from __future__ import unicode_literals

from datetime import datetime, date
import os
import time

from django.utils.dateformat import format
from django.utils import dateformat, translation, unittest
from django.utils.timezone import utc
from django.utils.tzinfo import FixedOffset, LocalTimezone


class DateFormatTests(unittest.TestCase):
    def setUp(self):
        self.old_TZ = os.environ.get('TZ')
        os.environ['TZ'] = 'Europe/Copenhagen'
        translation.activate('en-us')

        try:
            # Check if a timezone has been set
            time.tzset()
            self.tz_tests = True
        except AttributeError:
            # No timezone available. Don't run the tests that require a TZ
            self.tz_tests = False

    def tearDown(self):
        if self.old_TZ is None:
            del os.environ['TZ']
        else:
            os.environ['TZ'] = self.old_TZ

        # Cleanup - force re-evaluation of TZ environment variable.
        if self.tz_tests:
            time.tzset()

    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_datetime_with_local_tzinfo(self):
        ltz = LocalTimezone(datetime.now())
        dt = datetime(2009, 5, 16, 5, 30, 30, tzinfo=ltz)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz), dt)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U'))), dt.replace(tzinfo=None))

    def test_datetime_with_tzinfo(self):
        tz = FixedOffset(-510)
        ltz = LocalTimezone(datetime.now())
        dt = datetime(2009, 5, 16, 5, 30, 30, tzinfo=tz)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), tz), dt)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz), dt)
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U'))), dt.astimezone(ltz).replace(tzinfo=None))
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), tz).utctimetuple(), dt.utctimetuple())
        self.assertEqual(datetime.fromtimestamp(int(format(dt, 'U')), ltz).utctimetuple(), dt.utctimetuple())

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

        self.assertEqual(dateformat.format(my_birthday, 'a'), 'p.m.')

    def test_date_formats(self):
        my_birthday = datetime(1979, 7, 8, 22, 00)
        timestamp = datetime(2008, 5, 19, 11, 45, 23, 123456)

        self.assertEqual(dateformat.format(my_birthday, 'A'), 'PM')
        self.assertEqual(dateformat.format(timestamp, 'c'), '2008-05-19T11:45:23.123456')
        self.assertEqual(dateformat.format(my_birthday, 'd'), '08')
        self.assertEqual(dateformat.format(my_birthday, 'j'), '8')
        self.assertEqual(dateformat.format(my_birthday, 'l'), 'Sunday')
        self.assertEqual(dateformat.format(my_birthday, 'L'), 'False')
        self.assertEqual(dateformat.format(my_birthday, 'm'), '07')
        self.assertEqual(dateformat.format(my_birthday, 'M'), 'Jul')
        self.assertEqual(dateformat.format(my_birthday, 'b'), 'jul')
        self.assertEqual(dateformat.format(my_birthday, 'n'), '7')
        self.assertEqual(dateformat.format(my_birthday, 'N'), 'July')

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

        self.assertEqual(dateformat.format(my_birthday, 'P'), '10 p.m.')
        self.assertEqual(dateformat.format(my_birthday, 's'), '00')
        self.assertEqual(dateformat.format(my_birthday, 'S'), 'th')
        self.assertEqual(dateformat.format(my_birthday, 't'), '31')
        self.assertEqual(dateformat.format(my_birthday, 'w'), '0')
        self.assertEqual(dateformat.format(my_birthday, 'W'), '27')
        self.assertEqual(dateformat.format(my_birthday, 'y'), '79')
        self.assertEqual(dateformat.format(my_birthday, 'Y'), '1979')
        self.assertEqual(dateformat.format(my_birthday, 'z'), '189')

    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_timezones(self):
        my_birthday = datetime(1979, 7, 8, 22, 00)
        summertime = datetime(2005, 10, 30, 1, 00)
        wintertime = datetime(2005, 10, 30, 4, 00)
        timestamp = datetime(2008, 5, 19, 11, 45, 23, 123456)

        if self.tz_tests:
            self.assertEqual(dateformat.format(my_birthday, 'O'), '+0100')
            self.assertEqual(dateformat.format(my_birthday, 'r'), 'Sun, 8 Jul 1979 22:00:00 +0100')
            self.assertEqual(dateformat.format(my_birthday, 'T'), 'CET')
            self.assertEqual(dateformat.format(my_birthday, 'U'), '300315600')
            self.assertEqual(dateformat.format(timestamp, 'u'), '123456')
            self.assertEqual(dateformat.format(my_birthday, 'Z'), '3600')
            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')

        # Ticket #16924 -- We don't need timezone support to test this
        # 3h30m to the west of UTC
        tz = FixedOffset(-3*60 - 30)
        dt = datetime(2009, 5, 16, 5, 30, 30, tzinfo=tz)
        self.assertEqual(dateformat.format(dt, 'O'), '-0330')