Merge pull request #11 from edx/sofiya/milestones-test

API endpoint for milestones experiment.

AUTHORS

@@ -2,3 +2,4 @@ Alex Dusenbery <[email protected]>
 Simon Chen <[email protected]>
 Gregory Martin <[email protected]>
 Alessandro Roux <[email protected]>
+Sofiya Semenova <[email protected]>

CHANGELOG.rst

@@ -15,6 +15,12 @@ Unreleased
 ~~~~~~~~~~
 * Add query method for all completions by course
 
+[0.0.10] - 2018-03-20
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* Added "subsection-completion/{username}/{course_key}/{subsection_id}" API
+  endpoint, to be used with the completion milestones experiment.
+
 [0.0.9] - 2018-02-27
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

completion/__init__.py

@@ -5,6 +5,6 @@
 from __future__ import unicode_literals
 
 
-__version__ = '0.0.10'
+__version__ = '0.0.11'
 
 default_app_config = 'completion.apps.CompletionAppConfig'  # pylint: disable=invalid-name

completion/api/permissions.py

@@ -3,6 +3,7 @@
 """
 from __future__ import unicode_literals
 
+from django.http import Http404
 from rest_framework.permissions import BasePermission
 
 
@@ -22,3 +23,23 @@ def has_permission(self, request, view):
             or (user.username == getattr(request, 'data', {}).get('username')) \
             or (user.username == getattr(request, 'data', {}).get('user')) \
             or (user.username == getattr(view, 'kwargs', {}).get('username'))
+
+
+class IsUserInUrl(BasePermission):
+    """
+    Permission that checks to see if the request user matches the user in the URL.
+    """
+
+    def has_permission(self, request, view):
+        """
+        Returns true if the current request is by the user themselves.
+
+        Note: a 404 is returned for non-staff instead of a 403. This is to prevent
+        users from being able to detect the existence of accounts.
+        """
+        url_username = request.parser_context.get('kwargs', {}).get('username', '')
+        if request.user.username.lower() != url_username.lower():
+            if request.user.is_staff:
+                return False  # staff gets 403
+            raise Http404()
+        return True

completion/api/v1/urls.py

@@ -10,4 +10,11 @@
 
 urlpatterns = [
     url(r'^completion-batch', views.CompletionBatchView.as_view(), name='completion-batch'),
+    url(r'^subsection-completion/{username}/{course_key}/{subsection_id}'.format(
+        username=r'(?P<username>[^/]*)',
+        course_key=r'(?P<course_key>[^/+]+(/|\+)[^/+]+(/|\+)[^/?]+)',
+        subsection_id=r'(?P<subsection_id>[^/]*)'
+        ),
+        views.SubsectionCompletionView.as_view(),
+        name='subsection-completion')
 ]

completion/api/v1/views.py

@@ -21,11 +21,12 @@
 try:
     from openedx.core.djangoapps.content.course_structures.models import CourseStructure
     from student.models import CourseEnrollment
+    from lms.djangoapps.course_api.blocks.api import get_blocks
 except ImportError:
     pass
 
 from completion import waffle
-from completion.api.permissions import IsStaffOrOwner
+from completion.api.permissions import IsStaffOrOwner, IsUserInUrl
 from completion.models import BlockCompletion
 
 
@@ -148,3 +149,68 @@ def post(self, request, *args, **kwargs):  # pylint: disable=unused-argument
             }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
 
         return Response({"detail": _("ok")}, status=status.HTTP_200_OK)
+
+
+class SubsectionCompletionView(APIView):
+    """
+    Handles API endpoints for the milestones experiments.
+    TODO: EDUCATOR-2358 Remove this class after the
+    milestones experiment is no longer running.
+    """
+
+    permission_classes = (permissions.IsAuthenticated, IsUserInUrl)
+
+    def get(self, request, username, course_key, subsection_id):
+        """
+        Returns completion for a (user, subsection, course).
+        """
+        def get_completion(course_completions, all_blocks, block_id):
+            """
+            Recursively get the aggregate completion for a subsection,
+            given the subsection block and a list of all blocks.
+
+            Parameters:
+                course_completions: a dictionary of completion values by block IDs
+                all_blocks: a dictionary of the block structure for a subsection
+                block_id: an ID of a block for which to get completion
+            """
+            block = all_blocks.get(block_id)
+            child_ids = block.get('children', [])
+            if not child_ids:
+                return course_completions.get(block.serializer.instance, 0)
+
+            completion = 0
+            total_children = 0
+            for child_id in child_ids:
+                completion += get_completion(course_completions, all_blocks, child_id)
+                total_children += 1
+
+            return int(completion == total_children)
+
+        user_id = User.objects.get(username=username).id
+        block_types_filter = [
+            'course',
+            'chapter',
+            'sequential',
+            'vertical',
+            'html',
+            'problem',
+            'video',
+            'discussion',
+            'drag-and-drop-v2'
+        ]
+
+        blocks = get_blocks(
+            request,
+            UsageKey.from_string(subsection_id),
+            nav_depth=2,
+            requested_fields=[
+                'children'
+            ],
+            block_types_filter=block_types_filter
+        )
+
+        course_completions = BlockCompletion.get_course_completions(user_id, CourseKey.from_string(course_key))
+        aggregated_completion = get_completion(course_completions, blocks['blocks'], blocks['root'])
+
+        return Response({"completion": aggregated_completion}, status=status.HTTP_200_OK)