Add optional role parameter to course API endpoint. (#21059)

* Add optional role parameter to course API endpoint.

* fixup! Add optional role parameter to course API endpoint.

lms/djangoapps/course_api/api.py

@@ -4,14 +4,19 @@ Course API
 
 from __future__ import absolute_import
 
+from django.conf import settings
 from django.contrib.auth.models import AnonymousUser, User
 from rest_framework.exceptions import PermissionDenied
+import search
+import six
 
+from lms.djangoapps.courseware.access import has_access
 from lms.djangoapps.courseware.courses import (
     get_course_overview_with_access,
     get_courses,
     get_permission_for_course_about
 )
+from openedx.core.lib.api.view_utils import LazySequence
 
 from .permissions import can_view_courses_for_username
 
@@ -57,7 +62,54 @@ def course_detail(request, username, course_key):
     )
 
 
-def list_courses(request, username, org=None, filter_=None):
+def _filter_by_role(course_queryset, user, roles):
+    """
+    Filters a course queryset by the roles for which the user has access.
+    """
+    # Global staff have access to all courses. Filter course roles for non-global staff only.
+    if not user.is_staff:
+        if roles:
+            for role in roles:
+                # Filter the courses again to return only the courses for which the user has each specified role.
+                course_queryset = LazySequence(
+                    (
+                        course for course in course_queryset
+                        if has_access(user, role, course.id)
+                    ),
+                    est_len=len(course_queryset)
+                )
+    return course_queryset
+
+
+def _filter_by_search(course_queryset, search_term):
+    """
+    Filters a course queryset by the specified search term.
+    """
+    if not settings.FEATURES['ENABLE_COURSEWARE_SEARCH'] or not search_term:
+        return course_queryset
+
+    # Return all the results, 10K is the maximum allowed value for ElasticSearch.
+    # We should use 0 after upgrading to 1.1+:
+    #   - https://github.com/elastic/elasticsearch/commit/8b0a863d427b4ebcbcfb1dcd69c996c52e7ae05e
+    results_size_infinity = 10000
+
+    search_courses = search.api.course_discovery_search(
+        search_term,
+        size=results_size_infinity,
+    )
+
+    search_courses_ids = {course['data']['id'] for course in search_courses['results']}
+
+    return LazySequence(
+        (
+            course for course in course_queryset
+            if six.text_type(course.id) in search_courses_ids
+        ),
+        est_len=len(course_queryset)
+    )
+
+
+def list_courses(request, username, org=None, roles=None, filter_=None, search_term=None):
     """
     Yield all available courses.
 
@@ -78,12 +130,21 @@ def list_courses(request, username, org=None, filter_=None):
             If specified, visible `CourseOverview` objects are filtered
             such that only those belonging to the organization with the provided
             org code (e.g., "HarvardX") are returned. Case-insensitive.
+        roles (list of strings):
+            If specified, visible `CourseOverview` objects are filtered
+            such that only those for which the user has the specified role(s)
+            are returned. Multiple role parameters can be specified.
         filter_ (dict):
             If specified, visible `CourseOverview` objects are filtered
             by the given key-value pairs.
+        search_term (string):
+            Search term to filter courses (used by ElasticSearch).
 
     Return value:
         Yield `CourseOverview` objects representing the collection of courses.
     """
     user = get_effective_user(request.user, username)
-    return get_courses(user, org=org, filter_=filter_)
+    course_qs = get_courses(user, org=org, filter_=filter_)
+    course_qs = _filter_by_role(course_qs, user, roles)
+    course_qs = _filter_by_search(course_qs, search_term)
+    return course_qs