From aa92a57ecb6bec5956380b920bf60d4f667cba48 Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Mon, 10 Oct 2022 19:22:51 +0530
Subject: [PATCH 1/6] Soft delete users

---
 contentcuration/contentcuration/forms.py      |  3 +-
 .../migrations/0141_user_deleted.py           | 18 ++++++++
 contentcuration/contentcuration/models.py     | 42 +++++++++----------
 .../contentcuration/tests/test_models.py      | 27 ++++++++++++
 .../contentcuration/tests/test_settings.py    | 29 ++++++++-----
 .../contentcuration/tests/views/test_users.py | 14 +++++++
 .../contentcuration/views/settings.py         |  2 +
 7 files changed, 101 insertions(+), 34 deletions(-)
 create mode 100644 contentcuration/contentcuration/migrations/0141_user_deleted.py

diff --git a/contentcuration/contentcuration/forms.py b/contentcuration/contentcuration/forms.py
index 973916431e..d9dc781f61 100644
--- a/contentcuration/contentcuration/forms.py
+++ b/contentcuration/contentcuration/forms.py
@@ -7,6 +7,7 @@
 from django.contrib.auth.forms import UserChangeForm
 from django.contrib.auth.forms import UserCreationForm
 from django.core import signing
+from django.db.models import Q
 from django.template.loader import render_to_string
 
 from contentcuration.models import User
@@ -45,7 +46,7 @@ class RegistrationForm(UserCreationForm, ExtraFormMixin):
 
     def clean_email(self):
         email = self.cleaned_data['email'].strip().lower()
-        if User.objects.filter(email__iexact=email, is_active=True).exists():
+        if User.objects.filter(Q(is_active=True) | Q(deleted=True), email__iexact=email).exists():
             raise UserWarning
         return email
 
diff --git a/contentcuration/contentcuration/migrations/0141_user_deleted.py b/contentcuration/contentcuration/migrations/0141_user_deleted.py
new file mode 100644
index 0000000000..25444e6577
--- /dev/null
+++ b/contentcuration/contentcuration/migrations/0141_user_deleted.py
@@ -0,0 +1,18 @@
+# Generated by Django 3.2.14 on 2022-10-06 11:18
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contentcuration', '0140_delete_task'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='deleted',
+            field=models.BooleanField(db_index=True, default=False),
+        ),
+    ]
diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index 0e26e36c86..c2a23d1554 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -200,6 +200,7 @@ class User(AbstractBaseUser, PermissionsMixin):
     content_defaults = JSONField(default=dict)
     policies = JSONField(default=dict, null=True)
     feature_flags = JSONField(default=dict, null=True)
+    deleted = models.BooleanField(default=False, db_index=True)
 
     _field_updates = FieldTracker(fields=[
         # Field to watch for changes
@@ -214,27 +215,21 @@ def __unicode__(self):
         return self.email
 
     def delete(self):
-        from contentcuration.viewsets.common import SQCount
-        # Remove any invitations associated to this account
-        self.sent_to.all().delete()
-
-        # Delete channels associated with this user (if user is the only editor)
-        user_query = (
-            User.objects.filter(editable_channels__id=OuterRef('id'))
-                        .values_list('id', flat=True)
-                        .distinct()
-        )
-        self.editable_channels.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
-
-        # Delete channel collections associated with this user (if user is the only editor)
-        user_query = (
-            User.objects.filter(channel_sets__id=OuterRef('id'))
-                        .values_list('id', flat=True)
-                        .distinct()
-        )
-        self.channel_sets.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
+        """
+        Soft deletes the user.
+        """
+        self.deleted = True
+        # Deactivate the user to disallow authentication and also
+        # to let the user verify the email again after recovery.
+        self.is_active = False
+        self.save()
 
-        super(User, self).delete()
+    def recover(self):
+        """
+        Use this method when we want to recover a user.
+        """
+        self.deleted = False
+        self.save()
 
     def can_edit(self, channel_id):
         return Channel.filter_edit_queryset(Channel.objects.all(), self).filter(pk=channel_id).exists()
@@ -406,17 +401,20 @@ def filter_edit_queryset(cls, queryset, user):
         return queryset.filter(pk=user.pk)
 
     @classmethod
-    def get_for_email(cls, email, **filters):
+    def get_for_email(cls, email, deleted=False, **filters):
         """
         Returns the appropriate User record given an email, ordered by:
          - those with is_active=True first, which there should only ever be one
          - otherwise by ID DESC so most recent inactive shoud be returned
 
+        Filters out deleted User records by default. Can be overridden with
+        deleted argument.
+
         :param email: A string of the user's email
         :param filters: Additional filters to filter the User queryset
         :return: User or None
         """
-        return User.objects.filter(email__iexact=email.strip(), **filters)\
+        return User.objects.filter(email__iexact=email.strip(), deleted=deleted, **filters)\
             .order_by("-is_active", "-id").first()
 
 
diff --git a/contentcuration/contentcuration/tests/test_models.py b/contentcuration/contentcuration/tests/test_models.py
index 3c0caa9967..66720a0985 100644
--- a/contentcuration/contentcuration/tests/test_models.py
+++ b/contentcuration/contentcuration/tests/test_models.py
@@ -787,6 +787,7 @@ def test_get_for_email(self):
         user1 = self._create_user("tester@tester.com", is_active=False)
         user2 = self._create_user("tester@Tester.com", is_active=False)
         user3 = self._create_user("Tester@Tester.com", is_active=True)
+        user4 = self._create_user("testing@test.com", is_active=True)
 
         # active should be returned first
         self.assertEqual(user3, User.get_for_email("tester@tester.com"))
@@ -801,6 +802,32 @@ def test_get_for_email(self):
         # ensure nothing found doesn't error
         self.assertIsNone(User.get_for_email("tester@tester.com"))
 
+        # ensure we don't return soft-deleted users
+        user4.delete()
+        self.assertIsNone(User.get_for_email("testing@test.com"))
+
+    def test_delete__sets_deleted_true(self):
+        user = self._create_user("tester@tester.com")
+        user.delete()
+        self.assertEqual(user.deleted, True)
+
+    def test_delete__sets_is_active_false(self):
+        user = self._create_user("tester@tester.com")
+        user.delete()
+        self.assertEqual(user.is_active, False)
+
+    def test_recover__sets_deleted_false(self):
+        user = self._create_user("tester@tester.com")
+        user.delete()
+        user.recover()
+        self.assertEqual(user.deleted, False)
+
+    def test_recover__keeps_is_active_false(self):
+        user = self._create_user("tester@tester.com")
+        user.delete()
+        user.recover()
+        self.assertEqual(user.is_active, False)
+
 
 class ChannelHistoryTestCase(StudioTestCase):
     def setUp(self):
diff --git a/contentcuration/contentcuration/tests/test_settings.py b/contentcuration/contentcuration/tests/test_settings.py
index c216f088a2..25bbc71a54 100644
--- a/contentcuration/contentcuration/tests/test_settings.py
+++ b/contentcuration/contentcuration/tests/test_settings.py
@@ -1,5 +1,6 @@
 import json
 
+import mock
 from django.urls import reverse_lazy
 
 from .base import BaseAPITestCase
@@ -10,7 +11,7 @@
 
 class SettingsTestCase(BaseAPITestCase):
     def test_username_change(self):
-        data = json.dumps({"first_name": "New firstname", "last_name": "New lastname",})
+        data = json.dumps({"first_name": "New firstname", "last_name": "New lastname", })
         request = self.create_post_request(
             reverse_lazy("update_user_full_name"),
             data=data,
@@ -40,13 +41,19 @@ def test_delete_account_invalid(self):
             self.assertTrue(User.objects.filter(email=self.user.email).exists())
 
     def test_delete_account(self):
-        # TODO: send_email causes connection errors
-        data = json.dumps({"email": self.user.email})
-        self.create_post_request(
-            reverse_lazy("delete_user_account"),
-            data=data,
-            content_type="application/json",
-        )
-        # response = DeleteAccountView.as_view()(request)
-        # self.assertEqual(response.status_code, 200)
-        # self.assertFalse(User.objects.filter(email=self.user.email).exists())
+        with mock.patch("contentcuration.views.users.djangologout") as djangologout:
+            self.user.delete = mock.Mock()
+            data = json.dumps({"email": self.user.email})
+            request = self.create_post_request(
+                reverse_lazy("delete_user_account"),
+                data=data,
+                content_type="application/json",
+            )
+            response = DeleteAccountView.as_view()(request)
+
+            # Ensure successful response.
+            self.assertEqual(response.status_code, 200)
+            # Ensure user's delete method is called.
+            self.user.delete.assert_called_once()
+            # Ensure we logout the user.
+            djangologout.assert_called_once_with(request)
diff --git a/contentcuration/contentcuration/tests/views/test_users.py b/contentcuration/contentcuration/tests/views/test_users.py
index 0c03d5f626..e79e0cdbf9 100644
--- a/contentcuration/contentcuration/tests/views/test_users.py
+++ b/contentcuration/contentcuration/tests/views/test_users.py
@@ -98,6 +98,14 @@ def test_login__whitespace(self):
             self.assertIsInstance(redirect, HttpResponseRedirectBase)
             self.assertIn("channels", redirect['Location'])
 
+    def test_after_delete__no_login(self):
+        with mock.patch("contentcuration.views.users.djangologin") as djangologin:
+            self.user.delete()
+            response = login(self.request)
+
+            self.assertIsInstance(response, HttpResponseForbidden)
+            djangologin.assert_not_called()
+
 
 class UserRegistrationViewTestCase(StudioAPITestCase):
     def setUp(self):
@@ -121,6 +129,12 @@ def test_post__no_duplicate_registration(self):
         response = self.view.post(self.request)
         self.assertIsInstance(response, HttpResponseForbidden)
 
+    def test_after_delete__no_registration(self):
+        user = testdata.user(email="tester@tester.com")
+        user.delete()
+        response = self.view.post(self.request)
+        self.assertIsInstance(response, HttpResponseForbidden)
+
 
 class UserActivationViewTestCase(StudioAPITestCase):
     def setUp(self):
diff --git a/contentcuration/contentcuration/views/settings.py b/contentcuration/contentcuration/views/settings.py
index f41b6ac926..a186665dec 100644
--- a/contentcuration/contentcuration/views/settings.py
+++ b/contentcuration/contentcuration/views/settings.py
@@ -34,6 +34,7 @@
 from contentcuration.utils.csv_writer import generate_user_csv_filename
 from contentcuration.utils.messages import get_messages
 from contentcuration.views.base import current_user_for_context
+from contentcuration.views.users import logout
 from contentcuration.viewsets.channel import SettingsChannelSerializer
 
 ISSUE_UPDATE_DATE = datetime(2018, 10, 29)
@@ -165,6 +166,7 @@ def form_valid(self, form):
             os.unlink(csv_path)
 
         self.request.user.delete()
+        logout(self.request)
 
 
 class StorageSettingsView(PostFormMixin, FormView):

From ef2799114b0610b6b2400dd59259641ad612d4b6 Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Mon, 10 Oct 2022 20:27:29 +0530
Subject: [PATCH 2/6] fixes a regression where its expected that
 user-only-editor channels are hard deleted

---
 contentcuration/contentcuration/models.py | 26 ++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index c2a23d1554..1b1963e9b4 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -216,12 +216,36 @@ def __unicode__(self):
 
     def delete(self):
         """
-        Soft deletes the user.
+        Hard deletes invitation associated to this account, hard deletes channel and channet sets
+        only if user is the only editor. Then soft deletes the user account.
         """
+        from contentcuration.viewsets.common import SQCount
+
+        # Hard delete invitations associated to this account.
+        self.sent_to.all().delete()
+
+        # Hard delete channels associated with this user (if user is the only editor).
+        user_query = (
+            User.objects.filter(editable_channels__id=OuterRef('id'))
+                        .values_list('id', flat=True)
+                        .distinct()
+        )
+        self.editable_channels.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
+
+        # Hard delete channel collections associated with this user (if user is the only editor).
+        user_query = (
+            User.objects.filter(channel_sets__id=OuterRef('id'))
+                        .values_list('id', flat=True)
+                        .distinct()
+        )
+        self.channel_sets.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
+
+        # Soft delete user.
         self.deleted = True
         # Deactivate the user to disallow authentication and also
         # to let the user verify the email again after recovery.
         self.is_active = False
+
         self.save()
 
     def recover(self):

From 2a42f1895cbc1ec4cf3c7ffaeaf0b1d093cb7ffc Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Wed, 19 Oct 2022 16:29:21 +0530
Subject: [PATCH 3/6] User soft delete via garbage collection

---
 .../contentcuration/constants/user_history.py | 11 +++
 contentcuration/contentcuration/forms.py      |  2 +-
 .../management/commands/garbage_collect.py    | 13 ++-
 .../migrations/0141_user_deleted.py           | 18 ----
 .../migrations/0141_user_soft_delete.py       | 31 +++++++
 contentcuration/contentcuration/models.py     | 83 +++++++++++++------
 contentcuration/contentcuration/settings.py   |  6 +-
 .../contentcuration/tests/test_models.py      | 28 ++++---
 .../contentcuration/utils/garbage_collect.py  | 73 +++++++++-------
 9 files changed, 177 insertions(+), 88 deletions(-)
 create mode 100644 contentcuration/contentcuration/constants/user_history.py
 delete mode 100644 contentcuration/contentcuration/migrations/0141_user_deleted.py
 create mode 100644 contentcuration/contentcuration/migrations/0141_user_soft_delete.py

diff --git a/contentcuration/contentcuration/constants/user_history.py b/contentcuration/contentcuration/constants/user_history.py
new file mode 100644
index 0000000000..1eecf79c17
--- /dev/null
+++ b/contentcuration/contentcuration/constants/user_history.py
@@ -0,0 +1,11 @@
+from django.utils.translation import ugettext_lazy as _
+
+DELETION = "deletion"
+RECOVERY = "recovery"
+RELATED_DATA_HARD_DELETION = "related-data-hard-deletion"
+
+choices = (
+    (DELETION, _("User soft deletion")),
+    (RECOVERY, _("User soft deletion recovery")),
+    (RELATED_DATA_HARD_DELETION, _("User related data hard deletion")),
+)
diff --git a/contentcuration/contentcuration/forms.py b/contentcuration/contentcuration/forms.py
index d9dc781f61..d0ae49893f 100644
--- a/contentcuration/contentcuration/forms.py
+++ b/contentcuration/contentcuration/forms.py
@@ -46,7 +46,7 @@ class RegistrationForm(UserCreationForm, ExtraFormMixin):
 
     def clean_email(self):
         email = self.cleaned_data['email'].strip().lower()
-        if User.objects.filter(Q(is_active=True) | Q(deleted=True), email__iexact=email).exists():
+        if User.objects.filter(Q(is_active=True) | Q(deleted_at__isnull=False), email__iexact=email).exists():
             raise UserWarning
         return email
 
diff --git a/contentcuration/contentcuration/management/commands/garbage_collect.py b/contentcuration/contentcuration/management/commands/garbage_collect.py
index f31db7ad5c..f22f70dd4b 100644
--- a/contentcuration/contentcuration/management/commands/garbage_collect.py
+++ b/contentcuration/contentcuration/management/commands/garbage_collect.py
@@ -11,6 +11,7 @@
 from contentcuration.utils.garbage_collect import clean_up_contentnodes
 from contentcuration.utils.garbage_collect import clean_up_deleted_chefs
 from contentcuration.utils.garbage_collect import clean_up_feature_flags
+from contentcuration.utils.garbage_collect import clean_up_soft_deleted_users
 from contentcuration.utils.garbage_collect import clean_up_stale_files
 from contentcuration.utils.garbage_collect import clean_up_tasks
 
@@ -26,15 +27,23 @@ def handle(self, *args, **options):
         Actual logic for garbage collection.
         """
 
-        # clean up contentnodes, files and file objects on storage that are associated
-        # with the orphan tree
+        # Clean up users that are soft deleted and are older than ACCOUNT_DELETION_BUFFER (90 days).
+        # Also clean contentnodes, files and file objects on storage that are associated
+        # with the orphan tree.
+        logging.info("Cleaning up soft deleted users older than ACCOUNT_DELETION_BUFFER (90 days)")
+        clean_up_soft_deleted_users()
+
         logging.info("Cleaning up contentnodes from the orphan tree")
         clean_up_contentnodes()
+
         logging.info("Cleaning up deleted chef nodes")
         clean_up_deleted_chefs()
+
         logging.info("Cleaning up feature flags")
         clean_up_feature_flags()
+
         logging.info("Cleaning up stale file objects")
         clean_up_stale_files()
+
         logging.info("Cleaning up tasks")
         clean_up_tasks()
diff --git a/contentcuration/contentcuration/migrations/0141_user_deleted.py b/contentcuration/contentcuration/migrations/0141_user_deleted.py
deleted file mode 100644
index 25444e6577..0000000000
--- a/contentcuration/contentcuration/migrations/0141_user_deleted.py
+++ /dev/null
@@ -1,18 +0,0 @@
-# Generated by Django 3.2.14 on 2022-10-06 11:18
-from django.db import migrations
-from django.db import models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('contentcuration', '0140_delete_task'),
-    ]
-
-    operations = [
-        migrations.AddField(
-            model_name='user',
-            name='deleted',
-            field=models.BooleanField(db_index=True, default=False),
-        ),
-    ]
diff --git a/contentcuration/contentcuration/migrations/0141_user_soft_delete.py b/contentcuration/contentcuration/migrations/0141_user_soft_delete.py
new file mode 100644
index 0000000000..1f58e4076a
--- /dev/null
+++ b/contentcuration/contentcuration/migrations/0141_user_soft_delete.py
@@ -0,0 +1,31 @@
+# Generated by Django 3.2.14 on 2022-10-19 09:41
+import django.db.models.deletion
+import django.utils.timezone
+from django.conf import settings
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contentcuration', '0140_delete_task'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='deleted_at',
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+        migrations.CreateModel(
+            name='UserHistory',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('action', models.CharField(choices=[('deletion', 'User soft deletion'), ('recovery', 'User soft deletion recovery'),
+                                                     ('related-data-hard-deletion', 'User related data hard deletion')], max_length=32)),
+                ('performed_at', models.DateTimeField(default=django.utils.timezone.now)),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='history', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+    ]
diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index 079833c278..537f867978 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -66,6 +66,7 @@
 
 from contentcuration.constants import channel_history
 from contentcuration.constants import completion_criteria
+from contentcuration.constants import user_history
 from contentcuration.constants.contentnode import kind_activity_map
 from contentcuration.db.models.expressions import Array
 from contentcuration.db.models.functions import ArrayRemove
@@ -199,7 +200,7 @@ class User(AbstractBaseUser, PermissionsMixin):
     content_defaults = JSONField(default=dict)
     policies = JSONField(default=dict, null=True)
     feature_flags = JSONField(default=dict, null=True)
-    deleted = models.BooleanField(default=False, db_index=True)
+    deleted_at = models.DateTimeField(null=True, blank=True)
 
     _field_updates = FieldTracker(fields=[
         # Field to watch for changes
@@ -215,44 +216,66 @@ def __unicode__(self):
 
     def delete(self):
         """
-        Hard deletes invitation associated to this account, hard deletes channel and channet sets
-        only if user is the only editor. Then soft deletes the user account.
+        Soft deletes the user account.
+        """
+        self.deleted_at = timezone.now()
+        # Deactivate the user to disallow authentication and also
+        # to let the user verify the email again after recovery.
+        self.is_active = False
+        self.save()
+        self.history.create(user_id=self.pk, action=user_history.DELETION)
+
+    def recover(self):
+        """
+        Use this method when we want to recover a user.
+        """
+        self.deleted_at = None
+        self.save()
+        self.history.create(user_id=self.pk, action=user_history.RECOVERY)
+
+    def hard_delete_user_related_data(self):
+        """
+        Hard delete all user related data. But keeps the user record itself intact.
+
+        User related data that gets hard deleted are:
+            - sole editor non-public channels.
+            - sole editor non-public channelsets.
+            - sole editor non-public channels' content nodes and its underlying files that are not
+            used by any other channel.
+            - all user invitations.
         """
         from contentcuration.viewsets.common import SQCount
 
         # Hard delete invitations associated to this account.
         self.sent_to.all().delete()
+        self.sent_by.all().delete()
 
-        # Hard delete channels associated with this user (if user is the only editor).
-        user_query = (
+        editable_channels_user_query = (
             User.objects.filter(editable_channels__id=OuterRef('id'))
                         .values_list('id', flat=True)
                         .distinct()
         )
-        self.editable_channels.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
+        non_public_channels_sole_editor = self.editable_channels.annotate(num_editors=SQCount(
+            editable_channels_user_query, field="id")).filter(num_editors=1, public=False)
+
+        # Point sole editor non-public channels' contentnodes to orphan tree to let
+        # our garbage collection delete the nodes and underlying files.
+        ContentNode._annotate_channel_id(ContentNode.objects).filter(channel_id__in=list(
+            non_public_channels_sole_editor)).update(parent_id=settings.ORPHANAGE_ROOT_ID)
 
-        # Hard delete channel collections associated with this user (if user is the only editor).
+        # Hard delete non-public channels associated with this user (if user is the only editor).
+        non_public_channels_sole_editor.delete()
+
+        # Hard delete non-public channel collections associated with this user (if user is the only editor).
         user_query = (
             User.objects.filter(channel_sets__id=OuterRef('id'))
                         .values_list('id', flat=True)
                         .distinct()
         )
-        self.channel_sets.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1).delete()
+        self.channel_sets.annotate(num_editors=SQCount(user_query, field="id")).filter(num_editors=1, public=False).delete()
 
-        # Soft delete user.
-        self.deleted = True
-        # Deactivate the user to disallow authentication and also
-        # to let the user verify the email again after recovery.
-        self.is_active = False
-
-        self.save()
-
-    def recover(self):
-        """
-        Use this method when we want to recover a user.
-        """
-        self.deleted = False
-        self.save()
+        # Create history!
+        self.history.create(user_id=self.pk, action=user_history.RELATED_DATA_HARD_DELETION)
 
     def can_edit(self, channel_id):
         return Channel.filter_edit_queryset(Channel.objects.all(), self).filter(pk=channel_id).exists()
@@ -424,20 +447,20 @@ def filter_edit_queryset(cls, queryset, user):
         return queryset.filter(pk=user.pk)
 
     @classmethod
-    def get_for_email(cls, email, deleted=False, **filters):
+    def get_for_email(cls, email, deleted_at__isnull=True, **filters):
         """
         Returns the appropriate User record given an email, ordered by:
          - those with is_active=True first, which there should only ever be one
          - otherwise by ID DESC so most recent inactive shoud be returned
 
         Filters out deleted User records by default. Can be overridden with
-        deleted argument.
+        deleted_at__isnull argument.
 
         :param email: A string of the user's email
         :param filters: Additional filters to filter the User queryset
         :return: User or None
         """
-        return User.objects.filter(email__iexact=email.strip(), deleted=deleted, **filters)\
+        return User.objects.filter(email__iexact=email.strip(), deleted_at__isnull=deleted_at__isnull, **filters)\
             .order_by("-is_active", "-id").first()
 
 
@@ -1060,6 +1083,16 @@ class Meta:
         ]
 
 
+class UserHistory(models.Model):
+    """
+    Model that stores the user's action history.
+    """
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, null=False, blank=False, related_name="history", on_delete=models.CASCADE)
+    action = models.CharField(max_length=32, choices=user_history.choices)
+
+    performed_at = models.DateTimeField(default=timezone.now)
+
+
 class ChannelSet(models.Model):
     # NOTE: this is referred to as "channel collections" on the front-end, but we need to call it
     # something else as there is already a ChannelCollection model on the front-end
diff --git a/contentcuration/contentcuration/settings.py b/contentcuration/contentcuration/settings.py
index b9c3a73ca1..de05fb484a 100644
--- a/contentcuration/contentcuration/settings.py
+++ b/contentcuration/contentcuration/settings.py
@@ -329,8 +329,10 @@ def gettext(s):
 HELP_EMAIL = 'content@learningequality.org'
 DEFAULT_FROM_EMAIL = 'Kolibri Studio <noreply@learningequality.org>'
 POLICY_EMAIL = 'legal@learningequality.org'
-ACCOUNT_DELETION_BUFFER = 5  # Used to determine how many days a user
-# has to undo accidentally deleting account
+
+# Used to determine how many days a user
+# has to undo accidentally deleting account.
+ACCOUNT_DELETION_BUFFER = 90
 
 DEFAULT_LICENSE = 1
 
diff --git a/contentcuration/contentcuration/tests/test_models.py b/contentcuration/contentcuration/tests/test_models.py
index 66720a0985..e6fbe38a35 100644
--- a/contentcuration/contentcuration/tests/test_models.py
+++ b/contentcuration/contentcuration/tests/test_models.py
@@ -1,3 +1,4 @@
+import datetime
 import uuid
 
 import mock
@@ -11,6 +12,7 @@
 from le_utils.constants import format_presets
 
 from contentcuration.constants import channel_history
+from contentcuration.constants import user_history
 from contentcuration.models import AssessmentItem
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
@@ -22,6 +24,7 @@
 from contentcuration.models import Invitation
 from contentcuration.models import object_storage_name
 from contentcuration.models import User
+from contentcuration.models import UserHistory
 from contentcuration.tests import testdata
 from contentcuration.tests.base import StudioTestCase
 
@@ -806,27 +809,30 @@ def test_get_for_email(self):
         user4.delete()
         self.assertIsNone(User.get_for_email("testing@test.com"))
 
-    def test_delete__sets_deleted_true(self):
+    def test_delete(self):
         user = self._create_user("tester@tester.com")
         user.delete()
-        self.assertEqual(user.deleted, True)
 
-    def test_delete__sets_is_active_false(self):
-        user = self._create_user("tester@tester.com")
-        user.delete()
+        # Sets deleted_at?
+        self.assertIsInstance(user.deleted_at, datetime.datetime)
+        # Sets is_active to False?
         self.assertEqual(user.is_active, False)
+        # Creates user history?
+        user_delete_history = UserHistory.objects.filter(user_id=user.id, action=user_history.DELETION).first()
+        self.assertIsNotNone(user_delete_history)
 
-    def test_recover__sets_deleted_false(self):
+    def test_recover(self):
         user = self._create_user("tester@tester.com")
         user.delete()
         user.recover()
-        self.assertEqual(user.deleted, False)
 
-    def test_recover__keeps_is_active_false(self):
-        user = self._create_user("tester@tester.com")
-        user.delete()
-        user.recover()
+        # Sets deleted_at to None?
+        self.assertEqual(user.deleted_at, None)
+        # Keeps is_active to False?
         self.assertEqual(user.is_active, False)
+        # Creates user history?
+        user_recover_history = UserHistory.objects.filter(user_id=user.id, action=user_history.RECOVERY).first()
+        self.assertIsNotNone(user_recover_history)
 
 
 class ChannelHistoryTestCase(StudioTestCase):
diff --git a/contentcuration/contentcuration/utils/garbage_collect.py b/contentcuration/contentcuration/utils/garbage_collect.py
index 3343013b7c..de5a29921f 100755
--- a/contentcuration/contentcuration/utils/garbage_collect.py
+++ b/contentcuration/contentcuration/utils/garbage_collect.py
@@ -7,7 +7,9 @@
 
 from celery import states
 from django.conf import settings
+from django.core.files.storage import default_storage
 from django.db.models.expressions import CombinedExpression
+from django.db.models.expressions import Exists
 from django.db.models.expressions import F
 from django.db.models.expressions import Value
 from django.db.models.signals import post_delete
@@ -37,18 +39,57 @@ def __exit__(self, exc_type, exc_val, exc_tb):
         self.receivers = None
 
 
-def get_deleted_chefs_root():
+def _get_deleted_chefs_root():
     deleted_chefs_node, _new = ContentNode.objects.get_or_create(pk=settings.DELETED_CHEFS_ROOT_ID, kind_id=content_kinds.TOPIC)
     return deleted_chefs_node
 
 
+def _clean_up_files(contentnode_ids):
+    """
+    Clean up the files (both in the DB and in object storage)
+    associated with the `contentnode_ids` iterable that are
+    not pointed by any other contentnode.
+    """
+    files = File.objects.filter(contentnode__in=contentnode_ids)
+    files_on_storage = files.values_list("file_on_disk", flat=True)
+
+    for disk_file_path in files_on_storage:
+        is_other_node_pointing = Exists(File.objects.filter(file_on_disk=disk_file_path).exclude(contentnode__in=contentnode_ids))
+        if not is_other_node_pointing:
+            default_storage.delete(disk_file_path)
+
+    # use _raw_delete for much fast file deletions
+    files._raw_delete(files.db)
+
+
+def clean_up_soft_deleted_users():
+    """
+    Hard deletes user related data for soft deleted users that are older than ACCOUNT_DELETION_BUFFER.
+
+    Note: User record itself is not hard deleted.
+
+    User related data that gets hard deleted are:
+        - sole editor non-public channels.
+        - sole editor non-public channelsets.
+        - sole editor non-public channels' content nodes and its underlying files that are not
+          used by any other channel.
+        - all user invitations.
+    """
+    account_deletion_buffer_delta = now() - datetime.timedelta(days=settings.ACCOUNT_DELETION_BUFFER)
+    users_to_delete = User.objects.filter(deleted_at__lt=account_deletion_buffer_delta)
+
+    for user in users_to_delete:
+        user.hard_delete_user_related_data()
+        logging.info("Hard deleted user related data for user {}".format(user.email))
+
+
 def clean_up_deleted_chefs():
     """
     Clean up all deleted chefs attached to the deleted chefs tree, including all
     child nodes in that tree.
 
     """
-    deleted_chefs_node = get_deleted_chefs_root()
+    deleted_chefs_node = _get_deleted_chefs_root()
     # we cannot use MPTT methods like get_descendants() or use tree_id because for performance reasons
     # we are avoiding MPTT entirely.
     nodes_to_clean_up = ContentNode.objects.filter(parent=deleted_chefs_node)
@@ -81,7 +122,7 @@ def clean_up_contentnodes(delete_older_than=settings.ORPHAN_DATE_CLEAN_UP_THRESH
 
     # delete all files first
     with DisablePostDeleteSignal():
-        clean_up_files(nodes_to_clean_up)
+        _clean_up_files(nodes_to_clean_up)
 
     # Use _raw_delete for fast bulk deletions
     try:
@@ -92,32 +133,6 @@ def clean_up_contentnodes(delete_older_than=settings.ORPHAN_DATE_CLEAN_UP_THRESH
         pass
 
 
-def clean_up_files(contentnode_ids):
-    """
-    Clean up the files (both in the DB and in object storage)
-    associated with the contentnode_ids given in the `contentnode_ids`
-    iterable.
-    """
-
-    # get all file objects associated with these contentnodes
-    files = File.objects.filter(contentnode__in=contentnode_ids)
-    # get all their associated real files in object storage
-    files_on_storage = files.values_list("file_on_disk")
-    for f in files_on_storage:
-        # values_list returns each set of items in a tuple, even
-        # if there's only one item in there. Extract the file_on_disk
-        # string value from inside that singleton tuple
-        f[0]
-        # NOTE (aron):call the storage's delete method on each file, one by one
-        # disabled for now until we implement logic to not delete files
-        # that are referenced by non-orphan nodes
-        # storage.delete(file_path)
-
-    # finally, remove the entries from object storage
-    # use _raw_delete for much fast file deletions
-    files._raw_delete(files.db)
-
-
 def clean_up_feature_flags():
     """
     Removes lingering feature flag settings in User records that aren't currently present in the

From 4be9df4359a9638a21c11582e613f3d75dc38786 Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Fri, 21 Oct 2022 13:49:59 +0530
Subject: [PATCH 4/6] fix deleted chefs root references

---
 contentcuration/contentcuration/tests/test_user.py       | 6 ++++--
 contentcuration/contentcuration/utils/garbage_collect.py | 4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/contentcuration/contentcuration/tests/test_user.py b/contentcuration/contentcuration/tests/test_user.py
index f9995fb48c..36ae42f1c7 100644
--- a/contentcuration/contentcuration/tests/test_user.py
+++ b/contentcuration/contentcuration/tests/test_user.py
@@ -161,10 +161,12 @@ def test_user_csv_export(self):
                         self.assertIn(videos[index - 1].original_filename, row)
                         self.assertIn(_format_size(videos[index - 1].file_size), row)
             self.assertEqual(index, len(videos))
+    """
+    Write and refactor for related data hard delete test cases below.
+    """
 
     def test_account_deletion(self):
-        self.user.delete()
-        self.assertFalse(Channel.objects.filter(pk=self.channel.pk).exists())
+        pass
 
     def test_account_deletion_shared_channels_preserved(self):
         # Deleting a user account shouldn't delete shared channels
diff --git a/contentcuration/contentcuration/utils/garbage_collect.py b/contentcuration/contentcuration/utils/garbage_collect.py
index de5a29921f..206ad74865 100755
--- a/contentcuration/contentcuration/utils/garbage_collect.py
+++ b/contentcuration/contentcuration/utils/garbage_collect.py
@@ -39,7 +39,7 @@ def __exit__(self, exc_type, exc_val, exc_tb):
         self.receivers = None
 
 
-def _get_deleted_chefs_root():
+def get_deleted_chefs_root():
     deleted_chefs_node, _new = ContentNode.objects.get_or_create(pk=settings.DELETED_CHEFS_ROOT_ID, kind_id=content_kinds.TOPIC)
     return deleted_chefs_node
 
@@ -89,7 +89,7 @@ def clean_up_deleted_chefs():
     child nodes in that tree.
 
     """
-    deleted_chefs_node = _get_deleted_chefs_root()
+    deleted_chefs_node = get_deleted_chefs_root()
     # we cannot use MPTT methods like get_descendants() or use tree_id because for performance reasons
     # we are avoiding MPTT entirely.
     nodes_to_clean_up = ContentNode.objects.filter(parent=deleted_chefs_node)

From d3a4263ee3d0669f2c1c03c50373051dca12821b Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Sun, 23 Oct 2022 01:20:36 +0530
Subject: [PATCH 5/6] User UserHistory as single source of truth for
 timestamps!

---
 .../contentcuration/constants/user_history.py |  4 +-
 contentcuration/contentcuration/forms.py      |  2 +-
 ...oft_delete.py => 0141_soft_delete_user.py} | 10 +--
 contentcuration/contentcuration/models.py     | 20 +++--
 .../contentcuration/tests/test_models.py      | 84 +++++++++++++++++--
 .../contentcuration/tests/test_user.py        | 15 ----
 .../tests/utils/test_garbage_collect.py       | 34 ++++++++
 .../contentcuration/utils/garbage_collect.py  | 12 ++-
 8 files changed, 140 insertions(+), 41 deletions(-)
 rename contentcuration/contentcuration/migrations/{0141_user_soft_delete.py => 0141_soft_delete_user.py} (63%)

diff --git a/contentcuration/contentcuration/constants/user_history.py b/contentcuration/contentcuration/constants/user_history.py
index 1eecf79c17..76655993ef 100644
--- a/contentcuration/contentcuration/constants/user_history.py
+++ b/contentcuration/contentcuration/constants/user_history.py
@@ -1,7 +1,7 @@
 from django.utils.translation import ugettext_lazy as _
 
-DELETION = "deletion"
-RECOVERY = "recovery"
+DELETION = "soft-deletion"
+RECOVERY = "soft-recovery"
 RELATED_DATA_HARD_DELETION = "related-data-hard-deletion"
 
 choices = (
diff --git a/contentcuration/contentcuration/forms.py b/contentcuration/contentcuration/forms.py
index d0ae49893f..d9dc781f61 100644
--- a/contentcuration/contentcuration/forms.py
+++ b/contentcuration/contentcuration/forms.py
@@ -46,7 +46,7 @@ class RegistrationForm(UserCreationForm, ExtraFormMixin):
 
     def clean_email(self):
         email = self.cleaned_data['email'].strip().lower()
-        if User.objects.filter(Q(is_active=True) | Q(deleted_at__isnull=False), email__iexact=email).exists():
+        if User.objects.filter(Q(is_active=True) | Q(deleted=True), email__iexact=email).exists():
             raise UserWarning
         return email
 
diff --git a/contentcuration/contentcuration/migrations/0141_user_soft_delete.py b/contentcuration/contentcuration/migrations/0141_soft_delete_user.py
similarity index 63%
rename from contentcuration/contentcuration/migrations/0141_user_soft_delete.py
rename to contentcuration/contentcuration/migrations/0141_soft_delete_user.py
index 1f58e4076a..df66bafcc0 100644
--- a/contentcuration/contentcuration/migrations/0141_user_soft_delete.py
+++ b/contentcuration/contentcuration/migrations/0141_soft_delete_user.py
@@ -1,4 +1,4 @@
-# Generated by Django 3.2.14 on 2022-10-19 09:41
+# Generated by Django 3.2.14 on 2022-10-22 18:30
 import django.db.models.deletion
 import django.utils.timezone
 from django.conf import settings
@@ -15,15 +15,15 @@ class Migration(migrations.Migration):
     operations = [
         migrations.AddField(
             model_name='user',
-            name='deleted_at',
-            field=models.DateTimeField(blank=True, null=True),
+            name='deleted',
+            field=models.BooleanField(db_index=True, default=False),
         ),
         migrations.CreateModel(
             name='UserHistory',
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('action', models.CharField(choices=[('deletion', 'User soft deletion'), ('recovery', 'User soft deletion recovery'),
-                                                     ('related-data-hard-deletion', 'User related data hard deletion')], max_length=32)),
+                ('action', models.CharField(choices=[('soft-deletion', 'User soft deletion'), ('soft-recovery',
+                                                                                               'User soft deletion recovery'), ('related-data-hard-deletion', 'User related data hard deletion')], max_length=32)),
                 ('performed_at', models.DateTimeField(default=django.utils.timezone.now)),
                 ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='history', to=settings.AUTH_USER_MODEL)),
             ],
diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index 537f867978..07aa39f2b1 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -200,7 +200,7 @@ class User(AbstractBaseUser, PermissionsMixin):
     content_defaults = JSONField(default=dict)
     policies = JSONField(default=dict, null=True)
     feature_flags = JSONField(default=dict, null=True)
-    deleted_at = models.DateTimeField(null=True, blank=True)
+    deleted = models.BooleanField(default=False, db_index=True)
 
     _field_updates = FieldTracker(fields=[
         # Field to watch for changes
@@ -218,7 +218,7 @@ def delete(self):
         """
         Soft deletes the user account.
         """
-        self.deleted_at = timezone.now()
+        self.deleted = True
         # Deactivate the user to disallow authentication and also
         # to let the user verify the email again after recovery.
         self.is_active = False
@@ -229,7 +229,7 @@ def recover(self):
         """
         Use this method when we want to recover a user.
         """
-        self.deleted_at = None
+        self.deleted = False
         self.save()
         self.history.create(user_id=self.pk, action=user_history.RECOVERY)
 
@@ -261,7 +261,7 @@ def hard_delete_user_related_data(self):
         # Point sole editor non-public channels' contentnodes to orphan tree to let
         # our garbage collection delete the nodes and underlying files.
         ContentNode._annotate_channel_id(ContentNode.objects).filter(channel_id__in=list(
-            non_public_channels_sole_editor)).update(parent_id=settings.ORPHANAGE_ROOT_ID)
+            non_public_channels_sole_editor.values_list("id", flat=True))).update(parent_id=settings.ORPHANAGE_ROOT_ID)
 
         # Hard delete non-public channels associated with this user (if user is the only editor).
         non_public_channels_sole_editor.delete()
@@ -447,21 +447,23 @@ def filter_edit_queryset(cls, queryset, user):
         return queryset.filter(pk=user.pk)
 
     @classmethod
-    def get_for_email(cls, email, deleted_at__isnull=True, **filters):
+    def get_for_email(cls, email, deleted=False, **filters):
         """
         Returns the appropriate User record given an email, ordered by:
          - those with is_active=True first, which there should only ever be one
          - otherwise by ID DESC so most recent inactive shoud be returned
 
-        Filters out deleted User records by default. Can be overridden with
-        deleted_at__isnull argument.
+        Filters out deleted User records by default. To include both deleted and
+        undeleted user records pass None to the deleted argument.
 
         :param email: A string of the user's email
         :param filters: Additional filters to filter the User queryset
         :return: User or None
         """
-        return User.objects.filter(email__iexact=email.strip(), deleted_at__isnull=deleted_at__isnull, **filters)\
-            .order_by("-is_active", "-id").first()
+        user_qs = User.objects.filter(email__iexact=email.strip())
+        if deleted is not None:
+            user_qs = user_qs.filter(deleted=deleted)
+        return user_qs.filter(**filters).order_by("-is_active", "-id").first()
 
 
 class UUIDField(models.CharField):
diff --git a/contentcuration/contentcuration/tests/test_models.py b/contentcuration/contentcuration/tests/test_models.py
index e6fbe38a35..9734ef1309 100644
--- a/contentcuration/contentcuration/tests/test_models.py
+++ b/contentcuration/contentcuration/tests/test_models.py
@@ -1,4 +1,3 @@
-import datetime
 import uuid
 
 import mock
@@ -6,6 +5,7 @@
 from django.conf import settings
 from django.core.cache import cache
 from django.core.exceptions import ValidationError
+from django.db.models import Q
 from django.db.utils import IntegrityError
 from django.utils import timezone
 from le_utils.constants import content_kinds
@@ -16,6 +16,7 @@
 from contentcuration.models import AssessmentItem
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
+from contentcuration.models import ChannelSet
 from contentcuration.models import ContentNode
 from contentcuration.models import CONTENTNODE_TREE_ID_CACHE_KEY
 from contentcuration.models import File
@@ -781,6 +782,51 @@ def _create_user(self, email, password='password', is_active=True):
         user.save()
         return user
 
+    def _setup_user_related_data(self):
+        user_a = self._create_user("a@tester.com")
+        user_b = self._create_user("b@tester.com")
+
+        # Create a sole editor non-public channel.
+        sole_editor_channel = Channel.objects.create(name="sole-editor")
+        sole_editor_channel.editors.add(user_a)
+
+        # Create sole-editor channel nodes.
+        for i in range(0, 3):
+            testdata.node({
+                "title": "sole-editor-channel-node",
+                "kind_id": "video",
+            }, parent=sole_editor_channel.main_tree)
+
+        # Create a sole editor public channel.
+        public_channel = testdata.channel("public")
+        public_channel.editors.add(user_a)
+        public_channel.public = True
+        public_channel.save()
+
+        # Create a shared channel.
+        shared_channel = testdata.channel("shared-channel")
+        shared_channel.editors.add(user_a)
+        shared_channel.editors.add(user_b)
+
+        # Invitations.
+        Invitation.objects.create(sender_id=user_a.id, invited_id=user_b.id)
+        Invitation.objects.create(sender_id=user_b.id, invited_id=user_a.id)
+
+        # Channel sets.
+        channel_set = ChannelSet.objects.create(name="sole-editor")
+        channel_set.editors.add(user_a)
+
+        channel_set = ChannelSet.objects.create(name="public")
+        channel_set.editors.add(user_a)
+        channel_set.public = True
+        channel_set.save()
+
+        channel_set = ChannelSet.objects.create(name="shared-channelset")
+        channel_set.editors.add(user_a)
+        channel_set.editors.add(user_b)
+
+        return user_a
+
     def test_unique_lower_email(self):
         self._create_user("tester@tester.com")
         with self.assertRaises(IntegrityError):
@@ -813,8 +859,8 @@ def test_delete(self):
         user = self._create_user("tester@tester.com")
         user.delete()
 
-        # Sets deleted_at?
-        self.assertIsInstance(user.deleted_at, datetime.datetime)
+        # Sets deleted?
+        self.assertEqual(user.deleted, True)
         # Sets is_active to False?
         self.assertEqual(user.is_active, False)
         # Creates user history?
@@ -826,14 +872,42 @@ def test_recover(self):
         user.delete()
         user.recover()
 
-        # Sets deleted_at to None?
-        self.assertEqual(user.deleted_at, None)
+        # Sets deleted to False?
+        self.assertEqual(user.deleted, False)
         # Keeps is_active to False?
         self.assertEqual(user.is_active, False)
         # Creates user history?
         user_recover_history = UserHistory.objects.filter(user_id=user.id, action=user_history.RECOVERY).first()
         self.assertIsNotNone(user_recover_history)
 
+    def test_hard_delete_user_related_data(self):
+        user = self._setup_user_related_data()
+        user.hard_delete_user_related_data()
+
+        # Deletes sole-editor channels.
+        self.assertFalse(Channel.objects.filter(name="sole-editor").exists())
+        # Preserves shared channels.
+        self.assertTrue(Channel.objects.filter(name="shared-channel").exists())
+        # Preserves public channels.
+        self.assertTrue(Channel.objects.filter(name="public").exists())
+
+        # Deletes all user related invitations.
+        self.assertFalse(Invitation.objects.filter(Q(sender_id=user.id) | Q(invited_id=user.id)).exists())
+
+        # Deletes sole-editor channelsets.
+        self.assertFalse(ChannelSet.objects.filter(name="sole-editor").exists())
+        # Preserves shared channelsets.
+        self.assertTrue(ChannelSet.objects.filter(name="shared-channelset").exists())
+        # Preserves public channelsets.
+        self.assertTrue(ChannelSet.objects.filter(name="public").exists())
+
+        # All contentnodes of sole-editor channel points to ORPHANGE ROOT NODE?
+        self.assertFalse(ContentNode.objects.filter(~Q(parent_id=settings.ORPHANAGE_ROOT_ID)
+                                                    & Q(title="sole-editor-channel-node")).exists())
+        # Creates user history?
+        user_hard_delete_history = UserHistory.objects.filter(user_id=user.id, action=user_history.RELATED_DATA_HARD_DELETION).first()
+        self.assertIsNotNone(user_hard_delete_history)
+
 
 class ChannelHistoryTestCase(StudioTestCase):
     def setUp(self):
diff --git a/contentcuration/contentcuration/tests/test_user.py b/contentcuration/contentcuration/tests/test_user.py
index 36ae42f1c7..9fda1ceefe 100644
--- a/contentcuration/contentcuration/tests/test_user.py
+++ b/contentcuration/contentcuration/tests/test_user.py
@@ -15,7 +15,6 @@
 
 from .base import BaseAPITestCase
 from .testdata import fileobj_video
-from contentcuration.models import Channel
 from contentcuration.models import DEFAULT_CONTENT_DEFAULTS
 from contentcuration.models import Invitation
 from contentcuration.models import User
@@ -161,17 +160,3 @@ def test_user_csv_export(self):
                         self.assertIn(videos[index - 1].original_filename, row)
                         self.assertIn(_format_size(videos[index - 1].file_size), row)
             self.assertEqual(index, len(videos))
-    """
-    Write and refactor for related data hard delete test cases below.
-    """
-
-    def test_account_deletion(self):
-        pass
-
-    def test_account_deletion_shared_channels_preserved(self):
-        # Deleting a user account shouldn't delete shared channels
-        newuser = self.create_user()
-        self.channel.editors.add(newuser)
-        self.channel.save()
-        self.user.delete()
-        self.assertTrue(Channel.objects.filter(pk=self.channel.pk).exists())
diff --git a/contentcuration/contentcuration/tests/utils/test_garbage_collect.py b/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
index 6746fa43a6..178bc25656 100644
--- a/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
+++ b/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
@@ -17,15 +17,19 @@
 
 from contentcuration import models as cc
 from contentcuration.api import activate_channel
+from contentcuration.constants import user_history
 from contentcuration.models import ContentNode
 from contentcuration.models import File
 from contentcuration.models import TaskResult
+from contentcuration.models import UserHistory
 from contentcuration.tests.base import BaseAPITestCase
 from contentcuration.tests.base import StudioTestCase
 from contentcuration.tests.testdata import tree
+from contentcuration.utils.db_tools import create_user
 from contentcuration.utils.garbage_collect import clean_up_contentnodes
 from contentcuration.utils.garbage_collect import clean_up_deleted_chefs
 from contentcuration.utils.garbage_collect import clean_up_feature_flags
+from contentcuration.utils.garbage_collect import clean_up_soft_deleted_users
 from contentcuration.utils.garbage_collect import clean_up_stale_files
 from contentcuration.utils.garbage_collect import clean_up_tasks
 from contentcuration.utils.garbage_collect import get_deleted_chefs_root
@@ -192,6 +196,36 @@ def _create_expired_contentnode(creation_date=THREE_MONTHS_AGO):
     return c
 
 
+def _create_expired_deleted_user(email="test@test.com", deletion_date=THREE_MONTHS_AGO):
+    user = create_user(email, "password", "test", "test")
+    user.delete()
+
+    user_latest_delete_history = UserHistory.objects.filter(user_id=user.id, action=user_history.DELETION).order_by("-performed_at").first()
+    user_latest_delete_history.performed_at = deletion_date
+    user_latest_delete_history.save()
+    return user
+
+
+class CleanUpSoftDeletedExpiredUsersTestCase(StudioTestCase):
+    def test_cleanup__all_expired_soft_deleted_users(self):
+        expired_users = []
+        for i in range(0, 5):
+            expired_users.append(_create_expired_deleted_user(email=f"test-{i}@test.com"))
+
+        clean_up_soft_deleted_users()
+
+        for user in expired_users:
+            assert UserHistory.objects.filter(user_id=user.id, action=user_history.RELATED_DATA_HARD_DELETION).exists() is True
+
+    def test_no_cleanup__unexpired_soft_deleted_users(self):
+        # TO DO
+        pass
+
+    def test_no_cleanup__undeleted_users(self):
+        # TO DO
+        pass
+
+
 class CleanUpContentNodesTestCase(StudioTestCase):
 
     def test_delete_all_contentnodes_in_orphanage_tree(self):
diff --git a/contentcuration/contentcuration/utils/garbage_collect.py b/contentcuration/contentcuration/utils/garbage_collect.py
index 206ad74865..f7444f5f2e 100755
--- a/contentcuration/contentcuration/utils/garbage_collect.py
+++ b/contentcuration/contentcuration/utils/garbage_collect.py
@@ -17,11 +17,13 @@
 from le_utils.constants import content_kinds
 
 from contentcuration.constants import feature_flags
+from contentcuration.constants import user_history
 from contentcuration.db.models.functions import JSONObjectKeys
 from contentcuration.models import ContentNode
 from contentcuration.models import File
 from contentcuration.models import TaskResult
 from contentcuration.models import User
+from contentcuration.models import UserHistory
 
 
 class DisablePostDeleteSignal(object):
@@ -76,11 +78,13 @@ def clean_up_soft_deleted_users():
         - all user invitations.
     """
     account_deletion_buffer_delta = now() - datetime.timedelta(days=settings.ACCOUNT_DELETION_BUFFER)
-    users_to_delete = User.objects.filter(deleted_at__lt=account_deletion_buffer_delta)
+    deleted_users = User.objects.filter(deleted=True)
 
-    for user in users_to_delete:
-        user.hard_delete_user_related_data()
-        logging.info("Hard deleted user related data for user {}".format(user.email))
+    for user in deleted_users:
+        latest_deletion_time = UserHistory.objects.filter(user_id=user.id, action=user_history.DELETION).order_by("-performed_at").first()
+        if latest_deletion_time and latest_deletion_time.performed_at < account_deletion_buffer_delta:
+            user.hard_delete_user_related_data()
+            logging.info("Hard deleted user related data for user {}".format(user.email))
 
 
 def clean_up_deleted_chefs():

From 17a7ac1ec63ab197697eb1a89155cb5c588ee837 Mon Sep 17 00:00:00 2001
From: Vivek Agrawal <vivekmittalagrawal@gmail.com>
Date: Mon, 31 Oct 2022 14:11:05 +0530
Subject: [PATCH 6/6] User cleanup garbage collection tests

---
 contentcuration/contentcuration/models.py      |  1 +
 .../tests/utils/test_garbage_collect.py        | 18 +++++++++++-------
 .../contentcuration/utils/garbage_collect.py   | 17 ++++++++++-------
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index 07aa39f2b1..f6eb908a61 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -200,6 +200,7 @@ class User(AbstractBaseUser, PermissionsMixin):
     content_defaults = JSONField(default=dict)
     policies = JSONField(default=dict, null=True)
     feature_flags = JSONField(default=dict, null=True)
+
     deleted = models.BooleanField(default=False, db_index=True)
 
     _field_updates = FieldTracker(fields=[
diff --git a/contentcuration/contentcuration/tests/utils/test_garbage_collect.py b/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
index 178bc25656..e4c9941df4 100644
--- a/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
+++ b/contentcuration/contentcuration/tests/utils/test_garbage_collect.py
@@ -196,12 +196,12 @@ def _create_expired_contentnode(creation_date=THREE_MONTHS_AGO):
     return c
 
 
-def _create_expired_deleted_user(email="test@test.com", deletion_date=THREE_MONTHS_AGO):
+def _create_deleted_user_in_past(deletion_datetime, email="test@test.com"):
     user = create_user(email, "password", "test", "test")
     user.delete()
 
     user_latest_delete_history = UserHistory.objects.filter(user_id=user.id, action=user_history.DELETION).order_by("-performed_at").first()
-    user_latest_delete_history.performed_at = deletion_date
+    user_latest_delete_history.performed_at = deletion_datetime
     user_latest_delete_history.save()
     return user
 
@@ -210,7 +210,7 @@ class CleanUpSoftDeletedExpiredUsersTestCase(StudioTestCase):
     def test_cleanup__all_expired_soft_deleted_users(self):
         expired_users = []
         for i in range(0, 5):
-            expired_users.append(_create_expired_deleted_user(email=f"test-{i}@test.com"))
+            expired_users.append(_create_deleted_user_in_past(deletion_datetime=THREE_MONTHS_AGO, email=f"test-{i}@test.com"))
 
         clean_up_soft_deleted_users()
 
@@ -218,12 +218,16 @@ def test_cleanup__all_expired_soft_deleted_users(self):
             assert UserHistory.objects.filter(user_id=user.id, action=user_history.RELATED_DATA_HARD_DELETION).exists() is True
 
     def test_no_cleanup__unexpired_soft_deleted_users(self):
-        # TO DO
-        pass
+        two_months_ago = datetime.now() - timedelta(days=63)
+        user = _create_deleted_user_in_past(deletion_datetime=two_months_ago)
+        clean_up_soft_deleted_users()
+        assert UserHistory.objects.filter(user_id=user.id, action=user_history.RELATED_DATA_HARD_DELETION).exists() is False
 
     def test_no_cleanup__undeleted_users(self):
-        # TO DO
-        pass
+        user = create_user("test@test.com", "password", "test", "test")
+        clean_up_soft_deleted_users()
+        assert user.deleted is False
+        assert UserHistory.objects.filter(user_id=user.id, action=user_history.RELATED_DATA_HARD_DELETION).exists() is False
 
 
 class CleanUpContentNodesTestCase(StudioTestCase):
diff --git a/contentcuration/contentcuration/utils/garbage_collect.py b/contentcuration/contentcuration/utils/garbage_collect.py
index f7444f5f2e..44e09e4dab 100755
--- a/contentcuration/contentcuration/utils/garbage_collect.py
+++ b/contentcuration/contentcuration/utils/garbage_collect.py
@@ -8,9 +8,11 @@
 from celery import states
 from django.conf import settings
 from django.core.files.storage import default_storage
+from django.db.models import Subquery
 from django.db.models.expressions import CombinedExpression
 from django.db.models.expressions import Exists
 from django.db.models.expressions import F
+from django.db.models.expressions import OuterRef
 from django.db.models.expressions import Value
 from django.db.models.signals import post_delete
 from django.utils.timezone import now
@@ -78,13 +80,14 @@ def clean_up_soft_deleted_users():
         - all user invitations.
     """
     account_deletion_buffer_delta = now() - datetime.timedelta(days=settings.ACCOUNT_DELETION_BUFFER)
-    deleted_users = User.objects.filter(deleted=True)
-
-    for user in deleted_users:
-        latest_deletion_time = UserHistory.objects.filter(user_id=user.id, action=user_history.DELETION).order_by("-performed_at").first()
-        if latest_deletion_time and latest_deletion_time.performed_at < account_deletion_buffer_delta:
-            user.hard_delete_user_related_data()
-            logging.info("Hard deleted user related data for user {}".format(user.email))
+    user_latest_deletion_time_subquery = Subquery(UserHistory.objects.filter(user_id=OuterRef(
+        "id"), action=user_history.DELETION).values("performed_at").order_by("-performed_at")[:1])
+    users_to_delete = User.objects.annotate(latest_deletion_time=user_latest_deletion_time_subquery).filter(
+        deleted=True, latest_deletion_time__lt=account_deletion_buffer_delta)
+
+    for user in users_to_delete:
+        user.hard_delete_user_related_data()
+        logging.info("Hard deleted user related data for user {}.".format(user.email))
 
 
 def clean_up_deleted_chefs():