def test_delete_course_map(self):
        """
        Test that course location is properly remove from loc_mapper and cache when course is deleted
        """
        org = u'foo_org'
        course = u'bar_course'
        run = u'baz_run'
        course_location = SlashSeparatedCourseKey(org, course, run)
        loc_mapper().create_map_entry(course_location)
        # pylint: disable=protected-access
        entry = loc_mapper().location_map.find_one({
            '_id': loc_mapper()._construct_course_son(course_location)
        })
        self.assertIsNotNone(entry, 'Entry not found in loc_mapper')
        self.assertEqual(entry['offering'], u'{1}.{2}'.format(org, course, run))

        # now delete course location from loc_mapper and cache and test that course location no longer
        # exists in loca_mapper and cache
        loc_mapper().delete_course_mapping(course_location)
        # pylint: disable=protected-access
        entry = loc_mapper().location_map.find_one({
            '_id': loc_mapper()._construct_course_son(course_location)
        })
        self.assertIsNone(entry, 'Entry found in loc_mapper')
        # pylint: disable=protected-access
        cached_value = loc_mapper()._get_location_from_cache(course_location.make_usage_key('course', run))
        self.assertIsNone(cached_value, 'course_locator found in cache')
        # pylint: disable=protected-access
        cached_value = loc_mapper()._get_course_location_from_cache(course_location)
        self.assertIsNone(cached_value, 'Entry found in cache')

    def is_enrolled_by_partial(cls, user, course_id_partial):
        """
        Returns `True` if the user is enrolled in a course that starts with
        `course_id_partial`. Otherwise, returns False.

        Can be used to determine whether a student is enrolled in a course
        whose run name is unknown.

        `user` is a Django User object. If it hasn't been saved yet (no `.id`
               attribute), this method will automatically save it before
               adding an enrollment for it.

        `course_id_partial` (CourseKey) is missing the run component
        """
        assert isinstance(course_id_partial, SlashSeparatedCourseKey)
        assert not course_id_partial.run  # None or empty string
        course_key = SlashSeparatedCourseKey(course_id_partial.org, course_id_partial.course, '')
        querystring = unicode(course_key.to_deprecated_string())
        try:
            return CourseEnrollment.objects.filter(
                user=user,
                course_id__startswith=querystring,
                is_active=1
            ).exists()
        except cls.DoesNotExist:
            return False

 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 i_click_on_error_dialog(step):
    world.click_link_by_text('Correct failed component')
    assert_true(world.css_html("span.inline-error").startswith("Problem i4x://MITx/999/problem"))
    course_key = SlashSeparatedCourseKey("MITx", "999", "Robot_Super_Course")
    # we don't know the actual ID of the vertical. So just check that we did go to a
    # vertical page in the course (there should only be one).
    vertical_usage_key = course_key.make_usage_key("vertical", "")
    vertical_url = reverse_usage_url('unit_handler', vertical_usage_key)
    assert_equal(1, world.browser.url.count(vertical_url))

 def test_invalid_chars_ssck(self):
     """
     Test that the ssck constructor fails if given invalid chars
     """
     valid_base = SlashSeparatedCourseKey(u'org.dept-1%2', u'course.sub-2%3', u'run.faster-4%5')
     for key in SlashSeparatedCourseKey.KEY_FIELDS:
         with self.assertRaises(InvalidKeyError):
             # this ends up calling the constructor where the legality check should occur
             valid_base.replace(**{key: u'funny thing'})

class TestInstructorEnrollmentStudentModule(TestCase):
    """ Test student module manipulations. """
    def setUp(self):
        self.course_key = SlashSeparatedCourseKey('fake', 'course', 'id')

    def test_reset_student_attempts(self):
        user = UserFactory()
        msk = self.course_key.make_usage_key('dummy', 'module')
        original_state = json.dumps({'attempts': 32, 'otherstuff': 'alsorobots'})
        StudentModule.objects.create(student=user, course_id=self.course_key, module_state_key=msk, state=original_state)
        # lambda to reload the module state from the database
        module = lambda: StudentModule.objects.get(student=user, course_id=self.course_key, module_state_key=msk)
        self.assertEqual(json.loads(module().state)['attempts'], 32)
        reset_student_attempts(self.course_key, user, msk)
        self.assertEqual(json.loads(module().state)['attempts'], 0)

    def test_delete_student_attempts(self):
        user = UserFactory()
        msk = self.course_key.make_usage_key('dummy', 'module')
        original_state = json.dumps({'attempts': 32, 'otherstuff': 'alsorobots'})
        StudentModule.objects.create(student=user, course_id=self.course_key, module_state_key=msk, state=original_state)
        self.assertEqual(StudentModule.objects.filter(student=user, course_id=self.course_key, module_state_key=msk).count(), 1)
        reset_student_attempts(self.course_key, user, msk, delete_module=True)
        self.assertEqual(StudentModule.objects.filter(student=user, course_id=self.course_key, module_state_key=msk).count(), 0)

    def test_delete_submission_scores(self):
        user = UserFactory()
        problem_location = self.course_key.make_usage_key('dummy', 'module')

        # Create a student module for the user
        StudentModule.objects.create(
            student=user,
            course_id=self.course_key,
            module_state_key=problem_location,
            state=json.dumps({})
        )

        # Create a submission and score for the student using the submissions API
        student_item = {
            'student_id': anonymous_id_for_user(user, self.course_key),
            'course_id': self.course_key.to_deprecated_string(),
            'item_id': problem_location.to_deprecated_string(),
            'item_type': 'openassessment'
        }
        submission = sub_api.create_submission(student_item, 'test answer')
        sub_api.set_score(submission['uuid'], 1, 2)

        # Delete student state using the instructor dash
        reset_student_attempts(
            self.course_key, user, problem_location,
            delete_module=True
        )

        # Verify that the student's scores have been reset in the submissions API
        score = sub_api.get_score(student_item)
        self.assertIs(score, None)

    def setup_xml_course(self):
        """
        Define the XML backed course to use.
        Toy courses are already loaded in XML and mixed modulestores.
        """
        course_key = SlashSeparatedCourseKey('edX', 'toy', '2012_Fall')
        location = course_key.make_usage_key('chapter', 'Overview')
        descriptor = modulestore().get_item(location)

        self.module = self._get_module(course_key, descriptor, location)

 def setUp(self):
     system = get_test_descriptor_system()
     course_key = SlashSeparatedCourseKey('org', 'course', 'run')
     usage_key = course_key.make_usage_key('video', 'name')
     self.descriptor = system.construct_xblock_from_class(
         VideoDescriptor,
         scope_ids=ScopeIds(None, None, usage_key, usage_key),
         field_data=DictFieldData({}),
     )
     self.descriptor.runtime.handler_url = MagicMock()

 def test_invalid_chars_location(self):
     """
     Test that the location constructor fails if given invalid chars
     """
     course_key = SlashSeparatedCourseKey(u'org.dept-1%2', u'course.sub-2%3', u'run.faster-4%5')
     valid_base = course_key.make_usage_key('tomato-again%9', 'block-head:sub-4%9')
     for key in SlashSeparatedCourseKey.KEY_FIELDS:
         with self.assertRaises(InvalidKeyError):
             # this ends up calling the constructor where the legality check should occur
             valid_base.replace(**{key: u'funny thing'})

    def create_course(self, org, offering, user_id=None, fields=None, **kwargs):
        """
        Creates and returns the course.

        Args:
            org (str): the organization that owns the course
            offering (str): the name of the course offering
            user_id: id of the user creating the course
            fields (dict): Fields to set on the course at initialization
            kwargs: Any optional arguments understood by a subset of modulestores to customize instantiation

        Returns: a CourseDescriptor

        Raises:
            InvalidLocationError: If a course with the same org and offering already exists
        """

        course, _, run = offering.partition('/')
        course_id = SlashSeparatedCourseKey(org, course, run)

        # Check if a course with this org/course has been defined before (case-insensitive)
        course_search_location = SON([
            ('_id.tag', 'i4x'),
            ('_id.org', re.compile(u'^{}$'.format(course_id.org), re.IGNORECASE)),
            ('_id.course', re.compile(u'^{}$'.format(course_id.course), re.IGNORECASE)),
            ('_id.category', 'course'),
        ])
        courses = self.collection.find(course_search_location, fields=('_id'))
        if courses.count() > 0:
            raise InvalidLocationError(
                "There are already courses with the given org and course id: {}".format([
                    course['_id'] for course in courses
                ]))

        location = course_id.make_usage_key('course', course_id.run)
        course = self.create_and_save_xmodule(location, fields=fields, **kwargs)

        # clone a default 'about' overview module as well
        about_location = location.replace(
            category='about',
            name='overview'
        )
        overview_template = AboutDescriptor.get_template('overview.yaml')
        self.create_and_save_xmodule(
            about_location,
            system=course.system,
            definition_data=overview_template.get('data')
        )

        return course

    def handle(self, *args, **options):
        source_key = SlashSeparatedCourseKey.from_deprecated_string(options['source_course'])
        dest_key = SlashSeparatedCourseKey.from_deprecated_string(options['dest_course'])

        source_students = User.objects.filter(
            courseenrollment__course_id=source_key
        )

        for user in source_students:
            if CourseEnrollment.is_enrolled(user, dest_key):
                # Un Enroll from source course but don't mess
                # with the enrollment in the destination course.
                CourseEnrollment.unenroll(user, source_key)
                print("Unenrolled {} from {}".format(user.username, source_key.to_deprecated_string()))
                msg = "Skipping {}, already enrolled in destination course {}"
                print(msg.format(user.username, dest_key.to_deprecated_string()))
                continue

            print("Moving {}.".format(user.username))
            # Find the old enrollment.
            enrollment = CourseEnrollment.objects.get(
                user=user,
                course_id=source_key
            )

            # Move the Student between the classes.
            mode = enrollment.mode
            old_is_active = enrollment.is_active
            CourseEnrollment.unenroll(user, source_key)
            new_enrollment = CourseEnrollment.enroll(user, dest_key, mode=mode)

            # Unenroll from the new coures if the user had unenrolled
            # form the old course.
            if not old_is_active:
                new_enrollment.update_enrollment(is_active=False)

            if mode == 'verified':
                try:
                    certificate_item = CertificateItem.objects.get(
                        course_id=source_key,
                        course_enrollment=enrollment
                    )
                except CertificateItem.DoesNotExist:
                    print("No certificate for {}".format(user))
                    continue

                certificate_item.course_id = dest_key
                certificate_item.course_enrollment = new_enrollment
                certificate_item.save()

    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/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 test_graphicslidertool_import(self):
        '''
        Check to see if definition_from_xml in gst_module.py
        works properly.  Pulls data from the graphic_slider_tool directory
        in the test data directory.
        '''
        modulestore = XMLModuleStore(DATA_DIR, course_dirs=['graphic_slider_tool'])

        sa_id = SlashSeparatedCourseKey("edX", "gst_test", "2012_Fall")
        location = sa_id.make_usage_key("graphical_slider_tool", "sample_gst")
        gst_sample = modulestore.get_item(location)
        render_string_from_sample_gst_xml = """
        <slider var="a" style="width:400px;float:left;"/>\
<plot style="margin-top:15px;margin-bottom:15px;"/>""".strip()
        self.assertIn(render_string_from_sample_gst_xml, gst_sample.data)

    def handle(self, *args, **options):

        dry_run = options['dry_run']
        task_number = options['task_number']

        if len(args) == 4:
            course_id = SlashSeparatedCourseKey.from_deprecated_string(args[0])
            location = course_id.make_usage_key_from_deprecated_string(args[1])
            students_ids = [line.strip() for line in open(args[2])]
            hostname = args[3]
        else:
            print self.help
            return

        try:
            course = get_course(course_id)
        except ValueError as err:
            print err
            return

        descriptor = modulestore().get_item(location, depth=0)
        if descriptor is None:
            print "Location not found in course"
            return

        if dry_run:
            print "Doing a dry run."

        students = User.objects.filter(id__in=students_ids).order_by('username')
        print "Number of students: {0}".format(students.count())

        for student in students:
            post_submission_for_student(student, course, location, task_number, dry_run=dry_run, hostname=hostname)

def send_email(request, course_id):
    """
    Send an email to self, staff, or everyone involved in a course.
    Query Parameters:
    - 'send_to' specifies what group the email should be sent to
       Options are defined by the CourseEmail model in
       lms/djangoapps/bulk_email/models.py
    - 'subject' specifies email's subject
    - 'message' specifies email's content
    """
    course_id = SlashSeparatedCourseKey.from_deprecated_string(course_id)

    if not bulk_email_is_enabled_for_course(course_id):
        return HttpResponseForbidden("Email is not enabled for this course.")

    send_to = request.POST.get("send_to")
    subject = request.POST.get("subject")
    message = request.POST.get("message")

    # Create the CourseEmail object.  This is saved immediately, so that
    # any transaction that has been pending up to this point will also be
    # committed.
    email = CourseEmail.create(course_id, request.user, send_to, subject, message)

    # Submit the task, so that the correct InstructorTask object gets created (for monitoring purposes)
    instructor_task.api.submit_bulk_course_email(request, course_id, email.id)  # pylint: disable=E1101

    response_payload = {
        'course_id': course_id.to_deprecated_string(),
        'success': True,
    }
    return JsonResponse(response_payload)

    def test_xml_course_authorization(self):
        course_id = SlashSeparatedCourseKey('edX', 'toy', '2012_Fall')
        # Assert this is an XML course
        self.assertEqual(modulestore().get_modulestore_type(course_id), XML_MODULESTORE_TYPE)

        form_data = {'course_id': course_id.to_deprecated_string(), 'email_enabled': True}
        form = CourseAuthorizationAdminForm(data=form_data)
        # Validation shouldn't work
        self.assertFalse(form.is_valid())

        msg = u"Course Email feature is only available for courses authored in Studio. "
        msg += u'"{0}" appears to be an XML backed course.'.format(course_id.to_deprecated_string())
        self.assertEquals(msg, form._errors['course_id'][0])  # pylint: disable=protected-access

        with self.assertRaisesRegexp(ValueError, "The CourseAuthorization could not be created because the data didn't validate."):
            form.save()

    def test_form_typo(self):
        # Munge course id
        bad_id = SlashSeparatedCourseKey(u'Broken{}'.format(self.course.id.org), '', self.course.id.run + '_typo')

        form_data = {'course_id': bad_id.to_deprecated_string(), 'email_enabled': True}
        form = CourseAuthorizationAdminForm(data=form_data)
        # Validation shouldn't work
        self.assertFalse(form.is_valid())

        msg = u'COURSE NOT FOUND'
        msg += u' --- Entered course id was: "{0}". '.format(bad_id.to_deprecated_string())
        msg += 'Please recheck that you have supplied a valid course id.'
        self.assertEquals(msg, form._errors['course_id'][0])  # pylint: disable=protected-access

        with self.assertRaisesRegexp(ValueError, "The CourseAuthorization could not be created because the data didn't validate."):
            form.save()

    def clean_course_id(self):
        """Validate the course id"""
        cleaned_id = self.cleaned_data["course_id"]
        try:
            course_key = CourseKey.from_string(cleaned_id)
        except InvalidKeyError:
            try:
                course_key = SlashSeparatedCourseKey.from_deprecated_string(cleaned_id)
            except InvalidKeyError:
                msg = u'Course id invalid.' 
                msg += u' --- Entered course id was: "{0}". '.format(cleaned_id)
                msg += 'Please recheck that you have supplied a valid course id.'
                raise forms.ValidationError(msg)

        if not modulestore().has_course(course_key):
            msg = u'COURSE NOT FOUND'
            msg += u' --- Entered course id was: "{0}". '.format(course_key.to_deprecated_string())
            msg += 'Please recheck that you have supplied a valid course id.'
            raise forms.ValidationError(msg)

        # Now, try and discern if it is a Studio course - HTML editor doesn't work with XML courses
        is_studio_course = modulestore().get_modulestore_type(course_key) != XML_MODULESTORE_TYPE
        if not is_studio_course:
            msg = "Course Email feature is only available for courses authored in Studio. "
            msg += '"{0}" appears to be an XML backed course.'.format(course_key.to_deprecated_string())
            raise forms.ValidationError(msg)

        return course_key

def jump_to(request, course_id, location):
    """
    Show the page that contains a specific location.

    If the location is invalid or not in any class, return a 404.

    Otherwise, delegates to the index view to figure out whether this user
    has access, and what they should see.
    """
    try:
        course_key = SlashSeparatedCourseKey.from_deprecated_string(course_id)
        usage_key = course_key.make_usage_key_from_deprecated_string(location)
    except InvalidKeyError:
        raise Http404(u"Invalid course_key or usage_key")
    try:
        (course_key, chapter, section, position) = path_to_location(modulestore(), usage_key)
    except ItemNotFoundError:
        raise Http404(u"No data at this location: {0}".format(usage_key))
    except NoPathToItem:
        raise Http404(u"This location is not in any class: {0}".format(usage_key))

    # choose the appropriate view (and provide the necessary args) based on the
    # args provided by the redirect.
    # Rely on index to do all error handling and access control.
    if chapter is None:
        return redirect('courseware', course_id=course_key.to_deprecated_string())
    elif section is None:
        return redirect('courseware_chapter', course_id=course_key.to_deprecated_string(), chapter=chapter)
    elif position is None:
        return redirect('courseware_section', course_id=course_key.to_deprecated_string(), chapter=chapter, section=section)
    else:
        return redirect('courseware_position', course_id=course_key.to_deprecated_string(), chapter=chapter, section=section, position=position)

def course_info(request, course_id):
    """
    Display the course's info.html, or 404 if there is no such course.

    Assumes the course_id is in a valid format.
    """
    course_key = SlashSeparatedCourseKey.from_deprecated_string(course_id)
    course = get_course_with_access(request.user, 'load', course_key)
    staff_access = has_access(request.user, 'staff', course)
    masq = setup_masquerade(request, staff_access)    # allow staff to toggle masquerade on info page
    reverifications = fetch_reverify_banner_info(request, course_key)
    studio_url = get_studio_url(course_key, 'course_info')

    context = {
        'request': request,
        'course_id': course_key.to_deprecated_string(),
        'cache': None,
        'course': course,
        'staff_access': staff_access,
        'masquerade': masq,
        'studio_url': studio_url,
        'reverifications': reverifications,
    }

    return render_to_response('courseware/info.html', context)