billing: Add prototype remote billing sessions.

These new models are incomplete and totally untested, but merging this
will provide valuable scaffolding for doing smaller PRs working on
individual gaps, and reveals a clear set of TODOs/refactoring/model
changes needed to support where want to end up.

Co-authored-by: Tim Abbott <tabbott@zulip.com>

corporate/lib/stripe.py

@@ -31,6 +31,8 @@ from corporate.models import (
     get_current_plan_by_customer,
     get_current_plan_by_realm,
     get_customer_by_realm,
+    get_customer_by_remote_realm,
+    get_customer_by_remote_server,
 )
 from zerver.lib.exceptions import JsonableError
 from zerver.lib.logging_util import log_to_file
@@ -38,7 +40,12 @@ from zerver.lib.send_email import FromAddress, send_email_to_billing_admins_and_
 from zerver.lib.timestamp import datetime_to_timestamp, timestamp_to_datetime
 from zerver.lib.utils import assert_is_not_none
 from zerver.models import Realm, RealmAuditLog, UserProfile, get_system_bot
-from zilencer.models import RemoteZulipServer, RemoteZulipServerAuditLog
+from zilencer.models import (
+    RemoteRealm,
+    RemoteRealmAuditLog,
+    RemoteZulipServer,
+    RemoteZulipServerAuditLog,
+)
 from zproject.config import get_secret
 
 stripe.api_key = get_secret("stripe_secret_key")
@@ -1195,6 +1202,9 @@ class RealmBillingSession(BillingSession):
         assert self.support_session is False
         assert self.user is not None
         amount = price_per_license * licenses
+
+        # TODO: Don't hardcode plan name; it should be looked up for
+        # the tier.
         description = f"Upgrade to Zulip Cloud Standard, ${price_per_license/100} x {licenses}"
         plan_name = "Zulip Cloud Standard"
         return StripePaymentIntentData(
@@ -1275,6 +1285,7 @@ class RealmBillingSession(BillingSession):
                     "If you could {begin_link}list Zulip as a sponsor on your website{end_link}, "
                     "we would really appreciate it!"
                 ).format(
+                    # TODO: Don't hardcode plan names.
                     plan_name="Zulip Cloud Standard",
                     emoji=":tada:",
                     begin_link="[",
@@ -1283,6 +1294,338 @@ class RealmBillingSession(BillingSession):
                 internal_send_private_message(notification_bot, user, message)
 
 
+class RemoteRealmBillingSession(BillingSession):  # nocoverage
+    def __init__(
+        self, remote_realm: RemoteRealm, support_staff: Optional[UserProfile] = None
+    ) -> None:
+        self.remote_realm = remote_realm
+        if support_staff is not None:
+            assert support_staff.is_staff
+            self.support_session = True
+        else:
+            self.support_session = False
+
+    @override
+    @property
+    def billing_session_url(self) -> str:
+        return "TBD"
+
+    @override
+    def get_customer(self) -> Optional[Customer]:
+        return get_customer_by_remote_realm(self.remote_realm)
+
+    @override
+    def current_count_for_billed_licenses(self) -> int:
+        # TODO: Do the proper calculation here.
+        return 10
+
+    @override
+    def get_audit_log_event(self, event_type: AuditLogEventType) -> int:
+        if event_type is AuditLogEventType.STRIPE_CUSTOMER_CREATED:
+            return RemoteRealmAuditLog.STRIPE_CUSTOMER_CREATED
+        elif event_type is AuditLogEventType.STRIPE_CARD_CHANGED:
+            return RemoteRealmAuditLog.STRIPE_CARD_CHANGED
+        elif event_type is AuditLogEventType.CUSTOMER_PLAN_CREATED:
+            return RemoteRealmAuditLog.CUSTOMER_PLAN_CREATED
+        elif event_type is AuditLogEventType.DISCOUNT_CHANGED:
+            return RemoteRealmAuditLog.REMOTE_SERVER_DISCOUNT_CHANGED
+        elif event_type is AuditLogEventType.SPONSORSHIP_APPROVED:
+            return RemoteRealmAuditLog.REMOTE_SERVER_SPONSORSHIP_APPROVED
+        elif event_type is AuditLogEventType.SPONSORSHIP_PENDING_STATUS_CHANGED:
+            return RemoteRealmAuditLog.REMOTE_SERVER_SPONSORSHIP_PENDING_STATUS_CHANGED
+        elif event_type is AuditLogEventType.BILLING_METHOD_CHANGED:
+            return RemoteRealmAuditLog.REMOTE_SERVER_BILLING_METHOD_CHANGED
+        else:
+            raise BillingSessionAuditLogEventError(event_type)
+
+    @override
+    def write_to_audit_log(
+        self,
+        event_type: AuditLogEventType,
+        event_time: datetime,
+        *,
+        extra_data: Optional[Dict[str, Any]] = None,
+    ) -> None:
+        # BUG: This doesn't have a way to pass realm_id !
+        audit_log_event = self.get_audit_log_event(event_type)
+        if extra_data:
+            RemoteRealmAuditLog.objects.create(
+                server=self.remote_realm.server,
+                remote_realm=self.remote_realm,
+                event_type=audit_log_event,
+                event_time=event_time,
+                extra_data=extra_data,
+            )
+        else:
+            RemoteRealmAuditLog.objects.create(
+                server=self.remote_realm.server,
+                remote_realm=self.remote_realm,
+                event_type=audit_log_event,
+                event_time=event_time,
+            )
+
+    @override
+    def get_data_for_stripe_customer(self) -> StripeCustomerData:
+        # Support requests do not set any stripe billing information.
+        assert self.support_session is False
+        metadata: Dict[str, Any] = {}
+        metadata["remote_realm_uuid"] = self.remote_realm.uuid
+        metadata["remote_realm_host"] = str(self.remote_realm.host)
+        realm_stripe_customer_data = StripeCustomerData(
+            description=str(self.remote_realm),
+            # BUG: This is an email for the whole server. We probably
+            # need a separable field here.
+            email=self.remote_realm.server.contact_email,
+            metadata=metadata,
+        )
+        return realm_stripe_customer_data
+
+    @override
+    def update_data_for_checkout_session_and_payment_intent(
+        self, metadata: Dict[str, Any]
+    ) -> Dict[str, Any]:
+        # TODO: Figure out what this should do.
+        updated_metadata = dict(
+            **metadata,
+        )
+        return updated_metadata
+
+    @override
+    def get_data_for_stripe_payment_intent(
+        self, price_per_license: int, licenses: int
+    ) -> StripePaymentIntentData:
+        # Support requests do not set any stripe billing information.
+        assert self.support_session is False
+        amount = price_per_license * licenses
+        # TODO: Don't hardcode plan names.
+        description = f"Upgrade to Zulip X Standard, ${price_per_license/100} x {licenses}"
+        plan_name = "Zulip X Standard"
+        return StripePaymentIntentData(
+            amount=amount,
+            description=description,
+            plan_name=plan_name,
+            # BUG: This is an email for the whole server. We probably
+            # need a separable field here.
+            email=self.remote_realm.server.contact_email,
+        )
+
+    @override
+    def update_or_create_customer(
+        self, stripe_customer_id: Optional[str] = None, *, defaults: Optional[Dict[str, Any]] = None
+    ) -> Customer:
+        if stripe_customer_id is not None:
+            # Support requests do not set any stripe billing information.
+            assert self.support_session is False
+            customer, created = Customer.objects.update_or_create(
+                remote_realm=self.remote_realm,
+                defaults={"stripe_customer_id": stripe_customer_id},
+            )
+            return customer
+        else:
+            customer, created = Customer.objects.update_or_create(
+                remote_realm=self.remote_realm, defaults=defaults
+            )
+            return customer
+
+    @override
+    def do_change_plan_type(self, *, tier: Optional[int], is_sponsored: bool = False) -> None:
+        # TODO: Create actual plan types.
+
+        # This function needs to translate between the different
+        # formats of CustomerPlan.tier and Realm.plan_type.
+        if is_sponsored:
+            plan_type = RemoteRealm.PLAN_TYPE_COMMUNITY
+        elif tier == CustomerPlan.STANDARD:
+            plan_type = RemoteRealm.PLAN_TYPE_BUSINESS
+        elif tier == CustomerPlan.PLUS:  # nocoverage # Plus plan doesn't use this code path yet.
+            plan_type = RemoteRealm.PLAN_TYPE_ENTERPRISE
+        else:
+            raise AssertionError("Unexpected tier")
+
+        # TODO: Audit logging.
+
+        self.remote_realm.plan_type = plan_type
+        self.remote_realm.save(update_fields=["plan_type"])
+
+    @override
+    def approve_sponsorship(self) -> None:
+        # TBD
+        pass
+
+    @override
+    def process_downgrade(self, plan: CustomerPlan) -> None:
+        self.remote_realm.plan_type = RemoteRealm.PLAN_TYPE_SELF_HOSTED
+        self.remote_realm.save(update_fields=["plan_type"])
+
+        # TODO: Write audit log entry
+        plan.status = CustomerPlan.ENDED
+        plan.save(update_fields=["status"])
+
+
+class RemoteServerBillingSession(BillingSession):  # nocoverage
+    """Billing session for pre-8.0 servers that do not yet support
+    creating RemoteRealm objects."""
+
+    def __init__(
+        self, remote_server: RemoteZulipServer, support_staff: Optional[UserProfile] = None
+    ) -> None:
+        self.remote_server = remote_server
+        if support_staff is not None:
+            assert support_staff.is_staff
+            self.support_session = True
+        else:
+            self.support_session = False
+
+    @override
+    @property
+    def billing_session_url(self) -> str:
+        return "TBD"
+
+    @override
+    def get_customer(self) -> Optional[Customer]:
+        return get_customer_by_remote_server(self.remote_server)
+
+    @override
+    def current_count_for_billed_licenses(self) -> int:
+        # TODO: Do the proper calculation here.
+        return 10
+
+    @override
+    def get_audit_log_event(self, event_type: AuditLogEventType) -> int:
+        if event_type is AuditLogEventType.STRIPE_CUSTOMER_CREATED:
+            return RemoteZulipServerAuditLog.STRIPE_CUSTOMER_CREATED
+        elif event_type is AuditLogEventType.STRIPE_CARD_CHANGED:
+            return RemoteZulipServerAuditLog.STRIPE_CARD_CHANGED
+        elif event_type is AuditLogEventType.CUSTOMER_PLAN_CREATED:
+            return RemoteZulipServerAuditLog.CUSTOMER_PLAN_CREATED
+        elif event_type is AuditLogEventType.DISCOUNT_CHANGED:
+            return RemoteZulipServerAuditLog.REMOTE_SERVER_DISCOUNT_CHANGED
+        elif event_type is AuditLogEventType.SPONSORSHIP_APPROVED:
+            return RemoteZulipServerAuditLog.REMOTE_SERVER_SPONSORSHIP_APPROVED
+        elif event_type is AuditLogEventType.SPONSORSHIP_PENDING_STATUS_CHANGED:
+            return RemoteZulipServerAuditLog.REMOTE_SERVER_SPONSORSHIP_PENDING_STATUS_CHANGED
+        elif event_type is AuditLogEventType.BILLING_METHOD_CHANGED:
+            return RemoteZulipServerAuditLog.REMOTE_SERVER_BILLING_METHOD_CHANGED
+        else:
+            raise BillingSessionAuditLogEventError(event_type)
+
+    @override
+    def write_to_audit_log(
+        self,
+        event_type: AuditLogEventType,
+        event_time: datetime,
+        *,
+        extra_data: Optional[Dict[str, Any]] = None,
+    ) -> None:
+        audit_log_event = self.get_audit_log_event(event_type)
+        if extra_data:
+            RemoteZulipServerAuditLog.objects.create(
+                server=self.remote_server,
+                event_type=audit_log_event,
+                event_time=event_time,
+                extra_data=extra_data,
+            )
+        else:
+            RemoteZulipServerAuditLog.objects.create(
+                server=self.remote_server,
+                event_type=audit_log_event,
+                event_time=event_time,
+            )
+
+    @override
+    def get_data_for_stripe_customer(self) -> StripeCustomerData:
+        # Support requests do not set any stripe billing information.
+        assert self.support_session is False
+        metadata: Dict[str, Any] = {}
+        metadata["remote_server_uuid"] = self.remote_server.uuid
+        metadata["remote_server_str"] = str(self.remote_server)
+        realm_stripe_customer_data = StripeCustomerData(
+            description=str(self.remote_server),
+            email=self.remote_server.contact_email,
+            metadata=metadata,
+        )
+        return realm_stripe_customer_data
+
+    @override
+    def update_data_for_checkout_session_and_payment_intent(
+        self, metadata: Dict[str, Any]
+    ) -> Dict[str, Any]:
+        updated_metadata = dict(
+            server=self.remote_server,
+            email=self.remote_server.contact_email,
+            **metadata,
+        )
+        return updated_metadata
+
+    @override
+    def get_data_for_stripe_payment_intent(
+        self, price_per_license: int, licenses: int
+    ) -> StripePaymentIntentData:
+        # Support requests do not set any stripe billing information.
+        assert self.support_session is False
+        amount = price_per_license * licenses
+        description = f"Upgrade to Zulip X Standard, ${price_per_license/100} x {licenses}"
+        plan_name = "Zulip X Standard"
+        return StripePaymentIntentData(
+            amount=amount,
+            description=description,
+            plan_name=plan_name,
+            email=self.remote_server.contact_email,
+        )
+
+    @override
+    def update_or_create_customer(
+        self, stripe_customer_id: Optional[str] = None, *, defaults: Optional[Dict[str, Any]] = None
+    ) -> Customer:
+        if stripe_customer_id is not None:
+            # Support requests do not set any stripe billing information.
+            assert self.support_session is False
+            customer, created = Customer.objects.update_or_create(
+                remote_server=self.remote_server,
+                defaults={"stripe_customer_id": stripe_customer_id},
+            )
+            return customer
+        else:
+            customer, created = Customer.objects.update_or_create(
+                remote_server=self.remote_server, defaults=defaults
+            )
+            return customer
+
+    @override
+    def do_change_plan_type(self, *, tier: Optional[int], is_sponsored: bool = False) -> None:
+        # TODO: Create actual plan types.
+
+        # This function needs to translate between the different
+        # formats of CustomerPlan.tier and RealmZulipServer.plan_type.
+        if is_sponsored:
+            plan_type = RemoteZulipServer.PLAN_TYPE_COMMUNITY
+        elif tier == CustomerPlan.STANDARD:
+            plan_type = RemoteZulipServer.PLAN_TYPE_BUSINESS
+        elif tier == CustomerPlan.PLUS:  # nocoverage # Plus plan doesn't use this code path yet.
+            plan_type = RemoteZulipServer.PLAN_TYPE_ENTERPRISE
+        else:
+            raise AssertionError("Unexpected tier")
+
+        # TODO: Audit logging.
+
+        self.remote_server.plan_type = plan_type
+        self.remote_server.save(update_fields=["plan_type"])
+
+    @override
+    def approve_sponsorship(self) -> None:
+        # TBD
+        pass
+
+    @override
+    def process_downgrade(self, plan: CustomerPlan) -> None:
+        self.remote_server.plan_type = RemoteZulipServer.PLAN_TYPE_SELF_HOSTED
+        self.remote_server.save(update_fields=["plan_type"])
+
+        # TODO: Write audit log entry
+        plan.status = CustomerPlan.ENDED
+        plan.save(update_fields=["status"])
+
+
 def stripe_customer_has_credit_card_as_default_payment_method(
     stripe_customer: stripe.Customer,
 ) -> bool:

corporate/models.py

@@ -7,7 +7,7 @@ from django.db.models import CASCADE, Q
 from typing_extensions import override
 
 from zerver.models import Realm, UserProfile
-from zilencer.models import RemoteZulipServer
+from zilencer.models import RemoteRealm, RemoteZulipServer
 
 
 class Customer(models.Model):
@@ -56,6 +56,14 @@ def get_customer_by_realm(realm: Realm) -> Optional[Customer]:
     return Customer.objects.filter(realm=realm).first()
 
 
+def get_customer_by_remote_server(remote_server: RemoteZulipServer) -> Optional[Customer]:
+    return Customer.objects.filter(remote_server=remote_server).first()
+
+
+def get_customer_by_remote_realm(remote_realm: RemoteRealm) -> Optional[Customer]:  # nocoverage
+    return Customer.objects.filter(remote_realm=remote_realm).first()
+
+
 class Event(models.Model):
     stripe_event_id = models.CharField(max_length=255)
 

corporate/tests/test_stripe.py

@@ -46,6 +46,7 @@ from corporate.lib.stripe import (
     InvalidBillingScheduleError,
     InvalidTierError,
     RealmBillingSession,
+    RemoteServerBillingSession,
     StripeCardError,
     add_months,
     catch_stripe_errors,
@@ -4901,6 +4902,64 @@ class TestRealmBillingSession(StripeTestCase):
         ):
             billing_session.get_audit_log_event(event_type=fake_audit_log)
 
+    def test_get_customer(self) -> None:
+        user = self.example_user("hamlet")
+        billing_session = RealmBillingSession(user)
+        customer = billing_session.get_customer()
+        self.assertEqual(customer, None)
+
+        customer = Customer.objects.create(realm=user.realm, stripe_customer_id="cus_12345")
+        self.assertEqual(billing_session.get_customer(), customer)
+
+
+class TestRemoteServerBillingSession(StripeTestCase):
+    def test_get_audit_log_error(self) -> None:
+        server_uuid = str(uuid.uuid4())
+        remote_server = RemoteZulipServer.objects.create(
+            uuid=server_uuid,
+            api_key="magic_secret_api_key",
+            hostname="demo.example.com",
+            contact_email="email@example.com",
+        )
+        billing_session = RemoteServerBillingSession(remote_server)
+        fake_audit_log = typing.cast(AuditLogEventType, 0)
+        with self.assertRaisesRegex(
+            BillingSessionAuditLogEventError, "Unknown audit log event type: 0"
+        ):
+            billing_session.get_audit_log_event(event_type=fake_audit_log)
+
+    def test_get_customer(self) -> None:
+        server_uuid = str(uuid.uuid4())
+        remote_server = RemoteZulipServer.objects.create(
+            uuid=server_uuid,
+            api_key="magic_secret_api_key",
+            hostname="demo.example.com",
+            contact_email="email@example.com",
+        )
+        billing_session = RemoteServerBillingSession(remote_server)
+        customer = billing_session.get_customer()
+        self.assertEqual(customer, None)
+
+        customer = Customer.objects.create(
+            remote_server=remote_server, stripe_customer_id="cus_12345"
+        )
+        self.assertEqual(billing_session.get_customer(), customer)
+
+    # @mock_stripe
+    # def test_update_or_create_stripe_customer(self) -> None:
+    #     server_uuid = str(uuid.uuid4())
+    #     remote_server = RemoteZulipServer.objects.create(
+    #         uuid=server_uuid,
+    #         api_key="magic_secret_api_key",
+    #         hostname="demo.example.com",
+    #         contact_email="email@example.com",
+    #     )
+    #     billing_session = RemoteServerBillingSession(remote_server)
+    #     # We need to generate stripe fixture for this type of test.
+    #     customer = billing_session.update_or_create_stripe_customer()
+    #     assert customer.stripe_customer_id
+    #     # Confirm audit log, etc.
+
 
 class TestSupportBillingHelpers(StripeTestCase):
     def test_get_discount_for_realm(self) -> None:

zerver/models.py

@@ -4806,9 +4806,13 @@ class AbstractRealmAuditLog(models.Model):
     # Values should be exactly 10000 greater than the corresponding
     # value used for the same purpose in RealmAuditLog (e.g.
     # REALM_DEACTIVATED = 201, and REMOTE_SERVER_DEACTIVATED = 10201).
-    REMOTE_SERVER_CREATED = 10215
-    REMOTE_SERVER_PLAN_TYPE_CHANGED = 10204
     REMOTE_SERVER_DEACTIVATED = 10201
+    REMOTE_SERVER_PLAN_TYPE_CHANGED = 10204
+    REMOTE_SERVER_DISCOUNT_CHANGED = 10209
+    REMOTE_SERVER_SPONSORSHIP_APPROVED = 10210
+    REMOTE_SERVER_BILLING_METHOD_CHANGED = 10211
+    REMOTE_SERVER_SPONSORSHIP_PENDING_STATUS_CHANGED = 10213
+    REMOTE_SERVER_CREATED = 10215
 
     # This value is for RemoteRealmAuditLog entries tracking changes to the
     # RemoteRealm model resulting from modified realm information sent to us