""" Tests for utils. """
import collections
from datetime import datetime, timedelta

from django.test import TestCase
from opaque_keys.edx.locations import SlashSeparatedCourseKey
from pytz import UTC

from contentstore import utils
from contentstore.tests.utils import CourseTestCase
from openedx.core.djangoapps.site_configuration.tests.test_util import with_site_configuration_context
from xmodule.modulestore import ModuleStoreEnum
from xmodule.modulestore.django import modulestore
from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase, SharedModuleStoreTestCase
from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
from xmodule.partitions.partitions import Group, UserPartition


class LMSLinksTestCase(TestCase):
    """ Tests for LMS links. """

    def lms_link_test(self):
        """ Tests get_lms_link_for_item. """
        course_key = SlashSeparatedCourseKey('mitX', '101', 'test')
        location = course_key.make_usage_key('vertical', 'contacting_us')
        link = utils.get_lms_link_for_item(location, False)
        self.assertEquals(link, "//localhost:8000/courses/mitX/101/test/jump_to/i4x://mitX/101/vertical/contacting_us")

        # test preview
        link = utils.get_lms_link_for_item(location, True)
        self.assertEquals(
            link,
            "//preview.localhost/courses/mitX/101/test/jump_to/i4x://mitX/101/vertical/contacting_us"
        )

        # now test with the course' location
        location = course_key.make_usage_key('course', 'test')
        link = utils.get_lms_link_for_item(location)
        self.assertEquals(link, "//localhost:8000/courses/mitX/101/test/jump_to/i4x://mitX/101/course/test")

    def lms_link_for_certificate_web_view_test(self):
        """ Tests get_lms_link_for_certificate_web_view. """
        course_key = SlashSeparatedCourseKey('mitX', '101', 'test')
        dummy_user = ModuleStoreEnum.UserID.test
        mode = 'professional'

        self.assertEquals(
            utils.get_lms_link_for_certificate_web_view(dummy_user, course_key, mode),
            "//localhost:8000/certificates/user/{user_id}/course/{course_key}?preview={mode}".format(
                user_id=dummy_user,
                course_key=course_key,
                mode=mode
            )
        )

        with with_site_configuration_context(configuration={"course_org_filter": "mitX", "LMS_BASE": "dummyhost:8000"}):
            self.assertEquals(
                utils.get_lms_link_for_certificate_web_view(dummy_user, course_key, mode),
                "//dummyhost:8000/certificates/user/{user_id}/course/{course_key}?preview={mode}".format(
                    user_id=dummy_user,
                    course_key=course_key,
                    mode=mode
                )
            )


class ExtraPanelTabTestCase(TestCase):
    """ Tests adding and removing extra course tabs. """

    def get_tab_type_dicts(self, tab_types):
        """ Returns an array of tab dictionaries. """
        if tab_types:
            return [{'tab_type': tab_type} for tab_type in tab_types.split(',')]
        else:
            return []

    def get_course_with_tabs(self, tabs=None):
        """ Returns a mock course object with a tabs attribute. """
        if tabs is None:
            tabs = []
        course = collections.namedtuple('MockCourse', ['tabs'])
        if isinstance(tabs, basestring):
            course.tabs = self.get_tab_type_dicts(tabs)
        else:
            course.tabs = tabs
        return course


class XBlockVisibilityTestCase(SharedModuleStoreTestCase):
    """Tests for xblock visibility for students."""

    @classmethod
    def setUpClass(cls):
        super(XBlockVisibilityTestCase, cls).setUpClass()

        cls.dummy_user = ModuleStoreEnum.UserID.test
        cls.past = datetime(1970, 1, 1, tzinfo=UTC)
        cls.future = datetime.now(UTC) + timedelta(days=1)
        cls.course = CourseFactory.create()

    def test_private_unreleased_xblock(self):
        """Verifies that a private unreleased xblock is not visible"""
        self._test_visible_to_students(False, 'private_unreleased', self.future)

    def test_private_released_xblock(self):
        """Verifies that a private released xblock is not visible"""
        self._test_visible_to_students(False, 'private_released', self.past)

    def test_public_unreleased_xblock(self):
        """Verifies that a public (published) unreleased xblock is not visible"""
        self._test_visible_to_students(False, 'public_unreleased', self.future, publish=True)

    def test_public_released_xblock(self):
        """Verifies that public (published) released xblock is visible if staff lock is not enabled."""
        self._test_visible_to_students(True, 'public_released', self.past, publish=True)

    def test_private_no_start_xblock(self):
        """Verifies that a private xblock with no start date is not visible"""
        self._test_visible_to_students(False, 'private_no_start', None)

    def test_public_no_start_xblock(self):
        """Verifies that a public (published) xblock with no start date is visible unless staff lock is enabled"""
        self._test_visible_to_students(True, 'public_no_start', None, publish=True)

    def test_draft_released_xblock(self):
        """Verifies that a xblock with an unreleased draft and a released published version is visible"""
        vertical = self._create_xblock_with_start_date('draft_released', self.past, publish=True)

        # Create an unreleased draft version of the xblock
        vertical.start = self.future
        modulestore().update_item(vertical, self.dummy_user)

        self.assertTrue(utils.is_currently_visible_to_students(vertical))

    def _test_visible_to_students(self, expected_visible_without_lock, name, start_date, publish=False):
        """
        Helper method that checks that is_xblock_visible_to_students returns the correct value both
        with and without visible_to_staff_only set.
        """
        no_staff_lock = self._create_xblock_with_start_date(name, start_date, publish, visible_to_staff_only=False)
        self.assertEqual(expected_visible_without_lock, utils.is_currently_visible_to_students(no_staff_lock))

        # any xblock with visible_to_staff_only set to True should not be visible to students.
        staff_lock = self._create_xblock_with_start_date(
            name + "_locked", start_date, publish, visible_to_staff_only=True
        )
        self.assertFalse(utils.is_currently_visible_to_students(staff_lock))

    def _create_xblock_with_start_date(self, name, start_date, publish=False, visible_to_staff_only=False):
        """Helper to create an xblock with a start date, optionally publishing it"""

        vertical = modulestore().create_item(
            self.dummy_user, self.course.location.course_key, 'vertical', name,
            fields={'start': start_date, 'visible_to_staff_only': visible_to_staff_only}
        )

        if publish:
            modulestore().publish(vertical.location, self.dummy_user)

        return vertical


class ReleaseDateSourceTest(CourseTestCase):
    """Tests for finding the source of an xblock's release date."""

    def setUp(self):
        super(ReleaseDateSourceTest, self).setUp()

        self.chapter = ItemFactory.create(category='chapter', parent_location=self.course.location)
        self.sequential = ItemFactory.create(category='sequential', parent_location=self.chapter.location)
        self.vertical = ItemFactory.create(category='vertical', parent_location=self.sequential.location)

        # Read again so that children lists are accurate
        self.chapter = self.store.get_item(self.chapter.location)
        self.sequential = self.store.get_item(self.sequential.location)
        self.vertical = self.store.get_item(self.vertical.location)

        self.date_one = datetime(1980, 1, 1, tzinfo=UTC)
        self.date_two = datetime(2020, 1, 1, tzinfo=UTC)

    def _update_release_dates(self, chapter_start, sequential_start, vertical_start):
        """Sets the release dates of the chapter, sequential, and vertical"""
        self.chapter.start = chapter_start
        self.chapter = self.store.update_item(self.chapter, ModuleStoreEnum.UserID.test)
        self.sequential.start = sequential_start
        self.sequential = self.store.update_item(self.sequential, ModuleStoreEnum.UserID.test)
        self.vertical.start = vertical_start
        self.vertical = self.store.update_item(self.vertical, ModuleStoreEnum.UserID.test)

    def _verify_release_date_source(self, item, expected_source):
        """Helper to verify that the release date source of a given item matches the expected source"""
        source = utils.find_release_date_source(item)
        self.assertEqual(source.location, expected_source.location)
        self.assertEqual(source.start, expected_source.start)

    def test_chapter_source_for_vertical(self):
        """Tests a vertical's release date being set by its chapter"""
        self._update_release_dates(self.date_one, self.date_one, self.date_one)
        self._verify_release_date_source(self.vertical, self.chapter)

    def test_sequential_source_for_vertical(self):
        """Tests a vertical's release date being set by its sequential"""
        self._update_release_dates(self.date_one, self.date_two, self.date_two)
        self._verify_release_date_source(self.vertical, self.sequential)

    def test_chapter_source_for_sequential(self):
        """Tests a sequential's release date being set by its chapter"""
        self._update_release_dates(self.date_one, self.date_one, self.date_one)
        self._verify_release_date_source(self.sequential, self.chapter)

    def test_sequential_source_for_sequential(self):
        """Tests a sequential's release date being set by itself"""
        self._update_release_dates(self.date_one, self.date_two, self.date_two)
        self._verify_release_date_source(self.sequential, self.sequential)


class StaffLockTest(CourseTestCase):
    """Base class for testing staff lock functions."""

    def setUp(self):
        super(StaffLockTest, self).setUp()

        self.chapter = ItemFactory.create(category='chapter', parent_location=self.course.location)
        self.sequential = ItemFactory.create(category='sequential', parent_location=self.chapter.location)
        self.vertical = ItemFactory.create(category='vertical', parent_location=self.sequential.location)
        self.orphan = ItemFactory.create(category='vertical', parent_location=self.sequential.location)

        # Read again so that children lists are accurate
        self.chapter = self.store.get_item(self.chapter.location)
        self.sequential = self.store.get_item(self.sequential.location)
        self.vertical = self.store.get_item(self.vertical.location)

        # Orphan the orphaned xblock
        self.sequential.children = [self.vertical.location]
        self.sequential = self.store.update_item(self.sequential, ModuleStoreEnum.UserID.test)

    def _set_staff_lock(self, xblock, is_locked):
        """If is_locked is True, xblock is staff locked. Otherwise, the xblock staff lock field is removed."""
        field = xblock.fields['visible_to_staff_only']
        if is_locked:
            field.write_to(xblock, True)
        else:
            field.delete_from(xblock)
        return self.store.update_item(xblock, ModuleStoreEnum.UserID.test)

    def _update_staff_locks(self, chapter_locked, sequential_locked, vertical_locked):
        """
        Sets the staff lock on the chapter, sequential, and vertical
        If the corresponding argument is False, then the field is deleted from the xblock
        """
        self.chapter = self._set_staff_lock(self.chapter, chapter_locked)
        self.sequential = self._set_staff_lock(self.sequential, sequential_locked)
        self.vertical = self._set_staff_lock(self.vertical, vertical_locked)


class StaffLockSourceTest(StaffLockTest):
    """Tests for finding the source of an xblock's staff lock."""

    def _verify_staff_lock_source(self, item, expected_source):
        """Helper to verify that the staff lock source of a given item matches the expected source"""
        source = utils.find_staff_lock_source(item)
        self.assertEqual(source.location, expected_source.location)
        self.assertTrue(source.visible_to_staff_only)

    def test_chapter_source_for_vertical(self):
        """Tests a vertical's staff lock being set by its chapter"""
        self._update_staff_locks(True, False, False)
        self._verify_staff_lock_source(self.vertical, self.chapter)

    def test_sequential_source_for_vertical(self):
        """Tests a vertical's staff lock being set by its sequential"""
        self._update_staff_locks(True, True, False)
        self._verify_staff_lock_source(self.vertical, self.sequential)
        self._update_staff_locks(False, True, False)
        self._verify_staff_lock_source(self.vertical, self.sequential)

    def test_vertical_source_for_vertical(self):
        """Tests a vertical's staff lock being set by itself"""
        self._update_staff_locks(True, True, True)
        self._verify_staff_lock_source(self.vertical, self.vertical)
        self._update_staff_locks(False, True, True)
        self._verify_staff_lock_source(self.vertical, self.vertical)
        self._update_staff_locks(False, False, True)
        self._verify_staff_lock_source(self.vertical, self.vertical)

    def test_orphan_has_no_source(self):
        """Tests that a orphaned xblock has no staff lock source"""
        self.assertIsNone(utils.find_staff_lock_source(self.orphan))

    def test_no_source_for_vertical(self):
        """Tests a vertical with no staff lock set anywhere"""
        self._update_staff_locks(False, False, False)
        self.assertIsNone(utils.find_staff_lock_source(self.vertical))


class InheritedStaffLockTest(StaffLockTest):
    """Tests for determining if an xblock inherits a staff lock."""

    def test_no_inheritance(self):
        """Tests that a locked or unlocked vertical with no locked ancestors does not have an inherited lock"""
        self._update_staff_locks(False, False, False)
        self.assertFalse(utils.ancestor_has_staff_lock(self.vertical))
        self._update_staff_locks(False, False, True)
        self.assertFalse(utils.ancestor_has_staff_lock(self.vertical))

    def test_inheritance_in_locked_section(self):
        """Tests that a locked or unlocked vertical in a locked section has an inherited lock"""
        self._update_staff_locks(True, False, False)
        self.assertTrue(utils.ancestor_has_staff_lock(self.vertical))
        self._update_staff_locks(True, False, True)
        self.assertTrue(utils.ancestor_has_staff_lock(self.vertical))

    def test_inheritance_in_locked_subsection(self):
        """Tests that a locked or unlocked vertical in a locked subsection has an inherited lock"""
        self._update_staff_locks(False, True, False)
        self.assertTrue(utils.ancestor_has_staff_lock(self.vertical))
        self._update_staff_locks(False, True, True)
        self.assertTrue(utils.ancestor_has_staff_lock(self.vertical))

    def test_no_inheritance_for_orphan(self):
        """Tests that an orphaned xblock does not inherit staff lock"""
        self.assertFalse(utils.ancestor_has_staff_lock(self.orphan))


class GroupVisibilityTest(CourseTestCase):
    """
    Test content group access rules.
    """

    def setUp(self):
        super(GroupVisibilityTest, self).setUp()

        chapter = ItemFactory.create(category='chapter', parent_location=self.course.location)
        sequential = ItemFactory.create(category='sequential', parent_location=chapter.location)
        vertical = ItemFactory.create(category='vertical', parent_location=sequential.location)
        html = ItemFactory.create(category='html', parent_location=vertical.location)
        problem = ItemFactory.create(
            category='problem', parent_location=vertical.location, data="<problem></problem>"
        )
        self.sequential = self.store.get_item(sequential.location)
        self.vertical = self.store.get_item(vertical.location)
        self.html = self.store.get_item(html.location)
        self.problem = self.store.get_item(problem.location)

        # Add partitions to the course
        self.course.user_partitions = [
            UserPartition(
                id=0,
                name="Partition 0",
                description="Partition 0",
                scheme=UserPartition.get_scheme("random"),
                groups=[
                    Group(id=0, name="Group A"),
                    Group(id=1, name="Group B"),
                ],
            ),
            UserPartition(
                id=1,
                name="Partition 1",
                description="Partition 1",
                scheme=UserPartition.get_scheme("random"),
                groups=[
                    Group(id=0, name="Group C"),
                    Group(id=1, name="Group D"),
                ],
            ),
            UserPartition(
                id=2,
                name="Partition 2",
                description="Partition 2",
                scheme=UserPartition.get_scheme("random"),
                groups=[
                    Group(id=0, name="Group E"),
                    Group(id=1, name="Group F"),
                    Group(id=2, name="Group G"),
                    Group(id=3, name="Group H"),
                ],
            ),
        ]
        self.course = self.store.update_item(self.course, ModuleStoreEnum.UserID.test)

    def set_group_access(self, xblock, value):
        """ Sets group_access to specified value and calls update_item to persist the change. """
        xblock.group_access = value
        self.store.update_item(xblock, self.user.id)

    def test_no_visibility_set(self):
        """ Tests when group_access has not been set on anything. """

        def verify_all_components_visible_to_all():  # pylint: disable=invalid-name
            """ Verifies when group_access has not been set on anything. """
            for item in (self.sequential, self.vertical, self.html, self.problem):
                self.assertFalse(utils.has_children_visible_to_specific_partition_groups(item))
                self.assertFalse(utils.is_visible_to_specific_partition_groups(item))

        verify_all_components_visible_to_all()

        # Test with group_access set to Falsey values.
        self.set_group_access(self.vertical, {1: []})
        self.set_group_access(self.html, {2: None})

        verify_all_components_visible_to_all()

    def test_sequential_and_problem_have_group_access(self):
        """ Tests when group_access is set on a few different components. """
        self.set_group_access(self.sequential, {1: [0]})
        # This is a no-op.
        self.set_group_access(self.vertical, {1: []})
        self.set_group_access(self.problem, {2: [3, 4]})

        # Note that "has_children_visible_to_specific_partition_groups" only checks immediate children.
        self.assertFalse(utils.has_children_visible_to_specific_partition_groups(self.sequential))
        self.assertTrue(utils.has_children_visible_to_specific_partition_groups(self.vertical))
        self.assertFalse(utils.has_children_visible_to_specific_partition_groups(self.html))
        self.assertFalse(utils.has_children_visible_to_specific_partition_groups(self.problem))

        self.assertTrue(utils.is_visible_to_specific_partition_groups(self.sequential))
        self.assertFalse(utils.is_visible_to_specific_partition_groups(self.vertical))
        self.assertFalse(utils.is_visible_to_specific_partition_groups(self.html))
        self.assertTrue(utils.is_visible_to_specific_partition_groups(self.problem))


class GetUserPartitionInfoTest(ModuleStoreTestCase):
    """
    Tests for utility function that retrieves user partition info
    and formats it for consumption by the editing UI.
    """

    def setUp(self):
        """Create a dummy course. """
        super(GetUserPartitionInfoTest, self).setUp()
        self.course = CourseFactory()
        self.block = ItemFactory.create(category="problem", parent_location=self.course.location)  # pylint: disable=no-member

        # Set up some default partitions
        self._set_partitions([
            UserPartition(
                id=0,
                name="Cohort user partition",
                scheme=UserPartition.get_scheme("cohort"),
                description="Cohorted user partition",
                groups=[
                    Group(id=0, name="Group A"),
                    Group(id=1, name="Group B"),
                ],
            ),
            UserPartition(
                id=1,
                name="Random user partition",
                scheme=UserPartition.get_scheme("random"),
                description="Random user partition",
                groups=[
                    Group(id=0, name="Group C"),
                ],
            ),
        ])

    def test_retrieves_partition_info_with_selected_groups(self):
        # Initially, no group access is set on the block, so no groups should
        # be marked as selected.
        expected = [
            {
                "id": 0,
                "name": u"Cohort user partition",
                "scheme": u"cohort",
                "groups": [
                    {
                        "id": 0,
                        "name": u"Group A",
                        "selected": False,
                        "deleted": False,
                    },
                    {
                        "id": 1,
                        "name": u"Group B",
                        "selected": False,
                        "deleted": False,
                    },
                ]
            },
            {
                "id": 1,
                "name": u"Random user partition",
                "scheme": u"random",
                "groups": [
                    {
                        "id": 0,
                        "name": u"Group C",
                        "selected": False,
                        "deleted": False,
                    },
                ]
            }
        ]
        self.assertEqual(self._get_partition_info(schemes=["cohort", "random"]), expected)

        # Update group access and expect that now one group is marked as selected.
        self._set_group_access({0: [1]})
        expected[0]["groups"][1]["selected"] = True
        self.assertEqual(self._get_partition_info(schemes=["cohort", "random"]), expected)

    def test_deleted_groups(self):
        # Select a group that is not defined in the partition
        self._set_group_access({0: [3]})

        # Expect that the group appears as selected but is marked as deleted
        partitions = self._get_partition_info()
        groups = partitions[0]["groups"]
        self.assertEqual(len(groups), 3)
        self.assertEqual(groups[2], {
            "id": 3,
            "name": "Deleted Group",
            "selected": True,
            "deleted": True
        })

    def test_filter_by_partition_scheme(self):
        partitions = self._get_partition_info(schemes=["random"])
        self.assertEqual(len(partitions), 1)
        self.assertEqual(partitions[0]["scheme"], "random")

    def test_exclude_inactive_partitions(self):
        # Include an inactive verification scheme
        self._set_partitions([
            UserPartition(
                id=0,
                name="Cohort user partition",
                scheme=UserPartition.get_scheme("cohort"),
                description="Cohorted user partition",
                groups=[
                    Group(id=0, name="Group A"),
                    Group(id=1, name="Group B"),
                ],
            ),
            UserPartition(
                id=1,
                name="Completely random user partition",
                scheme=UserPartition.get_scheme("random"),
                description="Random user partition",
                groups=[
                    Group(id=0, name="Group C"),
                ],
                active=False,
            ),
        ])

        # Expect that the inactive scheme is excluded from the results
        partitions = self._get_partition_info(schemes=["cohort", "verification"])
        self.assertEqual(len(partitions), 1)
        self.assertEqual(partitions[0]["scheme"], "cohort")

    def test_exclude_partitions_with_no_groups(self):
        # The cohort partition has no groups defined
        self._set_partitions([
            UserPartition(
                id=0,
                name="Cohort user partition",
                scheme=UserPartition.get_scheme("cohort"),
                description="Cohorted user partition",
                groups=[],
            ),
            UserPartition(
                id=1,
                name="Completely random user partition",
                scheme=UserPartition.get_scheme("random"),
                description="Random user partition",
                groups=[
                    Group(id=0, name="Group C"),
                ],
            ),
        ])

        # Expect that the partition with no groups is excluded from the results
        partitions = self._get_partition_info(schemes=["cohort", "random"])
        self.assertEqual(len(partitions), 1)
        self.assertEqual(partitions[0]["scheme"], "random")

    def _set_partitions(self, partitions):
        """Set the user partitions of the course descriptor. """
        self.course.user_partitions = partitions
        self.course = self.store.update_item(self.course, ModuleStoreEnum.UserID.test)

    def _set_group_access(self, group_access):
        """Set group access of the block. """
        self.block.group_access = group_access
        self.block = self.store.update_item(self.block, ModuleStoreEnum.UserID.test)

    def _get_partition_info(self, schemes=None):
        """Retrieve partition info and selected groups. """
        return utils.get_user_partition_info(self.block, schemes=schemes)
