Added notifications for discussions events (openedx#32432)

* feat: added notifications for discussions app

* feat: added unit tests for handler

* feat: updated openedx-events package

* fix: updated notification creation logic and tests

* refactor: updated openedx-event version and event name

* refactor: moved logic to separate methods

common/djangoapps/student/models/course_enrollment.py

@@ -74,6 +74,7 @@ class EnrollStatusChange:
     # complete a paid course purchase
     paid_complete = 'paid_complete'
 
+
 UNENROLLED_TO_ALLOWEDTOENROLL = 'from unenrolled to allowed to enroll'
 ALLOWEDTOENROLL_TO_ENROLLED = 'from allowed to enroll to enrolled'
 ENROLLED_TO_ENROLLED = 'from enrolled to enrolled'
@@ -95,7 +96,6 @@ class EnrollStatusChange:
     (DEFAULT_TRANSITION_STATE, DEFAULT_TRANSITION_STATE)
 )
 
-
 EVENT_NAME_ENROLLMENT_ACTIVATED = 'edx.course.enrollment.activated'
 EVENT_NAME_ENROLLMENT_DEACTIVATED = 'edx.course.enrollment.deactivated'
 EVENT_NAME_ENROLLMENT_MODE_CHANGED = 'edx.course.enrollment.mode_changed'
@@ -292,7 +292,7 @@ def course_price(self):
     MODE_CACHE_NAMESPACE = 'CourseEnrollment.mode_and_active'
 
     class Meta:
-        unique_together = (('user', 'course'), )
+        unique_together = (('user', 'course'),)
         indexes = [Index(fields=['user', '-created'])]
         ordering = ('user', 'course')
 

lms/djangoapps/discussion/rest_api/api.py

@@ -128,7 +128,7 @@
     discussion_open_for_user,
     get_usernames_for_course,
     get_usernames_from_search_string,
-    set_attribute
+    set_attribute, send_response_notifications
 )
 
 
@@ -1532,7 +1532,8 @@ def create_comment(request, comment_data):
 
     track_comment_created_event(request, course, cc_comment, cc_thread["commentable_id"], followed=False,
                                 from_mfe_sidebar=from_mfe_sidebar)
-
+    send_response_notifications(thread=cc_thread, course=course, creator=request.user,
+                                parent_id=comment_data.get("parent_id"))
     return api_comment
 
 

lms/djangoapps/discussion/rest_api/tests/test_api.py

@@ -2243,13 +2243,16 @@ def test_success(self, parent_id, mock_emit):
             "/api/v1/threads/test_thread/comments"
         )
         assert urlparse(httpretty.last_request().path).path == expected_url  # lint-amnesty, pylint: disable=no-member
-        assert parsed_body(httpretty.last_request()) == {
+
+        data = httpretty.latest_requests()
+        assert parsed_body(data[len(data) - 2]) == {
             'course_id': [str(self.course.id)],
             'body': ['Test body'],
             'user_id': [str(self.user.id)],
             'anonymous': ['False'],
             'anonymous_to_peers': ['False'],
         }
+
         expected_event_name = (
             "edx.forum.comment.created" if parent_id else
             "edx.forum.response.created"
@@ -2340,7 +2343,8 @@ def test_success_in_black_out_with_user_access(self, parent_id, mock_emit):
             "/api/v1/threads/test_thread/comments"
         )
         assert urlparse(httpretty.last_request().path).path == expected_url  # pylint: disable=no-member
-        assert parsed_body(httpretty.last_request()) == {
+        data = httpretty.latest_requests()
+        assert parsed_body(data[len(data) - 2]) == {
             "course_id": [str(self.course.id)],
             "body": ["Test body"],
             "user_id": [str(self.user.id)],

lms/djangoapps/discussion/rest_api/tests/test_utils.py

@@ -3,10 +3,14 @@
 """
 
 from datetime import datetime, timedelta
+from unittest.mock import Mock
 
+from httpretty import httpretty
 from pytz import UTC
 import unittest
 from common.djangoapps.student.roles import CourseStaffRole, CourseInstructorRole
+from lms.djangoapps.discussion.django_comment_client.tests.utils import ForumsEnableMixin
+from lms.djangoapps.discussion.rest_api.tests.utils import CommentsServiceMockMixin, ThreadMock
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 
@@ -17,8 +21,11 @@
     get_course_ta_users_list,
     get_course_staff_users_list,
     get_moderator_users_list,
-    get_archived_topics, remove_empty_sequentials
+    get_archived_topics,
+    remove_empty_sequentials,
+    send_response_notifications
 )
+from openedx_events.learning.signals import USER_NOTIFICATION_REQUESTED
 
 
 class DiscussionAPIUtilsTestCase(ModuleStoreTestCase):
@@ -28,7 +35,7 @@ class DiscussionAPIUtilsTestCase(ModuleStoreTestCase):
     CREATE_USER = False
 
     def setUp(self):
-        super().setUp()     # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()  # lint-amnesty, pylint: disable=super-with-arguments
 
         self.course = CourseFactory.create()
         self.course.discussion_blackouts = [datetime.now(UTC) - timedelta(days=3),
@@ -100,6 +107,7 @@ class TestRemoveEmptySequentials(unittest.TestCase):
     """
     Test for the remove_empty_sequentials function
     """
+
     def test_empty_data(self):
         # Test that the function can handle an empty list
         data = []
@@ -135,8 +143,7 @@ def test_remove_empty_sequentials(self):
             {"type": "chapter", "children": [
                 {"type": "sequential", "children": []},
                 {"type": "sequential", "children": []},
-            ]
-            }
+            ]}
         ]
         expected_output = [
             {"type": "chapter", "children": [
@@ -150,3 +157,99 @@ def test_remove_empty_sequentials(self):
         ]
         result = remove_empty_sequentials(data)
         self.assertEqual(result, expected_output)
+
+
+class TestSendResponseNotifications(ForumsEnableMixin, CommentsServiceMockMixin, ModuleStoreTestCase):
+    """
+    Test for the send_response_notifications function
+    """
+    def setUp(self):
+        super().setUp()
+        httpretty.reset()
+        httpretty.enable()
+
+        self.user_1 = UserFactory.create()
+        self.user_2 = UserFactory.create()
+        self.user_3 = UserFactory.create()
+        self.thread = ThreadMock(thread_id=1, creator=self.user_1, title='test thread')
+        self.thread_2 = ThreadMock(thread_id=2, creator=self.user_2, title='test thread 2')
+        self.course = CourseFactory.create()
+
+    def test_send_notification_to_thread_creator(self):
+        """
+        Test that the notification is sent to the thread creator
+        """
+        handler = Mock()
+        USER_NOTIFICATION_REQUESTED.connect(handler)
+
+        # Post the form or do what it takes to send the signal
+
+        send_response_notifications(self.thread, self.course, self.user_2, parent_id=None)
+        self.assertEqual(handler.call_count, 1)
+        args = handler.call_args[1]['notification_data']
+        self.assertEqual(args.user_ids, [self.user_1.id])
+        self.assertEqual(args.notification_type, 'new_response')
+        expected_context = {
+            'replier_name': self.user_2.username,
+            'post_title': 'test thread',
+            'course_name': self.course.display_name,
+        }
+        self.assertDictEqual(args.context, expected_context)
+        self.assertEqual(args.content_url, 'http://example.com/1')
+        self.assertEqual(args.app_name, 'discussion')
+
+    def test_send_notification_to_parent_threads(self):
+        """
+        Test that the notification signal is sent to the parent response creator and
+        parent thread creator, it checks signal is sent with correct arguments for both
+        types of notifications.
+        """
+        handler = Mock()
+        USER_NOTIFICATION_REQUESTED.connect(handler)
+
+        self.register_get_comment_response({
+            'id': self.thread_2.id,
+            'thread_id': self.thread.id,
+            'user_id': self.thread_2.user_id
+        })
+
+        send_response_notifications(self.thread, self.course, self.user_3, parent_id=self.thread_2.id)
+        # check if 2 call are made to the handler i.e. one for the response creator and one for the thread creator
+        self.assertEqual(handler.call_count, 2)
+
+        # check if the notification is sent to the thread creator
+        args_comment = handler.call_args_list[0][1]['notification_data']
+        args_comment_on_response = handler.call_args_list[1][1]['notification_data']
+        self.assertEqual(args_comment.user_ids, [self.user_1.id])
+        self.assertEqual(args_comment.notification_type, 'new_comment')
+        expected_context = {
+            'replier_name': self.user_3.username,
+            'post_title': self.thread.title,
+            'author_name': 'dummy',
+            'course_name': self.course.display_name,
+        }
+        self.assertDictEqual(args_comment.context, expected_context)
+        self.assertEqual(args_comment.content_url, 'http://example.com/1')
+        self.assertEqual(args_comment.app_name, 'discussion')
+
+        # check if the notification is sent to the parent response creator
+        self.assertEqual(args_comment_on_response.user_ids, [self.user_2.id])
+        self.assertEqual(args_comment_on_response.notification_type, 'new_comment_on_response')
+        expected_context = {
+            'replier_name': self.user_3.username,
+            'post_title': self.thread.title,
+            'course_name': self.course.display_name,
+        }
+        self.assertDictEqual(args_comment_on_response.context, expected_context)
+        self.assertEqual(args_comment_on_response.content_url, 'http://example.com/1')
+        self.assertEqual(args_comment_on_response.app_name, 'discussion')
+
+    def test_no_signal_on_creators_own_thread(self):
+        """
+        Makes sure that no signal is emitted if user creates response on
+        their own thread.
+        """
+        handler = Mock()
+        USER_NOTIFICATION_REQUESTED.connect(handler)
+        send_response_notifications(self.thread, self.course, self.user_1, parent_id=None)
+        self.assertEqual(handler.call_count, 0)

lms/djangoapps/discussion/rest_api/tests/utils.py

@@ -656,3 +656,19 @@ def querystring(request):
     # This could just be HTTPrettyRequest.querystring, but that method double-decodes '%2B' -> '+' -> ' '.
     # You can just remove this method when this issue is fixed: https://github.com/gabrielfalcao/HTTPretty/issues/240
     return parse_qs(request.path.split('?', 1)[-1])
+
+
+class ThreadMock(object):
+    """
+    A mock thread object
+    """
+
+    def __init__(self, thread_id, creator, title, parent_id=None):
+        self.id = thread_id
+        self.user_id = creator.id
+        self.username = creator.username
+        self.title = title
+        self.parent_id = parent_id
+
+    def url_with_id(self, params):
+        return f"http://example.com/{params['id']}"

lms/djangoapps/discussion/rest_api/utils.py

@@ -16,6 +16,9 @@
     FORUM_ROLE_GROUP_MODERATOR,
     FORUM_ROLE_COMMUNITY_TA,
 )
+from openedx_events.learning.signals import USER_NOTIFICATION_REQUESTED
+from openedx_events.learning.data import UserNotificationData
+from openedx.core.djangoapps.django_comment_common.comment_client.comment import Comment
 
 
 class AttributeDict(dict):
@@ -351,3 +354,86 @@ def get_archived_topics(filtered_topic_ids: List[str], topics: List[Dict[str, st
             if topic['id'] == topic_id and topic['usage_key'] is not None:
                 archived_topics.append(topic)
     return archived_topics
+
+
+def send_response_notifications(thread, course, creator, parent_id=None):
+    """
+    Send notifications to users who are subscribed to the thread.
+    """
+    notification_sender = DiscussionNotificationSender(thread, course, creator, parent_id)
+    notification_sender.send_new_comment_notification()
+    notification_sender.send_new_response_notification()
+    notification_sender.send_new_comment_on_response_notification()
+
+
+class DiscussionNotificationSender:
+    """
+    Class to send notifications to users who are subscribed to the thread.
+    """
+
+    def __init__(self, thread, course, creator, parent_id=None):
+        self.thread = thread
+        self.course = course
+        self.creator = creator
+        self.parent_id = parent_id
+        self.parent_response = None
+        self._get_parent_response()
+
+    def _send_notification(self, user_ids, notification_type, extra_context=None):
+        """
+        Send notification to users
+        """
+        if not user_ids:
+            return
+
+        if extra_context is None:
+            extra_context = {}
+
+        notification_data = UserNotificationData(
+            user_ids=user_ids,
+            context={
+                "replier_name": self.creator.username,
+                "post_title": self.thread.title,
+                "course_name": self.course.display_name,
+                **extra_context,
+            },
+            notification_type=notification_type,
+            content_url=self.thread.url_with_id(params={'id': self.thread.id}),
+            app_name="discussion",
+            course_key=self.course.id,
+        )
+        USER_NOTIFICATION_REQUESTED.send_event(notification_data=notification_data)
+
+    def _get_parent_response(self):
+        """
+        Get parent response object
+        """
+        if self.parent_id and not self.parent_response:
+            self.parent_response = Comment(id=self.parent_id).retrieve()
+
+        return self.parent_response
+
+    def send_new_response_notification(self):
+        """
+        Send notification to users who are subscribed to the main thread/post i.e.
+        there is a response to the main thread.
+        """
+        if not self.parent_id and self.creator.id != self.thread.user_id:
+            self._send_notification([self.thread.user_id], "new_response")
+
+    def send_new_comment_notification(self):
+        """
+        Send notification to parent thread creator i.e. comment on the response.
+        """
+        if self.parent_response and self.creator.id != int(self.thread.user_id):
+            context = {
+                "author_name": self.parent_response.username,
+            }
+            self._send_notification([self.thread.user_id], "new_comment", extra_context=context)
+
+    def send_new_comment_on_response_notification(self):
+        """
+        Send notification to parent response creator i.e. comment on the response.
+        """
+        if self.parent_response and self.creator.id != int(self.parent_response.user_id):
+            self._send_notification([self.parent_response.user_id], "new_comment_on_response")

openedx/core/djangoapps/notifications/admin.py

@@ -4,7 +4,7 @@
 
 from django.contrib import admin
 
-from .models import Notification, CourseNotificationPreference
+from .models import CourseNotificationPreference, Notification
 
 
 class NotificationAdmin(admin.ModelAdmin):

openedx/core/djangoapps/notifications/base_notification.py

@@ -8,7 +8,6 @@
     find_pref_in_normalized_prefs,
 )
 
-
 COURSE_NOTIFICATION_TYPES = {
     'new_comment_on_response': {
         'notification_app': 'discussion',