"""
Content library unit tests that require the CMS runtime.
"""
from django.test.utils import override_settings
from contentstore.tests.utils import AjaxEnabledTestClient, parse_json
from contentstore.utils import reverse_url, reverse_usage_url, reverse_library_url
from contentstore.views.item import _duplicate_item
from contentstore.views.preview import _load_preview_module
from contentstore.views.tests.test_library import LIBRARY_REST_URL
import ddt
from mock import patch
from student.auth import has_studio_read_access, has_studio_write_access
from student.roles import (
    CourseInstructorRole, CourseStaffRole, LibraryUserRole,
    OrgStaffRole, OrgInstructorRole, OrgLibraryUserRole,
)
from xmodule.modulestore import ModuleStoreEnum
from xmodule.modulestore.django import modulestore
from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
from mock import Mock
from opaque_keys.edx.locator import CourseKey, LibraryLocator
from openedx.core.djangoapps.content.course_structures.tests import SignalDisconnectTestMixin
from xblock_django.user_service import DjangoXBlockUserService
from xmodule.x_module import STUDIO_VIEW
from student import auth
from student.tests.factories import UserFactory
from course_creators.views import add_user_with_status_granted


class LibraryTestCase(ModuleStoreTestCase):
    """
    Common functionality for content libraries tests
    """
    def setUp(self):
        super(LibraryTestCase, self).setUp()

        self.user = UserFactory(password=self.user_password, is_staff=True)
        self.client = AjaxEnabledTestClient()
        self._login_as_staff_user(logout_first=False)

        self.lib_key = self._create_library()
        self.library = modulestore().get_library(self.lib_key)

        self.session_data = {}  # Used by _bind_module

    def _login_as_staff_user(self, logout_first=True):
        """ Login as a staff user """
        if logout_first:
            self.client.logout()
        self.client.login(username=self.user.username, password=self.user_password)

    def _create_library(self, org="org", library="lib", display_name="Test Library"):
        """
        Helper method used to create a library. Uses the REST API.
        """
        response = self.client.ajax_post(LIBRARY_REST_URL, {
            'org': org,
            'library': library,
            'display_name': display_name,
        })
        self.assertEqual(response.status_code, 200)
        lib_info = parse_json(response)
        lib_key = CourseKey.from_string(lib_info['library_key'])
        self.assertIsInstance(lib_key, LibraryLocator)
        return lib_key

    def _add_library_content_block(self, course, library_key, publish_item=False, other_settings=None):
        """
        Helper method to add a LibraryContent block to a course.
        The block will be configured to select content from the library
        specified by library_key.
        other_settings can be a dict of Scope.settings fields to set on the block.
        """
        return ItemFactory.create(
            category='library_content',
            parent_location=course.location,
            user_id=self.user.id,
            publish_item=publish_item,
            source_library_id=unicode(library_key),
            **(other_settings or {})
        )

    def _add_simple_content_block(self):
        """ Adds simple HTML block to library """
        return ItemFactory.create(
            category="html", parent_location=self.library.location,
            user_id=self.user.id, publish_item=False
        )

    def _refresh_children(self, lib_content_block, status_code_expected=200):
        """
        Helper method: Uses the REST API to call the 'refresh_children' handler
        of a LibraryContent block
        """
        if 'user' not in lib_content_block.runtime._services:  # pylint: disable=protected-access
            user_service = DjangoXBlockUserService(self.user)
            lib_content_block.runtime._services['user'] = user_service  # pylint: disable=protected-access

        handler_url = reverse_usage_url(
            'component_handler',
            lib_content_block.location,
            kwargs={'handler': 'refresh_children'}
        )
        response = self.client.ajax_post(handler_url)
        self.assertEqual(response.status_code, status_code_expected)
        return modulestore().get_item(lib_content_block.location)

    def _bind_module(self, descriptor, user=None):
        """
        Helper to use the CMS's module system so we can access student-specific fields.
        """
        if user is None:
            user = self.user
        if user not in self.session_data:
            self.session_data[user] = {}
        request = Mock(user=user, session=self.session_data[user])
        _load_preview_module(request, descriptor)

    def _update_item(self, usage_key, metadata):
        """
        Helper method: Uses the REST API to update the fields of an XBlock.
        This will result in the XBlock's editor_saved() method being called.
        """
        update_url = reverse_usage_url("xblock_handler", usage_key)
        return self.client.ajax_post(
            update_url,
            data={
                'metadata': metadata,
            }
        )

    def _list_libraries(self):
        """
        Use the REST API to get a list of libraries visible to the current user.
        """
        response = self.client.get_json(LIBRARY_REST_URL)
        self.assertEqual(response.status_code, 200)
        return parse_json(response)


@ddt.ddt
class TestLibraries(LibraryTestCase):
    """
    High-level tests for libraries
    """
    @ddt.data(
        (2, 1, 1),
        (2, 2, 2),
        (2, 20, 2),
    )
    @ddt.unpack
    def test_max_items(self, num_to_create, num_to_select, num_expected):
        """
        Test the 'max_count' property of LibraryContent blocks.
        """
        for _ in range(num_to_create):
            self._add_simple_content_block()

        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        lc_block = self._add_library_content_block(course, self.lib_key, other_settings={'max_count': num_to_select})
        self.assertEqual(len(lc_block.children), 0)
        lc_block = self._refresh_children(lc_block)

        # Now, we want to make sure that .children has the total # of potential
        # children, and that get_child_descriptors() returns the actual children
        # chosen for a given student.
        # In order to be able to call get_child_descriptors(), we must first
        # call bind_for_student:
        self._bind_module(lc_block)
        self.assertEqual(len(lc_block.children), num_to_create)
        self.assertEqual(len(lc_block.get_child_descriptors()), num_expected)

    def test_consistent_children(self):
        """
        Test that the same student will always see the same selected child block
        """
        # Create many blocks in the library and add them to a course:
        for num in range(8):
            ItemFactory.create(
                data="This is #{}".format(num + 1),
                category="html", parent_location=self.library.location, user_id=self.user.id, publish_item=False
            )

        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        lc_block = self._add_library_content_block(course, self.lib_key, {'max_count': 1})
        lc_block_key = lc_block.location
        lc_block = self._refresh_children(lc_block)

        def get_child_of_lc_block(block):
            """
            Fetch the child shown to the current user.
            """
            children = block.get_child_descriptors()
            self.assertEqual(len(children), 1)
            return children[0]

        # Check which child a student will see:
        self._bind_module(lc_block)
        chosen_child = get_child_of_lc_block(lc_block)
        chosen_child_defn_id = chosen_child.definition_locator.definition_id
        lc_block.save()

        modulestore().update_item(lc_block, self.user.id)

        # Now re-load the block and try again:
        def check():
            """
            Confirm that chosen_child is still the child seen by the test student
            """
            for _ in range(6):  # Repeat many times b/c blocks are randomized
                lc_block = modulestore().get_item(lc_block_key)  # Reload block from the database
                self._bind_module(lc_block)
                current_child = get_child_of_lc_block(lc_block)
                self.assertEqual(current_child.location, chosen_child.location)
                self.assertEqual(current_child.data, chosen_child.data)
                self.assertEqual(current_child.definition_locator.definition_id, chosen_child_defn_id)

        check()
        # Refresh the children:
        lc_block = self._refresh_children(lc_block)
        # Now re-load the block and try yet again, in case refreshing the children changed anything:
        check()

    def test_definition_shared_with_library(self):
        """
        Test that the same block definition is used for the library and course[s]
        """
        block1 = self._add_simple_content_block()
        def_id1 = block1.definition_locator.definition_id
        block2 = self._add_simple_content_block()
        def_id2 = block2.definition_locator.definition_id
        self.assertNotEqual(def_id1, def_id2)

        # Next, create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        for child_key in lc_block.children:
            child = modulestore().get_item(child_key)
            def_id = child.definition_locator.definition_id
            self.assertIn(def_id, (def_id1, def_id2))

    def test_fields(self):
        """
        Test that blocks used from a library have the same field values as
        defined by the library author.
        """
        data_value = "A Scope.content value"
        name_value = "A Scope.settings value"
        lib_block = ItemFactory.create(
            category="html",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
            display_name=name_value,
            data=data_value,
        )
        self.assertEqual(lib_block.data, data_value)
        self.assertEqual(lib_block.display_name, name_value)

        # Next, create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        course_block = modulestore().get_item(lc_block.children[0])

        self.assertEqual(course_block.data, data_value)
        self.assertEqual(course_block.display_name, name_value)

    def test_block_with_children(self):
        """
        Test that blocks used from a library can have children.
        """
        data_value = "A Scope.content value"
        name_value = "A Scope.settings value"
        # In the library, create a vertical block with a child:
        vert_block = ItemFactory.create(
            category="vertical",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
        )
        child_block = ItemFactory.create(
            category="html",
            parent_location=vert_block.location,
            user_id=self.user.id,
            publish_item=False,
            display_name=name_value,
            data=data_value,
        )
        self.assertEqual(child_block.data, data_value)
        self.assertEqual(child_block.display_name, name_value)

        # Next, create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        self.assertEqual(len(lc_block.children), 1)
        course_vert_block = modulestore().get_item(lc_block.children[0])
        self.assertEqual(len(course_vert_block.children), 1)
        course_child_block = modulestore().get_item(course_vert_block.children[0])

        self.assertEqual(course_child_block.data, data_value)
        self.assertEqual(course_child_block.display_name, name_value)

    def test_change_after_first_sync(self):
        """
        Check that nothing goes wrong if we (A) Set up a LibraryContent block
        and use it successfully, then (B) Give it an invalid configuration.
        No children should be deleted until the configuration is fixed.
        """
        # Add a block to the library:
        data_value = "Hello world!"
        ItemFactory.create(
            category="html",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
            display_name="HTML BLock",
            data=data_value,
        )
        # Create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        self.assertEqual(len(lc_block.children), 1)

        # Now, change the block settings to have an invalid library key:
        resp = self._update_item(
            lc_block.location,
            {"source_library_id": "library-v1:NOT+FOUND"},
        )
        self.assertEqual(resp.status_code, 200)
        lc_block = modulestore().get_item(lc_block.location)
        self.assertEqual(len(lc_block.children), 1)  # Children should not be deleted due to a bad setting.
        html_block = modulestore().get_item(lc_block.children[0])
        self.assertEqual(html_block.data, data_value)

    def test_refreshes_children_if_libraries_change(self):
        """ Tests that children are automatically refreshed if libraries list changes """
        library2key = self._create_library("org2", "lib2", "Library2")
        library2 = modulestore().get_library(library2key)
        data1, data2 = "Hello world!", "Hello other world!"
        ItemFactory.create(
            category="html",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
            display_name="Lib1: HTML BLock",
            data=data1,
        )

        ItemFactory.create(
            category="html",
            parent_location=library2.location,
            user_id=self.user.id,
            publish_item=False,
            display_name="Lib 2: HTML BLock",
            data=data2,
        )

        # Create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        self.assertEqual(len(lc_block.children), 1)

        # Now, change the block settings to have an invalid library key:
        resp = self._update_item(
            lc_block.location,
            {"source_library_id": str(library2key)},
        )
        self.assertEqual(resp.status_code, 200)
        lc_block = modulestore().get_item(lc_block.location)

        self.assertEqual(len(lc_block.children), 1)
        html_block = modulestore().get_item(lc_block.children[0])
        self.assertEqual(html_block.data, data2)

    @patch("xmodule.library_tools.SearchEngine.get_search_engine", Mock(return_value=None, autospec=True))
    def test_refreshes_children_if_capa_type_change(self):
        """ Tests that children are automatically refreshed if capa type field changes """
        name1, name2 = "Option Problem", "Multiple Choice Problem"
        ItemFactory.create(
            category="problem",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
            display_name=name1,
            data="<problem><optionresponse></optionresponse></problem>",
        )
        ItemFactory.create(
            category="problem",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
            display_name=name2,
            data="<problem><multiplechoiceresponse></multiplechoiceresponse></problem>",
        )

        # Create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        self.assertEqual(len(lc_block.children), 2)

        resp = self._update_item(
            lc_block.location,
            {"capa_type": 'optionresponse'},
        )
        self.assertEqual(resp.status_code, 200)
        lc_block = modulestore().get_item(lc_block.location)

        self.assertEqual(len(lc_block.children), 1)
        html_block = modulestore().get_item(lc_block.children[0])
        self.assertEqual(html_block.display_name, name1)

        resp = self._update_item(
            lc_block.location,
            {"capa_type": 'multiplechoiceresponse'},
        )
        self.assertEqual(resp.status_code, 200)
        lc_block = modulestore().get_item(lc_block.location)

        self.assertEqual(len(lc_block.children), 1)
        html_block = modulestore().get_item(lc_block.children[0])
        self.assertEqual(html_block.display_name, name2)

    def test_refresh_fails_for_unknown_library(self):
        """ Tests that refresh children fails if unknown library is configured """
        # Create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        lc_block = self._add_library_content_block(course, self.lib_key)
        lc_block = self._refresh_children(lc_block)
        self.assertEqual(len(lc_block.children), 0)

        # Now, change the block settings to have an invalid library key:
        resp = self._update_item(
            lc_block.location,
            {"source_library_id": "library-v1:NOT+FOUND"},
        )
        self.assertEqual(resp.status_code, 200)
        with self.assertRaises(ValueError):
            self._refresh_children(lc_block, status_code_expected=400)


@ddt.ddt
@patch('django.conf.settings.SEARCH_ENGINE', None)
class TestLibraryAccess(SignalDisconnectTestMixin, LibraryTestCase):
    """
    Test Roles and Permissions related to Content Libraries
    """
    def setUp(self):
        """ Create a library, staff user, and non-staff user """
        super(TestLibraryAccess, self).setUp()
        self.non_staff_user_password = 'foo'
        self.non_staff_user = UserFactory(password=self.non_staff_user_password, is_staff=False)

    def _login_as_non_staff_user(self, logout_first=True):
        """ Login as a user that starts out with no roles/permissions granted. """
        if logout_first:
            self.client.logout()  # We start logged in as a staff user
        self.client.login(username=self.non_staff_user.username, password=self.non_staff_user_password)

    def _assert_cannot_create_library(self, org="org", library="libfail", expected_code=403):
        """ Ensure the current user is not able to create a library. """
        self.assertGreaterEqual(expected_code, 300)
        response = self.client.ajax_post(
            LIBRARY_REST_URL,
            {'org': org, 'library': library, 'display_name': "Irrelevant"}
        )
        self.assertEqual(response.status_code, expected_code)
        key = LibraryLocator(org=org, library=library)
        self.assertEqual(modulestore().get_library(key), None)

    def _can_access_library(self, library):
        """
        Use the normal studio library URL to check if we have access

        `library` can be a LibraryLocator or the library's root XBlock
        """
        if isinstance(library, (basestring, LibraryLocator)):
            lib_key = library
        else:
            lib_key = library.location.library_key
        response = self.client.get(reverse_library_url('library_handler', unicode(lib_key)))
        self.assertIn(response.status_code, (200, 302, 403))
        return response.status_code == 200

    def tearDown(self):
        """
        Log out when done each test
        """
        self.client.logout()
        super(TestLibraryAccess, self).tearDown()

    def test_creation(self):
        """
        The user that creates a library should have instructor (admin) and staff permissions
        """
        # self.library has been auto-created by the staff user.
        self.assertTrue(has_studio_write_access(self.user, self.lib_key))
        self.assertTrue(has_studio_read_access(self.user, self.lib_key))
        # Make sure the user was actually assigned the instructor role and not just using is_staff superpowers:
        self.assertTrue(CourseInstructorRole(self.lib_key).has_user(self.user))

        # Now log out and ensure we are forbidden from creating a library:
        self.client.logout()
        self._assert_cannot_create_library(expected_code=302)  # 302 redirect to login expected

        # Now check that logged-in users without CourseCreator role cannot create libraries
        self._login_as_non_staff_user(logout_first=False)
        with patch.dict('django.conf.settings.FEATURES', {'ENABLE_CREATOR_GROUP': True}):
            self._assert_cannot_create_library(expected_code=403)  # 403 user is not CourseCreator

        # Now check that logged-in users with CourseCreator role can create libraries
        add_user_with_status_granted(self.user, self.non_staff_user)
        with patch.dict('django.conf.settings.FEATURES', {'ENABLE_CREATOR_GROUP': True}):
            lib_key2 = self._create_library(library="lib2", display_name="Test Library 2")
            library2 = modulestore().get_library(lib_key2)
            self.assertIsNotNone(library2)

    @ddt.data(
        CourseInstructorRole,
        CourseStaffRole,
        LibraryUserRole,
    )
    def test_acccess(self, access_role):
        """
        Test the various roles that allow viewing libraries are working correctly.
        """
        # At this point, one library exists, created by the currently-logged-in staff user.
        # Create another library as staff:
        library2_key = self._create_library(library="lib2")
        # Login as non_staff_user:
        self._login_as_non_staff_user()

        # non_staff_user shouldn't be able to access any libraries:
        lib_list = self._list_libraries()
        self.assertEqual(len(lib_list), 0)
        self.assertFalse(self._can_access_library(self.library))
        self.assertFalse(self._can_access_library(library2_key))

        # Now manually intervene to give non_staff_user access to library2_key:
        access_role(library2_key).add_users(self.non_staff_user)

        # Now non_staff_user should be able to access library2_key only:
        lib_list = self._list_libraries()
        self.assertEqual(len(lib_list), 1)
        self.assertEqual(lib_list[0]["library_key"], unicode(library2_key))
        self.assertTrue(self._can_access_library(library2_key))
        self.assertFalse(self._can_access_library(self.library))

    @ddt.data(
        OrgStaffRole,
        OrgInstructorRole,
        OrgLibraryUserRole,
    )
    def test_org_based_access(self, org_access_role):
        """
        Test the various roles that allow viewing all of an organization's
        libraries are working correctly.
        """
        # Create some libraries as the staff user:
        lib_key_pacific = self._create_library(org="PacificX", library="libP")
        lib_key_atlantic = self._create_library(org="AtlanticX", library="libA")

        # Login as a non-staff:
        self._login_as_non_staff_user()

        # Now manually intervene to give non_staff_user access to all "PacificX" libraries:
        org_access_role(lib_key_pacific.org).add_users(self.non_staff_user)

        # Now non_staff_user should be able to access lib_key_pacific only:
        lib_list = self._list_libraries()
        self.assertEqual(len(lib_list), 1)
        self.assertEqual(lib_list[0]["library_key"], unicode(lib_key_pacific))
        self.assertTrue(self._can_access_library(lib_key_pacific))
        self.assertFalse(self._can_access_library(lib_key_atlantic))
        self.assertFalse(self._can_access_library(self.lib_key))

    @ddt.data(True, False)
    def test_read_only_role(self, use_org_level_role):
        """
        Test the read-only role (LibraryUserRole and its org-level equivalent)
        """
        # As staff user, add a block to self.library:
        block = self._add_simple_content_block()

        # Login as a non_staff_user:
        self._login_as_non_staff_user()
        self.assertFalse(self._can_access_library(self.library))

        block_url = reverse_usage_url('xblock_handler', block.location)

        def can_read_block():
            """ Check if studio lets us view the XBlock in the library """
            response = self.client.get_json(block_url)
            self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
            return response.status_code == 200

        def can_edit_block():
            """ Check if studio lets us edit the XBlock in the library """
            response = self.client.ajax_post(block_url)
            self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
            return response.status_code == 200

        def can_delete_block():
            """ Check if studio lets us delete the XBlock in the library """
            response = self.client.delete(block_url)
            self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
            return response.status_code == 200

        def can_copy_block():
            """ Check if studio lets us duplicate the XBlock in the library """
            response = self.client.ajax_post(reverse_url('xblock_handler'), {
                'parent_locator': unicode(self.library.location),
                'duplicate_source_locator': unicode(block.location),
            })
            self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
            return response.status_code == 200

        def can_create_block():
            """ Check if studio lets us make a new XBlock in the library """
            response = self.client.ajax_post(reverse_url('xblock_handler'), {
                'parent_locator': unicode(self.library.location), 'category': 'html',
            })
            self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
            return response.status_code == 200

        # Check that we do not have read or write access to block:
        self.assertFalse(can_read_block())
        self.assertFalse(can_edit_block())
        self.assertFalse(can_delete_block())
        self.assertFalse(can_copy_block())
        self.assertFalse(can_create_block())

        # Give non_staff_user read-only permission:
        if use_org_level_role:
            OrgLibraryUserRole(self.lib_key.org).add_users(self.non_staff_user)
        else:
            LibraryUserRole(self.lib_key).add_users(self.non_staff_user)

        self.assertTrue(self._can_access_library(self.library))
        self.assertTrue(can_read_block())
        self.assertFalse(can_edit_block())
        self.assertFalse(can_delete_block())
        self.assertFalse(can_copy_block())
        self.assertFalse(can_create_block())

    @ddt.data(
        (LibraryUserRole, CourseStaffRole, True),
        (CourseStaffRole, CourseStaffRole, True),
        (None, CourseStaffRole, False),
        (LibraryUserRole, None, False),
    )
    @ddt.unpack
    def test_duplicate_across_courses(self, library_role, course_role, expected_result):
        """
        Test that the REST API will correctly allow/refuse when copying
        from a library with (write, read, or no) access to a course with (write or no) access.
        """
        # As staff user, add a block to self.library:
        block = self._add_simple_content_block()
        # And create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        self._login_as_non_staff_user()

        # Assign roles:
        if library_role:
            library_role(self.lib_key).add_users(self.non_staff_user)
        if course_role:
            course_role(course.location.course_key).add_users(self.non_staff_user)

        # Copy block to the course:
        response = self.client.ajax_post(reverse_url('xblock_handler'), {
            'parent_locator': unicode(course.location),
            'duplicate_source_locator': unicode(block.location),
        })
        self.assertIn(response.status_code, (200, 403))  # 400 would be ambiguous
        duplicate_action_allowed = (response.status_code == 200)
        self.assertEqual(duplicate_action_allowed, expected_result)

    @ddt.data(
        (LibraryUserRole, CourseStaffRole, True),
        (CourseStaffRole, CourseStaffRole, True),
        (None, CourseStaffRole, False),
        (LibraryUserRole, None, False),
    )
    @ddt.unpack
    def test_refresh_library_content_permissions(self, library_role, course_role, expected_result):
        """
        Test that the LibraryContent block's 'refresh_children' handler will correctly
        handle permissions and allow/refuse when updating its content with the latest
        version of a library. We try updating from a library with (write, read, or no)
        access to a course with (write or no) access.
        """
        # As staff user, add a block to self.library:
        self._add_simple_content_block()
        # And create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        self._login_as_non_staff_user()

        # Assign roles:
        if library_role:
            library_role(self.lib_key).add_users(self.non_staff_user)
        if course_role:
            course_role(course.location.course_key).add_users(self.non_staff_user)

        # Try updating our library content block:
        lc_block = self._add_library_content_block(course, self.lib_key)
        # We must use the CMS's module system in order to get permissions checks.
        self._bind_module(lc_block, user=self.non_staff_user)
        lc_block = self._refresh_children(lc_block, status_code_expected=200 if expected_result else 403)
        self.assertEqual(len(lc_block.children), 1 if expected_result else 0)

    def test_studio_user_permissions(self):
        """
        Test that user could attach to the problem only libraries that he has access (or which were created by him).
        This test was created on the basis of bug described in the pull requests on github:
        https://github.com/edx/edx-platform/pull/11331
        https://github.com/edx/edx-platform/pull/11611
        """
        self._create_library(org='admin_org_1', library='lib_adm_1', display_name='admin_lib_1')
        self._create_library(org='admin_org_2', library='lib_adm_2', display_name='admin_lib_2')

        self._login_as_non_staff_user()

        self._create_library(org='staff_org_1', library='lib_staff_1', display_name='staff_lib_1')
        self._create_library(org='staff_org_2', library='lib_staff_2', display_name='staff_lib_2')

        with modulestore().default_store(ModuleStoreEnum.Type.split):
            course = CourseFactory.create()

        instructor_role = CourseInstructorRole(course.id)
        auth.add_users(self.user, instructor_role, self.non_staff_user)

        lib_block = ItemFactory.create(
            category='library_content',
            parent_location=course.location,
            user_id=self.non_staff_user.id,
            publish_item=False
        )

        def _get_settings_html():
            """
            Helper function to get block settings HTML
            Used to check the available libraries.
            """
            edit_view_url = reverse_usage_url("xblock_view_handler", lib_block.location, {"view_name": STUDIO_VIEW})

            resp = self.client.get_json(edit_view_url)
            self.assertEquals(resp.status_code, 200)

            return parse_json(resp)['html']

        self._login_as_staff_user()
        staff_settings_html = _get_settings_html()
        self.assertIn('staff_lib_1', staff_settings_html)
        self.assertIn('staff_lib_2', staff_settings_html)
        self.assertIn('admin_lib_1', staff_settings_html)
        self.assertIn('admin_lib_2', staff_settings_html)

        self._login_as_non_staff_user()
        response = self.client.get_json(LIBRARY_REST_URL)
        staff_libs = parse_json(response)
        self.assertEquals(2, len(staff_libs))

        non_staff_settings_html = _get_settings_html()
        self.assertIn('staff_lib_1', non_staff_settings_html)
        self.assertIn('staff_lib_2', non_staff_settings_html)
        self.assertNotIn('admin_lib_1', non_staff_settings_html)
        self.assertNotIn('admin_lib_2', non_staff_settings_html)


@ddt.ddt
@override_settings(SEARCH_ENGINE=None)
class TestOverrides(LibraryTestCase):
    """
    Test that overriding block Scope.settings fields from a library in a specific course works
    """
    def setUp(self):
        super(TestOverrides, self).setUp()
        self.original_display_name = "A Problem Block"
        self.original_weight = 1

        # Create a problem block in the library:
        self.problem = ItemFactory.create(
            category="problem",
            parent_location=self.library.location,
            display_name=self.original_display_name,  # display_name is a Scope.settings field
            weight=self.original_weight,  # weight is also a Scope.settings field
            user_id=self.user.id,
            publish_item=False,
        )

        # Refresh library now that we've added something.
        self.library = modulestore().get_library(self.lib_key)

        # Also create a course:
        with modulestore().default_store(ModuleStoreEnum.Type.split):
            self.course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        self.lc_block = self._add_library_content_block(self.course, self.lib_key)
        self.lc_block = self._refresh_children(self.lc_block)
        self.problem_in_course = modulestore().get_item(self.lc_block.children[0])

    def test_overrides(self):
        """
        Test that we can override Scope.settings values in a course.
        """
        new_display_name = "Modified Problem Title"
        new_weight = 10
        self.problem_in_course.display_name = new_display_name
        self.problem_in_course.weight = new_weight
        modulestore().update_item(self.problem_in_course, self.user.id)

        # Add a second LibraryContent block to the course, with no override:
        lc_block2 = self._add_library_content_block(self.course, self.lib_key)
        lc_block2 = self._refresh_children(lc_block2)
        # Re-load the two problem blocks - one with and one without an override:
        self.problem_in_course = modulestore().get_item(self.lc_block.children[0])
        problem2_in_course = modulestore().get_item(lc_block2.children[0])

        self.assertEqual(self.problem_in_course.display_name, new_display_name)
        self.assertEqual(self.problem_in_course.weight, new_weight)

        self.assertEqual(problem2_in_course.display_name, self.original_display_name)
        self.assertEqual(problem2_in_course.weight, self.original_weight)

    def test_reset_override(self):
        """
        If we override a setting and then reset it, we should get the library value.
        """
        new_display_name = "Modified Problem Title"
        new_weight = 10
        self.problem_in_course.display_name = new_display_name
        self.problem_in_course.weight = new_weight
        modulestore().update_item(self.problem_in_course, self.user.id)
        self.problem_in_course = modulestore().get_item(self.problem_in_course.location)

        self.assertEqual(self.problem_in_course.display_name, new_display_name)
        self.assertEqual(self.problem_in_course.weight, new_weight)

        # Reset:
        for field_name in ["display_name", "weight"]:
            self.problem_in_course.fields[field_name].delete_from(self.problem_in_course)

        # Save, reload, and verify:
        modulestore().update_item(self.problem_in_course, self.user.id)
        self.problem_in_course = modulestore().get_item(self.problem_in_course.location)

        self.assertEqual(self.problem_in_course.display_name, self.original_display_name)
        self.assertEqual(self.problem_in_course.weight, self.original_weight)

    def test_consistent_definitions(self):
        """
        Make sure that the new child of the LibraryContent block
        shares its definition with the original (self.problem).

        This test is specific to split mongo.
        """
        definition_id = self.problem.definition_locator.definition_id
        self.assertEqual(self.problem_in_course.definition_locator.definition_id, definition_id)

        # Now even if we change some Scope.settings fields and refresh, the definition should be unchanged
        self.problem.weight = 20
        self.problem.display_name = "NEW"
        modulestore().update_item(self.problem, self.user.id)
        self.lc_block = self._refresh_children(self.lc_block)
        self.problem_in_course = modulestore().get_item(self.problem_in_course.location)

        self.assertEqual(self.problem.definition_locator.definition_id, definition_id)
        self.assertEqual(self.problem_in_course.definition_locator.definition_id, definition_id)

    @ddt.data(False, True)
    def test_persistent_overrides(self, duplicate):
        """
        Test that when we override Scope.settings values in a course,
        the override values persist even when the block is refreshed
        with updated blocks from the library.
        """
        new_display_name = "Modified Problem Title"
        new_weight = 15
        self.problem_in_course.display_name = new_display_name
        self.problem_in_course.weight = new_weight

        modulestore().update_item(self.problem_in_course, self.user.id)
        if duplicate:
            # Check that this also works when the RCB is duplicated.
            self.lc_block = modulestore().get_item(
                _duplicate_item(self.course.location, self.lc_block.location, self.user)
            )
            self.problem_in_course = modulestore().get_item(self.lc_block.children[0])
        else:
            self.problem_in_course = modulestore().get_item(self.problem_in_course.location)
        self.assertEqual(self.problem_in_course.display_name, new_display_name)
        self.assertEqual(self.problem_in_course.weight, new_weight)

        # Change the settings in the library version:
        self.problem.display_name = "X"
        self.problem.weight = 99
        new_data_value = "<problem><p>Changed data to check that non-overriden fields *do* get updated.</p></problem>"
        self.problem.data = new_data_value
        modulestore().update_item(self.problem, self.user.id)

        self.lc_block = self._refresh_children(self.lc_block)
        self.problem_in_course = modulestore().get_item(self.problem_in_course.location)

        self.assertEqual(self.problem_in_course.display_name, new_display_name)
        self.assertEqual(self.problem_in_course.weight, new_weight)
        self.assertEqual(self.problem_in_course.data, new_data_value)

    def test_duplicated_version(self):
        """
        Test that if a library is updated, and the content block is duplicated,
        the new block will use the old library version and not the new one.
        """
        store = modulestore()
        self.assertEqual(len(self.library.children), 1)
        self.assertEqual(len(self.lc_block.children), 1)

        # Edit the only problem in the library:
        self.problem.display_name = "--changed in library--"
        store.update_item(self.problem, self.user.id)
        # Create an additional problem block in the library:
        ItemFactory.create(
            category="problem",
            parent_location=self.library.location,
            user_id=self.user.id,
            publish_item=False,
        )

        # Refresh our reference to the library
        self.library = store.get_library(self.lib_key)

        # Refresh our reference to the block
        self.lc_block = store.get_item(self.lc_block.location)
        self.problem_in_course = store.get_item(self.problem_in_course.location)

        # The library has changed...
        self.assertEqual(len(self.library.children), 2)

        # But the block hasn't.
        self.assertEqual(len(self.lc_block.children), 1)
        self.assertEqual(self.problem_in_course.location, self.lc_block.children[0])
        self.assertEqual(self.problem_in_course.display_name, self.original_display_name)

        # Duplicate self.lc_block:
        duplicate = store.get_item(
            _duplicate_item(self.course.location, self.lc_block.location, self.user)
        )
        # The duplicate should have identical children to the original:
        self.assertEqual(len(duplicate.children), 1)
        self.assertTrue(self.lc_block.source_library_version)
        self.assertEqual(self.lc_block.source_library_version, duplicate.source_library_version)
        problem2_in_course = store.get_item(duplicate.children[0])
        self.assertEqual(problem2_in_course.display_name, self.original_display_name)


class TestIncompatibleModuleStore(LibraryTestCase):
    """
    Tests for proper validation errors with an incompatible course modulestore.
    """
    def setUp(self):
        super(TestIncompatibleModuleStore, self).setUp()
        # Create a course in an incompatible modulestore.
        with modulestore().default_store(ModuleStoreEnum.Type.mongo):
            self.course = CourseFactory.create()

        # Add a LibraryContent block to the course:
        self.lc_block = self._add_library_content_block(self.course, self.lib_key)

    def test_incompatible_modulestore(self):
        """
        Verifies that, if a user is using a modulestore that doesn't support libraries,
        a validation error will be produced.
        """
        validation = self.lc_block.validate()
        self.assertEqual(validation.summary.type, validation.summary.ERROR)
        self.assertIn(
            "This course does not support content libraries.", validation.summary.text)
