from dateutil.parser import parse
from datetime import datetime

dt = datetime(31, 12, 30)
dstr = dt.strftime('%B.%04Y.%d')    # December.0031.30
parse(dt.strftime('%B.%04Y.%d'))     # datetime(30, 12, 31, 0, 0)

from datetime import datetime, time
import itertools

from hypothesis.strategies import integers, dates
from hypothesis import given

import pytest

from dateutil.parser import parserinfo, parse


def _get_ybd_formats():
    # If we have a 4-digit year, a non-numeric month (abbreviated or not),
    # and a day (1 or 2 digits), then there is no ambiguity as to which
    # token is a year/month/day.  This holds regardless of what order the
    # terms are in and for each of the separators below.
    try:
        datetime.now().strftime('%-d')
        PLATFORM_HAS_DASH_D = True
    except ValueError:
        PLATFORM_HAS_DASH_D = False

    seps = ['-', ' ', '/', '.']

    year_tokens = ['%04Y']
    month_tokens = ['%b', '%B']
    day_tokens = ['%d']

    if PLATFORM_HAS_DASH_D:
        day_tokens.append('%-d')

    prods = itertools.product(year_tokens, month_tokens, day_tokens)
    perms = [y for x in prods for y in itertools.permutations(x)]
    unambig_fmts = [sep.join(perm) for sep in seps for perm in perms]

    return unambig_fmts


@pytest.mark.parser
@pytest.mark.parametrize('fmt', _get_ybd_formats())
@given(dt=dates())
def test_ybd(dt, fmt):
    dt = datetime.combine(dt, time(0))  # Make this a datetime
    dstr = dt.strftime(fmt)
    res = parse(dstr)
    assert dt == res