feat: auto deletion of spam via AI

forum/__init__.py

@@ -2,4 +2,4 @@
 Openedx forum app.
 """
 
-__version__ = "0.4.1"
+__version__ = "0.4.2"

forum/ai_moderation.py

@@ -9,10 +9,13 @@
 import requests
 from django.conf import settings
 from django.contrib.auth import get_user_model
+from django.core.exceptions import ObjectDoesNotExist
 from django.utils import timezone
 from opaque_keys.edx.keys import CourseKey
+from rest_framework.serializers import ValidationError
 
 from forum.backends.mysql.models import ModerationAuditLog
+from forum.utils import ForumV2RequestError
 
 User = get_user_model()
 log = logging.getLogger(__name__)
@@ -218,6 +221,7 @@ def moderate_and_flag_content(
         # pylint: disable=import-outside-toplevel
         from forum.toggles import (
             is_ai_moderation_enabled,
+            is_ai_auto_delete_spam_enabled,
         )
 
         course_key = CourseKey.from_string(course_id) if course_id else None
@@ -246,16 +250,24 @@ def moderate_and_flag_content(
         )
 
         if is_spam:
+            # Flag content as spam and abuse first
             try:
                 content_instance["is_spam"] = True
 
-                self._mark_as_spam_and_flag_abuse(content_instance, backend)
-
+                self._mark_as_spam_and_moderate(content_instance, backend)
                 result["actions_taken"] = ["flagged"]
                 result["flagged"] = True
             except (AttributeError, ValueError, TypeError) as e:
                 log.error(f"Failed to flag content as spam: {e}")
                 result["actions_taken"] = ["no_action"]
+
+            # Only attempt deletion if flagging succeeded
+            if is_ai_auto_delete_spam_enabled(course_key) and result["flagged"]:  # type: ignore[no-untyped-call]
+                try:
+                    self._delete_content(content_instance)
+                    result["actions_taken"] = result["actions_taken"] + ["soft_deleted"]  # type: ignore[operator]
+                except (ForumV2RequestError, ObjectDoesNotExist, ValidationError) as e:
+                    log.error(f"Failed to delete content after flagging: {e}")
         else:
             result["actions_taken"] = ["no_action"]
 
@@ -269,7 +281,7 @@ def moderate_and_flag_content(
             )
         return result
 
-    def _mark_as_spam_and_flag_abuse(self, content_instance: Any, backend: Any) -> None:
+    def _mark_as_spam_and_moderate(self, content_instance: Any, backend: Any) -> None:
         """Flag content as abuse using backend methods."""
         content_id = str(content_instance.get("_id"))
         content_type = str(content_instance.get("_type"))
@@ -278,15 +290,45 @@ def _mark_as_spam_and_flag_abuse(self, content_instance: Any, backend: Any) -> N
                 "CommentThread" if content_type == "CommentThread" else "Comment"
             )
         }
-        try:
-            if not self.ai_moderation_user_id:
-                raise ValueError("AI_MODERATION_USER_ID setting is not configured.")
-            backend.flag_content_as_spam(content_type, content_id)
-            backend.flag_as_abuse(
-                str(self.ai_moderation_user_id), content_id, **extra_data
-            )
-        except (AttributeError, ValueError, TypeError, ImportError) as e:
-            log.error(f"Failed to flag content via backend: {e}")
+        if not self.ai_moderation_user_id:
+            raise ValueError("AI_MODERATION_USER_ID setting is not configured.")
+        backend.flag_content_as_spam(content_type, content_id)
+        backend.flag_as_abuse(str(self.ai_moderation_user_id), content_id, **extra_data)
+
+    def _delete_content(self, content_instance: Any) -> None:
+        """
+        Soft delete content using API layer delete functions.
+
+        Uses the API layer which handles all business logic including:
+        - Content validation
+        - Soft deletion
+        - Stats updates
+        - Subscription cleanup (for threads)
+        - Anonymous content handling
+
+        Args:
+            content_instance: Dict containing content data including _id, _type, and course_id
+        """
+        # Import here to avoid circular dependency (api modules import from ai_moderation)
+        # pylint: disable=import-outside-toplevel,cyclic-import
+        from forum.api.comments import delete_comment
+        from forum.api.threads import delete_thread
+
+        content_id = str(content_instance.get("_id"))
+        content_type = str(content_instance.get("_type"))
+        course_id = content_instance.get("course_id")
+        deleted_by = (
+            str(self.ai_moderation_user_id) if self.ai_moderation_user_id else None
+        )
+
+        # Use API layer functions which handle all business logic
+        # Exceptions propagate to caller for proper error handling
+        if content_type == "CommentThread":
+            delete_thread(content_id, course_id=course_id, deleted_by=deleted_by)
+            log.info(f"AI Moderation Deleted CommentThread: {content_id}")
+        elif content_type == "Comment":
+            delete_comment(content_id, course_id=course_id, deleted_by=deleted_by)
+            log.info(f"AI Moderation Deleted Comment: {content_id}")
 
 
 # Global instance

forum/toggles.py

@@ -29,6 +29,24 @@
     f"{DISCUSSION_WAFFLE_FLAG_NAMESPACE}.enable_ai_moderation", __name__
 )
 
+# .. toggle_name: discussions.enable_ai_auto_delete_spam
+# .. toggle_implementation: CourseWaffleFlag
+# .. toggle_default: False
+# .. toggle_description: Waffle flag to enable AI auto delete spam for discussions.
+# .. toggle_use_cases: temporary, open_edx
+# .. toggle_creation_date: 2026-02-05
+# .. toggle_target_removal_date: 2026-06-29
+ENABLE_AI_AUTO_DELETE_SPAM = CourseWaffleFlag(
+    f"{DISCUSSION_WAFFLE_FLAG_NAMESPACE}.enable_ai_auto_delete_spam", __name__
+)
+
+
+def is_ai_auto_delete_spam_enabled(course_key):  # type: ignore[no-untyped-def]
+    """
+    Check if AI auto delete spam is enabled for the given course.
+    """
+    return ENABLE_AI_AUTO_DELETE_SPAM.is_enabled(course_key)
+
 
 def is_ai_moderation_enabled(course_key):  # type: ignore[no-untyped-def]
     """