from test import support
import decimal
import enum
import locale
import math
import platform
import sys
import sysconfig
import time
import threading
import unittest
try:
    import _testcapi
except ImportError:
    _testcapi = None

from test.support import skip_if_buggy_ucrt_strfptime

# Max year is only limited by the size of C int.
SIZEOF_INT = sysconfig.get_config_var('SIZEOF_INT') or 4
TIME_MAXYEAR = (1 << 8 * SIZEOF_INT - 1) - 1
TIME_MINYEAR = -TIME_MAXYEAR - 1 + 1900

SEC_TO_US = 10 ** 6
US_TO_NS = 10 ** 3
MS_TO_NS = 10 ** 6
SEC_TO_NS = 10 ** 9
NS_TO_SEC = 10 ** 9

class _PyTime(enum.IntEnum):
    # Round towards minus infinity (-inf)
    ROUND_FLOOR = 0
    # Round towards infinity (+inf)
    ROUND_CEILING = 1
    # Round to nearest with ties going to nearest even integer
    ROUND_HALF_EVEN = 2
    # Round away from zero
    ROUND_UP = 3

# Rounding modes supported by PyTime
ROUNDING_MODES = (
    # (PyTime rounding method, decimal rounding method)
    (_PyTime.ROUND_FLOOR, decimal.ROUND_FLOOR),
    (_PyTime.ROUND_CEILING, decimal.ROUND_CEILING),
    (_PyTime.ROUND_HALF_EVEN, decimal.ROUND_HALF_EVEN),
    (_PyTime.ROUND_UP, decimal.ROUND_UP),
)


class TimeTestCase(unittest.TestCase):

    def setUp(self):
        self.t = time.time()

    def test_data_attributes(self):
        time.altzone
        time.daylight
        time.timezone
        time.tzname

    def test_time(self):
        time.time()
        info = time.get_clock_info('time')
        self.assertFalse(info.monotonic)
        self.assertTrue(info.adjustable)

    def test_time_ns_type(self):
        def check_ns(sec, ns):
            self.assertIsInstance(ns, int)

            sec_ns = int(sec * 1e9)
            # tolerate a difference of 50 ms
            self.assertLess((sec_ns - ns), 50 ** 6, (sec, ns))

        check_ns(time.time(),
                 time.time_ns())
        check_ns(time.monotonic(),
                 time.monotonic_ns())
        check_ns(time.perf_counter(),
                 time.perf_counter_ns())
        check_ns(time.process_time(),
                 time.process_time_ns())

        if hasattr(time, 'thread_time'):
            check_ns(time.thread_time(),
                     time.thread_time_ns())

        if hasattr(time, 'clock_gettime'):
            check_ns(time.clock_gettime(time.CLOCK_REALTIME),
                     time.clock_gettime_ns(time.CLOCK_REALTIME))

    @unittest.skipUnless(hasattr(time, 'clock_gettime'),
                         'need time.clock_gettime()')
    def test_clock_realtime(self):
        t = time.clock_gettime(time.CLOCK_REALTIME)
        self.assertIsInstance(t, float)

    @unittest.skipUnless(hasattr(time, 'clock_gettime'),
                         'need time.clock_gettime()')
    @unittest.skipUnless(hasattr(time, 'CLOCK_MONOTONIC'),
                         'need time.CLOCK_MONOTONIC')
    def test_clock_monotonic(self):
        a = time.clock_gettime(time.CLOCK_MONOTONIC)
        b = time.clock_gettime(time.CLOCK_MONOTONIC)
        self.assertLessEqual(a, b)

    @unittest.skipUnless(hasattr(time, 'pthread_getcpuclockid'),
                         'need time.pthread_getcpuclockid()')
    @unittest.skipUnless(hasattr(time, 'clock_gettime'),
                         'need time.clock_gettime()')
    def test_pthread_getcpuclockid(self):
        clk_id = time.pthread_getcpuclockid(threading.get_ident())
        self.assertTrue(type(clk_id) is int)
        # when in 32-bit mode AIX only returns the predefined constant
        if not platform.system() == "AIX":
            self.assertNotEqual(clk_id, time.CLOCK_THREAD_CPUTIME_ID)
        elif (sys.maxsize.bit_length() > 32):
            self.assertNotEqual(clk_id, time.CLOCK_THREAD_CPUTIME_ID)
        else:
            self.assertEqual(clk_id, time.CLOCK_THREAD_CPUTIME_ID)
        t1 = time.clock_gettime(clk_id)
        t2 = time.clock_gettime(clk_id)
        self.assertLessEqual(t1, t2)

    @unittest.skipUnless(hasattr(time, 'clock_getres'),
                         'need time.clock_getres()')
    def test_clock_getres(self):
        res = time.clock_getres(time.CLOCK_REALTIME)
        self.assertGreater(res, 0.0)
        self.assertLessEqual(res, 1.0)

    @unittest.skipUnless(hasattr(time, 'clock_settime'),
                         'need time.clock_settime()')
    def test_clock_settime(self):
        t = time.clock_gettime(time.CLOCK_REALTIME)
        try:
            time.clock_settime(time.CLOCK_REALTIME, t)
        except PermissionError:
            pass

        if hasattr(time, 'CLOCK_MONOTONIC'):
            self.assertRaises(OSError,
                              time.clock_settime, time.CLOCK_MONOTONIC, 0)

    def test_conversions(self):
        self.assertEqual(time.ctime(self.t),
                         time.asctime(time.localtime(self.t)))
        self.assertEqual(int(time.mktime(time.localtime(self.t))),
                         int(self.t))

    def test_sleep(self):
        self.assertRaises(ValueError, time.sleep, -2)
        self.assertRaises(ValueError, time.sleep, -1)
        time.sleep(1.2)

    def test_strftime(self):
        tt = time.gmtime(self.t)
        for directive in ('a', 'A', 'b', 'B', 'c', 'd', 'H', 'I',
                          'j', 'm', 'M', 'p', 'S',
                          'U', 'w', 'W', 'x', 'X', 'y', 'Y', 'Z', '%'):
            format = ' %' + directive
            try:
                time.strftime(format, tt)
            except ValueError:
                self.fail('conversion specifier: %r failed.' % format)

        self.assertRaises(TypeError, time.strftime, b'%S', tt)
        # embedded null character
        self.assertRaises(ValueError, time.strftime, '%S\0', tt)

    def _bounds_checking(self, func):
        # Make sure that strftime() checks the bounds of the various parts
        # of the time tuple (0 is valid for *all* values).

        # The year field is tested by other test cases above

        # Check month [1, 12] + zero support
        func((1900, 0, 1, 0, 0, 0, 0, 1, -1))
        func((1900, 12, 1, 0, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, -1, 1, 0, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 13, 1, 0, 0, 0, 0, 1, -1))
        # Check day of month [1, 31] + zero support
        func((1900, 1, 0, 0, 0, 0, 0, 1, -1))
        func((1900, 1, 31, 0, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, -1, 0, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 32, 0, 0, 0, 0, 1, -1))
        # Check hour [0, 23]
        func((1900, 1, 1, 23, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, -1, 0, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 24, 0, 0, 0, 1, -1))
        # Check minute [0, 59]
        func((1900, 1, 1, 0, 59, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, -1, 0, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 60, 0, 0, 1, -1))
        # Check second [0, 61]
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 0, -1, 0, 1, -1))
        # C99 only requires allowing for one leap second, but Python's docs say
        # allow two leap seconds (0..61)
        func((1900, 1, 1, 0, 0, 60, 0, 1, -1))
        func((1900, 1, 1, 0, 0, 61, 0, 1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 0, 62, 0, 1, -1))
        # No check for upper-bound day of week;
        #  value forced into range by a ``% 7`` calculation.
        # Start check at -2 since gettmarg() increments value before taking
        #  modulo.
        self.assertEqual(func((1900, 1, 1, 0, 0, 0, -1, 1, -1)),
                         func((1900, 1, 1, 0, 0, 0, +6, 1, -1)))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 0, 0, -2, 1, -1))
        # Check day of the year [1, 366] + zero support
        func((1900, 1, 1, 0, 0, 0, 0, 0, -1))
        func((1900, 1, 1, 0, 0, 0, 0, 366, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 0, 0, 0, -1, -1))
        self.assertRaises(ValueError, func,
                            (1900, 1, 1, 0, 0, 0, 0, 367, -1))

    def test_strftime_bounding_check(self):
        self._bounds_checking(lambda tup: time.strftime('', tup))

    def test_strftime_format_check(self):
        # Test that strftime does not crash on invalid format strings
        # that may trigger a buffer overread. When not triggered,
        # strftime may succeed or raise ValueError depending on
        # the platform.
        for x in [ '', 'A', '%A', '%AA' ]:
            for y in range(0x0, 0x10):
                for z in [ '%', 'A%', 'AA%', '%A%', 'A%A%', '%#' ]:
                    try:
                        time.strftime(x * y + z)
                    except ValueError:
                        pass

    def test_default_values_for_zero(self):
        # Make sure that using all zeros uses the proper default
        # values.  No test for daylight savings since strftime() does
        # not change output based on its value and no test for year
        # because systems vary in their support for year 0.
        expected = "2000 01 01 00 00 00 1 001"
        with support.check_warnings():
            result = time.strftime("%Y %m %d %H %M %S %w %j", (2000,)+(0,)*8)
        self.assertEqual(expected, result)

    @skip_if_buggy_ucrt_strfptime
    def test_strptime(self):
        # Should be able to go round-trip from strftime to strptime without
        # raising an exception.
        tt = time.gmtime(self.t)
        for directive in ('a', 'A', 'b', 'B', 'c', 'd', 'H', 'I',
                          'j', 'm', 'M', 'p', 'S',
                          'U', 'w', 'W', 'x', 'X', 'y', 'Y', 'Z', '%'):
            format = '%' + directive
            strf_output = time.strftime(format, tt)
            try:
                time.strptime(strf_output, format)
            except ValueError:
                self.fail("conversion specifier %r failed with '%s' input." %
                          (format, strf_output))

    def test_strptime_bytes(self):
        # Make sure only strings are accepted as arguments to strptime.
        self.assertRaises(TypeError, time.strptime, b'2009', "%Y")
        self.assertRaises(TypeError, time.strptime, '2009', b'%Y')

    def test_strptime_exception_context(self):
        # check that this doesn't chain exceptions needlessly (see #17572)
        with self.assertRaises(ValueError) as e:
            time.strptime('', '%D')
        self.assertIs(e.exception.__suppress_context__, True)
        # additional check for IndexError branch (issue #19545)
        with self.assertRaises(ValueError) as e:
            time.strptime('19', '%Y %')
        self.assertIs(e.exception.__suppress_context__, True)

    def test_asctime(self):
        time.asctime(time.gmtime(self.t))

        # Max year is only limited by the size of C int.
        for bigyear in TIME_MAXYEAR, TIME_MINYEAR:
            asc = time.asctime((bigyear, 6, 1) + (0,) * 6)
            self.assertEqual(asc[-len(str(bigyear)):], str(bigyear))
        self.assertRaises(OverflowError, time.asctime,
                          (TIME_MAXYEAR + 1,) + (0,) * 8)
        self.assertRaises(OverflowError, time.asctime,
                          (TIME_MINYEAR - 1,) + (0,) * 8)
        self.assertRaises(TypeError, time.asctime, 0)
        self.assertRaises(TypeError, time.asctime, ())
        self.assertRaises(TypeError, time.asctime, (0,) * 10)

    def test_asctime_bounding_check(self):
        self._bounds_checking(time.asctime)

    def test_ctime(self):
        t = time.mktime((1973, 9, 16, 1, 3, 52, 0, 0, -1))
        self.assertEqual(time.ctime(t), 'Sun Sep 16 01:03:52 1973')
        t = time.mktime((2000, 1, 1, 0, 0, 0, 0, 0, -1))
        self.assertEqual(time.ctime(t), 'Sat Jan  1 00:00:00 2000')
        for year in [-100, 100, 1000, 2000, 2050, 10000]:
            try:
                testval = time.mktime((year, 1, 10) + (0,)*6)
            except (ValueError, OverflowError):
                # If mktime fails, ctime will fail too.  This may happen
                # on some platforms.
                pass
            else:
                self.assertEqual(time.ctime(testval)[20:], str(year))

    @unittest.skipUnless(hasattr(time, "tzset"),
                         "time module has no attribute tzset")
    def test_tzset(self):

        from os import environ

        # Epoch time of midnight Dec 25th 2002. Never DST in northern
        # hemisphere.
        xmas2002 = 1040774400.0

        # These formats are correct for 2002, and possibly future years
        # This format is the 'standard' as documented at:
        # http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
        # They are also documented in the tzset(3) man page on most Unix
        # systems.
        eastern = 'EST+05EDT,M4.1.0,M10.5.0'
        victoria = 'AEST-10AEDT-11,M10.5.0,M3.5.0'
        utc='UTC+0'

        org_TZ = environ.get('TZ',None)
        try:
            # Make sure we can switch to UTC time and results are correct
            # Note that unknown timezones default to UTC.
            # Note that altzone is undefined in UTC, as there is no DST
            environ['TZ'] = eastern
            time.tzset()
            environ['TZ'] = utc
            time.tzset()