from datetime import date, datetime, time, tzinfo

from django.test import SimpleTestCase, override_settings
from django.test.utils import TZ_SUPPORT, requires_tz_support
from django.utils import dateformat, translation
from django.utils.dateformat import format
from django.utils.timezone import (
    get_default_timezone, get_fixed_timezone, make_aware, utc,
)


@override_settings(TIME_ZONE='Europe/Copenhagen')
class DateFormatTests(SimpleTestCase):

    def setUp(self):
        self._orig_lang = translation.get_language()
        translation.activate('en-us')

    def tearDown(self):
        translation.activate(self._orig_lang)

    def test_date(self):
        d = date(2009, 5, 16)
        self.assertEqual(date.fromtimestamp(int(format(d, 'U'))), d)

    def test_naive_datetime(self):
        dt = datetime(2009, 5, 16, 5, 30, 30)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U'))), dt)

    def test_naive_ambiguous_datetime(self):
        # dt is ambiguous in Europe/Copenhagen. pytz raises an exception for
        # the ambiguity, which results in an empty string.
        dt = datetime(2015, 10, 25, 2, 30, 0)

        # Try all formatters that involve self.timezone.
        self.assertEqual(format(dt, 'I'), '')
        self.assertEqual(format(dt, 'O'), '')
        self.assertEqual(format(dt, 'T'), '')
        self.assertEqual(format(dt, 'Z'), '')

    @requires_tz_support
    def test_datetime_with_local_tzinfo(self):
        ltz = get_default_timezone()
        dt = make_aware(datetime(2009, 5, 16, 5, 30, 30), ltz)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz), dt)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U'))), dt.replace(tzinfo=None))

    @requires_tz_support
    def test_datetime_with_tzinfo(self):
        tz = get_fixed_timezone(-510)
        ltz = get_default_timezone()
        dt = make_aware(datetime(2009, 5, 16, 5, 30, 30), ltz)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), tz), dt)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz), dt)
        # astimezone() is safe here because the target timezone doesn't have DST
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U'))), dt.astimezone(ltz).replace(tzinfo=None))
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), tz).timetuple(), dt.astimezone(tz).timetuple())
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz).timetuple(), dt.astimezone(ltz).timetuple())

    def test_epoch(self):
        udt = datetime(1970, 1, 1, tzinfo=utc)
        self.assertEqual(format(udt, 'U'), '0')

    def test_empty_format(self):
        my_birthday = datetime(1979, 7, 8, 22, 00)

        self.assertEqual(dateformat.format(my_birthday, ''), '')

    def test_am_pm(self):
        morning = time(7, 00)
        evening = time(19, 00)
        self.assertEqual(dateformat.format(morning, 'a'), 'a.m.')
        self.assertEqual(dateformat.format(evening, 'a'), 'p.m.')
        self.assertEqual(dateformat.format(morning, 'A'), 'AM')
        self.assertEqual(dateformat.format(evening, 'A'), 'PM')

    def test_microsecond(self):
        # Regression test for #18951
        dt = datetime(2009, 5, 16, microsecond=123)
        self.assertEqual(dateformat.format(dt, 'u'), '000123')

    def test_date_formats(self):
        # Specifiers 'I', 'r', and 'U' are covered in test_timezones().
        my_birthday = datetime(1979, 7, 8, 22, 00)
        for specifier, expected in [
            ('b', 'jul'),
            ('d', '08'),
            ('D', 'Sun'),
            ('E', 'July'),
            ('F', 'July'),
            ('j', '8'),
            ('l', 'Sunday'),
            ('L', 'False'),
            ('m', '07'),
            ('M', 'Jul'),
            ('n', '7'),
            ('N', 'July'),
            ('o', '1979'),
            ('S', 'th'),
            ('t', '31'),
            ('w', '0'),
            ('W', '27'),
            ('y', '79'),
            ('Y', '1979'),
            ('z', '189'),
        ]:
            with self.subTest(specifier=specifier):
                self.assertEqual(dateformat.format(my_birthday, specifier), expected)

    def test_date_formats_c_format(self):
        timestamp = datetime(2008, 5, 19, 11, 45, 23, 123456)
        self.assertEqual(dateformat.format(timestamp, 'c'), '2008-05-19T11:45:23.123456')

    def test_time_formats(self):
        # Specifiers 'I', 'r', and 'U' are covered in test_timezones().
        my_birthday = datetime(1979, 7, 8, 22, 00)
        for specifier, expected in [
            ('a', 'p.m.'),
            ('A', 'PM'),
            ('f', '10'),
            ('g', '10'),
            ('G', '22'),
            ('h', '10'),
            ('H', '22'),
            ('i', '00'),
            ('P', '10 p.m.'),
            ('s', '00'),
            ('u', '000000'),
        ]:
            with self.subTest(specifier=specifier):
                self.assertEqual(dateformat.format(my_birthday, specifier), expected)

    def test_dateformat(self):
        my_birthday = datetime(1979, 7, 8, 22, 00)

        self.assertEqual(dateformat.format(my_birthday, r'Y z \C\E\T'), '1979 189 CET')

        self.assertEqual(dateformat.format(my_birthday, r'jS \o\f F'), '8th of July')

    def test_futuredates(self):
        the_future = datetime(2100, 10, 25, 0, 00)
        self.assertEqual(dateformat.format(the_future, r'Y'), '2100')

    def test_day_of_year_leap(self):
        self.assertEqual(dateformat.format(datetime(2000, 12, 31), 'z'), '366')

    def test_timezones(self):
        my_birthday = datetime(1979, 7, 8, 22, 00)
        summertime = datetime(2005, 10, 30, 1, 00)
        wintertime = datetime(2005, 10, 30, 4, 00)
        noon = time(12, 0, 0)

        # 3h30m to the west of UTC
        tz = get_fixed_timezone(-210)
        aware_dt = datetime(2009, 5, 16, 5, 30, 30, tzinfo=tz)

        if TZ_SUPPORT:
            for specifier, expected in [
                ('e', ''),
                ('O', '+0100'),
                ('r', 'Sun, 08 Jul 1979 22:00:00 +0100'),
                ('T', 'CET'),
                ('U', '300315600'),
                ('Z', '3600'),
            ]:
                with self.subTest(specifier=specifier):
                    self.assertEqual(dateformat.format(my_birthday, specifier), expected)

            self.assertEqual(dateformat.format(aware_dt, 'e'), '-0330')
            self.assertEqual(
                dateformat.format(aware_dt, 'r'),
                'Sat, 16 May 2009 05:30:30 -0330',
            )

            self.assertEqual(dateformat.format(summertime, 'I'), '1')
            self.assertEqual(dateformat.format(summertime, 'O'), '+0200')

            self.assertEqual(dateformat.format(wintertime, 'I'), '0')
            self.assertEqual(dateformat.format(wintertime, 'O'), '+0100')

            for specifier in ['e', 'O', 'T', 'Z']:
                with self.subTest(specifier=specifier):
                    self.assertEqual(dateformat.time_format(noon, specifier), '')

        # Ticket #16924 -- We don't need timezone support to test this
        self.assertEqual(dateformat.format(aware_dt, 'O'), '-0330')

    def test_invalid_time_format_specifiers(self):
        my_birthday = date(1984, 8, 7)

        for specifier in ['a', 'A', 'f', 'g', 'G', 'h', 'H', 'i', 'P', 'r', 's', 'u']:
            with self.subTest(specifier=specifier):
                msg = (
                    'The format for date objects may not contain time-related '
                    f'format specifiers (found {specifier!r}).'
                )
                with self.assertRaisesMessage(TypeError, msg):
                    dateformat.format(my_birthday, specifier)

    @requires_tz_support
    def test_e_format_with_named_time_zone(self):
        dt = datetime(1970, 1, 1, tzinfo=utc)
        self.assertEqual(dateformat.format(dt, 'e'), 'UTC')

    @requires_tz_support
    def test_e_format_with_time_zone_with_unimplemented_tzname(self):
        class NoNameTZ(tzinfo):
            """Time zone without .tzname() defined."""
            def utcoffset(self, dt):
                return None

        dt = datetime(1970, 1, 1, tzinfo=NoNameTZ())
        self.assertEqual(dateformat.format(dt, 'e'), '')

    def test_P_format(self):
        for expected, t in [
            ('midnight', time(0)),
            ('noon', time(12)),
            ('4 a.m.', time(4)),
            ('8:30 a.m.', time(8, 30)),
            ('4 p.m.', time(16)),
            ('8:30 p.m.', time(20, 30)),
        ]:
            with self.subTest(time=t):
                self.assertEqual(dateformat.time_format(t, 'P'), expected)

    def test_r_format_with_non_en_locale(self):
        # Changing the locale doesn't change the "r" format.
        dt = datetime(1979, 7, 8, 22, 00)
        with translation.override('fr'):
            self.assertEqual(
                dateformat.format(dt, 'r'),
                'Sun, 08 Jul 1979 22:00:00 +0100',
            )

    def test_S_format(self):
        for expected, days in [
            ('st', [1, 21, 31]),
            ('nd', [2, 22]),
            ('rd', [3, 23]),
            ('th', (n for n in range(4, 31) if n not in [21, 22, 23])),
        ]:
            for day in days:
                dt = date(1970, 1, day)
                with self.subTest(day=day):
                    self.assertEqual(dateformat.format(dt, 'S'), expected)

    def test_y_format_year_before_1000(self):
        tests = [
            (476, '76'),
            (42, '42'),
            (4, '04'),
        ]
        for year, expected_date in tests:
            with self.subTest(year=year):
                self.assertEqual(
                    dateformat.format(datetime(year, 9, 8, 5, 0), 'y'),
                    expected_date,
                )

    def test_Y_format_year_before_1000(self):
        self.assertEqual(dateformat.format(datetime(1, 1, 1), 'Y'), '0001')
        self.assertEqual(dateformat.format(datetime(999, 1, 1), 'Y'), '0999')

    def test_twelve_hour_format(self):
        tests = [
            (0, '12', '12'),
            (1, '1', '01'),
            (11, '11', '11'),
            (12, '12', '12'),
            (13, '1', '01'),
            (23, '11', '11'),
        ]
        for hour, g_expected, h_expected in tests:
            dt = datetime(2000, 1, 1, hour)
            with self.subTest(hour=hour):
                self.assertEqual(dateformat.format(dt, 'g'), g_expected)
                self.assertEqual(dateformat.format(dt, 'h'), h_expected)
