from unittest.mock import patch

from dateutil.relativedelta import relativedelta
from django.test import TestCase
from django.utils import timezone

from bookmarks.utils import humanize_absolute_date, humanize_relative_date, parse_timestamp


class UtilsTestCase(TestCase):

    def test_humanize_absolute_date(self):
        test_cases = [
            (timezone.datetime(2021, 1, 1), timezone.datetime(2023, 1, 1), '01/01/2021'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 2, 1), '01/01/2021'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 8), '01/01/2021'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 7), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 7, 23, 59), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 3), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 2), 'Yesterday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 2, 23, 59), 'Yesterday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 1), 'Today'),
        ]

        for test_case in test_cases:
            result = humanize_absolute_date(test_case[0], test_case[1])
            self.assertEqual(test_case[2], result)

    def test_humanize_absolute_date_should_use_current_date_as_default(self):
        with patch.object(timezone, 'now', return_value=timezone.datetime(2021, 1, 1)):
            self.assertEqual(humanize_absolute_date(timezone.datetime(2021, 1, 1)), 'Today')

        # Regression: Test that subsequent calls use current date instead of cached date (#107)
        with patch.object(timezone, 'now', return_value=timezone.datetime(2021, 1, 13)):
            self.assertEqual(humanize_absolute_date(timezone.datetime(2021, 1, 13)), 'Today')

    def test_humanize_relative_date(self):
        test_cases = [
            (timezone.datetime(2021, 1, 1), timezone.datetime(2022, 1, 1), '1 year ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2022, 12, 31), '1 year ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2023, 1, 1), '2 years ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2023, 12, 31), '2 years ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 12, 31), '11 months ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 2, 1), '1 month ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 31), '4 weeks ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 14), '1 week ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 8), '1 week ago'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 7), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 7, 23, 59), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 3), 'Friday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 2), 'Yesterday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 2, 23, 59), 'Yesterday'),
            (timezone.datetime(2021, 1, 1), timezone.datetime(2021, 1, 1), 'Today'),
        ]

        for test_case in test_cases:
            result = humanize_relative_date(test_case[0], test_case[1])
            self.assertEqual(test_case[2], result)

    def test_humanize_relative_date_should_use_current_date_as_default(self):
        with patch.object(timezone, 'now', return_value=timezone.datetime(2021, 1, 1)):
            self.assertEqual(humanize_relative_date(timezone.datetime(2021, 1, 1)), 'Today')

        # Regression: Test that subsequent calls use current date instead of cached date (#107)
        with patch.object(timezone, 'now', return_value=timezone.datetime(2021, 1, 13)):
            self.assertEqual(humanize_relative_date(timezone.datetime(2021, 1, 13)), 'Today')

    def verify_timestamp(self, date, factor=1):
        timestamp_string = str(int(date.timestamp() * factor))
        parsed_date = parse_timestamp(timestamp_string)
        self.assertEqual(date, parsed_date)

    def test_parse_timestamp_fails_for_invalid_timestamps(self):
        with self.assertRaises(ValueError):
            parse_timestamp('invalid')

    def test_parse_timestamp_parses_millisecond_timestamps(self):
        now = timezone.now().replace(microsecond=0)
        fifty_years_ago = now - relativedelta(year=50)
        fifty_years_from_now = now + relativedelta(year=50)

        self.verify_timestamp(now)
        self.verify_timestamp(fifty_years_ago)
        self.verify_timestamp(fifty_years_from_now)

    def test_parse_timestamp_parses_microsecond_timestamps(self):
        now = timezone.now().replace(microsecond=0)
        fifty_years_ago = now - relativedelta(year=50)
        fifty_years_from_now = now + relativedelta(year=50)

        self.verify_timestamp(now, 1000)
        self.verify_timestamp(fifty_years_ago, 1000)
        self.verify_timestamp(fifty_years_from_now, 1000)

    def test_parse_timestamp_parses_nanosecond_timestamps(self):
        now = timezone.now().replace(microsecond=0)
        fifty_years_ago = now - relativedelta(year=50)
        fifty_years_from_now = now + relativedelta(year=50)

        self.verify_timestamp(now, 1000000)
        self.verify_timestamp(fifty_years_ago, 1000000)
        self.verify_timestamp(fifty_years_from_now, 1000000)

    def test_parse_timestamp_fails_for_out_of_range_timestamp(self):
        now = timezone.now().replace(microsecond=0)

        with self.assertRaises(ValueError):
            self.verify_timestamp(now, 1000000000)