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)