tasks and tests

# tasks.py

@celery.task
def notify_lazy_students():
    """ Get the list of lazy students and notify them. Students who were notified recently will be skipped """

    date_when_can_send_second_notification = timezone.now() - settings.SKIP_REPETITIVE_LAZY_STUDENT_EMAIL_PERIOD

    for student in Customer.objects.get_lazy_students():
        if (student.lazy_student_notification_last_time is None or
                student.lazy_student_notification_last_time <= date_when_can_send_second_notification):

            lazy_student_detected.send(sender=notify_lazy_students, instance=student)
            student.lazy_student_notification_last_time = timezone.now()
            student.save()


# -----------------
# test_tasks.py

class TestPushLazyStudentEmail(ScheduleLessonsFromSubscriptionTestCase):
    """ TestCase for checking celery task is properly being run and signal reaches send email method. """
    def setUp(self):
        super().setUp()
        self.customers_all_types = {
            'lazy': {
                'obj': create_customer(),
                'class_dates': [self.tzdatetime(2042, 4, 20, 12, 0),
                                self.tzdatetime(2042, 4, 21, 12, 0),
                                self.tzdatetime(2042, 4, 22, 12, 0)]
            },
            'lazy2': {
                'obj': create_customer(),
                'class_dates': [self.tzdatetime(2042, 4, 19, 12, 0),
                                self.tzdatetime(2042, 4, 18, 12, 0),
                                self.tzdatetime(2042, 4, 17, 12, 0)]
            },
            'not_lazy': {
                'obj': create_customer(),
                'class_dates': [self.tzdatetime(2042, 5, 25, 12, 0),
                                self.tzdatetime(2042, 5, 14, 12, 0),
                                self.tzdatetime(2042, 5, 13, 12, 0),
                                self.tzdatetime(2042, 5, 12, 12, 0)]
            },
            'mix': {
                'obj': create_customer(),
                'class_dates': [self.tzdatetime(2042, 5, 24, 12, 0),  # future date case
                                self.tzdatetime(2042, 5, 23, 12, 0),
                                self.tzdatetime(2042, 5, 4, 12, 0),
                                self.tzdatetime(2042, 5, 1, 12, 0)]
            },
            'without_first_lesson': {
                'obj': create_customer(),
                'class_dates': []  # means subscription is not activated yet
            },
        }

    @freeze_time('2042-05-15 15:00')
    @patch('crm.signals.Owl')
    def test_lazy_student_notification(self, owl_send_mock):
        """
        Check that lazy students are detected by task run and are notified with email send.
        """
        expected_number_of_emails = 2

        for customer in self.customers_all_types.values():
            subscription = self._buy_subscription(customer=customer['obj'])
            self._schedule_several_lessons(dates=customer['class_dates'], subscription=subscription)

        notify_lazy_students.apply()  # run the celery task synchronously

        self.assertEqual(owl_send_mock.call_count, expected_number_of_emails)

    @patch('crm.signals.Owl')
    def test_skip_repetitive_email(self, owl_send_mock):
        """
        Check that notify_lazy_students will skip the student during the SKIP_REPETITIVE_LAZY_STUDENT_EMAIL_PERIOD
        if he has been already notified.
        """
        expected_number_of_emails = 2
        expected_number_of_emails_when_skip = 0

        with freeze_time('2042-05-15 15:00'):
            for customer in self.customers_all_types.values():
                subscription = self._buy_subscription(customer=customer['obj'])
                self._schedule_several_lessons(dates=customer['class_dates'], subscription=subscription)

            notify_lazy_students.apply()

            self.assertEqual(owl_send_mock.call_count, expected_number_of_emails)

        with freeze_time('2042-05-16 15:00'):  # skip repetitive emails
            owl_send_mock.call_count = 0
            notify_lazy_students.apply()

            self.assertEqual(owl_send_mock.call_count, expected_number_of_emails_when_skip)

        with freeze_time('2042-05-20 15:00'):
            owl_send_mock.call_count = 0
            notify_lazy_students.apply()

            self.assertEqual(owl_send_mock.call_count, expected_number_of_emails)