"""
Unit tests for ProgramEnrollment models.
"""


from uuid import uuid4

import ddt
from django.db.utils import IntegrityError
from django.test import TestCase
from edx_django_utils.cache import RequestCache
from opaque_keys.edx.keys import CourseKey

from course_modes.models import CourseMode
from lms.djangoapps.program_enrollments.models import ProgramCourseEnrollment, ProgramEnrollment
from openedx.core.djangoapps.catalog.tests.factories import generate_course_run_key
from openedx.core.djangoapps.content.course_overviews.tests.factories import CourseOverviewFactory
from student.tests.factories import CourseEnrollmentFactory, UserFactory


class ProgramEnrollmentModelTests(TestCase):
    """
    Tests for the ProgramEnrollment model.
    """
    def setUp(self):
        """
        Set up the test data used in the specific tests
        """
        super(ProgramEnrollmentModelTests, self).setUp()
        self.user = UserFactory.create()
        self.program_uuid = uuid4()
        self.other_program_uuid = uuid4()
        self.curriculum_uuid = uuid4()
        self.enrollment = ProgramEnrollment.objects.create(
            user=self.user,
            external_user_key='abc',
            program_uuid=self.program_uuid,
            curriculum_uuid=self.curriculum_uuid,
            status='enrolled'
        )

    def test_unique_external_key_program_curriculum(self):
        """
        A record with the same (external_user_key, program_uuid, curriculum_uuid) cannot be duplicated.
        """
        with self.assertRaises(IntegrityError):
            _ = ProgramEnrollment.objects.create(
                user=None,
                external_user_key='abc',
                program_uuid=self.program_uuid,
                curriculum_uuid=self.curriculum_uuid,
                status='pending',
            )

    def test_unique_user_program_curriculum(self):
        """
        A record with the same (user, program_uuid, curriculum_uuid) cannot be duplicated.
        """
        with self.assertRaises(IntegrityError):
            _ = ProgramEnrollment.objects.create(
                user=self.user,
                external_user_key=None,
                program_uuid=self.program_uuid,
                curriculum_uuid=self.curriculum_uuid,
                status='suspended',
            )

    def test_user_retirement(self):
        """
        Test that the external_user_key is successfully retired for a user's program enrollments
        and history.
        """
        new_status = 'canceled'

        self.enrollment.status = new_status
        self.enrollment.save()

        # Ensure that all the records had values for external_user_key
        self.assertEqual(self.enrollment.external_user_key, 'abc')

        self.assertTrue(self.enrollment.historical_records.all())
        for record in self.enrollment.historical_records.all():
            self.assertEqual(record.external_user_key, 'abc')

        ProgramEnrollment.retire_user(self.user.id)
        self.enrollment.refresh_from_db()

        # Ensure those values are retired
        self.assertEqual(self.enrollment.external_user_key, None)

        self.assertTrue(self.enrollment.historical_records.all())
        for record in self.enrollment.historical_records.all():
            self.assertEqual(record.external_user_key, None)


@ddt.ddt
class ProgramCourseEnrollmentModelTests(TestCase):
    """
    Tests for the ProgramCourseEnrollment model.
    """
    def setUp(self):
        """
        Set up test data
        """
        super(ProgramCourseEnrollmentModelTests, self).setUp()
        RequestCache.clear_all_namespaces()
        self.user = UserFactory.create()
        self.program_uuid = uuid4()
        self.program_enrollment = ProgramEnrollment.objects.create(
            user=self.user,
            external_user_key='abc',
            program_uuid=self.program_uuid,
            curriculum_uuid=uuid4(),
            status='enrolled'
        )
        self.course_key = CourseKey.from_string(generate_course_run_key())
        CourseOverviewFactory(id=self.course_key)

    def test_unique_completed_enrollment(self):
        """
        A record with the same (program_enrollment, course_enrollment)
        cannot be created.
        """
        pce = self._create_completed_program_course_enrollment()
        with self.assertRaises(IntegrityError):
            # Purposefully mis-set the course_key in order to test
            # that there is a constraint on
            # (program_enrollment, course_enrollment) alone.
            ProgramCourseEnrollment.objects.create(
                program_enrollment=pce.program_enrollment,
                course_key="course-v1:dummy+value+101",
                course_enrollment=pce.course_enrollment,
                status="inactive",
            )

    def test_unique_waiting_enrollment(self):
        """
        A record with the same (program_enrollment, course_key)
        cannot be created.
        """
        pce = self._create_waiting_program_course_enrollment()
        with self.assertRaises(IntegrityError):
            ProgramCourseEnrollment.objects.create(
                program_enrollment=pce.program_enrollment,
                course_key=pce.course_key,
                course_enrollment=None,
                status="inactive",
            )

    def _create_completed_program_course_enrollment(self):
        """ helper function create program course enrollment """
        course_enrollment = CourseEnrollmentFactory.create(
            course_id=self.course_key,
            user=self.user,
            mode=CourseMode.MASTERS
        )
        program_course_enrollment = ProgramCourseEnrollment.objects.create(
            program_enrollment=self.program_enrollment,
            course_key=self.course_key,
            course_enrollment=course_enrollment,
            status="active"
        )
        return program_course_enrollment

    def _create_waiting_program_course_enrollment(self):
        """ helper function create program course enrollment with no lms user """
        return ProgramCourseEnrollment.objects.create(
            program_enrollment=self.program_enrollment,
            course_key=self.course_key,
            course_enrollment=None,
            status="active"
        )