support: Add ability to update max daily invitations for realm.

Adds some validation for changing the realm's max invites via the
support view so that it is not set below the default max for the
realm's plan type, and so that if it's currently set to the default
max it's not reset to that same value.

corporate/tests/test_support_views.py

@@ -4,6 +4,7 @@ from unittest import mock
 
 import orjson
 import time_machine
+from django.conf import settings
 from django.utils.timezone import now as timezone_now
 from typing_extensions import override
 
@@ -1158,6 +1159,55 @@ class TestSupportEndpoint(ZulipTestCase):
                 ["Organization type of zulip changed from Business to Government"], result
             )
 
+    def test_change_max_invites(self) -> None:
+        realm = get_realm("zulip")
+        iago = self.example_user("iago")
+        self.login_user(iago)
+
+        self.assertEqual(realm.max_invites, settings.INVITES_DEFAULT_REALM_DAILY_MAX)
+        result = self.client_post(
+            "/activity/support", {"realm_id": f"{realm.id}", "max_invites": "1"}
+        )
+        self.assert_in_success_response(
+            [
+                "Cannot update maximum number of daily invitations for zulip, because 1 is less than the default for the current plan type."
+            ],
+            result,
+        )
+        realm.refresh_from_db()
+        self.assertEqual(realm.max_invites, settings.INVITES_DEFAULT_REALM_DAILY_MAX)
+
+        result = self.client_post(
+            "/activity/support", {"realm_id": f"{realm.id}", "max_invites": "700"}
+        )
+        self.assert_in_success_response(
+            ["Maximum number of daily invitations for zulip updated to 700."], result
+        )
+        realm.refresh_from_db()
+        self.assertEqual(realm.max_invites, 700)
+
+        result = self.client_post(
+            "/activity/support", {"realm_id": f"{realm.id}", "max_invites": "0"}
+        )
+        self.assert_in_success_response(
+            [
+                "Maximum number of daily invitations for zulip updated to the default for the current plan type."
+            ],
+            result,
+        )
+        realm.refresh_from_db()
+        self.assertEqual(realm.max_invites, settings.INVITES_DEFAULT_REALM_DAILY_MAX)
+
+        result = self.client_post(
+            "/activity/support", {"realm_id": f"{realm.id}", "max_invites": "0"}
+        )
+        self.assert_in_success_response(
+            [
+                "Cannot update maximum number of daily invitations for zulip, because the default for the current plan type is already set."
+            ],
+            result,
+        )
+
     def test_attach_discount(self) -> None:
         lear_realm = get_realm("lear")
         customer = self.create_customer_and_plan(lear_realm, True)

corporate/views/support.py

@@ -46,6 +46,7 @@ from corporate.lib.support import (
 from corporate.models import CustomerPlan
 from zerver.actions.create_realm import do_change_realm_subdomain
 from zerver.actions.realm_settings import (
+    do_change_realm_max_invites,
     do_change_realm_org_type,
     do_change_realm_plan_type,
     do_deactivate_realm,
@@ -312,6 +313,22 @@ def get_realm_plan_type_options_for_discount() -> list[SupportSelectOption]:
     return plan_types
 
 
+def get_default_max_invites_for_plan_type(realm: Realm) -> int:
+    if realm.plan_type in [
+        Realm.PLAN_TYPE_PLUS,
+        Realm.PLAN_TYPE_STANDARD,
+        Realm.PLAN_TYPE_STANDARD_FREE,
+    ]:
+        return Realm.INVITES_STANDARD_REALM_DAILY_MAX
+    return settings.INVITES_DEFAULT_REALM_DAILY_MAX
+
+
+def check_update_max_invites(realm: Realm, new_max: int, default_max: int) -> bool:
+    if new_max in [0, default_max]:
+        return realm.max_invites != default_max
+    return new_max > default_max
+
+
 VALID_MODIFY_PLAN_METHODS = Literal[
     "downgrade_at_billing_cycle_end",
     "downgrade_now_without_additional_licenses",
@@ -348,6 +365,7 @@ def support(
     delete_user_by_id: Json[NonNegativeInt] | None = None,
     query: Annotated[str | None, ApiParamConfig("q")] = None,
     org_type: Json[NonNegativeInt] | None = None,
+    max_invites: Json[NonNegativeInt] | None = None,
 ) -> HttpResponse:
     context: dict[str, Any] = {}
 
@@ -419,6 +437,22 @@ def support(
             do_change_realm_org_type(realm, org_type, acting_user=acting_user)
             msg = f"Organization type of {realm.string_id} changed from {get_org_type_display_name(current_realm_type)} to {get_org_type_display_name(org_type)} "
             context["success_message"] = msg
+        elif max_invites is not None:
+            default_max = get_default_max_invites_for_plan_type(realm)
+            if check_update_max_invites(realm, max_invites, default_max):
+                do_change_realm_max_invites(realm, max_invites, acting_user=acting_user)
+                update_text = str(max_invites)
+                if max_invites == 0:
+                    update_text = "the default for the current plan type"
+                msg = f"Maximum number of daily invitations for {realm.string_id} updated to {update_text}."
+                context["success_message"] = msg
+            else:
+                update_text = f"{max_invites} is less than the default for the current plan type"
+                if max_invites in [0, default_max]:
+                    update_text = "the default for the current plan type is already set"
+                context["error_message"] = (
+                    f"Cannot update maximum number of daily invitations for {realm.string_id}, because {update_text}."
+                )
         elif new_subdomain is not None:
             old_subdomain = realm.string_id
             try: