fix delete user function

Author: YashK2005

backend/app/models/AvailableTime.py

@@ -22,7 +22,6 @@
     User,
     UserData,
 )
-from app.models.AvailableTime import available_times
 from app.models.SuggestedTime import suggested_times
 from app.schemas.availability import AvailabilityTemplateSlot
 from app.schemas.user import (
@@ -124,19 +123,18 @@ async def delete_user_by_id(self, user_id: str):
         Delete a user and all related data in the correct order to respect FK constraints.
 
         Deletion order:
-        1. available_times junction table (User <-> TimeBlock)
-        2. UserData many-to-many relationships (treatments, experiences, loved_one_*)
-        3. UserData
-        4. VolunteerData
-        5. AvailabilityTemplate records
-        6. RankingPreference records
-        7. FormSubmission records
-        8. suggested_times junction table (Match <-> TimeBlock) for user's matches
-        9. Soft-delete Match records (set deleted_at for audit)
-        10. Hard delete Match records
-        11. Handle Task records (set participant_id/assignee_id to NULL)
-        12. Delete User record
-        13. Delete Firebase user
+        1. UserData many-to-many relationships (treatments, experiences, loved_one_*)
+        2. UserData
+        3. VolunteerData
+        4. AvailabilityTemplate records
+        5. RankingPreference records
+        6. FormSubmission records
+        7. suggested_times junction table (Match <-> TimeBlock) for user's matches
+        8. Soft-delete Match records (set deleted_at for audit)
+        9. Hard delete Match records
+        10. Handle Task records (set participant_id/assignee_id to NULL)
+        11. Delete User record
+        12. Delete Firebase user
         """
         firebase_auth_id = None
         try:
@@ -147,34 +145,31 @@ async def delete_user_by_id(self, user_id: str):
             # Store Firebase auth_id before deletion
             firebase_auth_id = db_user.auth_id
 
-            # 1. Delete available_times entries (User <-> TimeBlock junction table)
-            self.db.execute(available_times.delete().where(available_times.c.user_id == db_user.id))
-
-            # 2. Clear many-to-many relationships in UserData
+            # 1. Clear many-to-many relationships in UserData
             if db_user.user_data:
                 db_user.user_data.treatments.clear()
                 db_user.user_data.experiences.clear()
                 db_user.user_data.loved_one_treatments.clear()
                 db_user.user_data.loved_one_experiences.clear()
 
-            # 3. Delete UserData
+            # 2. Delete UserData
             if db_user.user_data:
                 self.db.delete(db_user.user_data)
 
-            # 4. Delete VolunteerData
+            # 3. Delete VolunteerData
             if db_user.volunteer_data:
                 self.db.delete(db_user.volunteer_data)
 
-            # 5. Delete AvailabilityTemplate records
+            # 4. Delete AvailabilityTemplate records
             self.db.query(AvailabilityTemplate).filter(AvailabilityTemplate.user_id == db_user.id).delete()
 
-            # 6. Delete RankingPreference records
+            # 5. Delete RankingPreference records
             self.db.query(RankingPreference).filter(RankingPreference.user_id == db_user.id).delete()
 
-            # 7. Delete FormSubmission records
+            # 6. Delete FormSubmission records
             self.db.query(FormSubmission).filter(FormSubmission.user_id == db_user.id).delete()
 
-            # 8. Delete suggested_times entries for matches involving this user
+            # 7. Delete suggested_times entries for matches involving this user
             # First get all match IDs for this user
             user_match_ids = (
                 self.db.query(Match.id)
@@ -187,31 +182,31 @@ async def delete_user_by_id(self, user_id: str):
                 # Delete suggested_times entries for these matches
                 self.db.execute(suggested_times.delete().where(suggested_times.c.match_id.in_(match_ids)))
 
-            # 9. Soft-delete Match records (set deleted_at timestamp for audit trail)
+            # 8. Soft-delete Match records (set deleted_at timestamp for audit trail)
             self.db.query(Match).filter(
                 (Match.participant_id == db_user.id) | (Match.volunteer_id == db_user.id)
             ).update({Match.deleted_at: func.now()}, synchronize_session=False)
 
-            # 10. Hard delete Match records (now safe - all FK constraints cleared)
+            # 9. Hard delete Match records (now safe - all FK constraints cleared)
             self.db.query(Match).filter(
                 (Match.participant_id == db_user.id) | (Match.volunteer_id == db_user.id)
             ).delete(synchronize_session=False)
 
-            # 11. Handle Task records - set participant_id and assignee_id to NULL
+            # 10. Handle Task records - set participant_id and assignee_id to NULL
             self.db.query(Task).filter(Task.participant_id == db_user.id).update(
                 {Task.participant_id: None}, synchronize_session=False
             )
             self.db.query(Task).filter(Task.assignee_id == db_user.id).update(
                 {Task.assignee_id: None}, synchronize_session=False
             )
 
-            # 12. Delete the User record
+            # 11. Delete the User record
             self.db.delete(db_user)
 
             # Commit all database changes
             self.db.commit()
 
-            # 13. Delete Firebase user (after successful DB deletion)
+            # 12. Delete Firebase user (after successful DB deletion)
             if firebase_auth_id:
                 try:
                     firebase_admin.auth.delete_user(firebase_auth_id)