zulip/corporate/tests/test_stripe.py

import json
import operator
import os
import random
import re
import sys
from datetime import datetime, timedelta, timezone
from decimal import Decimal
from functools import wraps
from typing import (
    Any,
    Callable,
    Dict,
    List,
    Mapping,
    NamedTuple,
    Optional,
    Sequence,
    Tuple,
    TypeVar,
    Union,
    cast,
)
from unittest.mock import Mock, patch

import orjson
import responses
import stripe
from django.conf import settings
from django.core import signing
from django.http import HttpResponse
from django.urls.resolvers import get_resolver
from django.utils.timezone import now as timezone_now

from corporate.lib.stripe import (
    DEFAULT_INVOICE_DAYS_UNTIL_DUE,
    MAX_INVOICED_LICENSES,
    MIN_INVOICED_LICENSES,
    BillingError,
    InvalidBillingSchedule,
    StripeCardError,
    add_months,
    approve_sponsorship,
    attach_discount_to_realm,
    catch_stripe_errors,
    compute_plan_parameters,
    customer_has_credit_card_as_default_source,
    do_create_stripe_customer,
    downgrade_small_realms_behind_on_payments_as_needed,
    get_discount_for_realm,
    get_latest_seat_count,
    get_price_per_license,
    get_realms_to_default_discount_dict,
    invoice_plan,
    invoice_plans_as_needed,
    is_realm_on_free_trial,
    is_sponsored_realm,
    make_end_of_cycle_updates_if_needed,
    next_month,
    process_initial_upgrade,
    sign_string,
    stripe_customer_has_credit_card_as_default_source,
    stripe_get_customer,
    unsign_string,
    update_billing_method_of_current_plan,
    update_license_ledger_for_automanaged_plan,
    update_license_ledger_for_manual_plan,
    update_license_ledger_if_needed,
    update_or_create_stripe_customer,
    update_sponsorship_status,
    void_all_open_invoices,
)
from corporate.models import (
    Customer,
    CustomerPlan,
    LicenseLedger,
    ZulipSponsorshipRequest,
    get_current_plan_by_customer,
    get_current_plan_by_realm,
    get_customer_by_realm,
)
from zerver.lib.actions import (
    do_activate_mirror_dummy_user,
    do_create_realm,
    do_create_user,
    do_deactivate_realm,
    do_deactivate_user,
    do_reactivate_realm,
    do_reactivate_user,
)
from zerver.lib.test_classes import ZulipTestCase
from zerver.lib.timestamp import datetime_to_timestamp, timestamp_to_datetime
from zerver.models import (
    Message,
    Realm,
    RealmAuditLog,
    Recipient,
    UserProfile,
    get_realm,
    get_system_bot,
)

CallableT = TypeVar("CallableT", bound=Callable[..., Any])

STRIPE_FIXTURES_DIR = "corporate/tests/stripe_fixtures"

# TODO: check that this creates a token similar to what is created by our
# actual Stripe Checkout flows
def stripe_create_token(card_number: str = "4242424242424242") -> stripe.Token:
    return stripe.Token.create(
        card={
            "number": card_number,
            "exp_month": 3,
            "exp_year": 2033,
            "cvc": "333",
            "name": "Ada Starr",
            "address_line1": "Under the sea,",
            "address_city": "Pacific",
            "address_zip": "33333",
            "address_country": "United States",
        }
    )


def stripe_fixture_path(
    decorated_function_name: str, mocked_function_name: str, call_count: int
) -> str:
    # Make the eventual filename a bit shorter, and also we conventionally
    # use test_* for the python test files
    if decorated_function_name[:5] == "test_":
        decorated_function_name = decorated_function_name[5:]
    return f"{STRIPE_FIXTURES_DIR}/{decorated_function_name}--{mocked_function_name[7:]}.{call_count}.json"


def fixture_files_for_function(decorated_function: CallableT) -> List[str]:  # nocoverage
    decorated_function_name = decorated_function.__name__
    if decorated_function_name[:5] == "test_":
        decorated_function_name = decorated_function_name[5:]
    return sorted(
        f"{STRIPE_FIXTURES_DIR}/{f}"
        for f in os.listdir(STRIPE_FIXTURES_DIR)
        if f.startswith(decorated_function_name + "--")
    )


def generate_and_save_stripe_fixture(
    decorated_function_name: str, mocked_function_name: str, mocked_function: CallableT
) -> Callable[[Any, Any], Any]:  # nocoverage
    def _generate_and_save_stripe_fixture(*args: Any, **kwargs: Any) -> Any:
        # Note that mock is not the same as mocked_function, even though their
        # definitions look the same
        mock = operator.attrgetter(mocked_function_name)(sys.modules[__name__])
        fixture_path = stripe_fixture_path(
            decorated_function_name, mocked_function_name, mock.call_count
        )
        try:
            with responses.RequestsMock() as request_mock:
                request_mock.add_passthru("https://api.stripe.com")
                # Talk to Stripe
                stripe_object = mocked_function(*args, **kwargs)
        except stripe.error.StripeError as e:
            with open(fixture_path, "w") as f:
                error_dict = e.__dict__
                error_dict["headers"] = dict(error_dict["headers"])
                f.write(
                    json.dumps(error_dict, indent=2, separators=(",", ": "), sort_keys=True) + "\n"
                )
            raise e
        with open(fixture_path, "w") as f:
            if stripe_object is not None:
                f.write(str(stripe_object) + "\n")
            else:
                f.write("{}\n")
        return stripe_object

    return _generate_and_save_stripe_fixture


def read_stripe_fixture(
    decorated_function_name: str, mocked_function_name: str
) -> Callable[[Any, Any], Any]:
    def _read_stripe_fixture(*args: Any, **kwargs: Any) -> Any:
        mock = operator.attrgetter(mocked_function_name)(sys.modules[__name__])
        fixture_path = stripe_fixture_path(
            decorated_function_name, mocked_function_name, mock.call_count
        )
        with open(fixture_path, "rb") as f:
            fixture = orjson.loads(f.read())
        # Check for StripeError fixtures
        if "json_body" in fixture:
            requestor = stripe.api_requestor.APIRequestor()
            # This function will raise the relevant StripeError according to the fixture
            requestor.interpret_response(
                fixture["http_body"], fixture["http_status"], fixture["headers"]
            )
        return stripe.util.convert_to_stripe_object(fixture)

    return _read_stripe_fixture


def delete_fixture_data(decorated_function: CallableT) -> None:  # nocoverage
    for fixture_file in fixture_files_for_function(decorated_function):
        os.remove(fixture_file)


def normalize_fixture_data(
    decorated_function: CallableT, tested_timestamp_fields: Sequence[str] = []
) -> None:  # nocoverage
    # stripe ids are all of the form cus_D7OT2jf5YAtZQ2
    id_lengths = [
        ("cus", 14),
        ("sub", 14),
        ("si", 14),
        ("sli", 14),
        ("req", 14),
        ("tok", 24),
        ("card", 24),
        ("txn", 24),
        ("ch", 24),
        ("in", 24),
        ("ii", 24),
        ("test", 12),
        ("src_client_secret", 24),
        ("src", 24),
        ("invst", 26),
        ("acct", 16),
        ("rcpt", 31),
    ]
    # We'll replace cus_D7OT2jf5YAtZQ2 with something like cus_NORMALIZED0001
    pattern_translations = {
        f"{prefix}_[A-Za-z0-9]{{{length}}}": f"{prefix}_NORMALIZED%0{length - 10}d"
        for prefix, length in id_lengths
    }
    # We'll replace "invoice_prefix": "A35BC4Q" with something like "invoice_prefix": "NORMA01"
    pattern_translations.update(
        {
            '"invoice_prefix": "([A-Za-z0-9]{7,8})"': "NORMA%02d",
            '"fingerprint": "([A-Za-z0-9]{16})"': "NORMALIZED%06d",
            '"number": "([A-Za-z0-9]{7,8}-[A-Za-z0-9]{4})"': "NORMALI-%04d",
            '"address": "([A-Za-z0-9]{9}-test_[A-Za-z0-9]{12})"': "000000000-test_NORMALIZED%02d",
            # Don't use (..) notation, since the matched strings may be small integers that will also match
            # elsewhere in the file
            '"realm_id": "[0-9]+"': '"realm_id": "%d"',
            r'"account_name": "[\w\s]+"': '"account_name": "NORMALIZED-%d"',
        }
    )
    # Normalizing across all timestamps still causes a lot of variance run to run, which is
    # why we're doing something a bit more complicated
    for i, timestamp_field in enumerate(tested_timestamp_fields):
        # Don't use (..) notation, since the matched timestamp can easily appear in other fields
        pattern_translations[
            f'"{timestamp_field}": 1[5-9][0-9]{{8}}(?![0-9-])'
        ] = f'"{timestamp_field}": 1{i+1:02}%07d'

    normalized_values: Dict[str, Dict[str, str]] = {
        pattern: {} for pattern in pattern_translations.keys()
    }
    for fixture_file in fixture_files_for_function(decorated_function):
        with open(fixture_file) as f:
            file_content = f.read()
        for pattern, translation in pattern_translations.items():
            for match in re.findall(pattern, file_content):
                if match not in normalized_values[pattern]:
                    normalized_values[pattern][match] = translation % (
                        len(normalized_values[pattern]) + 1,
                    )
                file_content = file_content.replace(match, normalized_values[pattern][match])
        file_content = re.sub(r'(?<="risk_score": )(\d+)', "0", file_content)
        file_content = re.sub(r'(?<="times_redeemed": )(\d+)', "0", file_content)
        file_content = re.sub(
            r'(?<="idempotency-key": )"([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f-]*)"',
            '"00000000-0000-0000-0000-000000000000"',
            file_content,
        )
        # Dates
        file_content = re.sub(r'(?<="Date": )"(.* GMT)"', '"NORMALIZED DATETIME"', file_content)
        file_content = re.sub(r"[0-3]\d [A-Z][a-z]{2} 20[1-2]\d", "NORMALIZED DATE", file_content)
        # IP addresses
        file_content = re.sub(r'"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"', '"0.0.0.0"', file_content)
        # All timestamps not in tested_timestamp_fields
        file_content = re.sub(r": (1[5-9][0-9]{8})(?![0-9-])", ": 1000000000", file_content)

        with open(fixture_file, "w") as f:
            f.write(file_content)


MOCKED_STRIPE_FUNCTION_NAMES = [
    f"stripe.{name}"
    for name in [
        "Charge.create",
        "Charge.list",
        "Coupon.create",
        "Customer.create",
        "Customer.retrieve",
        "Customer.save",
        "Invoice.create",
        "Invoice.finalize_invoice",
        "Invoice.list",
        "Invoice.pay",
        "Invoice.refresh",
        "Invoice.upcoming",
        "Invoice.void_invoice",
        "InvoiceItem.create",
        "InvoiceItem.list",
        "Plan.create",
        "Product.create",
        "Subscription.create",
        "Subscription.delete",
        "Subscription.retrieve",
        "Subscription.save",
        "Token.create",
    ]
]


def mock_stripe(
    tested_timestamp_fields: Sequence[str] = [], generate: Optional[bool] = None
) -> Callable[[CallableT], CallableT]:
    def _mock_stripe(decorated_function: CallableT) -> CallableT:
        generate_fixture = generate
        if generate_fixture is None:
            generate_fixture = settings.GENERATE_STRIPE_FIXTURES
        for mocked_function_name in MOCKED_STRIPE_FUNCTION_NAMES:
            mocked_function = operator.attrgetter(mocked_function_name)(sys.modules[__name__])
            if generate_fixture:
                side_effect = generate_and_save_stripe_fixture(
                    decorated_function.__name__, mocked_function_name, mocked_function
                )  # nocoverage
            else:
                side_effect = read_stripe_fixture(decorated_function.__name__, mocked_function_name)
            decorated_function = cast(
                CallableT, patch(mocked_function_name, side_effect=side_effect)(decorated_function)
            )

        @wraps(decorated_function)
        def wrapped(*args: object, **kwargs: object) -> object:
            if generate_fixture:  # nocoverage
                delete_fixture_data(decorated_function)
                val = decorated_function(*args, **kwargs)
                normalize_fixture_data(decorated_function, tested_timestamp_fields)
                return val
            else:
                return decorated_function(*args, **kwargs)

        return cast(CallableT, wrapped)

    return _mock_stripe


# A Kandra is a fictional character that can become anything. Used as a
# wildcard when testing for equality.
class Kandra:  # nocoverage: TODO
    def __eq__(self, other: Any) -> bool:
        return True


class StripeTestCase(ZulipTestCase):
    def setUp(self, *mocks: Mock) -> None:
        super().setUp()
        realm = get_realm("zulip")

        # Explicitly limit our active users to 6 regular users,
        # to make seat_count less prone to changes in our test data.
        # We also keep a guest user and a bot to make the data
        # slightly realistic.
        active_emails = [
            self.example_email("AARON"),
            self.example_email("cordelia"),
            self.example_email("hamlet"),
            self.example_email("iago"),
            self.example_email("othello"),
            self.example_email("desdemona"),
            self.example_email("polonius"),  # guest
            self.example_email("default_bot"),  # bot
        ]

        # Deactivate all users in our realm that aren't in our whitelist.
        for user_profile in UserProfile.objects.filter(realm_id=realm.id).exclude(
            delivery_email__in=active_emails
        ):
            do_deactivate_user(user_profile, acting_user=None)

        # sanity check our 8 expected users are active
        self.assertEqual(
            UserProfile.objects.filter(realm=realm, is_active=True).count(),
            8,
        )

        # Make sure we have active users outside our realm (to make
        # sure relevant queries restrict on realm).
        self.assertEqual(
            UserProfile.objects.exclude(realm=realm).filter(is_active=True).count(),
            10,
        )

        # Our seat count excludes our guest user and bot, and
        # we want this to be predictable for certain tests with
        # arithmetic calculations.
        self.assertEqual(get_latest_seat_count(realm), 6)
        self.seat_count = 6
        self.signed_seat_count, self.salt = sign_string(str(self.seat_count))
        # Choosing dates with corresponding timestamps below 1500000000 so that they are
        # not caught by our timestamp normalization regex in normalize_fixture_data
        self.now = datetime(2012, 1, 2, 3, 4, 5, tzinfo=timezone.utc)
        self.next_month = datetime(2012, 2, 2, 3, 4, 5, tzinfo=timezone.utc)
        self.next_year = datetime(2013, 1, 2, 3, 4, 5, tzinfo=timezone.utc)

    def get_signed_seat_count_from_response(self, response: HttpResponse) -> Optional[str]:
        match = re.search(
            r"name=\"signed_seat_count\" value=\"(.+)\"", response.content.decode("utf-8")
        )
        return match.group(1) if match else None

    def get_salt_from_response(self, response: HttpResponse) -> Optional[str]:
        match = re.search(r"name=\"salt\" value=\"(\w+)\"", response.content.decode("utf-8"))
        return match.group(1) if match else None

    def upgrade(
        self,
        invoice: bool = False,
        talk_to_stripe: bool = True,
        realm: Optional[Realm] = None,
        del_args: Sequence[str] = [],
        **kwargs: Any,
    ) -> HttpResponse:
        host_args = {}
        if realm is not None:  # nocoverage: TODO
            host_args["HTTP_HOST"] = realm.host
        response = self.client_get("/upgrade/", {}, **host_args)
        params: Dict[str, Any] = {
            "schedule": "annual",
            "signed_seat_count": self.get_signed_seat_count_from_response(response),
            "salt": self.get_salt_from_response(response),
        }
        if invoice:  # send_invoice
            params.update(
                billing_modality="send_invoice",
                licenses=kwargs.get("licenses", 123),
            )
        else:  # charge_automatically
            stripe_token = None
            if not talk_to_stripe:
                stripe_token = "token"
            stripe_token = kwargs.get("stripe_token", stripe_token)
            if stripe_token is None:
                stripe_token = stripe_create_token().id
            params.update(
                billing_modality="charge_automatically",
                license_management="automatic",
                stripe_token=stripe_token,
            )

        params.update(kwargs)
        for key in del_args:
            if key in params:
                del params[key]
        return self.client_post("/json/billing/upgrade", params, **host_args)

    # Upgrade without talking to Stripe
    def local_upgrade(self, *args: Any) -> None:
        class StripeMock(Mock):
            def __init__(self, depth: int = 1):
                super().__init__(spec=stripe.Card)
                self.id = "id"
                self.created = "1000"
                self.last4 = "4242"
                if depth == 1:
                    self.source = StripeMock(depth=2)

        def upgrade_func(*args: Any) -> Any:
            return process_initial_upgrade(self.example_user("hamlet"), *args[:4])

        for mocked_function_name in MOCKED_STRIPE_FUNCTION_NAMES:
            upgrade_func = patch(mocked_function_name, return_value=StripeMock())(upgrade_func)
        upgrade_func(*args)


class StripeTest(StripeTestCase):
    def test_catch_stripe_errors(self) -> None:
        @catch_stripe_errors
        def raise_invalid_request_error() -> None:
            raise stripe.error.InvalidRequestError("message", "param", "code", json_body={})

        with self.assertLogs("corporate.stripe", "ERROR") as error_log:
            with self.assertRaises(BillingError) as context:
                raise_invalid_request_error()
            self.assertEqual("other stripe error", context.exception.error_description)
            self.assertEqual(
                error_log.output, ["ERROR:corporate.stripe:Stripe error: None None None None"]
            )

        @catch_stripe_errors
        def raise_card_error() -> None:
            error_message = "The card number is not a valid credit card number."
            json_body = {"error": {"message": error_message}}
            raise stripe.error.CardError(
                error_message, "number", "invalid_number", json_body=json_body
            )

        with self.assertLogs("corporate.stripe", "INFO") as info_log:
            with self.assertRaises(StripeCardError) as context:
                raise_card_error()
            self.assertIn("not a valid credit card", str(context.exception))
            self.assertEqual("card error", context.exception.error_description)
            self.assertEqual(
                info_log.output, ["INFO:corporate.stripe:Stripe card error: None None None None"]
            )

    def test_billing_not_enabled(self) -> None:
        iago = self.example_user("iago")
        with self.settings(BILLING_ENABLED=False):
            self.login_user(iago)
            response = self.client_get("/upgrade/", follow=True)
            self.assertEqual(response.status_code, 404)

    @mock_stripe(tested_timestamp_fields=["created"])
    def test_upgrade_by_card(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        response = self.client_get("/upgrade/")
        self.assert_in_success_response(["Pay annually"], response)
        self.assertNotEqual(user.realm.plan_type, Realm.STANDARD)
        self.assertFalse(Customer.objects.filter(realm=user.realm).exists())

        # Click "Make payment" in Stripe Checkout
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade()

        # Check that we correctly created a Customer object in Stripe
        stripe_customer = stripe_get_customer(
            Customer.objects.get(realm=user.realm).stripe_customer_id
        )
        self.assertEqual(stripe_customer.default_source.id[:5], "card_")
        self.assertTrue(stripe_customer_has_credit_card_as_default_source(stripe_customer))
        self.assertEqual(stripe_customer.description, "zulip (Zulip Dev)")
        self.assertEqual(stripe_customer.discount, None)
        self.assertEqual(stripe_customer.email, user.delivery_email)
        metadata_dict = dict(stripe_customer.metadata)
        self.assertEqual(metadata_dict["realm_str"], "zulip")
        try:
            int(metadata_dict["realm_id"])
        except ValueError:  # nocoverage
            raise AssertionError("realm_id is not a number")

        # Check Charges in Stripe
        [charge] = stripe.Charge.list(customer=stripe_customer.id)
        self.assertEqual(charge.amount, 8000 * self.seat_count)
        # TODO: fix Decimal
        self.assertEqual(
            charge.description, f"Upgrade to Zulip Standard, $80.0 x {self.seat_count}"
        )
        self.assertEqual(charge.receipt_email, user.delivery_email)
        self.assertEqual(charge.statement_descriptor, "Zulip Standard")
        # Check Invoices in Stripe
        [invoice] = stripe.Invoice.list(customer=stripe_customer.id)
        self.assertIsNotNone(invoice.status_transitions.finalized_at)
        invoice_params = {
            # auto_advance is False because the invoice has been paid
            "amount_due": 0,
            "amount_paid": 0,
            "auto_advance": False,
            "billing": "charge_automatically",
            "charge": None,
            "status": "paid",
            "total": 0,
        }
        for key, value in invoice_params.items():
            self.assertEqual(invoice.get(key), value)
        # Check Line Items on Stripe Invoice
        [item0, item1] = invoice.lines
        line_item_params = {
            "amount": 8000 * self.seat_count,
            "description": "Zulip Standard",
            "discountable": False,
            "period": {
                "end": datetime_to_timestamp(self.next_year),
                "start": datetime_to_timestamp(self.now),
            },
            # There's no unit_amount on Line Items, probably because it doesn't show up on the
            # user-facing invoice. We could pull the Invoice Item instead and test unit_amount there,
            # but testing the amount and quantity seems sufficient.
            "plan": None,
            "proration": False,
            "quantity": self.seat_count,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item0.get(key), value)
        line_item_params = {
            "amount": -8000 * self.seat_count,
            "description": "Payment (Card ending in 4242)",
            "discountable": False,
            "plan": None,
            "proration": False,
            "quantity": 1,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item1.get(key), value)

        # Check that we correctly populated Customer, CustomerPlan, and LicenseLedger in Zulip
        customer = Customer.objects.get(stripe_customer_id=stripe_customer.id, realm=user.realm)
        plan = CustomerPlan.objects.get(
            customer=customer,
            automanage_licenses=True,
            price_per_license=8000,
            fixed_price=None,
            discount=None,
            billing_cycle_anchor=self.now,
            billing_schedule=CustomerPlan.ANNUAL,
            invoiced_through=LicenseLedger.objects.first(),
            next_invoice_date=self.next_month,
            tier=CustomerPlan.STANDARD,
            status=CustomerPlan.ACTIVE,
        )
        LicenseLedger.objects.get(
            plan=plan,
            is_renewal=True,
            event_time=self.now,
            licenses=self.seat_count,
            licenses_at_next_renewal=self.seat_count,
        )
        # Check RealmAuditLog
        audit_log_entries = list(
            RealmAuditLog.objects.filter(acting_user=user)
            .values_list("event_type", "event_time")
            .order_by("id")
        )
        self.assertEqual(
            audit_log_entries[:3],
            [
                (
                    RealmAuditLog.STRIPE_CUSTOMER_CREATED,
                    timestamp_to_datetime(stripe_customer.created),
                ),
                (RealmAuditLog.STRIPE_CARD_CHANGED, timestamp_to_datetime(stripe_customer.created)),
                (RealmAuditLog.CUSTOMER_PLAN_CREATED, self.now),
            ],
        )
        self.assertEqual(audit_log_entries[3][0], RealmAuditLog.REALM_PLAN_TYPE_CHANGED)
        self.assertEqual(
            orjson.loads(
                RealmAuditLog.objects.filter(event_type=RealmAuditLog.CUSTOMER_PLAN_CREATED)
                .values_list("extra_data", flat=True)
                .first()
            )["automanage_licenses"],
            True,
        )
        # Check that we correctly updated Realm
        realm = get_realm("zulip")
        self.assertEqual(realm.plan_type, Realm.STANDARD)
        self.assertEqual(realm.max_invites, Realm.INVITES_STANDARD_REALM_DAILY_MAX)
        # Check that we can no longer access /upgrade
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/billing/", response.url)

        # Check /billing has the correct information
        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            response = self.client_get("/billing/")
        self.assert_not_in_success_response(["Pay annually"], response)
        for substring in [
            "Zulip Standard",
            str(self.seat_count),
            "You are using",
            f"{self.seat_count} of {self.seat_count} licenses",
            "Licenses are automatically managed by Zulip; when you add",
            "Your plan will renew on",
            "January 2, 2013",
            f"${80 * self.seat_count}.00",
            f"Billing email: <strong>{user.delivery_email}</strong>",
            "Visa ending in 4242",
            "Update card",
        ]:
            self.assert_in_response(substring, response)

        self.assert_not_in_success_response(
            [
                "You can only increase the number of licenses.",
                "Number of licenses",
                "Licenses in next renewal",
            ],
            response,
        )

    @mock_stripe(tested_timestamp_fields=["created"])
    def test_upgrade_by_invoice(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        # Click "Make payment" in Stripe Checkout
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade(invoice=True)
        # Check that we correctly created a Customer in Stripe
        stripe_customer = stripe_get_customer(
            Customer.objects.get(realm=user.realm).stripe_customer_id
        )
        self.assertFalse(stripe_customer_has_credit_card_as_default_source(stripe_customer))
        # It can take a second for Stripe to attach the source to the customer, and in
        # particular it may not be attached at the time stripe_get_customer is called above,
        # causing test flakes.
        # So commenting the next line out, but leaving it here so future readers know what
        # is supposed to happen here
        # self.assertEqual(stripe_customer.default_source.type, 'ach_credit_transfer')

        # Check Charges in Stripe
        self.assertFalse(stripe.Charge.list(customer=stripe_customer.id))
        # Check Invoices in Stripe
        [invoice] = stripe.Invoice.list(customer=stripe_customer.id)
        self.assertIsNotNone(invoice.due_date)
        self.assertIsNotNone(invoice.status_transitions.finalized_at)
        invoice_params = {
            "amount_due": 8000 * 123,
            "amount_paid": 0,
            "attempt_count": 0,
            "auto_advance": True,
            "billing": "send_invoice",
            "statement_descriptor": "Zulip Standard",
            "status": "open",
            "total": 8000 * 123,
        }
        for key, value in invoice_params.items():
            self.assertEqual(invoice.get(key), value)
        # Check Line Items on Stripe Invoice
        [item] = invoice.lines
        line_item_params = {
            "amount": 8000 * 123,
            "description": "Zulip Standard",
            "discountable": False,
            "period": {
                "end": datetime_to_timestamp(self.next_year),
                "start": datetime_to_timestamp(self.now),
            },
            "plan": None,
            "proration": False,
            "quantity": 123,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item.get(key), value)

        # Check that we correctly populated Customer, CustomerPlan and LicenseLedger in Zulip
        customer = Customer.objects.get(stripe_customer_id=stripe_customer.id, realm=user.realm)
        plan = CustomerPlan.objects.get(
            customer=customer,
            automanage_licenses=False,
            charge_automatically=False,
            price_per_license=8000,
            fixed_price=None,
            discount=None,
            billing_cycle_anchor=self.now,
            billing_schedule=CustomerPlan.ANNUAL,
            invoiced_through=LicenseLedger.objects.first(),
            next_invoice_date=self.next_year,
            tier=CustomerPlan.STANDARD,
            status=CustomerPlan.ACTIVE,
        )
        LicenseLedger.objects.get(
            plan=plan,
            is_renewal=True,
            event_time=self.now,
            licenses=123,
            licenses_at_next_renewal=123,
        )
        # Check RealmAuditLog
        audit_log_entries = list(
            RealmAuditLog.objects.filter(acting_user=user)
            .values_list("event_type", "event_time")
            .order_by("id")
        )
        self.assertEqual(
            audit_log_entries[:2],
            [
                (
                    RealmAuditLog.STRIPE_CUSTOMER_CREATED,
                    timestamp_to_datetime(stripe_customer.created),
                ),
                (RealmAuditLog.CUSTOMER_PLAN_CREATED, self.now),
            ],
        )
        self.assertEqual(audit_log_entries[2][0], RealmAuditLog.REALM_PLAN_TYPE_CHANGED)
        self.assertEqual(
            orjson.loads(
                RealmAuditLog.objects.filter(event_type=RealmAuditLog.CUSTOMER_PLAN_CREATED)
                .values_list("extra_data", flat=True)
                .first()
            )["automanage_licenses"],
            False,
        )
        # Check that we correctly updated Realm
        realm = get_realm("zulip")
        self.assertEqual(realm.plan_type, Realm.STANDARD)
        self.assertEqual(realm.max_invites, Realm.INVITES_STANDARD_REALM_DAILY_MAX)
        # Check that we can no longer access /upgrade
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/billing/", response.url)

        # Check /billing has the correct information
        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            response = self.client_get("/billing/")
        self.assert_not_in_success_response(["Pay annually", "Update card"], response)
        for substring in [
            "Zulip Standard",
            str(123),
            "You are using",
            f"{self.seat_count} of {123} licenses",
            "Licenses are manually managed. You will not be able to add ",
            "Your plan will renew on",
            "January 2, 2013",
            "$9,840.00",  # 9840 = 80 * 123
            f"Billing email: <strong>{user.delivery_email}</strong>",
            "Billed by invoice",
            "You can only increase the number of licenses.",
            "Number of licenses",
            "Licenses in next renewal",
        ]:
            self.assert_in_response(substring, response)

    @mock_stripe(tested_timestamp_fields=["created"])
    def test_free_trial_upgrade_by_card(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)

        with self.settings(FREE_TRIAL_DAYS=60):
            response = self.client_get("/upgrade/")
            free_trial_end_date = self.now + timedelta(days=60)

            self.assert_in_success_response(["Pay annually", "Free Trial", "60 day"], response)
            self.assertNotEqual(user.realm.plan_type, Realm.STANDARD)
            self.assertFalse(Customer.objects.filter(realm=user.realm).exists())

            with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
                self.upgrade()

            stripe_customer = stripe_get_customer(
                Customer.objects.get(realm=user.realm).stripe_customer_id
            )
            self.assertEqual(stripe_customer.default_source.id[:5], "card_")
            self.assertEqual(stripe_customer.description, "zulip (Zulip Dev)")
            self.assertEqual(stripe_customer.discount, None)
            self.assertEqual(stripe_customer.email, user.delivery_email)
            metadata_dict = dict(stripe_customer.metadata)
            self.assertEqual(metadata_dict["realm_str"], "zulip")
            try:
                int(metadata_dict["realm_id"])
            except ValueError:  # nocoverage
                raise AssertionError("realm_id is not a number")

            self.assertFalse(stripe.Charge.list(customer=stripe_customer.id))

            self.assertFalse(stripe.Invoice.list(customer=stripe_customer.id))

            customer = Customer.objects.get(stripe_customer_id=stripe_customer.id, realm=user.realm)
            plan = CustomerPlan.objects.get(
                customer=customer,
                automanage_licenses=True,
                price_per_license=8000,
                fixed_price=None,
                discount=None,
                billing_cycle_anchor=self.now,
                billing_schedule=CustomerPlan.ANNUAL,
                invoiced_through=LicenseLedger.objects.first(),
                next_invoice_date=free_trial_end_date,
                tier=CustomerPlan.STANDARD,
                status=CustomerPlan.FREE_TRIAL,
            )
            LicenseLedger.objects.get(
                plan=plan,
                is_renewal=True,
                event_time=self.now,
                licenses=self.seat_count,
                licenses_at_next_renewal=self.seat_count,
            )
            audit_log_entries = list(
                RealmAuditLog.objects.filter(acting_user=user)
                .values_list("event_type", "event_time")
                .order_by("id")
            )
            self.assertEqual(
                audit_log_entries[:3],
                [
                    (
                        RealmAuditLog.STRIPE_CUSTOMER_CREATED,
                        timestamp_to_datetime(stripe_customer.created),
                    ),
                    (
                        RealmAuditLog.STRIPE_CARD_CHANGED,
                        timestamp_to_datetime(stripe_customer.created),
                    ),
                    (RealmAuditLog.CUSTOMER_PLAN_CREATED, self.now),
                ],
            )
            self.assertEqual(audit_log_entries[3][0], RealmAuditLog.REALM_PLAN_TYPE_CHANGED)
            self.assertEqual(
                orjson.loads(
                    RealmAuditLog.objects.filter(event_type=RealmAuditLog.CUSTOMER_PLAN_CREATED)
                    .values_list("extra_data", flat=True)
                    .first()
                )["automanage_licenses"],
                True,
            )

            realm = get_realm("zulip")
            self.assertEqual(realm.plan_type, Realm.STANDARD)
            self.assertEqual(realm.max_invites, Realm.INVITES_STANDARD_REALM_DAILY_MAX)

            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_get("/billing/")
            self.assert_not_in_success_response(["Pay annually"], response)
            for substring in [
                "Zulip Standard",
                "Free Trial",
                str(self.seat_count),
                "You are using",
                f"{self.seat_count} of {self.seat_count} licenses",
                "Your plan will be upgraded to",
                "March 2, 2012",
                f"${80 * self.seat_count}.00",
                f"Billing email: <strong>{user.delivery_email}</strong>",
                "Visa ending in 4242",
                "Update card",
            ]:
                self.assert_in_response(substring, response)
            self.assert_not_in_success_response(["Go to your Zulip organization"], response)

            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_get("/billing/", {"onboarding": "true"})
                self.assert_in_success_response(["Go to your Zulip organization"], response)

            with patch("corporate.lib.stripe.get_latest_seat_count", return_value=12):
                update_license_ledger_if_needed(realm, self.now)
            self.assertEqual(
                LicenseLedger.objects.order_by("-id")
                .values_list("licenses", "licenses_at_next_renewal")
                .first(),
                (12, 12),
            )

            with patch("corporate.lib.stripe.get_latest_seat_count", return_value=15):
                update_license_ledger_if_needed(realm, self.next_month)
            self.assertEqual(
                LicenseLedger.objects.order_by("-id")
                .values_list("licenses", "licenses_at_next_renewal")
                .first(),
                (15, 15),
            )

            invoice_plans_as_needed(self.next_month)
            self.assertFalse(stripe.Invoice.list(customer=stripe_customer.id))
            customer_plan = CustomerPlan.objects.get(customer=customer)
            self.assertEqual(customer_plan.status, CustomerPlan.FREE_TRIAL)
            self.assertEqual(customer_plan.next_invoice_date, free_trial_end_date)

            invoice_plans_as_needed(free_trial_end_date)
            customer_plan.refresh_from_db()
            realm.refresh_from_db()
            self.assertEqual(customer_plan.status, CustomerPlan.ACTIVE)
            self.assertEqual(customer_plan.next_invoice_date, add_months(free_trial_end_date, 1))
            self.assertEqual(realm.plan_type, Realm.STANDARD)
            [invoice] = stripe.Invoice.list(customer=stripe_customer.id)
            invoice_params = {
                "amount_due": 15 * 80 * 100,
                "amount_paid": 0,
                "amount_remaining": 15 * 80 * 100,
                "auto_advance": True,
                "billing": "charge_automatically",
                "collection_method": "charge_automatically",
                "customer_email": self.example_email("hamlet"),
                "discount": None,
                "paid": False,
                "status": "open",
                "total": 15 * 80 * 100,
            }
            for key, value in invoice_params.items():
                self.assertEqual(invoice.get(key), value)
            [invoice_item] = invoice.get("lines")
            invoice_item_params = {
                "amount": 15 * 80 * 100,
                "description": "Zulip Standard - renewal",
                "plan": None,
                "quantity": 15,
                "subscription": None,
                "discountable": False,
                "period": {
                    "start": datetime_to_timestamp(free_trial_end_date),
                    "end": datetime_to_timestamp(add_months(free_trial_end_date, 12)),
                },
            }
            for key, value in invoice_item_params.items():
                self.assertEqual(invoice_item[key], value)

            invoice_plans_as_needed(add_months(free_trial_end_date, 1))
            [invoice] = stripe.Invoice.list(customer=stripe_customer.id)

            with patch("corporate.lib.stripe.get_latest_seat_count", return_value=19):
                update_license_ledger_if_needed(realm, add_months(free_trial_end_date, 10))
            self.assertEqual(
                LicenseLedger.objects.order_by("-id")
                .values_list("licenses", "licenses_at_next_renewal")
                .first(),
                (19, 19),
            )
            invoice_plans_as_needed(add_months(free_trial_end_date, 10))
            [invoice0, invoice1] = stripe.Invoice.list(customer=stripe_customer.id)
            invoice_params = {
                "amount_due": 5172,
                "auto_advance": True,
                "billing": "charge_automatically",
                "collection_method": "charge_automatically",
                "customer_email": "hamlet@zulip.com",
            }
            [invoice_item] = invoice0.get("lines")
            invoice_item_params = {
                "amount": 5172,
                "description": "Additional license (Jan 2, 2013 - Mar 2, 2013)",
                "discountable": False,
                "quantity": 4,
                "period": {
                    "start": datetime_to_timestamp(add_months(free_trial_end_date, 10)),
                    "end": datetime_to_timestamp(add_months(free_trial_end_date, 12)),
                },
            }

            invoice_plans_as_needed(add_months(free_trial_end_date, 12))
            [invoice0, invoice1, invoice2] = stripe.Invoice.list(customer=stripe_customer.id)

    @mock_stripe(tested_timestamp_fields=["created"])
    def test_free_trial_upgrade_by_invoice(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)

        free_trial_end_date = self.now + timedelta(days=60)
        with self.settings(FREE_TRIAL_DAYS=60):
            response = self.client_get("/upgrade/")

            self.assert_in_success_response(["Pay annually", "Free Trial", "60 day"], response)
            self.assertNotEqual(user.realm.plan_type, Realm.STANDARD)
            self.assertFalse(Customer.objects.filter(realm=user.realm).exists())

            with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
                self.upgrade(invoice=True)

            stripe_customer = stripe_get_customer(
                Customer.objects.get(realm=user.realm).stripe_customer_id
            )
            self.assertEqual(stripe_customer.discount, None)
            self.assertEqual(stripe_customer.email, user.delivery_email)
            metadata_dict = dict(stripe_customer.metadata)
            self.assertEqual(metadata_dict["realm_str"], "zulip")
            try:
                int(metadata_dict["realm_id"])
            except ValueError:  # nocoverage
                raise AssertionError("realm_id is not a number")

            self.assertFalse(stripe.Invoice.list(customer=stripe_customer.id))

            customer = Customer.objects.get(stripe_customer_id=stripe_customer.id, realm=user.realm)
            plan = CustomerPlan.objects.get(
                customer=customer,
                automanage_licenses=False,
                price_per_license=8000,
                fixed_price=None,
                discount=None,
                billing_cycle_anchor=self.now,
                billing_schedule=CustomerPlan.ANNUAL,
                invoiced_through=LicenseLedger.objects.first(),
                next_invoice_date=free_trial_end_date,
                tier=CustomerPlan.STANDARD,
                status=CustomerPlan.FREE_TRIAL,
            )

            LicenseLedger.objects.get(
                plan=plan,
                is_renewal=True,
                event_time=self.now,
                licenses=123,
                licenses_at_next_renewal=123,
            )
            audit_log_entries = list(
                RealmAuditLog.objects.filter(acting_user=user)
                .values_list("event_type", "event_time")
                .order_by("id")
            )
            self.assertEqual(
                audit_log_entries[:2],
                [
                    (
                        RealmAuditLog.STRIPE_CUSTOMER_CREATED,
                        timestamp_to_datetime(stripe_customer.created),
                    ),
                    (RealmAuditLog.CUSTOMER_PLAN_CREATED, self.now),
                ],
            )
            self.assertEqual(audit_log_entries[2][0], RealmAuditLog.REALM_PLAN_TYPE_CHANGED)
            self.assertEqual(
                orjson.loads(
                    RealmAuditLog.objects.filter(event_type=RealmAuditLog.CUSTOMER_PLAN_CREATED)
                    .values_list("extra_data", flat=True)
                    .first()
                )["automanage_licenses"],
                False,
            )

            realm = get_realm("zulip")
            self.assertEqual(realm.plan_type, Realm.STANDARD)
            self.assertEqual(realm.max_invites, Realm.INVITES_STANDARD_REALM_DAILY_MAX)

            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_get("/billing/")
            self.assert_not_in_success_response(["Pay annually"], response)
            for substring in [
                "Zulip Standard",
                "Free Trial",
                str(self.seat_count),
                "You are using",
                f"{self.seat_count} of {123} licenses",
                "Your plan will be upgraded to",
                "March 2, 2012",
                f"{80 * 123:,.2f}",
                f"Billing email: <strong>{user.delivery_email}</strong>",
                "Billed by invoice",
            ]:
                self.assert_in_response(substring, response)

            with patch("corporate.lib.stripe.invoice_plan") as mocked:
                invoice_plans_as_needed(self.next_month)
            mocked.assert_not_called()
            mocked.reset_mock()
            customer_plan = CustomerPlan.objects.get(customer=customer)
            self.assertEqual(customer_plan.status, CustomerPlan.FREE_TRIAL)
            self.assertEqual(customer_plan.next_invoice_date, free_trial_end_date)

            invoice_plans_as_needed(free_trial_end_date)
            customer_plan.refresh_from_db()
            realm.refresh_from_db()
            self.assertEqual(customer_plan.status, CustomerPlan.ACTIVE)
            self.assertEqual(customer_plan.next_invoice_date, add_months(free_trial_end_date, 12))
            self.assertEqual(realm.plan_type, Realm.STANDARD)
            [invoice] = stripe.Invoice.list(customer=stripe_customer.id)
            invoice_params = {
                "amount_due": 123 * 80 * 100,
                "amount_paid": 0,
                "amount_remaining": 123 * 80 * 100,
                "auto_advance": True,
                "billing": "send_invoice",
                "collection_method": "send_invoice",
                "customer_email": self.example_email("hamlet"),
                "discount": None,
                "paid": False,
                "status": "open",
                "total": 123 * 80 * 100,
            }
            for key, value in invoice_params.items():
                self.assertEqual(invoice.get(key), value)
            [invoice_item] = invoice.get("lines")
            invoice_item_params = {
                "amount": 123 * 80 * 100,
                "description": "Zulip Standard - renewal",
                "plan": None,
                "quantity": 123,
                "subscription": None,
                "discountable": False,
                "period": {
                    "start": datetime_to_timestamp(free_trial_end_date),
                    "end": datetime_to_timestamp(add_months(free_trial_end_date, 12)),
                },
            }
            for key, value in invoice_item_params.items():
                self.assertEqual(invoice_item[key], value)

            invoice_plans_as_needed(add_months(free_trial_end_date, 1))
            [invoice] = stripe.Invoice.list(customer=stripe_customer.id)

            invoice_plans_as_needed(add_months(free_trial_end_date, 10))
            [invoice] = stripe.Invoice.list(customer=stripe_customer.id)

            invoice_plans_as_needed(add_months(free_trial_end_date, 12))
            [invoice0, invoice1] = stripe.Invoice.list(customer=stripe_customer.id)

    @mock_stripe()
    def test_billing_page_permissions(self, *mocks: Mock) -> None:
        # Guest users can't access /upgrade page
        self.login_user(self.example_user("polonius"))
        response = self.client_get("/upgrade/", follow=True)
        self.assertEqual(response.status_code, 404)

        # Check that non-admins can access /upgrade via /billing, when there is no Customer object
        self.login_user(self.example_user("hamlet"))
        response = self.client_get("/billing/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/upgrade/", response.url)
        # Check that non-admins can sign up and pay
        self.upgrade()
        # Check that the non-admin hamlet can still access /billing
        response = self.client_get("/billing/")
        self.assert_in_success_response(["Your current plan is"], response)

        # Check realm owners can access billing, even though they are not a billing admin
        desdemona = self.example_user("desdemona")
        desdemona.role = UserProfile.ROLE_REALM_OWNER
        desdemona.save(update_fields=["role"])
        self.login_user(self.example_user("desdemona"))
        response = self.client_get("/billing/")
        self.assert_in_success_response(["Your current plan is"], response)

        # Check that member who is not a billing admin does not have access
        self.login_user(self.example_user("cordelia"))
        response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["You must be an organization owner or a billing administrator"], response
        )

    @mock_stripe(tested_timestamp_fields=["created"])
    def test_upgrade_by_card_with_outdated_seat_count(self, *mocks: Mock) -> None:
        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        new_seat_count = 23
        # Change the seat count while the user is going through the upgrade flow
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=new_seat_count):
            self.upgrade()
        stripe_customer_id = Customer.objects.first().stripe_customer_id
        # Check that the Charge used the old quantity, not new_seat_count
        [charge] = stripe.Charge.list(customer=stripe_customer_id)
        self.assertEqual(8000 * self.seat_count, charge.amount)
        # Check that the invoice has a credit for the old amount and a charge for the new one
        [stripe_invoice] = stripe.Invoice.list(customer=stripe_customer_id)
        self.assertEqual(
            [8000 * new_seat_count, -8000 * self.seat_count],
            [item.amount for item in stripe_invoice.lines],
        )
        # Check LicenseLedger has the new amount
        self.assertEqual(LicenseLedger.objects.first().licenses, new_seat_count)
        self.assertEqual(LicenseLedger.objects.first().licenses_at_next_renewal, new_seat_count)

    @mock_stripe()
    def test_upgrade_where_first_card_fails(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        # From https://stripe.com/docs/testing#cards: Attaching this card to
        # a Customer object succeeds, but attempts to charge the customer fail.
        with self.assertLogs("corporate.stripe", "INFO") as m:
            self.upgrade(stripe_token=stripe_create_token("4000000000000341").id)
            self.assertEqual(
                m.output,
                ["INFO:corporate.stripe:Stripe card error: 402 card_error card_declined None"],
            )
        # Check that we created a Customer object but no CustomerPlan
        stripe_customer_id = Customer.objects.get(realm=get_realm("zulip")).stripe_customer_id
        self.assertFalse(CustomerPlan.objects.exists())
        # Check that we created a Customer in stripe, a failed Charge, and no Invoices or Invoice Items
        self.assertTrue(stripe_get_customer(stripe_customer_id))
        [charge] = stripe.Charge.list(customer=stripe_customer_id)
        self.assertEqual(charge.failure_code, "card_declined")
        # TODO: figure out what these actually are
        self.assertFalse(stripe.Invoice.list(customer=stripe_customer_id))
        self.assertFalse(stripe.InvoiceItem.list(customer=stripe_customer_id))
        # Check that we correctly populated RealmAuditLog
        audit_log_entries = list(
            RealmAuditLog.objects.filter(acting_user=user)
            .values_list("event_type", flat=True)
            .order_by("id")
        )
        self.assertEqual(
            audit_log_entries,
            [RealmAuditLog.STRIPE_CUSTOMER_CREATED, RealmAuditLog.STRIPE_CARD_CHANGED],
        )
        # Check that we did not update Realm
        realm = get_realm("zulip")
        self.assertNotEqual(realm.plan_type, Realm.STANDARD)
        # Check that we still get redirected to /upgrade
        response = self.client_get("/billing/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/upgrade/", response.url)

        # Try again, with a valid card, after they added a few users
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=23):
            with patch("corporate.views.upgrade.get_latest_seat_count", return_value=23):
                self.upgrade()
        customer = Customer.objects.get(realm=get_realm("zulip"))
        # It's impossible to create two Customers, but check that we didn't
        # change stripe_customer_id
        self.assertEqual(customer.stripe_customer_id, stripe_customer_id)
        # Check that we successfully added a CustomerPlan, and have the right number of licenses
        plan = CustomerPlan.objects.get(customer=customer)
        ledger_entry = LicenseLedger.objects.get(plan=plan)
        self.assertEqual(ledger_entry.licenses, 23)
        self.assertEqual(ledger_entry.licenses_at_next_renewal, 23)
        # Check the Charges and Invoices in Stripe
        [charge0, charge1] = stripe.Charge.list(customer=stripe_customer_id)
        self.assertEqual(8000 * 23, charge0.amount)
        [stripe_invoice] = stripe.Invoice.list(customer=stripe_customer_id)
        self.assertEqual([8000 * 23, -8000 * 23], [item.amount for item in stripe_invoice.lines])
        # Check that we correctly populated RealmAuditLog
        audit_log_entries = list(
            RealmAuditLog.objects.filter(acting_user=user)
            .values_list("event_type", flat=True)
            .order_by("id")
        )
        self.assertEqual(
            audit_log_entries,
            [
                RealmAuditLog.STRIPE_CUSTOMER_CREATED,
                RealmAuditLog.STRIPE_CARD_CHANGED,
                RealmAuditLog.STRIPE_CARD_CHANGED,
                RealmAuditLog.CUSTOMER_PLAN_CREATED,
                RealmAuditLog.REALM_PLAN_TYPE_CHANGED,
            ],
        )
        # Check that we correctly updated Realm
        realm = get_realm("zulip")
        self.assertEqual(realm.plan_type, Realm.STANDARD)
        # Check that we can no longer access /upgrade
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/billing/", response.url)

    def test_upgrade_with_tampered_seat_count(self) -> None:
        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        response = self.upgrade(talk_to_stripe=False, salt="badsalt")
        self.assert_json_error_contains(response, "Something went wrong. Please contact")
        self.assertEqual(orjson.loads(response.content)["error_description"], "tampered seat count")

    def test_upgrade_race_condition(self) -> None:
        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        with self.assertLogs("corporate.stripe", "WARNING") as m:
            with self.assertRaises(BillingError) as context:
                self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        self.assertEqual(
            "subscribing with existing subscription", context.exception.error_description
        )
        self.assertEqual(
            m.output[0],
            f"WARNING:corporate.stripe:Customer <Customer <Realm: zulip {hamlet.realm.id}> id> trying to upgrade, but has an active subscription",
        )
        self.assert_length(m.output, 1)

    def test_check_upgrade_parameters(self) -> None:
        # Tests all the error paths except 'not enough licenses'
        def check_error(
            error_message: str,
            error_description: str,
            upgrade_params: Mapping[str, Any],
            del_args: Sequence[str] = [],
        ) -> None:
            response = self.upgrade(talk_to_stripe=False, del_args=del_args, **upgrade_params)
            self.assert_json_error_contains(response, error_message)
            if error_description:
                self.assertEqual(
                    orjson.loads(response.content)["error_description"], error_description
                )

        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        check_error("Invalid billing_modality", "", {"billing_modality": "invalid"})
        check_error("Invalid schedule", "", {"schedule": "invalid"})
        check_error("Invalid license_management", "", {"license_management": "invalid"})
        check_error(
            "Something went wrong. Please contact",
            "autopay with no card",
            {},
            del_args=["stripe_token"],
        )

    def test_upgrade_license_counts(self) -> None:
        def check_min_licenses_error(
            invoice: bool,
            licenses: Optional[int],
            min_licenses_in_response: int,
            upgrade_params: Dict[str, Any] = {},
        ) -> None:
            if licenses is None:
                del_args = ["licenses"]
            else:
                del_args = []
                upgrade_params["licenses"] = licenses
            response = self.upgrade(
                invoice=invoice, talk_to_stripe=False, del_args=del_args, **upgrade_params
            )
            self.assert_json_error_contains(response, f"at least {min_licenses_in_response} users")
            self.assertEqual(
                orjson.loads(response.content)["error_description"], "not enough licenses"
            )

        def check_max_licenses_error(licenses: int) -> None:
            response = self.upgrade(invoice=True, talk_to_stripe=False, licenses=licenses)
            self.assert_json_error_contains(
                response, f"with more than {MAX_INVOICED_LICENSES} licenses"
            )
            self.assertEqual(
                orjson.loads(response.content)["error_description"], "too many licenses"
            )

        def check_success(
            invoice: bool, licenses: Optional[int], upgrade_params: Dict[str, Any] = {}
        ) -> None:
            if licenses is None:
                del_args = ["licenses"]
            else:
                del_args = []
                upgrade_params["licenses"] = licenses
            with patch("corporate.views.upgrade.process_initial_upgrade"):
                response = self.upgrade(
                    invoice=invoice, talk_to_stripe=False, del_args=del_args, **upgrade_params
                )
            self.assert_json_success(response)

        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        # Autopay with licenses < seat count
        check_min_licenses_error(
            False, self.seat_count - 1, self.seat_count, {"license_management": "manual"}
        )
        # Autopay with not setting licenses
        check_min_licenses_error(False, None, self.seat_count, {"license_management": "manual"})
        # Invoice with licenses < MIN_INVOICED_LICENSES
        check_min_licenses_error(True, MIN_INVOICED_LICENSES - 1, MIN_INVOICED_LICENSES)
        # Invoice with licenses < seat count
        with patch("corporate.lib.stripe.MIN_INVOICED_LICENSES", 3):
            check_min_licenses_error(True, 4, self.seat_count)
        # Invoice with not setting licenses
        check_min_licenses_error(True, None, MIN_INVOICED_LICENSES)
        # Invoice exceeding max licenses
        check_max_licenses_error(MAX_INVOICED_LICENSES + 1)
        with patch(
            "corporate.lib.stripe.get_latest_seat_count", return_value=MAX_INVOICED_LICENSES + 5
        ):
            check_max_licenses_error(MAX_INVOICED_LICENSES + 5)

        # Autopay with automatic license_management
        check_success(False, None)
        # Autopay with automatic license_management, should just ignore the licenses entry
        check_success(False, self.seat_count)
        # Autopay
        check_success(False, self.seat_count, {"license_management": "manual"})
        # Autopay has no limit on max licenses
        check_success(False, MAX_INVOICED_LICENSES + 1, {"license_management": "manual"})
        # Invoice
        check_success(True, self.seat_count + MIN_INVOICED_LICENSES)
        # Invoice
        check_success(True, MAX_INVOICED_LICENSES)

    def test_upgrade_with_uncaught_exception(self) -> None:
        hamlet = self.example_user("hamlet")
        self.login_user(hamlet)
        with patch(
            "corporate.views.upgrade.process_initial_upgrade", side_effect=Exception
        ), self.assertLogs("corporate.stripe", "WARNING") as m:
            response = self.upgrade(talk_to_stripe=False)
            self.assertIn("ERROR:corporate.stripe:Uncaught exception in billing", m.output[0])
            self.assertIn(m.records[0].stack_info, m.output[0])
        self.assert_json_error_contains(
            response, "Something went wrong. Please contact desdemona+admin@zulip.com."
        )
        self.assertEqual(
            orjson.loads(response.content)["error_description"], "uncaught exception during upgrade"
        )

    def test_request_sponsorship(self) -> None:
        user = self.example_user("hamlet")
        self.assertIsNone(get_customer_by_realm(user.realm))

        self.login_user(user)

        data = {
            "organization-type": Realm.ORG_TYPES["opensource"]["id"],
            "website": "https://infinispan.org/",
            "description": "Infinispan is a distributed in-memory key/value data store with optional schema.",
        }
        response = self.client_post("/json/billing/sponsorship", data)
        self.assert_json_success(response)

        sponsorship_request = ZulipSponsorshipRequest.objects.filter(
            realm=user.realm, requested_by=user
        ).first()
        assert sponsorship_request is not None
        self.assertEqual(sponsorship_request.org_website, data["website"])
        self.assertEqual(sponsorship_request.org_description, data["description"])
        self.assertEqual(
            sponsorship_request.org_type,
            Realm.ORG_TYPES["opensource"]["id"],
        )

        customer = get_customer_by_realm(user.realm)
        assert customer is not None
        self.assertEqual(customer.sponsorship_pending, True)
        from django.core.mail import outbox

        self.assert_length(outbox, 1)

        for message in outbox:
            self.assert_length(message.to, 1)
            self.assertEqual(message.to[0], "desdemona+admin@zulip.com")
            self.assertEqual(message.subject, "Sponsorship request (Open-source project) for zulip")
            self.assertEqual(message.reply_to, ["hamlet@zulip.com"])
            self.assertEqual(self.email_envelope_from(message), settings.NOREPLY_EMAIL_ADDRESS)
            self.assertIn("Zulip sponsorship <noreply-", self.email_display_from(message))
            self.assertIn("Requested by: King Hamlet (Member)", message.body)
            self.assertIn(
                "Support URL: http://zulip.testserver/activity/support?q=zulip", message.body
            )
            self.assertIn("Website: https://infinispan.org", message.body)
            self.assertIn("Organization type: Open-source", message.body)
            self.assertIn("Description:\nInfinispan is a distributed in-memory", message.body)

        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual(response.url, "/billing/")

        response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["Your organization has requested sponsored or discounted hosting."], response
        )

        self.login_user(self.example_user("othello"))
        response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["You must be an organization owner or a billing administrator to view this page."],
            response,
        )

        user.realm.plan_type = Realm.STANDARD_FREE
        user.realm.save()
        self.login_user(self.example_user("hamlet"))
        response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["Your organization is fully sponsored and is on the <b>Zulip Standard</b>"], response
        )

    def test_redirect_for_billing_home(self) -> None:
        user = self.example_user("iago")
        self.login_user(user)
        response = self.client_get("/billing/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/upgrade/", response.url)

        user.realm.plan_type = Realm.STANDARD_FREE
        user.realm.save()
        response = self.client_get("/billing/")
        self.assertEqual(response.status_code, 200)

        user.realm.plan_type = Realm.LIMITED
        user.realm.save()
        Customer.objects.create(realm=user.realm, stripe_customer_id="cus_123")
        response = self.client_get("/billing/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual("/upgrade/", response.url)

    def test_redirect_for_upgrade_page(self) -> None:
        user = self.example_user("iago")
        self.login_user(user)

        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 200)

        user.realm.plan_type = Realm.STANDARD_FREE
        user.realm.save()
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual(response.url, "/billing/")

        user.realm.plan_type = Realm.LIMITED
        user.realm.save()
        customer = Customer.objects.create(realm=user.realm, stripe_customer_id="cus_123")
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 200)

        CustomerPlan.objects.create(
            customer=customer,
            billing_cycle_anchor=timezone_now(),
            billing_schedule=CustomerPlan.ANNUAL,
            tier=CustomerPlan.STANDARD,
        )
        response = self.client_get("/upgrade/")
        self.assertEqual(response.status_code, 302)
        self.assertEqual(response.url, "/billing/")

        with self.settings(FREE_TRIAL_DAYS=30):
            response = self.client_get("/upgrade/")
            self.assertEqual(response.status_code, 302)
            self.assertEqual(response.url, "/billing/")

            response = self.client_get("/upgrade/", {"onboarding": "true"})
            self.assertEqual(response.status_code, 302)
            self.assertEqual(response.url, "/billing/?onboarding=true")

    def test_get_latest_seat_count(self) -> None:
        realm = get_realm("zulip")
        initial_count = get_latest_seat_count(realm)
        user1 = UserProfile.objects.create(
            realm=realm, email="user1@zulip.com", delivery_email="user1@zulip.com"
        )
        user2 = UserProfile.objects.create(
            realm=realm, email="user2@zulip.com", delivery_email="user2@zulip.com"
        )
        self.assertEqual(get_latest_seat_count(realm), initial_count + 2)

        # Test that bots aren't counted
        user1.is_bot = True
        user1.save(update_fields=["is_bot"])
        self.assertEqual(get_latest_seat_count(realm), initial_count + 1)

        # Test that inactive users aren't counted
        do_deactivate_user(user2, acting_user=None)
        self.assertEqual(get_latest_seat_count(realm), initial_count)

        # Test guests
        # Adding a guest to a realm with a lot of members shouldn't change anything
        UserProfile.objects.create(
            realm=realm,
            email="user3@zulip.com",
            delivery_email="user3@zulip.com",
            role=UserProfile.ROLE_GUEST,
        )
        self.assertEqual(get_latest_seat_count(realm), initial_count)
        # Test 1 member and 5 guests
        realm = do_create_realm(string_id="second", name="second")
        UserProfile.objects.create(
            realm=realm, email="member@second.com", delivery_email="member@second.com"
        )
        for i in range(5):
            UserProfile.objects.create(
                realm=realm,
                email=f"guest{i}@second.com",
                delivery_email=f"guest{i}@second.com",
                role=UserProfile.ROLE_GUEST,
            )
        self.assertEqual(get_latest_seat_count(realm), 1)
        # Test 1 member and 6 guests
        UserProfile.objects.create(
            realm=realm,
            email="guest5@second.com",
            delivery_email="guest5@second.com",
            role=UserProfile.ROLE_GUEST,
        )
        self.assertEqual(get_latest_seat_count(realm), 2)

    def test_sign_string(self) -> None:
        string = "abc"
        signed_string, salt = sign_string(string)
        self.assertEqual(string, unsign_string(signed_string, salt))

        with self.assertRaises(signing.BadSignature):
            unsign_string(signed_string, "randomsalt")

    # This tests both the payment method string, and also is a very basic
    # test that the various upgrade paths involving non-standard payment
    # histories don't throw errors
    @mock_stripe()
    def test_payment_method_string(self, *mocks: Mock) -> None:
        pass
        # If you sign up with a card, we should show your card as the payment method
        # Already tested in test_initial_upgrade

        # If you pay by invoice, your payment method should be
        # "Billed by invoice", even if you have a card on file
        # user = self.example_user("hamlet")
        # do_create_stripe_customer(user, stripe_create_token().id)
        # self.login_user(user)
        # self.upgrade(invoice=True)
        # stripe_customer = stripe_get_customer(Customer.objects.get(realm=user.realm).stripe_customer_id)
        # self.assertEqual('Billed by invoice', payment_method_string(stripe_customer))

        # If you sign up with a card and then downgrade, we still have your
        # card on file, and should show it
        # TODO

    @mock_stripe()
    def test_attach_discount_to_realm(self, *mocks: Mock) -> None:
        # Attach discount before Stripe customer exists
        user = self.example_user("hamlet")
        attach_discount_to_realm(user.realm, Decimal(85), acting_user=user)
        realm_audit_log = RealmAuditLog.objects.filter(
            event_type=RealmAuditLog.REALM_DISCOUNT_CHANGED
        ).last()
        expected_extra_data = str({"old_discount": None, "new_discount": Decimal("85")})
        self.assertEqual(realm_audit_log.extra_data, expected_extra_data)
        self.login_user(user)
        # Check that the discount appears in page_params
        self.assert_in_success_response(["85"], self.client_get("/upgrade/"))
        # Check that the customer was charged the discounted amount
        self.upgrade()
        customer = Customer.objects.first()
        [charge] = stripe.Charge.list(customer=customer.stripe_customer_id)
        self.assertEqual(1200 * self.seat_count, charge.amount)
        [invoice] = stripe.Invoice.list(customer=customer.stripe_customer_id)
        self.assertEqual(
            [1200 * self.seat_count, -1200 * self.seat_count],
            [item.amount for item in invoice.lines],
        )
        # Check CustomerPlan reflects the discount
        plan = CustomerPlan.objects.get(price_per_license=1200, discount=Decimal(85))

        # Attach discount to existing Stripe customer
        plan.status = CustomerPlan.ENDED
        plan.save(update_fields=["status"])
        attach_discount_to_realm(user.realm, Decimal(25), acting_user=user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            process_initial_upgrade(
                user, self.seat_count, True, CustomerPlan.ANNUAL, stripe_create_token().id
            )
        [charge, _] = stripe.Charge.list(customer=customer.stripe_customer_id)
        self.assertEqual(6000 * self.seat_count, charge.amount)
        [invoice, _] = stripe.Invoice.list(customer=customer.stripe_customer_id)
        self.assertEqual(
            [6000 * self.seat_count, -6000 * self.seat_count],
            [item.amount for item in invoice.lines],
        )
        plan = CustomerPlan.objects.get(price_per_license=6000, discount=Decimal(25))

        attach_discount_to_realm(user.realm, Decimal(50), acting_user=user)
        plan.refresh_from_db()
        self.assertEqual(plan.price_per_license, 4000)
        self.assertEqual(plan.discount, 50)
        customer.refresh_from_db()
        self.assertEqual(customer.default_discount, 50)
        invoice_plans_as_needed(self.next_year + timedelta(days=10))
        [invoice, _, _] = stripe.Invoice.list(customer=customer.stripe_customer_id)
        self.assertEqual([4000 * self.seat_count], [item.amount for item in invoice.lines])
        realm_audit_log = RealmAuditLog.objects.filter(
            event_type=RealmAuditLog.REALM_DISCOUNT_CHANGED
        ).last()
        expected_extra_data = str(
            {"old_discount": Decimal("25.0000"), "new_discount": Decimal("50")}
        )
        self.assertEqual(realm_audit_log.extra_data, expected_extra_data)
        self.assertEqual(realm_audit_log.acting_user, user)

    def test_approve_sponsorship(self) -> None:
        user = self.example_user("hamlet")
        approve_sponsorship(user.realm, acting_user=user)
        realm = get_realm("zulip")
        self.assertEqual(realm.plan_type, Realm.STANDARD_FREE)

        expected_message = "Your organization's request for sponsored hosting has been approved! :tada:.\nYou have been upgraded to Zulip Cloud Standard, free of charge."
        sender = get_system_bot(settings.NOTIFICATION_BOT)
        recipient_id = self.example_user("desdemona").recipient_id
        message = Message.objects.filter(sender=sender.id).first()
        self.assertEqual(message.content, expected_message)
        self.assertEqual(message.recipient.type, Recipient.PERSONAL)
        self.assertEqual(message.recipient_id, recipient_id)

    def test_update_sponsorship_status(self) -> None:
        lear = get_realm("lear")
        iago = self.example_user("iago")
        update_sponsorship_status(lear, True, acting_user=iago)
        customer = get_customer_by_realm(realm=lear)
        assert customer is not None
        self.assertTrue(customer.sponsorship_pending)
        realm_audit_log = RealmAuditLog.objects.filter(
            event_type=RealmAuditLog.REALM_SPONSORSHIP_PENDING_STATUS_CHANGED
        ).last()
        expected_extra_data = {"sponsorship_pending": True}
        self.assertEqual(realm_audit_log.extra_data, str(expected_extra_data))
        self.assertEqual(realm_audit_log.acting_user, iago)

    def test_get_discount_for_realm(self) -> None:
        user = self.example_user("hamlet")
        self.assertEqual(get_discount_for_realm(user.realm), None)

        attach_discount_to_realm(user.realm, Decimal(85), acting_user=None)
        self.assertEqual(get_discount_for_realm(user.realm), 85)

    @mock_stripe()
    def test_replace_payment_source(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        self.upgrade()
        # Create an open invoice
        stripe_customer_id = Customer.objects.first().stripe_customer_id
        stripe.InvoiceItem.create(amount=5000, currency="usd", customer=stripe_customer_id)
        stripe_invoice = stripe.Invoice.create(customer=stripe_customer_id)
        stripe.Invoice.finalize_invoice(stripe_invoice)
        RealmAuditLog.objects.filter(event_type=RealmAuditLog.STRIPE_CARD_CHANGED).delete()

        # Replace with an invalid card
        stripe_token = stripe_create_token(card_number="4000000000009987").id
        with patch("stripe.Invoice.list") as mock_invoice_list, self.assertLogs(
            "corporate.stripe", "INFO"
        ) as m:
            response = self.client_post(
                "/json/billing/sources/change",
                {"stripe_token": stripe_token},
            )
            self.assertEqual(
                m.output, ["INFO:corporate.stripe:Stripe card error: 402 card_error card_declined "]
            )
        mock_invoice_list.assert_not_called()
        self.assertEqual(orjson.loads(response.content)["error_description"], "card error")
        self.assert_json_error_contains(response, "Your card was declined")
        for stripe_source in stripe_get_customer(stripe_customer_id).sources:
            assert isinstance(stripe_source, stripe.Card)
            self.assertEqual(stripe_source.last4, "4242")
        self.assertFalse(
            RealmAuditLog.objects.filter(event_type=RealmAuditLog.STRIPE_CARD_CHANGED).exists()
        )

        # Replace with a card that's valid, but charging the card fails
        stripe_token = stripe_create_token(card_number="4000000000000341").id
        with self.assertLogs("corporate.stripe", "INFO") as m:
            response = self.client_post(
                "/json/billing/sources/change",
                {"stripe_token": stripe_token},
            )
            self.assertEqual(
                m.output,
                ["INFO:corporate.stripe:Stripe card error: 402 card_error card_declined None"],
            )
        self.assertEqual(orjson.loads(response.content)["error_description"], "card error")
        self.assert_json_error_contains(response, "Your card was declined")
        for stripe_source in stripe_get_customer(stripe_customer_id).sources:
            assert isinstance(stripe_source, stripe.Card)
            self.assertEqual(stripe_source.last4, "0341")
        self.assertEqual(
            len(list(stripe.Invoice.list(customer=stripe_customer_id, status="open"))), 1
        )
        self.assertEqual(
            1, RealmAuditLog.objects.filter(event_type=RealmAuditLog.STRIPE_CARD_CHANGED).count()
        )

        # Replace with a valid card
        stripe_token = stripe_create_token(card_number="5555555555554444").id
        response = self.client_post("/json/billing/sources/change", {"stripe_token": stripe_token})
        self.assert_json_success(response)
        number_of_sources = 0
        for stripe_source in stripe_get_customer(stripe_customer_id).sources:
            assert isinstance(stripe_source, stripe.Card)
            self.assertEqual(stripe_source.last4, "4444")
            number_of_sources += 1
        # Verify that we replaced the previous card, rather than adding a new one
        self.assertEqual(number_of_sources, 1)
        # Ideally we'd also test that we don't pay invoices with billing=='send_invoice'
        for stripe_invoice in stripe.Invoice.list(customer=stripe_customer_id):
            self.assertEqual(stripe_invoice.status, "paid")
        self.assertEqual(
            2, RealmAuditLog.objects.filter(event_type=RealmAuditLog.STRIPE_CARD_CHANGED).count()
        )

    def test_downgrade(self) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        plan = get_current_plan_by_realm(user.realm)
        assert plan is not None
        self.assertEqual(plan.licenses(), self.seat_count)
        self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count)
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}
                )
                stripe_customer_id = Customer.objects.get(realm=user.realm).id
                new_plan = get_current_plan_by_realm(user.realm)
                assert new_plan is not None
                expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}"
                self.assertEqual(m.output[0], expected_log)
                self.assert_json_success(response)
        plan.refresh_from_db()
        self.assertEqual(plan.licenses(), self.seat_count)
        self.assertEqual(plan.licenses_at_next_renewal(), None)

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            mock_customer = Mock(email=user.delivery_email, default_source=None)
            with patch(
                "corporate.views.billing_page.stripe_get_customer", return_value=mock_customer
            ):
                response = self.client_get("/billing/")
                self.assert_in_success_response(
                    [
                        "Your plan will be downgraded to <strong>Zulip Limited</strong> on "
                        "<strong>January 2, 2013</strong>",
                        "You plan is scheduled for downgrade on <strong>January 2, 2013</strong>",
                        "Cancel downgrade",
                    ],
                    response,
                )

        # Verify that we still write LicenseLedger rows during the remaining
        # part of the cycle
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=20):
            update_license_ledger_if_needed(user.realm, self.now)
        self.assertEqual(
            LicenseLedger.objects.order_by("-id")
            .values_list("licenses", "licenses_at_next_renewal")
            .first(),
            (20, 20),
        )

        # Verify that we invoice them for the additional users
        from stripe import Invoice

        Invoice.create = lambda **args: None  # type: ignore[assignment] # cleaner than mocking
        Invoice.finalize_invoice = lambda *args: None  # type: ignore[assignment] # cleaner than mocking
        with patch("stripe.InvoiceItem.create") as mocked:
            invoice_plans_as_needed(self.next_month)
        mocked.assert_called_once()
        mocked.reset_mock()

        # Check that we downgrade properly if the cycle is over
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=30):
            update_license_ledger_if_needed(user.realm, self.next_year)
        self.assertEqual(get_realm("zulip").plan_type, Realm.LIMITED)
        self.assertEqual(CustomerPlan.objects.first().status, CustomerPlan.ENDED)
        self.assertEqual(
            LicenseLedger.objects.order_by("-id")
            .values_list("licenses", "licenses_at_next_renewal")
            .first(),
            (20, 20),
        )

        # Verify that we don't write LicenseLedger rows once we've downgraded
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=40):
            update_license_ledger_if_needed(user.realm, self.next_year)
        self.assertEqual(
            LicenseLedger.objects.order_by("-id")
            .values_list("licenses", "licenses_at_next_renewal")
            .first(),
            (20, 20),
        )

        # Verify that we call invoice_plan once more after cycle end but
        # don't invoice them for users added after the cycle end
        self.assertIsNotNone(CustomerPlan.objects.first().next_invoice_date)
        with patch("stripe.InvoiceItem.create") as mocked:
            invoice_plans_as_needed(self.next_year + timedelta(days=32))
        mocked.assert_not_called()
        mocked.reset_mock()
        # Check that we updated next_invoice_date in invoice_plan
        self.assertIsNone(CustomerPlan.objects.first().next_invoice_date)

        # Check that we don't call invoice_plan after that final call
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=50):
            update_license_ledger_if_needed(user.realm, self.next_year + timedelta(days=80))
        with patch("corporate.lib.stripe.invoice_plan") as mocked:
            invoice_plans_as_needed(self.next_year + timedelta(days=400))
        mocked.assert_not_called()

    @mock_stripe()
    def test_switch_from_monthly_plan_to_annual_plan_for_automatic_license_management(
        self, *mocks: Mock
    ) -> None:
        user = self.example_user("hamlet")

        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade(schedule="monthly")
        monthly_plan = get_current_plan_by_realm(user.realm)
        assert monthly_plan is not None
        self.assertEqual(monthly_plan.automanage_licenses, True)
        self.assertEqual(monthly_plan.billing_schedule, CustomerPlan.MONTHLY)

        stripe_customer_id = Customer.objects.get(realm=user.realm).id
        new_plan = get_current_plan_by_realm(user.realm)
        assert new_plan is not None

        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_patch(
                    "/json/billing/plan",
                    {"status": CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE},
                )
                expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE}"
                self.assertEqual(m.output[0], expected_log)
                self.assert_json_success(response)
        monthly_plan.refresh_from_db()
        self.assertEqual(monthly_plan.status, CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE)
        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["be switched from monthly to annual billing on <strong>February 2, 2012"], response
        )

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=20):
            update_license_ledger_if_needed(user.realm, self.now)
        self.assertEqual(LicenseLedger.objects.filter(plan=monthly_plan).count(), 2)
        self.assertEqual(
            LicenseLedger.objects.order_by("-id")
            .values_list("licenses", "licenses_at_next_renewal")
            .first(),
            (20, 20),
        )

        with patch("corporate.lib.stripe.timezone_now", return_value=self.next_month):
            with patch("corporate.lib.stripe.get_latest_seat_count", return_value=25):
                update_license_ledger_if_needed(user.realm, self.next_month)
        self.assertEqual(LicenseLedger.objects.filter(plan=monthly_plan).count(), 2)
        customer = get_customer_by_realm(user.realm)
        assert customer is not None
        self.assertEqual(CustomerPlan.objects.filter(customer=customer).count(), 2)
        monthly_plan.refresh_from_db()
        self.assertEqual(monthly_plan.status, CustomerPlan.ENDED)
        self.assertEqual(monthly_plan.next_invoice_date, self.next_month)
        annual_plan = get_current_plan_by_realm(user.realm)
        assert annual_plan is not None
        self.assertEqual(annual_plan.status, CustomerPlan.ACTIVE)
        self.assertEqual(annual_plan.billing_schedule, CustomerPlan.ANNUAL)
        self.assertEqual(annual_plan.invoicing_status, CustomerPlan.INITIAL_INVOICE_TO_BE_SENT)
        self.assertEqual(annual_plan.billing_cycle_anchor, self.next_month)
        self.assertEqual(annual_plan.next_invoice_date, self.next_month)
        self.assertEqual(annual_plan.invoiced_through, None)
        annual_ledger_entries = LicenseLedger.objects.filter(plan=annual_plan).order_by("id")
        self.assert_length(annual_ledger_entries, 2)
        self.assertEqual(annual_ledger_entries[0].is_renewal, True)
        self.assertEqual(
            annual_ledger_entries.values_list("licenses", "licenses_at_next_renewal")[0], (20, 20)
        )
        self.assertEqual(annual_ledger_entries[1].is_renewal, False)
        self.assertEqual(
            annual_ledger_entries.values_list("licenses", "licenses_at_next_renewal")[1], (25, 25)
        )
        audit_log = RealmAuditLog.objects.get(
            event_type=RealmAuditLog.CUSTOMER_SWITCHED_FROM_MONTHLY_TO_ANNUAL_PLAN
        )
        self.assertEqual(audit_log.realm, user.realm)
        self.assertEqual(orjson.loads(audit_log.extra_data)["monthly_plan_id"], monthly_plan.id)
        self.assertEqual(orjson.loads(audit_log.extra_data)["annual_plan_id"], annual_plan.id)

        invoice_plans_as_needed(self.next_month)

        annual_ledger_entries = LicenseLedger.objects.filter(plan=annual_plan).order_by("id")
        self.assert_length(annual_ledger_entries, 2)
        annual_plan.refresh_from_db()
        self.assertEqual(annual_plan.invoicing_status, CustomerPlan.DONE)
        self.assertEqual(annual_plan.invoiced_through, annual_ledger_entries[1])
        self.assertEqual(annual_plan.billing_cycle_anchor, self.next_month)
        self.assertEqual(annual_plan.next_invoice_date, add_months(self.next_month, 1))
        monthly_plan.refresh_from_db()
        self.assertEqual(monthly_plan.next_invoice_date, None)

        assert customer.stripe_customer_id
        [invoice0, invoice1, invoice2] = stripe.Invoice.list(customer=customer.stripe_customer_id)

        [invoice_item0, invoice_item1] = invoice0.get("lines")
        annual_plan_invoice_item_params = {
            "amount": 5 * 80 * 100,
            "description": "Additional license (Feb 2, 2012 - Feb 2, 2013)",
            "plan": None,
            "quantity": 5,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.next_month),
                "end": datetime_to_timestamp(add_months(self.next_month, 12)),
            },
        }
        for key, value in annual_plan_invoice_item_params.items():
            self.assertEqual(invoice_item0[key], value)

        annual_plan_invoice_item_params = {
            "amount": 20 * 80 * 100,
            "description": "Zulip Standard - renewal",
            "plan": None,
            "quantity": 20,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.next_month),
                "end": datetime_to_timestamp(add_months(self.next_month, 12)),
            },
        }
        for key, value in annual_plan_invoice_item_params.items():
            self.assertEqual(invoice_item1[key], value)

        [monthly_plan_invoice_item] = invoice1.get("lines")
        monthly_plan_invoice_item_params = {
            "amount": 14 * 8 * 100,
            "description": "Additional license (Jan 2, 2012 - Feb 2, 2012)",
            "plan": None,
            "quantity": 14,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.now),
                "end": datetime_to_timestamp(self.next_month),
            },
        }
        for key, value in monthly_plan_invoice_item_params.items():
            self.assertEqual(monthly_plan_invoice_item[key], value)

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=30):
            update_license_ledger_if_needed(user.realm, add_months(self.next_month, 1))
        invoice_plans_as_needed(add_months(self.next_month, 1))

        [invoice0, invoice1, invoice2, invoice3] = stripe.Invoice.list(
            customer=customer.stripe_customer_id
        )

        [monthly_plan_invoice_item] = invoice0.get("lines")
        monthly_plan_invoice_item_params = {
            "amount": 5 * 7366,
            "description": "Additional license (Mar 2, 2012 - Feb 2, 2013)",
            "plan": None,
            "quantity": 5,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(add_months(self.next_month, 1)),
                "end": datetime_to_timestamp(add_months(self.next_month, 12)),
            },
        }
        for key, value in monthly_plan_invoice_item_params.items():
            self.assertEqual(monthly_plan_invoice_item[key], value)
        invoice_plans_as_needed(add_months(self.now, 13))

        [invoice0, invoice1, invoice2, invoice3, invoice4] = stripe.Invoice.list(
            customer=customer.stripe_customer_id
        )

        [invoice_item] = invoice0.get("lines")
        annual_plan_invoice_item_params = {
            "amount": 30 * 80 * 100,
            "description": "Zulip Standard - renewal",
            "plan": None,
            "quantity": 30,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(add_months(self.next_month, 12)),
                "end": datetime_to_timestamp(add_months(self.next_month, 24)),
            },
        }
        for key, value in annual_plan_invoice_item_params.items():
            self.assertEqual(invoice_item[key], value)

    @mock_stripe()
    def test_switch_from_monthly_plan_to_annual_plan_for_manual_license_management(
        self, *mocks: Mock
    ) -> None:
        user = self.example_user("hamlet")
        num_licenses = 35

        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade(schedule="monthly", license_management="manual", licenses=num_licenses)
        monthly_plan = get_current_plan_by_realm(user.realm)
        assert monthly_plan is not None
        self.assertEqual(monthly_plan.automanage_licenses, False)
        self.assertEqual(monthly_plan.billing_schedule, CustomerPlan.MONTHLY)
        stripe_customer_id = Customer.objects.get(realm=user.realm).id
        new_plan = get_current_plan_by_realm(user.realm)
        assert new_plan is not None
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_patch(
                    "/json/billing/plan",
                    {"status": CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE},
                )
                self.assertEqual(
                    m.output[0],
                    f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE}",
                )
                self.assert_json_success(response)
        monthly_plan.refresh_from_db()
        self.assertEqual(monthly_plan.status, CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE)
        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            response = self.client_get("/billing/")
        self.assert_in_success_response(
            ["be switched from monthly to annual billing on <strong>February 2, 2012"], response
        )

        invoice_plans_as_needed(self.next_month)

        self.assertEqual(LicenseLedger.objects.filter(plan=monthly_plan).count(), 1)
        customer = get_customer_by_realm(user.realm)
        assert customer is not None
        self.assertEqual(CustomerPlan.objects.filter(customer=customer).count(), 2)
        monthly_plan.refresh_from_db()
        self.assertEqual(monthly_plan.status, CustomerPlan.ENDED)
        self.assertEqual(monthly_plan.next_invoice_date, None)
        annual_plan = get_current_plan_by_realm(user.realm)
        assert annual_plan is not None
        self.assertEqual(annual_plan.status, CustomerPlan.ACTIVE)
        self.assertEqual(annual_plan.billing_schedule, CustomerPlan.ANNUAL)
        self.assertEqual(annual_plan.invoicing_status, CustomerPlan.INITIAL_INVOICE_TO_BE_SENT)
        self.assertEqual(annual_plan.billing_cycle_anchor, self.next_month)
        self.assertEqual(annual_plan.next_invoice_date, self.next_month)
        annual_ledger_entries = LicenseLedger.objects.filter(plan=annual_plan).order_by("id")
        self.assert_length(annual_ledger_entries, 1)
        self.assertEqual(annual_ledger_entries[0].is_renewal, True)
        self.assertEqual(
            annual_ledger_entries.values_list("licenses", "licenses_at_next_renewal")[0],
            (num_licenses, num_licenses),
        )
        self.assertEqual(annual_plan.invoiced_through, None)

        # First call of invoice_plans_as_needed creates the new plan. Second call
        # calls invoice_plan on the newly created plan.
        invoice_plans_as_needed(self.next_month + timedelta(days=1))

        annual_plan.refresh_from_db()
        self.assertEqual(annual_plan.invoiced_through, annual_ledger_entries[0])
        self.assertEqual(annual_plan.next_invoice_date, add_months(self.next_month, 12))
        self.assertEqual(annual_plan.invoicing_status, CustomerPlan.DONE)

        assert customer.stripe_customer_id
        [invoice0, invoice1] = stripe.Invoice.list(customer=customer.stripe_customer_id)

        [invoice_item] = invoice0.get("lines")
        annual_plan_invoice_item_params = {
            "amount": num_licenses * 80 * 100,
            "description": "Zulip Standard - renewal",
            "plan": None,
            "quantity": num_licenses,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.next_month),
                "end": datetime_to_timestamp(add_months(self.next_month, 12)),
            },
        }
        for key, value in annual_plan_invoice_item_params.items():
            self.assertEqual(invoice_item[key], value)

        with patch("corporate.lib.stripe.invoice_plan") as m:
            invoice_plans_as_needed(add_months(self.now, 2))
            m.assert_not_called()

        invoice_plans_as_needed(add_months(self.now, 13))

        [invoice0, invoice1, invoice2] = stripe.Invoice.list(customer=customer.stripe_customer_id)

        [invoice_item] = invoice0.get("lines")
        annual_plan_invoice_item_params = {
            "amount": num_licenses * 80 * 100,
            "description": "Zulip Standard - renewal",
            "plan": None,
            "quantity": num_licenses,
            "subscription": None,
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(add_months(self.next_month, 12)),
                "end": datetime_to_timestamp(add_months(self.next_month, 24)),
            },
        }
        for key, value in annual_plan_invoice_item_params.items():
            self.assertEqual(invoice_item[key], value)

    def test_reupgrade_after_plan_status_changed_to_downgrade_at_end_of_cycle(self) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}
                )
                stripe_customer_id = Customer.objects.get(realm=user.realm).id
                new_plan = get_current_plan_by_realm(user.realm)
                assert new_plan is not None
                expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}"
                self.assertEqual(m.output[0], expected_log)
                self.assert_json_success(response)
        self.assertEqual(
            CustomerPlan.objects.first().status, CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE
        )
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                response = self.client_patch("/json/billing/plan", {"status": CustomerPlan.ACTIVE})
                expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.ACTIVE}"
                self.assertEqual(m.output[0], expected_log)
                self.assert_json_success(response)
        self.assertEqual(CustomerPlan.objects.first().status, CustomerPlan.ACTIVE)

    @patch("stripe.Invoice.create")
    @patch("stripe.Invoice.finalize_invoice")
    @patch("stripe.InvoiceItem.create")
    def test_downgrade_during_invoicing(self, *mocks: Mock) -> None:
        # The difference between this test and test_downgrade is that
        # CustomerPlan.status is DOWNGRADE_AT_END_OF_CYCLE rather than ENDED
        # when we call invoice_plans_as_needed
        # This test is essentially checking that we call make_end_of_cycle_updates_if_needed
        # during the invoicing process.
        user = self.example_user("hamlet")
        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        with self.assertLogs("corporate.stripe", "INFO") as m:
            stripe_customer_id = Customer.objects.get(realm=user.realm).id
            new_plan = get_current_plan_by_realm(user.realm)
            assert new_plan is not None
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}
                )
            expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}"
            self.assertEqual(m.output[0], expected_log)

        plan = CustomerPlan.objects.first()
        self.assertIsNotNone(plan.next_invoice_date)
        self.assertEqual(plan.status, CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE)
        invoice_plans_as_needed(self.next_year)
        plan = CustomerPlan.objects.first()
        self.assertIsNone(plan.next_invoice_date)
        self.assertEqual(plan.status, CustomerPlan.ENDED)

    def test_downgrade_free_trial(self) -> None:
        user = self.example_user("hamlet")

        free_trial_end_date = self.now + timedelta(days=60)
        with self.settings(FREE_TRIAL_DAYS=60):
            with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
                self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

            plan = CustomerPlan.objects.get()
            self.assertEqual(plan.next_invoice_date, free_trial_end_date)
            self.assertEqual(get_realm("zulip").plan_type, Realm.STANDARD)
            self.assertEqual(plan.status, CustomerPlan.FREE_TRIAL)

            # Add some extra users before the realm is deactivated
            with patch("corporate.lib.stripe.get_latest_seat_count", return_value=21):
                update_license_ledger_if_needed(user.realm, self.now)

            last_ledger_entry = LicenseLedger.objects.order_by("id").last()
            self.assertEqual(last_ledger_entry.licenses, 21)
            self.assertEqual(last_ledger_entry.licenses_at_next_renewal, 21)

            self.login_user(user)

            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                self.client_patch("/json/billing/plan", {"status": CustomerPlan.ENDED})

            plan.refresh_from_db()
            self.assertEqual(get_realm("zulip").plan_type, Realm.LIMITED)
            self.assertEqual(plan.status, CustomerPlan.ENDED)
            self.assertEqual(plan.invoiced_through, last_ledger_entry)
            self.assertIsNone(plan.next_invoice_date)

            self.login_user(user)
            response = self.client_get("/billing/")
            self.assert_in_success_response(
                ["Your organization is on the <b>Zulip Free</b>"], response
            )

            # The extra users added in the final month are not charged
            with patch("corporate.lib.stripe.invoice_plan") as mocked:
                invoice_plans_as_needed(self.next_month)
            mocked.assert_not_called()

            # The plan is not renewed after an year
            with patch("corporate.lib.stripe.invoice_plan") as mocked:
                invoice_plans_as_needed(self.next_year)
            mocked.assert_not_called()

    def test_reupgrade_by_billing_admin_after_downgrade(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        self.login_user(user)
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}
                )
            stripe_customer_id = Customer.objects.get(realm=user.realm).id
            new_plan = get_current_plan_by_realm(user.realm)
            assert new_plan is not None
            expected_log = f"INFO:corporate.stripe:Change plan status: Customer.id: {stripe_customer_id}, CustomerPlan.id: {new_plan.id}, status: {CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}"
            self.assertEqual(m.output[0], expected_log)

        with self.assertRaises(BillingError) as context, self.assertLogs(
            "corporate.stripe", "WARNING"
        ) as m:
            with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
                self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        self.assertEqual(
            m.output[0],
            f"WARNING:corporate.stripe:Customer <Customer <Realm: zulip {user.realm.id}> id> trying to upgrade, but has an active subscription",
        )
        self.assertEqual(
            context.exception.error_description, "subscribing with existing subscription"
        )

        invoice_plans_as_needed(self.next_year)

        response = self.client_get("/billing/")
        self.assert_in_success_response(["Your organization is on the <b>Zulip Free</b>"], response)

        with patch("corporate.lib.stripe.timezone_now", return_value=self.next_year):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        self.assertEqual(Customer.objects.count(), 1)
        self.assertEqual(CustomerPlan.objects.count(), 2)

        current_plan = CustomerPlan.objects.all().order_by("id").last()
        next_invoice_date = add_months(self.next_year, 1)
        self.assertEqual(current_plan.next_invoice_date, next_invoice_date)
        self.assertEqual(get_realm("zulip").plan_type, Realm.STANDARD)
        self.assertEqual(current_plan.status, CustomerPlan.ACTIVE)

        old_plan = CustomerPlan.objects.all().order_by("id").first()
        self.assertEqual(old_plan.next_invoice_date, None)
        self.assertEqual(old_plan.status, CustomerPlan.ENDED)

    @mock_stripe()
    def test_update_licenses_of_manual_plan_from_billing_page(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade(invoice=True, licenses=100)

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses": 100})
            self.assert_json_error_contains(
                result, "Your plan is already on 100 licenses in the current billing period."
            )

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses_at_next_renewal": 100})
            self.assert_json_error_contains(
                result, "Your plan is already scheduled to renew with 100 licenses."
            )

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses": 50})
            self.assert_json_error_contains(
                result, "You cannot decrease the licenses in the current billing period."
            )

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses_at_next_renewal": 25})
            self.assert_json_error_contains(result, "You must invoice for at least 30 users.")

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses": 2000})
            self.assert_json_error_contains(
                result, "Invoices with more than 1000 licenses can't be processed from this page."
            )

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses": 150})
            self.assert_json_success(result)
        invoice_plans_as_needed(self.next_year)
        stripe_customer = stripe_get_customer(
            Customer.objects.get(realm=user.realm).stripe_customer_id
        )
        [invoice, _] = stripe.Invoice.list(customer=stripe_customer.id)
        invoice_params = {
            "amount_due": (8000 * 150 + 8000 * 50),
            "amount_paid": 0,
            "attempt_count": 0,
            "auto_advance": True,
            "billing": "send_invoice",
            "statement_descriptor": "Zulip Standard",
            "status": "open",
            "total": (8000 * 150 + 8000 * 50),
        }
        for key, value in invoice_params.items():
            self.assertEqual(invoice.get(key), value)
        [renewal_item, extra_license_item] = invoice.lines
        line_item_params = {
            "amount": 8000 * 150,
            "description": "Zulip Standard - renewal",
            "discountable": False,
            "period": {
                "end": datetime_to_timestamp(self.next_year + timedelta(days=365)),
                "start": datetime_to_timestamp(self.next_year),
            },
            "plan": None,
            "proration": False,
            "quantity": 150,
        }
        for key, value in line_item_params.items():
            self.assertEqual(renewal_item.get(key), value)
        line_item_params = {
            "amount": 8000 * 50,
            "description": "Additional license (Jan 2, 2012 - Jan 2, 2013)",
            "discountable": False,
            "period": {
                "end": datetime_to_timestamp(self.next_year),
                "start": datetime_to_timestamp(self.now),
            },
            "plan": None,
            "proration": False,
            "quantity": 50,
        }
        for key, value in line_item_params.items():
            self.assertEqual(extra_license_item.get(key), value)

        with patch("corporate.views.billing_page.timezone_now", return_value=self.next_year):
            result = self.client_patch("/json/billing/plan", {"licenses_at_next_renewal": 120})
            self.assert_json_success(result)
        invoice_plans_as_needed(self.next_year + timedelta(days=365))
        stripe_customer = stripe_get_customer(
            Customer.objects.get(realm=user.realm).stripe_customer_id
        )
        [invoice, _, _] = stripe.Invoice.list(customer=stripe_customer.id)
        invoice_params = {
            "amount_due": 8000 * 120,
            "amount_paid": 0,
            "attempt_count": 0,
            "auto_advance": True,
            "billing": "send_invoice",
            "statement_descriptor": "Zulip Standard",
            "status": "open",
            "total": 8000 * 120,
        }
        for key, value in invoice_params.items():
            self.assertEqual(invoice.get(key), value)
        [renewal_item] = invoice.lines
        line_item_params = {
            "amount": 8000 * 120,
            "description": "Zulip Standard - renewal",
            "discountable": False,
            "period": {
                "end": datetime_to_timestamp(self.next_year + timedelta(days=2 * 365)),
                "start": datetime_to_timestamp(self.next_year + timedelta(days=365)),
            },
            "plan": None,
            "proration": False,
            "quantity": 120,
        }
        for key, value in line_item_params.items():
            self.assertEqual(renewal_item.get(key), value)

    def test_update_licenses_of_automatic_plan_from_billing_page(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses": 100})
            self.assert_json_error_contains(result, "Your plan is on automatic license management.")

        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            result = self.client_patch("/json/billing/plan", {"licenses_at_next_renewal": 100})
            self.assert_json_error_contains(result, "Your plan is on automatic license management.")

    def test_update_plan_with_invalid_status(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        self.login_user(self.example_user("hamlet"))

        response = self.client_patch(
            "/json/billing/plan",
            {"status": CustomerPlan.NEVER_STARTED},
        )
        self.assert_json_error_contains(response, "Invalid status")

    def test_update_plan_without_any_params(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        self.login_user(self.example_user("hamlet"))
        with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
            response = self.client_patch("/json/billing/plan", {})
        self.assert_json_error_contains(response, "Nothing to change")

    def test_update_plan_that_which_is_due_for_expiry(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        self.login_user(self.example_user("hamlet"))
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                result = self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE}
                )
                self.assert_json_success(result)
                self.assertRegexpMatches(
                    m.output[0],
                    r"INFO:corporate.stripe:Change plan status: Customer.id: \d*, CustomerPlan.id: \d*, status: 2",
                )

        with patch("corporate.lib.stripe.timezone_now", return_value=self.next_year):
            result = self.client_patch("/json/billing/plan", {"status": CustomerPlan.ACTIVE})
            self.assert_json_error_contains(
                result, "Unable to update the plan. The plan has ended."
            )

    def test_update_plan_that_which_is_due_for_replacement(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.MONTHLY, "token")

        self.login_user(self.example_user("hamlet"))
        with self.assertLogs("corporate.stripe", "INFO") as m:
            with patch("corporate.views.billing_page.timezone_now", return_value=self.now):
                result = self.client_patch(
                    "/json/billing/plan", {"status": CustomerPlan.SWITCH_TO_ANNUAL_AT_END_OF_CYCLE}
                )
                self.assert_json_success(result)
                self.assertRegexpMatches(
                    m.output[0],
                    r"INFO:corporate.stripe:Change plan status: Customer.id: \d*, CustomerPlan.id: \d*, status: 4",
                )

        with patch("corporate.lib.stripe.timezone_now", return_value=self.next_month):
            result = self.client_patch("/json/billing/plan", {})
            self.assert_json_error_contains(
                result,
                "Unable to update the plan. The plan has been expired and replaced with a new plan.",
            )

    @patch("corporate.lib.stripe.billing_logger.info")
    def test_deactivate_realm(self, mock_: Mock) -> None:
        user = self.example_user("hamlet")
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        plan = CustomerPlan.objects.get()
        self.assertEqual(plan.next_invoice_date, self.next_month)
        self.assertEqual(get_realm("zulip").plan_type, Realm.STANDARD)
        self.assertEqual(plan.status, CustomerPlan.ACTIVE)

        # Add some extra users before the realm is deactivated
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=20):
            update_license_ledger_if_needed(user.realm, self.now)

        last_ledger_entry = LicenseLedger.objects.order_by("id").last()
        self.assertEqual(last_ledger_entry.licenses, 20)
        self.assertEqual(last_ledger_entry.licenses_at_next_renewal, 20)

        do_deactivate_realm(get_realm("zulip"), acting_user=None)

        plan.refresh_from_db()
        self.assertTrue(get_realm("zulip").deactivated)
        self.assertEqual(get_realm("zulip").plan_type, Realm.LIMITED)
        self.assertEqual(plan.status, CustomerPlan.ENDED)
        self.assertEqual(plan.invoiced_through, last_ledger_entry)
        self.assertIsNone(plan.next_invoice_date)

        do_reactivate_realm(get_realm("zulip"))

        self.login_user(user)
        response = self.client_get("/billing/")
        self.assert_in_success_response(["Your organization is on the <b>Zulip Free</b>"], response)

        # The extra users added in the final month are not charged
        with patch("corporate.lib.stripe.invoice_plan") as mocked:
            invoice_plans_as_needed(self.next_month)
        mocked.assert_not_called()

        # The plan is not renewed after an year
        with patch("corporate.lib.stripe.invoice_plan") as mocked:
            invoice_plans_as_needed(self.next_year)
        mocked.assert_not_called()

    def test_reupgrade_by_billing_admin_after_realm_deactivation(self) -> None:
        user = self.example_user("hamlet")

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        do_deactivate_realm(get_realm("zulip"), acting_user=None)
        self.assertTrue(get_realm("zulip").deactivated)
        do_reactivate_realm(get_realm("zulip"))

        self.login_user(user)
        response = self.client_get("/billing/")
        self.assert_in_success_response(["Your organization is on the <b>Zulip Free</b>"], response)

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")

        self.assertEqual(Customer.objects.count(), 1)

        self.assertEqual(CustomerPlan.objects.count(), 2)

        current_plan = CustomerPlan.objects.all().order_by("id").last()
        self.assertEqual(current_plan.next_invoice_date, self.next_month)
        self.assertEqual(get_realm("zulip").plan_type, Realm.STANDARD)
        self.assertEqual(current_plan.status, CustomerPlan.ACTIVE)

        old_plan = CustomerPlan.objects.all().order_by("id").first()
        self.assertEqual(old_plan.next_invoice_date, None)
        self.assertEqual(old_plan.status, CustomerPlan.ENDED)

    @mock_stripe()
    def test_void_all_open_invoices(self, *mock: Mock) -> None:
        iago = self.example_user("iago")
        king = self.lear_user("king")

        self.assertEqual(void_all_open_invoices(iago.realm), 0)

        zulip_customer = update_or_create_stripe_customer(iago)
        lear_customer = update_or_create_stripe_customer(king)

        assert zulip_customer.stripe_customer_id
        stripe.InvoiceItem.create(
            currency="usd",
            customer=zulip_customer.stripe_customer_id,
            description="Zulip standard upgrade",
            discountable=False,
            unit_amount=800,
            quantity=8,
        )
        stripe_invoice = stripe.Invoice.create(
            auto_advance=True,
            billing="send_invoice",
            customer=zulip_customer.stripe_customer_id,
            days_until_due=30,
            statement_descriptor="Zulip Standard",
        )
        stripe.Invoice.finalize_invoice(stripe_invoice)

        assert lear_customer.stripe_customer_id
        stripe.InvoiceItem.create(
            currency="usd",
            customer=lear_customer.stripe_customer_id,
            description="Zulip standard upgrade",
            discountable=False,
            unit_amount=800,
            quantity=8,
        )
        stripe_invoice = stripe.Invoice.create(
            auto_advance=True,
            billing="send_invoice",
            customer=lear_customer.stripe_customer_id,
            days_until_due=30,
            statement_descriptor="Zulip Standard",
        )
        stripe.Invoice.finalize_invoice(stripe_invoice)

        self.assertEqual(void_all_open_invoices(iago.realm), 1)
        invoices = stripe.Invoice.list(customer=zulip_customer.stripe_customer_id)
        self.assert_length(invoices, 1)
        for invoice in invoices:
            self.assertEqual(invoice.status, "void")

        lear_stripe_customer_id = lear_customer.stripe_customer_id
        lear_customer.stripe_customer_id = None
        lear_customer.save(update_fields=["stripe_customer_id"])
        self.assertEqual(void_all_open_invoices(king.realm), 0)

        lear_customer.stripe_customer_id = lear_stripe_customer_id
        lear_customer.save(update_fields=["stripe_customer_id"])
        self.assertEqual(void_all_open_invoices(king.realm), 1)
        invoices = stripe.Invoice.list(customer=lear_customer.stripe_customer_id)
        self.assert_length(invoices, 1)
        for invoice in invoices:
            self.assertEqual(invoice.status, "void")

    def create_invoices(self, customer: Customer, num_invoices: int) -> List[stripe.Invoice]:
        invoices = []
        assert customer.stripe_customer_id is not None
        for _ in range(num_invoices):
            stripe.InvoiceItem.create(
                amount=10000,
                currency="usd",
                customer=customer.stripe_customer_id,
                description="Zulip standard",
                discountable=False,
            )
            invoice = stripe.Invoice.create(
                auto_advance=True,
                billing="send_invoice",
                customer=customer.stripe_customer_id,
                days_until_due=DEFAULT_INVOICE_DAYS_UNTIL_DUE,
                statement_descriptor="Zulip Standard",
            )
            stripe.Invoice.finalize_invoice(invoice)
            invoices.append(invoice)
        return invoices

    @mock_stripe()
    def test_downgrade_small_realms_behind_on_payments_as_needed(self, *mock: Mock) -> None:
        def create_realm(
            users_to_create: int,
            create_stripe_customer: bool,
            create_plan: bool,
            num_invoices: Optional[int] = None,
        ) -> Tuple[Realm, Optional[Customer], Optional[CustomerPlan], List[stripe.Invoice]]:
            realm_string_id = "realm_" + str(random.randrange(1, 1000000))
            realm = Realm.objects.create(string_id=realm_string_id)
            users = []
            for i in range(users_to_create):
                user = UserProfile.objects.create(
                    delivery_email=f"user-{i}-{realm_string_id}@zulip.com",
                    email=f"user-{i}-{realm_string_id}@zulip.com",
                    realm=realm,
                )
                users.append(user)

            customer = None
            if create_stripe_customer:
                customer = do_create_stripe_customer(users[0])
            plan = None
            if create_plan:
                plan, _ = self.subscribe_realm_to_monthly_plan_on_manual_license_management(
                    realm, users_to_create, users_to_create
                )
            invoices = []
            if num_invoices is not None:
                assert customer is not None
                invoices = self.create_invoices(customer, num_invoices)
            return realm, customer, plan, invoices

        class Row(NamedTuple):
            realm: Realm
            expected_plan_type: int
            plan: Optional[CustomerPlan]
            expected_plan_status: Optional[int]
            void_all_open_invoices_mock_called: bool
            email_expected_to_be_sent: bool

        rows: List[Row] = []
        realm, _, _, _ = create_realm(
            users_to_create=1, create_stripe_customer=False, create_plan=False
        )
        # To create local Customer object but no Stripe customer.
        attach_discount_to_realm(realm, Decimal(20), acting_user=None)
        rows.append(Row(realm, Realm.SELF_HOSTED, None, None, False, False))

        realm, _, _, _ = create_realm(
            users_to_create=1, create_stripe_customer=True, create_plan=False
        )
        rows.append(Row(realm, Realm.SELF_HOSTED, None, None, False, False))

        realm, _, plan, _ = create_realm(
            users_to_create=1, create_stripe_customer=True, create_plan=True
        )
        rows.append(Row(realm, Realm.STANDARD, plan, CustomerPlan.ACTIVE, False, False))

        realm, customer, plan, _ = create_realm(
            users_to_create=1, create_stripe_customer=True, create_plan=True, num_invoices=1
        )
        rows.append(Row(realm, Realm.STANDARD, plan, CustomerPlan.ACTIVE, False, False))

        realm, customer, plan, _ = create_realm(
            users_to_create=3, create_stripe_customer=True, create_plan=True, num_invoices=2
        )
        rows.append(Row(realm, Realm.LIMITED, plan, CustomerPlan.ENDED, True, True))

        realm, customer, plan, invoices = create_realm(
            users_to_create=1, create_stripe_customer=True, create_plan=True, num_invoices=2
        )
        for invoice in invoices:
            stripe.Invoice.pay(invoice, paid_out_of_band=True)
        rows.append(Row(realm, Realm.STANDARD, plan, CustomerPlan.ACTIVE, False, False))

        realm, customer, plan, _ = create_realm(
            users_to_create=20, create_stripe_customer=True, create_plan=True, num_invoices=2
        )
        rows.append(Row(realm, Realm.STANDARD, plan, CustomerPlan.ACTIVE, False, False))

        with patch("corporate.lib.stripe.void_all_open_invoices") as void_all_open_invoices_mock:
            downgrade_small_realms_behind_on_payments_as_needed()

        from django.core.mail import outbox

        for row in rows:
            row.realm.refresh_from_db()
            self.assertEqual(row.realm.plan_type, row.expected_plan_type)
            if row.plan is not None:
                row.plan.refresh_from_db()
                self.assertEqual(row.plan.status, row.expected_plan_status)
            if row.void_all_open_invoices_mock_called:
                void_all_open_invoices_mock.assert_any_call(row.realm)
            else:
                try:
                    void_all_open_invoices_mock.assert_any_call(row.realm)
                except AssertionError:
                    pass
                else:  # nocoverage
                    raise AssertionError("void_all_open_invoices_mock should not be called")

            email_found = False
            for email in outbox:
                recipient = UserProfile.objects.get(email=email.to[0])
                if recipient.realm == row.realm:
                    self.assertIn(
                        f"Your organization, http://{row.realm.string_id}.testserver, has been downgraded",
                        outbox[0].body,
                    )
                    self.assert_length(email.to, 1)
                    self.assertTrue(recipient.is_billing_admin)
                    email_found = True
            self.assertEqual(row.email_expected_to_be_sent, email_found)

    def test_update_billing_method_of_current_plan(self) -> None:
        realm = get_realm("zulip")
        customer = Customer.objects.create(realm=realm, stripe_customer_id="cus_12345")
        plan = CustomerPlan.objects.create(
            customer=customer,
            status=CustomerPlan.ACTIVE,
            billing_cycle_anchor=timezone_now(),
            billing_schedule=CustomerPlan.ANNUAL,
            tier=CustomerPlan.STANDARD,
        )
        self.assertEqual(plan.charge_automatically, False)

        iago = self.example_user("iago")
        update_billing_method_of_current_plan(realm, True, acting_user=iago)
        plan.refresh_from_db()
        self.assertEqual(plan.charge_automatically, True)
        realm_audit_log = RealmAuditLog.objects.filter(
            event_type=RealmAuditLog.REALM_BILLING_METHOD_CHANGED
        ).last()
        expected_extra_data = {"charge_automatically": plan.charge_automatically}
        self.assertEqual(realm_audit_log.acting_user, iago)
        self.assertEqual(realm_audit_log.extra_data, str(expected_extra_data))

        update_billing_method_of_current_plan(realm, False, acting_user=iago)
        plan.refresh_from_db()
        self.assertEqual(plan.charge_automatically, False)
        realm_audit_log = RealmAuditLog.objects.filter(
            event_type=RealmAuditLog.REALM_BILLING_METHOD_CHANGED
        ).last()
        expected_extra_data = {"charge_automatically": plan.charge_automatically}
        self.assertEqual(realm_audit_log.acting_user, iago)
        self.assertEqual(realm_audit_log.extra_data, str(expected_extra_data))

    @mock_stripe()
    def test_customer_has_credit_card_as_default_source(self, *mocks: Mock) -> None:
        iago = self.example_user("iago")
        customer = Customer.objects.create(realm=iago.realm)
        self.assertFalse(customer_has_credit_card_as_default_source(customer))

        customer = do_create_stripe_customer(iago)
        self.assertFalse(customer_has_credit_card_as_default_source(customer))

        customer = do_create_stripe_customer(iago, stripe_token=stripe_create_token().id)
        self.assertTrue(customer_has_credit_card_as_default_source(customer))


class RequiresBillingAccessTest(ZulipTestCase):
    def setUp(self) -> None:
        super().setUp()
        hamlet = self.example_user("hamlet")
        hamlet.is_billing_admin = True
        hamlet.save(update_fields=["is_billing_admin"])

        desdemona = self.example_user("desdemona")
        desdemona.role = UserProfile.ROLE_REALM_OWNER
        desdemona.save(update_fields=["role"])

    def test_who_can_access_json_endpoints(self) -> None:
        # Billing admins have access
        self.login_user(self.example_user("hamlet"))
        with patch("corporate.views.billing_page.do_replace_payment_source") as mocked1:
            response = self.client_post("/json/billing/sources/change", {"stripe_token": "token"})
        self.assert_json_success(response)
        mocked1.assert_called_once()

        # Realm owners have access, even if they are not billing admins
        self.login_user(self.example_user("desdemona"))
        with patch("corporate.views.billing_page.do_replace_payment_source") as mocked2:
            response = self.client_post("/json/billing/sources/change", {"stripe_token": "token"})
        self.assert_json_success(response)
        mocked2.assert_called_once()

    def test_who_cant_access_json_endpoints(self) -> None:
        def verify_user_cant_access_endpoint(
            username: str,
            endpoint: str,
            method: str,
            request_data: Dict[str, Union[str, int]],
            error_message: str,
        ) -> None:

            self.login_user(self.example_user(username))
            if method == "POST":
                response = self.client_post(endpoint, request_data)
            elif method == "PATCH":
                response = self.client_patch(endpoint, request_data)
            else:
                raise AssertionError("Invalid method")
            self.assert_json_error_contains(response, error_message)

        verify_user_cant_access_endpoint(
            "polonius",
            "/json/billing/upgrade",
            "POST",
            {
                "billing_modality": "charge_automatically",
                "schedule": "annual",
                "signed_seat_count": "signed count",
                "salt": "salt",
            },
            "Must be an organization member",
        )

        verify_user_cant_access_endpoint(
            "polonius",
            "/json/billing/sponsorship",
            "POST",
            {
                "organization-type": "event",
                "description": "event description",
                "website": "example.com",
            },
            "Must be an organization member",
        )

        for username in ["cordelia", "iago"]:
            self.login_user(self.example_user(username))
            verify_user_cant_access_endpoint(
                username,
                "/json/billing/sources/change",
                "POST",
                {"stripe_token": "token"},
                "Must be a billing administrator or an organization owner",
            )

            verify_user_cant_access_endpoint(
                username,
                "/json/billing/plan",
                "PATCH",
                {"status": 1},
                "Must be a billing administrator or an organization owner",
            )

        # Make sure that we are testing all the JSON endpoints
        # Quite a hack, but probably fine for now
        string_with_all_endpoints = str(get_resolver("corporate.urls").reverse_dict)
        json_endpoints = {
            word.strip("\"'()[],$") for word in string_with_all_endpoints.split() if "json/" in word
        }
        self.assert_length(json_endpoints, 4)


class BillingHelpersTest(ZulipTestCase):
    def test_next_month(self) -> None:
        anchor = datetime(2019, 12, 31, 1, 2, 3, tzinfo=timezone.utc)
        period_boundaries = [
            anchor,
            datetime(2020, 1, 31, 1, 2, 3, tzinfo=timezone.utc),
            # Test that this is the 28th even during leap years
            datetime(2020, 2, 28, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 3, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 4, 30, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 5, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 6, 30, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 7, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 8, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 9, 30, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 10, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 11, 30, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2020, 12, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2021, 1, 31, 1, 2, 3, tzinfo=timezone.utc),
            datetime(2021, 2, 28, 1, 2, 3, tzinfo=timezone.utc),
        ]
        with self.assertRaises(AssertionError):
            add_months(anchor, -1)
        # Explicitly test add_months for each value of MAX_DAY_FOR_MONTH and
        # for crossing a year boundary
        for i, boundary in enumerate(period_boundaries):
            self.assertEqual(add_months(anchor, i), boundary)
        # Test next_month for small values
        for last, next_ in zip(period_boundaries[:-1], period_boundaries[1:]):
            self.assertEqual(next_month(anchor, last), next_)
        # Test next_month for large values
        period_boundaries = [dt.replace(year=dt.year + 100) for dt in period_boundaries]
        for last, next_ in zip(period_boundaries[:-1], period_boundaries[1:]):
            self.assertEqual(next_month(anchor, last), next_)

    def test_compute_plan_parameters(self) -> None:
        # TODO: test rounding down microseconds
        anchor = datetime(2019, 12, 31, 1, 2, 3, tzinfo=timezone.utc)
        month_later = datetime(2020, 1, 31, 1, 2, 3, tzinfo=timezone.utc)
        year_later = datetime(2020, 12, 31, 1, 2, 3, tzinfo=timezone.utc)
        test_cases = [
            # test all possibilities, since there aren't that many
            ((True, CustomerPlan.ANNUAL, None), (anchor, month_later, year_later, 8000)),
            ((True, CustomerPlan.ANNUAL, 85), (anchor, month_later, year_later, 1200)),
            ((True, CustomerPlan.MONTHLY, None), (anchor, month_later, month_later, 800)),
            ((True, CustomerPlan.MONTHLY, 85), (anchor, month_later, month_later, 120)),
            ((False, CustomerPlan.ANNUAL, None), (anchor, year_later, year_later, 8000)),
            ((False, CustomerPlan.ANNUAL, 85), (anchor, year_later, year_later, 1200)),
            ((False, CustomerPlan.MONTHLY, None), (anchor, month_later, month_later, 800)),
            ((False, CustomerPlan.MONTHLY, 85), (anchor, month_later, month_later, 120)),
            # test exact math of Decimals; 800 * (1 - 87.25) = 101.9999999..
            ((False, CustomerPlan.MONTHLY, 87.25), (anchor, month_later, month_later, 102)),
            # test dropping of fractional cents; without the int it's 102.8
            ((False, CustomerPlan.MONTHLY, 87.15), (anchor, month_later, month_later, 102)),
        ]
        with patch("corporate.lib.stripe.timezone_now", return_value=anchor):
            for (automanage_licenses, discount, free_trial), output in test_cases:
                output_ = compute_plan_parameters(
                    automanage_licenses,
                    discount,
                    None if free_trial is None else Decimal(free_trial),
                )
                self.assertEqual(output_, output)

    def test_get_price_per_license(self) -> None:
        self.assertEqual(get_price_per_license(CustomerPlan.STANDARD, CustomerPlan.ANNUAL), 8000)
        self.assertEqual(get_price_per_license(CustomerPlan.STANDARD, CustomerPlan.MONTHLY), 800)
        self.assertEqual(
            get_price_per_license(
                CustomerPlan.STANDARD, CustomerPlan.MONTHLY, discount=Decimal(50)
            ),
            400,
        )

        with self.assertRaises(AssertionError):
            get_price_per_license(CustomerPlan.PLUS, CustomerPlan.MONTHLY)

        with self.assertRaisesRegex(InvalidBillingSchedule, "Unknown billing_schedule: 1000"):
            get_price_per_license(CustomerPlan.STANDARD, 1000)

    def test_update_or_create_stripe_customer_logic(self) -> None:
        user = self.example_user("hamlet")
        # No existing Customer object
        with patch(
            "corporate.lib.stripe.do_create_stripe_customer", return_value="returned"
        ) as mocked1:
            returned = update_or_create_stripe_customer(user, stripe_token="token")
        mocked1.assert_called_once()
        self.assertEqual(returned, "returned")

        customer = Customer.objects.create(realm=get_realm("zulip"))
        # Customer exists but stripe_customer_id is None
        with patch(
            "corporate.lib.stripe.do_create_stripe_customer", return_value="returned"
        ) as mocked2:
            returned = update_or_create_stripe_customer(user, stripe_token="token")
        mocked2.assert_called_once()
        self.assertEqual(returned, "returned")

        customer.stripe_customer_id = "cus_12345"
        customer.save()
        # Customer exists, replace payment source
        with patch("corporate.lib.stripe.do_replace_payment_source") as mocked3:
            returned_customer = update_or_create_stripe_customer(
                self.example_user("hamlet"), "token"
            )
        mocked3.assert_called_once()
        self.assertEqual(returned_customer, customer)

        # Customer exists, do nothing
        with patch("corporate.lib.stripe.do_replace_payment_source") as mocked4:
            returned_customer = update_or_create_stripe_customer(self.example_user("hamlet"), None)
        mocked4.assert_not_called()
        self.assertEqual(returned_customer, customer)

    def test_get_customer_by_realm(self) -> None:
        realm = get_realm("zulip")

        self.assertEqual(get_customer_by_realm(realm), None)

        customer = Customer.objects.create(realm=realm, stripe_customer_id="cus_12345")
        self.assertEqual(get_customer_by_realm(realm), customer)

    def test_get_current_plan_by_customer(self) -> None:
        realm = get_realm("zulip")
        customer = Customer.objects.create(realm=realm, stripe_customer_id="cus_12345")

        self.assertEqual(get_current_plan_by_customer(customer), None)

        plan = CustomerPlan.objects.create(
            customer=customer,
            status=CustomerPlan.ACTIVE,
            billing_cycle_anchor=timezone_now(),
            billing_schedule=CustomerPlan.ANNUAL,
            tier=CustomerPlan.STANDARD,
        )
        self.assertEqual(get_current_plan_by_customer(customer), plan)

        plan.status = CustomerPlan.DOWNGRADE_AT_END_OF_CYCLE
        plan.save(update_fields=["status"])
        self.assertEqual(get_current_plan_by_customer(customer), plan)

        plan.status = CustomerPlan.ENDED
        plan.save(update_fields=["status"])
        self.assertEqual(get_current_plan_by_customer(customer), None)

        plan.status = CustomerPlan.NEVER_STARTED
        plan.save(update_fields=["status"])
        self.assertEqual(get_current_plan_by_customer(customer), None)

    def test_get_current_plan_by_realm(self) -> None:
        realm = get_realm("zulip")

        self.assertEqual(get_current_plan_by_realm(realm), None)

        customer = Customer.objects.create(realm=realm, stripe_customer_id="cus_12345")
        self.assertEqual(get_current_plan_by_realm(realm), None)

        plan = CustomerPlan.objects.create(
            customer=customer,
            status=CustomerPlan.ACTIVE,
            billing_cycle_anchor=timezone_now(),
            billing_schedule=CustomerPlan.ANNUAL,
            tier=CustomerPlan.STANDARD,
        )
        self.assertEqual(get_current_plan_by_realm(realm), plan)

    def test_get_realms_to_default_discount_dict(self) -> None:
        Customer.objects.create(realm=get_realm("zulip"), stripe_customer_id="cus_1")
        lear_customer = Customer.objects.create(realm=get_realm("lear"), stripe_customer_id="cus_2")
        lear_customer.default_discount = 30
        lear_customer.save(update_fields=["default_discount"])
        zephyr_customer = Customer.objects.create(
            realm=get_realm("zephyr"), stripe_customer_id="cus_3"
        )
        zephyr_customer.default_discount = 0
        zephyr_customer.save(update_fields=["default_discount"])

        self.assertEqual(
            get_realms_to_default_discount_dict(),
            {
                "lear": Decimal("30.0000"),
            },
        )

    def test_is_realm_on_free_trial(self) -> None:
        realm = get_realm("zulip")
        self.assertFalse(is_realm_on_free_trial(realm))

        customer = Customer.objects.create(realm=realm, stripe_customer_id="cus_12345")
        plan = CustomerPlan.objects.create(
            customer=customer,
            status=CustomerPlan.ACTIVE,
            billing_cycle_anchor=timezone_now(),
            billing_schedule=CustomerPlan.ANNUAL,
            tier=CustomerPlan.STANDARD,
        )
        self.assertFalse(is_realm_on_free_trial(realm))

        plan.status = CustomerPlan.FREE_TRIAL
        plan.save(update_fields=["status"])
        self.assertTrue(is_realm_on_free_trial(realm))

    def test_is_sponsored_realm(self) -> None:
        realm = get_realm("zulip")
        self.assertFalse(is_sponsored_realm(realm))

        realm.plan_type = Realm.STANDARD_FREE
        realm.save()
        self.assertTrue(is_sponsored_realm(realm))


class LicenseLedgerTest(StripeTestCase):
    def test_add_plan_renewal_if_needed(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        self.assertEqual(LicenseLedger.objects.count(), 1)
        plan = CustomerPlan.objects.get()
        # Plan hasn't renewed yet
        make_end_of_cycle_updates_if_needed(plan, self.next_year - timedelta(days=1))
        self.assertEqual(LicenseLedger.objects.count(), 1)
        # Plan needs to renew
        # TODO: do_deactivate_user for a user, so that licenses_at_next_renewal != licenses
        new_plan, ledger_entry = make_end_of_cycle_updates_if_needed(plan, self.next_year)
        self.assertIsNone(new_plan)
        self.assertEqual(LicenseLedger.objects.count(), 2)
        ledger_params = {
            "plan": plan,
            "is_renewal": True,
            "event_time": self.next_year,
            "licenses": self.seat_count,
            "licenses_at_next_renewal": self.seat_count,
        }
        for key, value in ledger_params.items():
            self.assertEqual(getattr(ledger_entry, key), value)
        # Plan needs to renew, but we already added the plan_renewal ledger entry
        make_end_of_cycle_updates_if_needed(plan, self.next_year + timedelta(days=1))
        self.assertEqual(LicenseLedger.objects.count(), 2)

    def test_update_license_ledger_if_needed(self) -> None:
        realm = get_realm("zulip")
        # Test no Customer
        update_license_ledger_if_needed(realm, self.now)
        self.assertFalse(LicenseLedger.objects.exists())
        # Test plan not automanaged
        self.local_upgrade(self.seat_count + 1, False, CustomerPlan.ANNUAL, "token")
        plan = CustomerPlan.objects.get()
        self.assertEqual(LicenseLedger.objects.count(), 1)
        self.assertEqual(plan.licenses(), self.seat_count + 1)
        self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count + 1)
        update_license_ledger_if_needed(realm, self.now)
        self.assertEqual(LicenseLedger.objects.count(), 1)
        # Test no active plan
        plan.automanage_licenses = True
        plan.status = CustomerPlan.ENDED
        plan.save(update_fields=["automanage_licenses", "status"])
        update_license_ledger_if_needed(realm, self.now)
        self.assertEqual(LicenseLedger.objects.count(), 1)
        # Test update needed
        plan.status = CustomerPlan.ACTIVE
        plan.save(update_fields=["status"])
        update_license_ledger_if_needed(realm, self.now)
        self.assertEqual(LicenseLedger.objects.count(), 2)

    def test_update_license_ledger_for_automanaged_plan(self) -> None:
        realm = get_realm("zulip")
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        plan = CustomerPlan.objects.first()
        self.assertEqual(plan.licenses(), self.seat_count)
        self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count)
        # Simple increase
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=23):
            update_license_ledger_for_automanaged_plan(realm, plan, self.now)
            self.assertEqual(plan.licenses(), 23)
            self.assertEqual(plan.licenses_at_next_renewal(), 23)
        # Decrease
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=20):
            update_license_ledger_for_automanaged_plan(realm, plan, self.now)
            self.assertEqual(plan.licenses(), 23)
            self.assertEqual(plan.licenses_at_next_renewal(), 20)
        # Increase, but not past high watermark
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=21):
            update_license_ledger_for_automanaged_plan(realm, plan, self.now)
            self.assertEqual(plan.licenses(), 23)
            self.assertEqual(plan.licenses_at_next_renewal(), 21)
        # Increase, but after renewal date, and below last year's high watermark
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=22):
            update_license_ledger_for_automanaged_plan(
                realm, plan, self.next_year + timedelta(seconds=1)
            )
            self.assertEqual(plan.licenses(), 22)
            self.assertEqual(plan.licenses_at_next_renewal(), 22)

        ledger_entries = list(
            LicenseLedger.objects.values_list(
                "is_renewal", "event_time", "licenses", "licenses_at_next_renewal"
            ).order_by("id")
        )
        self.assertEqual(
            ledger_entries,
            [
                (True, self.now, self.seat_count, self.seat_count),
                (False, self.now, 23, 23),
                (False, self.now, 23, 20),
                (False, self.now, 23, 21),
                (True, self.next_year, 21, 21),
                (False, self.next_year + timedelta(seconds=1), 22, 22),
            ],
        )

    def test_update_license_ledger_for_manual_plan(self) -> None:
        realm = get_realm("zulip")

        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count + 1, False, CustomerPlan.ANNUAL, "token")

        plan = get_current_plan_by_realm(realm)
        assert plan is not None

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            update_license_ledger_for_manual_plan(plan, self.now, licenses=self.seat_count + 3)
            self.assertEqual(plan.licenses(), self.seat_count + 3)
            self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count + 3)

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            with self.assertRaises(AssertionError):
                update_license_ledger_for_manual_plan(plan, self.now, licenses=self.seat_count)

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            update_license_ledger_for_manual_plan(
                plan, self.now, licenses_at_next_renewal=self.seat_count
            )
            self.assertEqual(plan.licenses(), self.seat_count + 3)
            self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count)

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            with self.assertRaises(AssertionError):
                update_license_ledger_for_manual_plan(
                    plan, self.now, licenses_at_next_renewal=self.seat_count - 1
                )

        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            update_license_ledger_for_manual_plan(plan, self.now, licenses=self.seat_count + 10)
            self.assertEqual(plan.licenses(), self.seat_count + 10)
            self.assertEqual(plan.licenses_at_next_renewal(), self.seat_count + 10)

        make_end_of_cycle_updates_if_needed(plan, self.next_year)
        self.assertEqual(plan.licenses(), self.seat_count + 10)

        ledger_entries = list(
            LicenseLedger.objects.values_list(
                "is_renewal", "event_time", "licenses", "licenses_at_next_renewal"
            ).order_by("id")
        )

        self.assertEqual(
            ledger_entries,
            [
                (True, self.now, self.seat_count + 1, self.seat_count + 1),
                (False, self.now, self.seat_count + 3, self.seat_count + 3),
                (False, self.now, self.seat_count + 3, self.seat_count),
                (False, self.now, self.seat_count + 10, self.seat_count + 10),
                (True, self.next_year, self.seat_count + 10, self.seat_count + 10),
            ],
        )

        with self.assertRaises(AssertionError):
            update_license_ledger_for_manual_plan(plan, self.now)

    def test_user_changes(self) -> None:
        self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        user = do_create_user("email", "password", get_realm("zulip"), "name", acting_user=None)
        do_deactivate_user(user, acting_user=None)
        do_reactivate_user(user, acting_user=None)
        # Not a proper use of do_activate_mirror_dummy_user, but fine for this test
        do_activate_mirror_dummy_user(user, acting_user=None)
        ledger_entries = list(
            LicenseLedger.objects.values_list(
                "is_renewal", "licenses", "licenses_at_next_renewal"
            ).order_by("id")
        )
        self.assertEqual(
            ledger_entries,
            [
                (True, self.seat_count, self.seat_count),
                (False, self.seat_count + 1, self.seat_count + 1),
                (False, self.seat_count + 1, self.seat_count),
                (False, self.seat_count + 1, self.seat_count + 1),
                (False, self.seat_count + 1, self.seat_count + 1),
            ],
        )


class InvoiceTest(StripeTestCase):
    def test_invoicing_status_is_started(self) -> None:
        self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        plan = CustomerPlan.objects.first()
        plan.invoicing_status = CustomerPlan.STARTED
        plan.save(update_fields=["invoicing_status"])
        with self.assertRaises(NotImplementedError):
            invoice_plan(CustomerPlan.objects.first(), self.now)

    def test_invoice_plan_without_stripe_customer(self) -> None:
        self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL)
        plan = get_current_plan_by_realm(get_realm("zulip"))
        assert plan and plan.customer
        plan.customer.stripe_customer_id = None
        plan.customer.save(update_fields=["stripe_customer_id"])
        with self.assertRaises(BillingError) as context:
            invoice_plan(plan, timezone_now())
        self.assertRegex(
            context.exception.error_description,
            "Realm zulip has a paid plan without a Stripe customer",
        )

    @mock_stripe()
    def test_invoice_plan(self, *mocks: Mock) -> None:
        user = self.example_user("hamlet")
        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade()
        # Increase
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count + 3):
            update_license_ledger_if_needed(get_realm("zulip"), self.now + timedelta(days=100))
        # Decrease
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count):
            update_license_ledger_if_needed(get_realm("zulip"), self.now + timedelta(days=200))
        # Increase, but not past high watermark
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count + 1):
            update_license_ledger_if_needed(get_realm("zulip"), self.now + timedelta(days=300))
        # Increase, but after renewal date, and below last year's high watermark
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count + 2):
            update_license_ledger_if_needed(get_realm("zulip"), self.now + timedelta(days=400))
        # Increase, but after event_time
        with patch("corporate.lib.stripe.get_latest_seat_count", return_value=self.seat_count + 3):
            update_license_ledger_if_needed(get_realm("zulip"), self.now + timedelta(days=500))
        plan = CustomerPlan.objects.first()
        invoice_plan(plan, self.now + timedelta(days=400))

        [invoice0, invoice1] = stripe.Invoice.list(customer=plan.customer.stripe_customer_id)
        self.assertIsNotNone(invoice0.status_transitions.finalized_at)
        [item0, item1, item2] = invoice0.lines
        line_item_params = {
            "amount": int(8000 * (1 - ((400 - 366) / 365)) + 0.5),
            "description": "Additional license (Feb 5, 2013 - Jan 2, 2014)",
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.now + timedelta(days=400)),
                "end": datetime_to_timestamp(self.now + timedelta(days=2 * 365 + 1)),
            },
            "quantity": 1,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item0.get(key), value)
        line_item_params = {
            "amount": 8000 * (self.seat_count + 1),
            "description": "Zulip Standard - renewal",
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.now + timedelta(days=366)),
                "end": datetime_to_timestamp(self.now + timedelta(days=2 * 365 + 1)),
            },
            "quantity": (self.seat_count + 1),
        }
        for key, value in line_item_params.items():
            self.assertEqual(item1.get(key), value)
        line_item_params = {
            "amount": 3 * int(8000 * (366 - 100) / 366 + 0.5),
            "description": "Additional license (Apr 11, 2012 - Jan 2, 2013)",
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.now + timedelta(days=100)),
                "end": datetime_to_timestamp(self.now + timedelta(days=366)),
            },
            "quantity": 3,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item2.get(key), value)

    @mock_stripe()
    def test_fixed_price_plans(self, *mocks: Mock) -> None:
        # Also tests charge_automatically=False
        user = self.example_user("hamlet")
        self.login_user(user)
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.upgrade(invoice=True)
        plan = CustomerPlan.objects.first()
        plan.fixed_price = 100
        plan.price_per_license = 0
        plan.save(update_fields=["fixed_price", "price_per_license"])
        invoice_plan(plan, self.next_year)
        [invoice0, invoice1] = stripe.Invoice.list(customer=plan.customer.stripe_customer_id)
        self.assertEqual(invoice0.billing, "send_invoice")
        [item] = invoice0.lines
        line_item_params = {
            "amount": 100,
            "description": "Zulip Standard - renewal",
            "discountable": False,
            "period": {
                "start": datetime_to_timestamp(self.next_year),
                "end": datetime_to_timestamp(self.next_year + timedelta(days=365)),
            },
            "quantity": 1,
        }
        for key, value in line_item_params.items():
            self.assertEqual(item.get(key), value)

    def test_no_invoice_needed(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        plan = CustomerPlan.objects.first()
        self.assertEqual(plan.next_invoice_date, self.next_month)
        # Test this doesn't make any calls to stripe.Invoice or stripe.InvoiceItem
        invoice_plan(plan, self.next_month)
        plan = CustomerPlan.objects.first()
        # Test that we still update next_invoice_date
        self.assertEqual(plan.next_invoice_date, self.next_month + timedelta(days=29))

    def test_invoice_plans_as_needed(self) -> None:
        with patch("corporate.lib.stripe.timezone_now", return_value=self.now):
            self.local_upgrade(self.seat_count, True, CustomerPlan.ANNUAL, "token")
        plan = CustomerPlan.objects.first()
        self.assertEqual(plan.next_invoice_date, self.next_month)
        # Test nothing needed to be done
        with patch("corporate.lib.stripe.invoice_plan") as mocked:
            invoice_plans_as_needed(self.next_month - timedelta(days=1))
        mocked.assert_not_called()
        # Test something needing to be done
        invoice_plans_as_needed(self.next_month)
        plan = CustomerPlan.objects.first()
        self.assertEqual(plan.next_invoice_date, self.next_month + timedelta(days=29))


class TestTestClasses(ZulipTestCase):
    def test_subscribe_realm_to_manual_license_management_plan(self) -> None:
        realm = get_realm("zulip")
        plan, ledger = self.subscribe_realm_to_manual_license_management_plan(
            realm, 50, 60, CustomerPlan.ANNUAL
        )

        plan.refresh_from_db()
        self.assertEqual(plan.automanage_licenses, False)
        self.assertEqual(plan.billing_schedule, CustomerPlan.ANNUAL)
        self.assertEqual(plan.tier, CustomerPlan.STANDARD)
        self.assertEqual(plan.licenses(), 50)
        self.assertEqual(plan.licenses_at_next_renewal(), 60)

        ledger.refresh_from_db()
        self.assertEqual(ledger.plan, plan)
        self.assertEqual(ledger.licenses, 50)
        self.assertEqual(ledger.licenses_at_next_renewal, 60)

        realm.refresh_from_db()
        self.assertEqual(realm.plan_type, Realm.STANDARD)

    def test_subscribe_realm_to_monthly_plan_on_manual_license_management(self) -> None:
        realm = get_realm("zulip")
        plan, ledger = self.subscribe_realm_to_monthly_plan_on_manual_license_management(
            realm, 20, 30
        )

        plan.refresh_from_db()
        self.assertEqual(plan.automanage_licenses, False)
        self.assertEqual(plan.billing_schedule, CustomerPlan.MONTHLY)
        self.assertEqual(plan.tier, CustomerPlan.STANDARD)
        self.assertEqual(plan.licenses(), 20)
        self.assertEqual(plan.licenses_at_next_renewal(), 30)

        ledger.refresh_from_db()
        self.assertEqual(ledger.plan, plan)
        self.assertEqual(ledger.licenses, 20)
        self.assertEqual(ledger.licenses_at_next_renewal, 30)

        realm.refresh_from_db()
        self.assertEqual(realm.plan_type, Realm.STANDARD)