from datetime import datetime

from django.contrib.admin.options import IncorrectLookupParameters
from django.contrib.auth.models import User
from django.test import RequestFactory, TestCase
from django.utils.timezone import make_aware

from .admin import EventAdmin, site as custom_site
from .models import Event


class DateHierarchyTests(TestCase):
    factory = RequestFactory()

    @classmethod
    def setUpTestData(cls):
        cls.superuser = User.objects.create_superuser(username='super', email='a@b.com', password='xxx')

    def assertDateParams(self, query, expected_from_date, expected_to_date):
        query = {'date__%s' % field: val for field, val in query.items()}
        request = self.factory.get('/', query)
        request.user = self.superuser
        changelist = EventAdmin(Event, custom_site).get_changelist_instance(request)
        _, _, lookup_params, *_ = changelist.get_filters(request)
        self.assertEqual(lookup_params['date__gte'], expected_from_date)
        self.assertEqual(lookup_params['date__lt'], expected_to_date)

    def test_bounded_params(self):
        tests = (
            ({'year': 2017}, datetime(2017, 1, 1), datetime(2018, 1, 1)),
            ({'year': 2017, 'month': 2}, datetime(2017, 2, 1), datetime(2017, 3, 1)),
            ({'year': 2017, 'month': 12}, datetime(2017, 12, 1), datetime(2018, 1, 1)),
            ({'year': 2017, 'month': 12, 'day': 15}, datetime(2017, 12, 15), datetime(2017, 12, 16)),
            ({'year': 2017, 'month': 12, 'day': 31}, datetime(2017, 12, 31), datetime(2018, 1, 1)),
            ({'year': 2017, 'month': 2, 'day': 28}, datetime(2017, 2, 28), datetime(2017, 3, 1)),
        )
        for query, expected_from_date, expected_to_date in tests:
            with self.subTest(query=query):
                self.assertDateParams(query, expected_from_date, expected_to_date)

    def test_bounded_params_with_time_zone(self):
        with self.settings(USE_TZ=True, TIME_ZONE='Asia/Jerusalem'):
            self.assertDateParams(
                {'year': 2017, 'month': 2, 'day': 28},
                make_aware(datetime(2017, 2, 28)),
                make_aware(datetime(2017, 3, 1)),
            )

    def test_bounded_params_with_dst_time_zone(self):
        tests = [
            # Northern hemisphere.
            ('Asia/Jerusalem', 3),
            ('Asia/Jerusalem', 10),
            # Southern hemisphere.
            ('Pacific/Chatham', 4),
            ('Pacific/Chatham', 9),
        ]
        for time_zone, month in tests:
            with self.subTest(time_zone=time_zone, month=month):
                with self.settings(USE_TZ=True, TIME_ZONE=time_zone):
                    self.assertDateParams(
                        {'year': 2019, 'month': month},
                        make_aware(datetime(2019, month, 1)),
                        make_aware(datetime(2019, month + 1, 1)),
                    )

    def test_invalid_params(self):
        tests = (
            {'year': 'x'},
            {'year': 2017, 'month': 'x'},
            {'year': 2017, 'month': 12, 'day': 'x'},
            {'year': 2017, 'month': 13},
            {'year': 2017, 'month': 12, 'day': 32},
            {'year': 2017, 'month': 0},
            {'year': 2017, 'month': 12, 'day': 0},
        )
        for invalid_query in tests:
            with self.subTest(query=invalid_query), self.assertRaises(IncorrectLookupParameters):
                self.assertDateParams(invalid_query, None, None)