import datetime
import unittest

try:
    import pytz
except ImportError:
    pytz = None

from django.test import TestCase, ignore_warnings, override_settings
from django.utils import timezone
from django.utils.deprecation import RemovedInDjango50Warning

from .models import Article, Category, Comment


class DateTimesTests(TestCase):
    def test_related_model_traverse(self):
        a1 = Article.objects.create(
            title="First one",
            pub_date=datetime.datetime(2005, 7, 28, 9, 0, 0),
        )
        a2 = Article.objects.create(
            title="Another one",
            pub_date=datetime.datetime(2010, 7, 28, 10, 0, 0),
        )
        a3 = Article.objects.create(
            title="Third one, in the first day",
            pub_date=datetime.datetime(2005, 7, 28, 17, 0, 0),
        )

        a1.comments.create(
            text="Im the HULK!",
            pub_date=datetime.datetime(2005, 7, 28, 9, 30, 0),
        )
        a1.comments.create(
            text="HULK SMASH!",
            pub_date=datetime.datetime(2005, 7, 29, 1, 30, 0),
        )
        a2.comments.create(
            text="LMAO",
            pub_date=datetime.datetime(2010, 7, 28, 10, 10, 10),
        )
        a3.comments.create(
            text="+1",
            pub_date=datetime.datetime(2005, 8, 29, 10, 10, 10),
        )

        c = Category.objects.create(name="serious-news")
        c.articles.add(a1, a3)

        self.assertSequenceEqual(
            Comment.objects.datetimes("article__pub_date", "year"),
            [
                datetime.datetime(2005, 1, 1),
                datetime.datetime(2010, 1, 1),
            ],
        )
        self.assertSequenceEqual(
            Comment.objects.datetimes("article__pub_date", "month"),
            [
                datetime.datetime(2005, 7, 1),
                datetime.datetime(2010, 7, 1),
            ],
        )
        self.assertSequenceEqual(
            Comment.objects.datetimes("article__pub_date", "week"),
            [
                datetime.datetime(2005, 7, 25),
                datetime.datetime(2010, 7, 26),
            ],
        )
        self.assertSequenceEqual(
            Comment.objects.datetimes("article__pub_date", "day"),
            [
                datetime.datetime(2005, 7, 28),
                datetime.datetime(2010, 7, 28),
            ],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("comments__pub_date", "day"),
            [
                datetime.datetime(2005, 7, 28),
                datetime.datetime(2005, 7, 29),
                datetime.datetime(2005, 8, 29),
                datetime.datetime(2010, 7, 28),
            ],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("comments__approval_date", "day"), []
        )
        self.assertSequenceEqual(
            Category.objects.datetimes("articles__pub_date", "day"),
            [
                datetime.datetime(2005, 7, 28),
            ],
        )

    @override_settings(USE_TZ=True)
    def test_21432(self):
        now = timezone.localtime(timezone.now().replace(microsecond=0))
        Article.objects.create(title="First one", pub_date=now)
        qs = Article.objects.datetimes("pub_date", "second")
        self.assertEqual(qs[0], now)

    @unittest.skipUnless(pytz is not None, "Test requires pytz")
    @ignore_warnings(category=RemovedInDjango50Warning)
    @override_settings(USE_TZ=True, TIME_ZONE="UTC", USE_DEPRECATED_PYTZ=True)
    def test_datetimes_ambiguous_and_invalid_times(self):
        sao = pytz.timezone("America/Sao_Paulo")
        utc = pytz.UTC
        article = Article.objects.create(
            title="Article 1",
            pub_date=utc.localize(datetime.datetime(2016, 2, 21, 1)),
        )
        Comment.objects.create(
            article=article,
            pub_date=utc.localize(datetime.datetime(2016, 10, 16, 13)),
        )
        with timezone.override(sao):
            with self.assertRaisesMessage(
                pytz.AmbiguousTimeError, "2016-02-20 23:00:00"
            ):
                Article.objects.datetimes("pub_date", "hour").get()
            with self.assertRaisesMessage(
                pytz.NonExistentTimeError, "2016-10-16 00:00:00"
            ):
                Comment.objects.datetimes("pub_date", "day").get()
            self.assertEqual(
                Article.objects.datetimes("pub_date", "hour", is_dst=False).get().dst(),
                datetime.timedelta(0),
            )
            self.assertEqual(
                Comment.objects.datetimes("pub_date", "day", is_dst=False).get().dst(),
                datetime.timedelta(0),
            )
            self.assertEqual(
                Article.objects.datetimes("pub_date", "hour", is_dst=True).get().dst(),
                datetime.timedelta(0, 3600),
            )
            self.assertEqual(
                Comment.objects.datetimes("pub_date", "hour", is_dst=True).get().dst(),
                datetime.timedelta(0, 3600),
            )

    def test_datetimes_returns_available_dates_for_given_scope_and_given_field(self):
        pub_dates = [
            datetime.datetime(2005, 7, 28, 12, 15),
            datetime.datetime(2005, 7, 29, 2, 15),
            datetime.datetime(2005, 7, 30, 5, 15),
            datetime.datetime(2005, 7, 31, 19, 15),
        ]
        for i, pub_date in enumerate(pub_dates):
            Article(pub_date=pub_date, title="title #{}".format(i)).save()

        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "year"),
            [datetime.datetime(2005, 1, 1, 0, 0)],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "month"),
            [datetime.datetime(2005, 7, 1, 0, 0)],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "week"),
            [datetime.datetime(2005, 7, 25, 0, 0)],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "day"),
            [
                datetime.datetime(2005, 7, 28, 0, 0),
                datetime.datetime(2005, 7, 29, 0, 0),
                datetime.datetime(2005, 7, 30, 0, 0),
                datetime.datetime(2005, 7, 31, 0, 0),
            ],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "day", order="ASC"),
            [
                datetime.datetime(2005, 7, 28, 0, 0),
                datetime.datetime(2005, 7, 29, 0, 0),
                datetime.datetime(2005, 7, 30, 0, 0),
                datetime.datetime(2005, 7, 31, 0, 0),
            ],
        )
        self.assertSequenceEqual(
            Article.objects.datetimes("pub_date", "day", order="DESC"),
            [
                datetime.datetime(2005, 7, 31, 0, 0),
                datetime.datetime(2005, 7, 30, 0, 0),
                datetime.datetime(2005, 7, 29, 0, 0),
                datetime.datetime(2005, 7, 28, 0, 0),
            ],
        )

    def test_datetimes_has_lazy_iterator(self):
        pub_dates = [
            datetime.datetime(2005, 7, 28, 12, 15),
            datetime.datetime(2005, 7, 29, 2, 15),
            datetime.datetime(2005, 7, 30, 5, 15),
            datetime.datetime(2005, 7, 31, 19, 15),
        ]
        for i, pub_date in enumerate(pub_dates):
            Article(pub_date=pub_date, title="title #{}".format(i)).save()
        # Use iterator() with datetimes() to return a generator that lazily
        # requests each result one at a time, to save memory.
        dates = []
        with self.assertNumQueries(0):
            article_datetimes_iterator = Article.objects.datetimes(
                "pub_date", "day", order="DESC"
            ).iterator()

        with self.assertNumQueries(1):
            for article in article_datetimes_iterator:
                dates.append(article)
        self.assertEqual(
            dates,
            [
                datetime.datetime(2005, 7, 31, 0, 0),
                datetime.datetime(2005, 7, 30, 0, 0),
                datetime.datetime(2005, 7, 29, 0, 0),
                datetime.datetime(2005, 7, 28, 0, 0),
            ],
        )

    def test_datetimes_disallows_date_fields(self):
        dt = datetime.datetime(2005, 7, 28, 12, 15)
        Article.objects.create(
            pub_date=dt,
            published_on=dt.date(),
            title="Don't put dates into datetime functions!",
        )
        with self.assertRaisesMessage(
            ValueError, "Cannot truncate DateField 'published_on' to DateTimeField"
        ):
            list(Article.objects.datetimes("published_on", "second"))

    def test_datetimes_fails_when_given_invalid_kind_argument(self):
        msg = (
            "'kind' must be one of 'year', 'month', 'week', 'day', 'hour', "
            "'minute', or 'second'."
        )
        with self.assertRaisesMessage(ValueError, msg):
            Article.objects.datetimes("pub_date", "bad_kind")

    def test_datetimes_fails_when_given_invalid_order_argument(self):
        msg = "'order' must be either 'ASC' or 'DESC'."
        with self.assertRaisesMessage(ValueError, msg):
            Article.objects.datetimes("pub_date", "year", order="bad order")
