import: import RealmAuditLog when 'zerver_realmauditlog` is missing.

* If `zerver_realmauditlog` is present in the exported data,
  `RealmAuditLog` would be imported normally.

* If it is not present, `create_subscription_events`
  function in would create the `subscription_created`
  events for RealmAuditLog. The reason this function
  is in `import_realm` module and not in the individual
  export tool scripts (like Slack) is because this
  function would be common for all export tools.

This fixes #9846 for users who have not already done an import of
their organization from Slack.

Fixes #9846.

zerver/lib/import_realm.py

@@ -9,7 +9,8 @@ from boto.s3.connection import S3Connection
 from boto.s3.key import Key
 from django.conf import settings
 from django.db import connection
-from django.utils.timezone import utc as timezone_utc
+from django.db.models import Max
+from django.utils.timezone import utc as timezone_utc, now as timezone_now
 from typing import Any, Dict, List, Optional, Set, Tuple, \
     Iterable
 
@@ -95,6 +96,42 @@ def fix_upload_links(data: TableData, message_table: TableName) -> None:
                     if message['rendered_content']:
                         message['rendered_content'] = message['rendered_content'].replace(key, value)
 
+def create_subscription_events(data: TableData, table: TableName) -> None:
+    """
+    When the export data doesn't contain the table `zerver_realmauditlog`,
+    this function creates RealmAuditLog objects for `subscription_created`
+    type event for all the existing Stream subscriptions.
+
+    This is needed for all the export tools which do not include the
+    table `zerver_realmauditlog` (Slack, Gitter, etc.) because the appropriate
+    data about when a user was subscribed is not exported by the third-party
+    service.
+    """
+    all_subscription_logs = []
+
+    # from bulk_add_subscriptions in lib/actions
+    event_last_message_id = Message.objects.aggregate(Max('id'))['id__max']
+    if event_last_message_id is None:
+        event_last_message_id = -1
+    event_time = timezone_now()
+
+    for item in data[table]:
+        recipient = Recipient.objects.get(id=item['recipient_id'])
+        if recipient.type != Recipient.STREAM:
+            continue
+
+        stream = Stream.objects.get(id=recipient.type_id)
+        user = UserProfile.objects.get(id=item['user_profile_id'])
+
+        all_subscription_logs.append(RealmAuditLog(realm=user.realm,
+                                                   acting_user=user,
+                                                   modified_user=user,
+                                                   modified_stream=stream,
+                                                   event_last_message_id=event_last_message_id,
+                                                   event_time=event_time,
+                                                   event_type=RealmAuditLog.SUBSCRIPTION_CREATED))
+    RealmAuditLog.objects.bulk_create(all_subscription_logs)
+
 def current_table_ids(data: TableData, table: TableName) -> List[int]:
     """
     Returns the ids present in the current table
@@ -512,6 +549,21 @@ def do_import_realm(import_dir: Path, subdomain: str) -> Realm:
     update_model_ids(Subscription, data, 'zerver_subscription', 'subscription')
     bulk_import_model(data, Subscription, 'zerver_subscription')
 
+    if 'zerver_realmauditlog' in data:
+        fix_datetime_fields(data, 'zerver_realmauditlog')
+        re_map_foreign_keys(data, 'zerver_realmauditlog', 'realm', related_table="realm")
+        re_map_foreign_keys(data, 'zerver_realmauditlog', 'modified_user',
+                            related_table='user_profile')
+        re_map_foreign_keys(data, 'zerver_realmauditlog', 'acting_user',
+                            related_table='user_profile')
+        re_map_foreign_keys(data, 'zerver_realmauditlog', 'modified_stream',
+                            related_table="stream")
+        update_model_ids(RealmAuditLog, data, 'zerver_realmauditlog',
+                         related_table="realmauditlog")
+        bulk_import_model(data, RealmAuditLog, 'zerver_realmauditlog')
+    else:
+        create_subscription_events(data, 'zerver_subscription')
+
     fix_datetime_fields(data, 'zerver_userpresence')
     re_map_foreign_keys(data, 'zerver_userpresence', 'user_profile', related_table="user_profile")
     re_map_foreign_keys(data, 'zerver_userpresence', 'client', related_table='client')
@@ -543,18 +595,6 @@ def do_import_realm(import_dir: Path, subdomain: str) -> Realm:
                      related_table="customprofilefieldvalue")
     bulk_import_model(data, CustomProfileFieldValue, 'zerver_customprofilefieldvalue')
 
-    fix_datetime_fields(data, 'zerver_realmauditlog')
-    re_map_foreign_keys(data, 'zerver_realmauditlog', 'realm', related_table="realm")
-    re_map_foreign_keys(data, 'zerver_realmauditlog', 'modified_user',
-                        related_table='user_profile')
-    re_map_foreign_keys(data, 'zerver_realmauditlog', 'acting_user',
-                        related_table='user_profile')
-    re_map_foreign_keys(data, 'zerver_realmauditlog', 'modified_stream',
-                        related_table="stream")
-    update_model_ids(RealmAuditLog, data, 'zerver_realmauditlog',
-                     related_table="realmauditlog")
-    bulk_import_model(data, RealmAuditLog, 'zerver_realmauditlog')
-
     # Import uploaded files and avatars
     import_uploads(os.path.join(import_dir, "avatars"), processing_avatars=True)
     import_uploads(os.path.join(import_dir, "uploads"))

zerver/tests/test_slack_importer.py

@@ -36,6 +36,7 @@ from zerver.lib.test_classes import (
 from zerver.models import (
     Realm,
     get_realm,
+    RealmAuditLog,
 )
 from zerver.lib import mdiff
 
@@ -539,7 +540,14 @@ class SlackImporter(ZulipTestCase):
 
         # test import of the converted slack data into an existing database
         do_import_realm(output_dir, test_realm_subdomain)
-        self.assertTrue(get_realm(test_realm_subdomain).name, test_realm_subdomain)
+        realm = get_realm(test_realm_subdomain)
+        self.assertTrue(realm.name, test_realm_subdomain)
+
+        # test RealmAuditLog
+        realmauditlog = RealmAuditLog.objects.filter(realm=realm)
+        realmauditlog_event_type = {log.event_type for log in realmauditlog}
+        self.assertEqual(realmauditlog_event_type, {'subscription_created'})
+
         Realm.objects.filter(name=test_realm_subdomain).delete()
 
         remove_folder(output_dir)