"""
Test entitlements tasks
"""


from datetime import datetime, timedelta
from unittest import mock

import pytest
import pytz
from django.test import TestCase

from common.djangoapps.entitlements import tasks
from common.djangoapps.entitlements.models import CourseEntitlementPolicy
from common.djangoapps.entitlements.tests.factories import CourseEntitlementFactory
from openedx.core.djangolib.testing.utils import skip_unless_lms


def make_entitlement(expired=False):  # lint-amnesty, pylint: disable=missing-function-docstring
    age = CourseEntitlementPolicy.DEFAULT_EXPIRATION_PERIOD_DAYS
    past_datetime = datetime.now(tz=pytz.UTC) - timedelta(days=age)
    expired_at = past_datetime if expired else None
    entitlement = CourseEntitlementFactory.create(created=past_datetime, expired_at=expired_at)
    return entitlement


def boom():
    raise Exception('boom')


@skip_unless_lms
class TestExpireOldEntitlementsTask(TestCase):
    """
    Tests for the 'expire_old_entitlements' method.
    """
    def test_checks_expiration(self):
        """
        Test that we actually do check expiration on each entitlement (happy path)
        """
        make_entitlement()
        make_entitlement()

        with mock.patch(
            'common.djangoapps.entitlements.models.CourseEntitlement.expired_at_datetime',
            new_callable=mock.PropertyMock
        ) as mock_datetime:
            tasks.expire_old_entitlements.delay(1, 3).get()

        assert mock_datetime.call_count == 2

    def test_only_unexpired(self):
        """
        Verify that only unexpired entitlements are included
        """
        # Create an old expired and an old unexpired entitlement
        make_entitlement(expired=True)
        make_entitlement()

        with mock.patch(
            'common.djangoapps.entitlements.models.CourseEntitlement.expired_at_datetime',
            new_callable=mock.PropertyMock
        ) as mock_datetime:
            tasks.expire_old_entitlements.delay(1, 3).get()

        # Make sure only the unexpired one gets used
        assert mock_datetime.call_count == 1

    def test_retry(self):
        """
        Test that we retry when an exception occurs while checking old
        entitlements.
        """
        make_entitlement()

        with mock.patch(
            'common.djangoapps.entitlements.models.CourseEntitlement.expired_at_datetime',
            new_callable=mock.PropertyMock,
            side_effect=boom
        ) as mock_datetime:
            task = tasks.expire_old_entitlements.delay(1, 2)

        pytest.raises(Exception, task.get)
        assert mock_datetime.call_count == (tasks.MAX_RETRIES + 1)


@skip_unless_lms
class TestExpireOldEntitlementsTaskIntegration(TestCase):
    """
    Tests for the 'expire_old_entitlements' method without mocking.
    """
    def test_actually_expired(self):
        """
        Integration test with CourseEntitlement to make sure we are calling the
        correct API.
        """
        entitlement = make_entitlement()

        # Sanity check
        assert entitlement.expired_at is None

        # Run enforcement
        tasks.expire_old_entitlements.delay(1, 2).get()
        entitlement.refresh_from_db()

        assert entitlement.expired_at is not None