock"));
    var reParsed = escaped.parse(escaped.format(aDate));
    expect(escaped.format(reParsed), equals(escaped.format(aDate)));
    var noSeparators = DateFormat('HHmmss');
    expect(noSeparators.format(aDate), equals('205859'));
  });

  test('Test fractional seconds padding', () {
    var one = DateTime(2012, 1, 27, 20, 58, 59, 1);
    var oneHundred = DateTime(2012, 1, 27, 20, 58, 59, 100);
    var fractional = DateFormat('hh:mm:ss.SSS', 'en_US');
    expect(fractional.format(one), equals('08:58:59.001'));
    expect(fractional.format(oneHundred), equals('08:58:59.100'));
    var long = DateFormat('ss.SSSSSSSS', 'en_US');
    expect(long.format(oneHundred), equals('59.10000000'));
    expect(long.format(one), equals('59.00100000'));
  });

  test('Test parseUTC', () {
    var local = DateTime(2012, 1, 27, 20, 58, 59, 1);
    var utc = DateTime.utc(2012, 1, 27, 20, 58, 59, 1);
    // Getting the offset as a duration via difference() would be simpler,
    // but doesn't work on dart2js in checked mode. See issue 4437.
    var offset = utc.millisecondsSinceEpoch - local.millisecondsSinceEpoch;
    var format = DateFormat('yyyy-MM-dd HH:mm:ss');
    var localPrinted = format.format(local);
    var parsed = format.parse(localPrinted);
    var parsedUTC = format.parseUTC(format.format(utc));
    var parsedOffset =
        parsedUTC.millisecondsSinceEpoch - parsed.millisecondsSinceEpoch;
    expect(parsedOffset, equals(offset));
    expect(utc.hour, equals(parsedUTC.hour));
    expect(local.hour, equals(parsed.hour));
  });

  test('Test 0-padding', () {
    var someDate = DateTime(123, 1, 2, 3, 4, 5);
    var format = DateFormat('yyyy-MM-dd HH:mm:ss');
    expect(format.format(someDate), '0123-01-02 03:04:05');
  });

  test('Test default format', () {
    var someDate = DateTime(2012, 1, 27, 20, 58, 59, 1);
    var emptyFormat = DateFormat(null, 'en_US');
    var knownDefault = DateFormat.yMMMMd('en_US').add_jms();
    var result = emptyFormat.format(someDate);
    var knownResult = knownDefault.format(someDate);
    expect(result, knownResult);
  });

  test('Get symbols', () {
    var emptyFormat = DateFormat(null, 'en_US');
    var symbols = emptyFormat.dateSymbols;
    expect(symbols.NARROWWEEKDAYS, ['S', 'M', 'T', 'W', 'T', 'F', 'S']);
  });

  test('Quarter calculation', () {
    var quarters = [
      'Q1',
      'Q1',
      'Q1',
      'Q2',
      'Q2',
      'Q2',
      'Q3',
      'Q3',
      'Q3',
      'Q4',
      'Q4',
      'Q4'
    ];
    var quarterFormat = DateFormat.QQQ();
    for (var i = 0; i < 12; i++) {
      var month = i + 1;
      var aDate = DateTime(2012, month, 27, 13, 58, 59, 012);
      var formatted = quarterFormat.format(aDate);
      expect(formatted, quarters[i]);
    }
  });

  test('Quarter formatting', () {
    var date = DateTime(2012, 02, 27);
    var formats = {
      'Q': '1',
      'QQ': '01',
      'QQQ': 'Q1',
      'QQQQ': '1st quarter',
      'QQQQQ': '00001'
    };
    formats.forEach((pattern, result) {
      expect(DateFormat(pattern, 'en_US').format(date), result);
    });

    if (subset.contains('zh_CN')) {
      // Especially test zh_CN formatting for `QQQ` and `yQQQ` because it
      // contains a single `Q`.
      expect(DateFormat.QQQ('zh_CN').format(date), '1季度');
      expect(DateFormat.yQQQ('zh_CN').format(date), '2012年第1季度');
    }
  });

  /// Generate a map from day numbers in the given [year] (where Jan 1 == 1)
  /// to a Date object. If [year] is a leap year, then pass 1 for
  /// [leapDay], otherwise pass 0.
  Map<int, DateTime> generateDates(int year, int leapDay) =>
      Iterable.generate(365 + leapDay, (n) => n + 1)
          .map((day) {
            // Typically a "date" would have a time value of zero, but we
            // give them an hour value, because they can get created with an
            // offset to the previous day in time zones where the daylight
            // savings transition happens at midnight (e.g. Brazil).
            var result = DateTime(year, 1, day, 3);
            // TODO(alanknight): This is a workaround for dartbug.com/15560.
            if (result.toUtc() == result) result = DateTime(year, 1, day);
            return result;
          })
          .toList()
          .asMap();

  void verifyOrdinals(Map<int, DateTime> dates) {
    var f = DateFormat('D');
    var withYear = DateFormat('yyyy D');
    dates.forEach((number, date) {
      var formatted = f.format(date);
      expect(formatted, (number + 1).toString());
      var formattedWithYear = withYear.format(date);
      var parsed = withYear.parse(formattedWithYear);
      // Only compare the date portion, because time zone changes (e.g. DST) can
      // cause the hour values to be different.
      expect(parsed.year, date.year);
      expect(parsed.month, date.month);
      expect(parsed.day, date.day,
          reason: 'Mismatch between parsed ($parsed) and original ($date)');
    });
  }

  test('Ordinal Date', () {
    var f = DateFormat('D');
    var dates = generateDates(2012, 1);
    var nonLeapDates = generateDates(2013, 0);
    verifyOrdinals(dates);
    verifyOrdinals(nonLeapDates);
    // Check one hard-coded just to be on the safe side.
    var aDate = DateTime(2012, 4, 27, 13, 58, 59, 012);
    expect(f.format(aDate), '118');
  });

  // There are some very odd off-by-one bugs when parsing dates. Put in
  // some very basic tests to try and get more information.
  test('Simple Date Creation', () {
    var format = DateFormat(DateFormat.NUM_MONTH);
    var first = format.parse('7');
    var second = format.parse('7');
    var basic = DateTime(1970, 7);
    var basicAgain = DateTime(1970, 7);
    expect(first, second);
    expect(first, basic);
    expect(basic, basicAgain);
    expect(first.month, 7);
  });

  test('Native digit default', () {
    if (!subset.contains('ar')) return;
    var nativeFormat = DateFormat.yMd('ar');
    var date = DateTime(1974, 12, 30);
    var native = nativeFormat.format(date);
    expect(DateFormat.shouldUseNativeDigitsByDefaultFor('ar'), true);
    DateFormat.useNativeDigitsByDefaultFor('ar', false);
    expect(DateFormat.shouldUseNativeDigitsByDefaultFor('ar'), false);
    var asciiFormat = DateFormat.yMd('ar');
    var ascii = asciiFormat.format(date);
    // This prints with RTL markers before the slashes. That doesn't seem good,
    // but it's what the data says.
    expect(ascii, '30\u200f/12\u200f/1974');
    expect(native, '٣٠\u200f/١٢\u200f/١٩٧٤');
    // Reset the value.
    DateFormat.useNativeDigitsByDefaultFor('ar', true);
  });

  // This just tests the basic logic, which was in error, not
  // formatting in different locales. See #215.
  test('hours', () {
    var oneToTwentyFour = DateFormat('kk');
    var oneToTwelve = DateFormat('hh');
    var zeroToTwentyThree = DateFormat('KK');
    var zeroToEleven = DateFormat('HH');
    var late = DateTime(2019, 1, 2, 0, 4, 6);
    expect(oneToTwentyFour.format(late), '24');
    expect(zeroToTwentyThree.format(late), '00');
    expect(oneToTwelve.format(late), '12');
    expect(zeroToEleven.format(late), '00');
  });
}