migrations: Add migration to create system groups for internal realms.

There may be some internal realms which were created after applying
"0382_create_role_based_system_groups.py" migration and this migration
is used to create system groups for those realms.

zerver/migrations/0403_create_role_based_groups_for_internal_realms.py

@@ -0,0 +1,168 @@
+# Generated by Django 3.2.13 on 2022-06-28 17:36
+
+from django.conf import settings
+from django.db import migrations, transaction
+from django.db.backends.postgresql.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+from django.utils.timezone import now as timezone_now
+
+# This migration is a copy of
+# zerver/migrations/0402_alter_usertopic_visibility_policy.py" run
+# for the internal realm only.
+
+
+def create_role_based_system_groups_for_internal_realms(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    Realm = apps.get_model("zerver", "Realm")
+    UserProfile = apps.get_model("zerver", "UserProfile")
+    UserGroup = apps.get_model("zerver", "UserGroup")
+    GroupGroupMembership = apps.get_model("zerver", "GroupGroupMembership")
+    UserGroupMembership = apps.get_model("zerver", "UserGroupMembership")
+
+    UserProfile.ROLE_REALM_OWNER = 100
+    UserProfile.ROLE_REALM_ADMINISTRATOR = 200
+    UserProfile.ROLE_MODERATOR = 300
+    UserProfile.ROLE_MEMBER = 400
+    UserProfile.ROLE_GUEST = 600
+
+    try:
+        realm = Realm.objects.get(string_id=settings.SYSTEM_BOT_REALM)
+    except Realm.DoesNotExist:
+        # Server not initialized, or no system bot realm. Either way,
+        # we shouldn't do anything.
+        return
+
+    SYSTEM_USER_GROUP_ROLE_MAP = {
+        UserProfile.ROLE_REALM_OWNER: {
+            "name": "@role:owners",
+            "description": "Owners of this organization",
+        },
+        UserProfile.ROLE_REALM_ADMINISTRATOR: {
+            "name": "@role:administrators",
+            "description": "Administrators of this organization, including owners",
+        },
+        UserProfile.ROLE_MODERATOR: {
+            "name": "@role:moderators",
+            "description": "Moderators of this organization, including administrators",
+        },
+        UserProfile.ROLE_MEMBER: {
+            "name": "@role:members",
+            "description": "Members of this organization, not including guests",
+        },
+        UserProfile.ROLE_GUEST: {
+            "name": "@role:everyone",
+            "description": "Everyone in this organization, including guests",
+        },
+    }
+
+    with transaction.atomic():
+        if UserGroup.objects.filter(
+            realm=realm, name="@role:internet", is_system_group=True
+        ).exists():
+            # Handle the case where we are rerunning after a
+            # failure, and had already created groups.
+            return
+
+        role_system_groups_dict = {}
+        for role in SYSTEM_USER_GROUP_ROLE_MAP.keys():
+            user_group_params = SYSTEM_USER_GROUP_ROLE_MAP[role]
+            user_group = UserGroup(
+                name=user_group_params["name"],
+                description=user_group_params["description"],
+                realm=realm,
+                is_system_group=True,
+            )
+            role_system_groups_dict[role] = user_group
+
+        full_members_system_group = UserGroup(
+            name="@role:fullmembers",
+            description="Members of this organization, not including new accounts and guests",
+            realm=realm,
+            is_system_group=True,
+        )
+        everyone_on_internet_system_group = UserGroup(
+            name="@role:internet",
+            description="Everyone on the Internet",
+            realm=realm,
+            is_system_group=True,
+        )
+
+        system_user_groups_list = [
+            role_system_groups_dict[UserProfile.ROLE_REALM_OWNER],
+            role_system_groups_dict[UserProfile.ROLE_REALM_ADMINISTRATOR],
+            role_system_groups_dict[UserProfile.ROLE_MODERATOR],
+            full_members_system_group,
+            role_system_groups_dict[UserProfile.ROLE_MEMBER],
+            role_system_groups_dict[UserProfile.ROLE_GUEST],
+            everyone_on_internet_system_group,
+        ]
+
+        UserGroup.objects.bulk_create(system_user_groups_list)
+
+        subgroup_objects = []
+        subgroup, remaining_groups = system_user_groups_list[0], system_user_groups_list[1:]
+        for supergroup in remaining_groups:
+            subgroup_objects.append(GroupGroupMembership(subgroup=subgroup, supergroup=supergroup))
+            subgroup = supergroup
+
+        GroupGroupMembership.objects.bulk_create(subgroup_objects)
+
+        users = UserProfile.objects.filter(realm=realm).only("id", "role", "date_joined")
+        group_membership_objects = []
+        for user in users:
+            system_group = role_system_groups_dict[user.role]
+            group_membership_objects.append(
+                UserGroupMembership(user_profile=user, user_group=system_group)
+            )
+
+            if (
+                user.role == UserProfile.ROLE_MEMBER
+                and (timezone_now() - user.date_joined).days >= realm.waiting_period_threshold
+            ):
+                group_membership_objects.append(
+                    UserGroupMembership(user_profile=user, user_group=full_members_system_group)
+                )
+
+        UserGroupMembership.objects.bulk_create(group_membership_objects)
+
+
+def delete_role_based_system_groups_for_internal_realms(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    UserGroup = apps.get_model("zerver", "UserGroup")
+    GroupGroupMembership = apps.get_model("zerver", "GroupGroupMembership")
+    UserGroupMembership = apps.get_model("zerver", "UserGroupMembership")
+    Realm = apps.get_model("zerver", "Realm")
+
+    try:
+        realm = Realm.objects.get(string_id=settings.SYSTEM_BOT_REALM)
+    except Realm.DoesNotExist:
+        # Server not initialized, or no system bot realm. Either way, we shouldn't do anything.
+        return
+
+    with transaction.atomic():
+        GroupGroupMembership.objects.filter(subgroup__realm=realm).delete()
+        UserGroupMembership.objects.filter(
+            user_group__realm=realm, user_group__is_system_group=True
+        ).delete()
+        UserGroup.objects.filter(realm=realm, is_system_group=True).delete()
+
+
+class Migration(migrations.Migration):
+    """This migration is a copy of
+    "zerver/migrations/0402_alter_usertopic_visibility_policy.py" run
+    for the internal realm only.
+    """
+
+    dependencies = [
+        ("zerver", "0402_alter_usertopic_visibility_policy"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            create_role_based_system_groups_for_internal_realms,
+            reverse_code=delete_role_based_system_groups_for_internal_realms,
+            elidable=True,
+        ),
+    ]