import courseware.access as access
import datetime

import mock
from mock import Mock

from django.test import TestCase

from courseware.tests.factories import UserFactory, StaffFactory, InstructorFactory
from student.tests.factories import AnonymousUserFactory, CourseEnrollmentAllowedFactory
import pytz
from opaque_keys.edx.locations import SlashSeparatedCourseKey

# pylint: disable=C0111


class AccessTestCase(TestCase):
    """
    Tests for the various access controls on the student dashboard
    """

    def setUp(self):
        course_key = SlashSeparatedCourseKey('edX', 'toy', '2012_Fall')
        self.course = course_key.make_usage_key('course', course_key.run)
        self.anonymous_user = AnonymousUserFactory()
        self.student = UserFactory()
        self.global_staff = UserFactory(is_staff=True)
        self.course_staff = StaffFactory(course_key=self.course.course_key)
        self.course_instructor = InstructorFactory(course_key=self.course.course_key)

    def test_has_access_to_course(self):
        self.assertFalse(access._has_access_to_course(
            None, 'staff', self.course.course_key
        ))

        self.assertFalse(access._has_access_to_course(
            self.anonymous_user, 'staff', self.course.course_key
        ))
        self.assertFalse(access._has_access_to_course(
            self.anonymous_user, 'instructor', self.course.course_key
        ))

        self.assertTrue(access._has_access_to_course(
            self.global_staff, 'staff', self.course.course_key
        ))
        self.assertTrue(access._has_access_to_course(
            self.global_staff, 'instructor', self.course.course_key
        ))

        # A user has staff access if they are in the staff group
        self.assertTrue(access._has_access_to_course(
            self.course_staff, 'staff', self.course.course_key
        ))
        self.assertFalse(access._has_access_to_course(
            self.course_staff, 'instructor', self.course.course_key
        ))

        # A user has staff and instructor access if they are in the instructor group
        self.assertTrue(access._has_access_to_course(
            self.course_instructor, 'staff', self.course.course_key
        ))
        self.assertTrue(access._has_access_to_course(
            self.course_instructor, 'instructor', self.course.course_key
        ))

        # A user does not have staff or instructor access if they are
        # not in either the staff or the the instructor group
        self.assertFalse(access._has_access_to_course(
            self.student, 'staff', self.course.course_key
        ))
        self.assertFalse(access._has_access_to_course(
            self.student, 'instructor', self.course.course_key
        ))

    def test__has_access_string(self):
        user = Mock(is_staff=True)
        self.assertFalse(access._has_access_string(user, 'staff', 'not_global', self.course.course_key))

        user._has_global_staff_access.return_value = True
        self.assertTrue(access._has_access_string(user, 'staff', 'global', self.course.course_key))

        self.assertRaises(ValueError, access._has_access_string, user, 'not_staff', 'global', self.course.course_key)

    def test__has_access_error_desc(self):
        descriptor = Mock()

        self.assertFalse(access._has_access_error_desc(self.student, 'load', descriptor, self.course.course_key))
        self.assertTrue(access._has_access_error_desc(self.course_staff, 'load', descriptor, self.course.course_key))
        self.assertTrue(access._has_access_error_desc(self.course_instructor, 'load', descriptor, self.course.course_key))

        self.assertFalse(access._has_access_error_desc(self.student, 'staff', descriptor, self.course.course_key))
        self.assertTrue(access._has_access_error_desc(self.course_staff, 'staff', descriptor, self.course.course_key))
        self.assertTrue(access._has_access_error_desc(self.course_instructor, 'staff', descriptor, self.course.course_key))

        self.assertFalse(access._has_access_error_desc(self.student, 'instructor', descriptor, self.course.course_key))
        self.assertFalse(access._has_access_error_desc(self.course_staff, 'instructor', descriptor, self.course.course_key))
        self.assertTrue(access._has_access_error_desc(self.course_instructor, 'instructor', descriptor, self.course.course_key))

        with self.assertRaises(ValueError):
            access._has_access_error_desc(self.course_instructor, 'not_load_or_staff', descriptor, self.course.course_key)

    def test__has_access_descriptor(self):
        # TODO: override DISABLE_START_DATES and test the start date branch of the method
        user = Mock()
        descriptor = Mock()

        # Always returns true because DISABLE_START_DATES is set in test.py
        self.assertTrue(access._has_access_descriptor(user, 'load', descriptor))
        self.assertTrue(access._has_access_descriptor(user, 'instructor', descriptor))
        with self.assertRaises(ValueError):
            access._has_access_descriptor(user, 'not_load_or_staff', descriptor)

    @mock.patch.dict('django.conf.settings.FEATURES', {'DISABLE_START_DATES': False})
    def test__has_access_descriptor_staff_lock(self):
        """
        Tests that "visible_to_staff_only" overrides start date.
        """
        mock_unit = Mock()
        mock_unit._class_tags = {}  # Needed for detached check in _has_access_descriptor

        def verify_access(student_should_have_access):
            """ Verify the expected result from _has_access_descriptor """
            self.assertEqual(student_should_have_access, access._has_access_descriptor(
                self.anonymous_user, 'load', mock_unit, course_key=self.course.course_key)
            )
            # staff always has access
            self.assertTrue(access._has_access_descriptor(
                self.course_staff, 'load', mock_unit, course_key=self.course.course_key)
            )

        # No start date, staff lock on
        mock_unit.visible_to_staff_only = True
        verify_access(False)

        # No start date, staff lock off.
        mock_unit.visible_to_staff_only = False
        verify_access(True)

        # Start date in the past, staff lock on.
        mock_unit.start = datetime.datetime.now(pytz.utc) - datetime.timedelta(days=1)
        mock_unit.visible_to_staff_only = True
        verify_access(False)

        # Start date in the past, staff lock off.
        mock_unit.visible_to_staff_only = False
        verify_access(True)

        # Start date in the future, staff lock on.
        mock_unit.start = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=1)  # release date in the future
        mock_unit.visible_to_staff_only = True
        verify_access(False)

        # Start date in the future, staff lock off.
        mock_unit.visible_to_staff_only = False
        verify_access(False)

    def test__has_access_course_desc_can_enroll(self):
        yesterday = datetime.datetime.now(pytz.utc) - datetime.timedelta(days=1)
        tomorrow = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=1)

        # Non-staff can enroll if authenticated and specifically allowed for that course
        # even outside the open enrollment period
        user = UserFactory.create()
        course = Mock(
            enrollment_start=tomorrow, enrollment_end=tomorrow,
            id=SlashSeparatedCourseKey('edX', 'test', '2012_Fall'), enrollment_domain=''
        )
        CourseEnrollmentAllowedFactory(email=user.email, course_id=course.id)
        self.assertTrue(access._has_access_course_desc(user, 'enroll', course))

        # Staff can always enroll even outside the open enrollment period
        user = StaffFactory.create(course_key=course.id)
        self.assertTrue(access._has_access_course_desc(user, 'enroll', course))

        # Non-staff cannot enroll if it is between the start and end dates and invitation only
        # and not specifically allowed
        course = Mock(
            enrollment_start=yesterday, enrollment_end=tomorrow,
            id=SlashSeparatedCourseKey('edX', 'test', '2012_Fall'), enrollment_domain='',
            invitation_only=True
        )
        user = UserFactory.create()
        self.assertFalse(access._has_access_course_desc(user, 'enroll', course))

        # Non-staff can enroll if it is between the start and end dates and not invitation only
        course = Mock(
            enrollment_start=yesterday, enrollment_end=tomorrow,
            id=SlashSeparatedCourseKey('edX', 'test', '2012_Fall'), enrollment_domain='',
            invitation_only=False
        )
        self.assertTrue(access._has_access_course_desc(user, 'enroll', course))

        # Non-staff cannot enroll outside the open enrollment period if not specifically allowed
        course = Mock(
            enrollment_start=tomorrow, enrollment_end=tomorrow,
            id=SlashSeparatedCourseKey('edX', 'test', '2012_Fall'), enrollment_domain='',
            invitation_only=False
        )
        self.assertFalse(access._has_access_course_desc(user, 'enroll', course))

    def test__user_passed_as_none(self):
        """Ensure has_access handles a user being passed as null"""
        access.has_access(None, 'staff', 'global', None)


class UserRoleTestCase(TestCase):
    """
    Tests for user roles.
    """
    def setUp(self):
        self.course_key = SlashSeparatedCourseKey('edX', 'toy', '2012_Fall')
        self.anonymous_user = AnonymousUserFactory()
        self.student = UserFactory()
        self.global_staff = UserFactory(is_staff=True)
        self.course_staff = StaffFactory(course_key=self.course_key)
        self.course_instructor = InstructorFactory(course_key=self.course_key)

    def test_user_role_staff(self):
        """Ensure that user role is student for staff masqueraded as student."""
        self.assertEqual(
            'staff',
            access.get_user_role(self.course_staff, self.course_key)
        )
        # Masquerade staff
        self.course_staff.masquerade_as_student = True
        self.assertEqual(
            'student',
            access.get_user_role(self.course_staff, self.course_key)
        )

    def test_user_role_instructor(self):
        """Ensure that user role is student for instructor masqueraded as student."""
        self.assertEqual(
            'instructor',
            access.get_user_role(self.course_instructor, self.course_key)
        )
        # Masquerade instructor
        self.course_instructor.masquerade_as_student = True
        self.assertEqual(
            'student',
            access.get_user_role(self.course_instructor, self.course_key)
        )

    def test_user_role_anonymous(self):
        """Ensure that user role is student for anonymous user."""
        self.assertEqual(
            'student',
            access.get_user_role(self.anonymous_user, self.course_key)
        )