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remove network calls inside transaction.atomic()
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@devxpy
devxpy committed Jul 14, 2024
1 parent b9df617 commit e6b9955
Showing 1 changed file with 98 additions and 155 deletions.
253 changes: 98 additions & 155 deletions payments/webhooks.py
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Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
import stripe
from django.db import transaction
from loguru import logger
from requests.models import HTTPError

from app_users.models import AppUser, PaymentProvider, TransactionReason
from daras_ai_v2 import paypal
Expand All @@ -10,112 +9,6 @@
from .tasks import send_monthly_spending_notification_email


def add_balance_for_payment(
*,
uid: str,
amount: int,
invoice_id: str,
payment_provider: PaymentProvider,
charged_amount: int,
**kwargs,
):
user = AppUser.objects.get_or_create_from_uid(uid)[0]
user.add_balance(
amount=amount,
invoice_id=invoice_id,
charged_amount=charged_amount,
payment_provider=payment_provider,
**kwargs,
)

if not user.is_paying:
user.is_paying = True
user.save(update_fields=["is_paying"])

if (
user.subscription
and user.subscription.should_send_monthly_spending_notification()
):
send_monthly_spending_notification_email.delay(user.id)


@transaction.atomic
def _after_subscription_updated(
*, provider: PaymentProvider, uid: str, sub_id: str, plan: PricingPlan
):
if not is_sub_active(provider=provider, sub_id=sub_id):
# subscription is not in an active state, just ignore
logger.info(
"Subscription is not active. Ignoring event",
provider=provider,
sub_id=sub_id,
)
return

user = AppUser.objects.get_or_create_from_uid(uid)[0]
# select_for_update: we want to lock the row until we are done reading &
# updating the subscription
#
# anther transaction shouldn't update the subscription in the meantime
user: AppUser = AppUser.objects.select_for_update().get(pk=user.pk)
if not user.subscription:
# new subscription
logger.info("Creating new subscription for user", uid=uid)
user.subscription = Subscription.objects.get_or_create(
payment_provider=provider,
external_id=sub_id,
defaults={"plan": plan.db_value},
)[0]
user.subscription.plan = plan.db_value

elif is_same_sub(user.subscription, provider=provider, sub_id=sub_id):
if user.subscription.plan == plan.db_value:
# same subscription exists with the same plan in DB
logger.info("Nothing to do")
return
else:
# provider & sub_id is same, but plan is different. so we update only the plan
logger.info("Updating plan for user", uid=uid)
user.subscription.plan = plan.db_value

else:
logger.critical(
"Invalid state: last subscription was not cleared for user", uid=uid
)

# we have a different existing subscription in DB
# this is invalid state! we should cancel the subscription if it is active
if is_sub_active(
provider=user.subscription.payment_provider,
sub_id=user.subscription.external_id,
):
logger.critical(
"Found existing active subscription for user. Cancelling that...",
uid=uid,
provider=user.subscription.get_payment_provider_display(),
sub_id=user.subscription.external_id,
)
user.subscription.cancel()

logger.info("Creating new subscription for user", uid=uid)
user.subscription = Subscription(
payment_provider=provider, plan=plan, external_id=sub_id
)

user.subscription.full_clean()
user.subscription.save()
user.save(update_fields=["subscription"])


def _after_subscription_cancelled(*, provider: PaymentProvider, uid: str, sub_id: str):
user = AppUser.objects.get_or_create_from_uid(uid=uid)[0]
if user.subscription and is_same_sub(
user.subscription, provider=provider, sub_id=sub_id
):
user.subscription = None
user.save(update_fields=["subscription"])


class PaypalWebhookHandler:
PROVIDER = PaymentProvider.PAYPAL

Expand Down Expand Up @@ -158,17 +51,26 @@ def handle_subscription_updated(cls, pp_sub: paypal.Subscription):
assert pp_sub.plan_id, f"PayPal subscription {pp_sub.id} is missing plan ID"

plan = PricingPlan.get_by_paypal_plan_id(pp_sub.plan_id)
assert plan, f"Plan {pp_sub.plan_id} not found"
assert plan, f"Plan with id={pp_sub.plan_id} not found"

if pp_sub.status.lower() != "active":
logger.info(
"Subscription is not active. Ignoring event", subscription=pp_sub
)
return

_after_subscription_updated(
provider=cls.PROVIDER, uid=pp_sub.custom_id, sub_id=pp_sub.id, plan=plan
_set_user_subscription(
provider=cls.PROVIDER,
plan=plan,
uid=pp_sub.custom_id,
external_id=pp_sub.id,
)

@classmethod
def handle_subscription_cancelled(cls, pp_sub: paypal.Subscription):
assert pp_sub.custom_id, f"PayPal subscription {pp_sub.id} is missing uid"
_after_subscription_cancelled(
provider=cls.PROVIDER, uid=pp_sub.custom_id, sub_id=pp_sub.id
_remove_subscription_for_user(
provider=cls.PROVIDER, uid=pp_sub.custom_id, external_id=pp_sub.id
)


Expand Down Expand Up @@ -218,13 +120,12 @@ def handle_checkout_session_completed(cls, uid: str, session_data):
sub_id
), f"subscription_id is missing in setup_intent metadata {setup_intent}"

if is_sub_active(provider=PaymentProvider.STRIPE, sub_id=sub_id):
stripe.Subscription.modify(
sub_id, default_payment_method=setup_intent.payment_method
)
stripe.Subscription.modify(
sub_id, default_payment_method=setup_intent.payment_method
)

@classmethod
def handle_subscription_updated(cls, uid: str, stripe_sub):
def handle_subscription_updated(cls, uid: str, stripe_sub: stripe.Subscription):
logger.info(f"Stripe subscription updated: {stripe_sub.id}")

assert stripe_sub.plan, f"Stripe subscription {stripe_sub.id} is missing plan"
Expand All @@ -239,52 +140,94 @@ def handle_subscription_updated(cls, uid: str, stripe_sub):
f"PricingPlan not found for product {stripe_sub.plan.product}"
)

_after_subscription_updated(
provider=cls.PROVIDER, uid=uid, sub_id=stripe_sub.id, plan=plan
if stripe_sub.status.lower() != "active":
logger.info(
"Subscription is not active. Ignoring event", subscription=stripe_sub
)
return

_set_user_subscription(
provider=cls.PROVIDER,
plan=plan,
uid=uid,
external_id=stripe_sub.id,
)

@classmethod
def handle_subscription_cancelled(cls, uid: str, stripe_sub):
logger.info(f"Stripe subscription cancelled: {stripe_sub.id}")

_after_subscription_cancelled(
provider=cls.PROVIDER, uid=uid, sub_id=stripe_sub.id
_remove_subscription_for_user(
provider=cls.PROVIDER, uid=uid, external_id=stripe_sub.id
)


def is_same_sub(
subscription: Subscription, *, provider: PaymentProvider, sub_id: str
) -> bool:
return (
subscription.payment_provider == provider and subscription.external_id == sub_id
def add_balance_for_payment(
*,
uid: str,
amount: int,
invoice_id: str,
payment_provider: PaymentProvider,
charged_amount: int,
**kwargs,
):
user = AppUser.objects.get_or_create_from_uid(uid)[0]
user.add_balance(
amount=amount,
invoice_id=invoice_id,
charged_amount=charged_amount,
payment_provider=payment_provider,
**kwargs,
)

if not user.is_paying:
user.is_paying = True
user.save(update_fields=["is_paying"])

def is_sub_active(*, provider: PaymentProvider, sub_id: str) -> bool:
match provider:
case PaymentProvider.PAYPAL:
try:
sub = paypal.Subscription.retrieve(sub_id)
except HTTPError as e:
if e.response.status_code != 404:
# if not 404, it likely means there is a bug in our code...
# we want to know about it, but not break the end user experience
logger.exception(f"Unexpected PayPal error for sub: {sub_id}")
return False

return sub.status == "ACTIVE"

case PaymentProvider.STRIPE:
try:
sub = stripe.Subscription.retrieve(sub_id)
except stripe.error.InvalidRequestError as e:
if e.http_status != 404:
# if not 404, it likely means there is a bug in our code...
# we want to know about it, but not break the end user experience
logger.exception(f"Unexpected Stripe error for sub: {sub_id}")
return False
except stripe.error.StripeError as e:
logger.exception(f"Unexpected Stripe error for sub: {sub_id}")
return False

return sub.status == "active"
if (
user.subscription
and user.subscription.should_send_monthly_spending_notification()
):
send_monthly_spending_notification_email.delay(user.id)


def _set_user_subscription(
*, provider: PaymentProvider, plan: PricingPlan, uid: str, external_id: str
):
with transaction.atomic():
subscription, created = Subscription.objects.get_or_create(
payment_provider=provider,
external_id=external_id,
defaults=dict(plan=plan.db_value),
)
subscription.plan = plan.db_value
subscription.full_clean()
subscription.save()

user = AppUser.objects.get_or_create_from_uid(uid)[0]
existing = user.subscription

user.subscription = subscription
user.save(update_fields=["subscription"])

if not existing:
return

# cancel existing subscription if it's not the same as the new one
if existing.external_id != external_id:
existing.cancel()

# delete old db record if it exists
if existing.id != subscription.id:
existing.delete()


def _remove_subscription_for_user(
*, uid: str, provider: PaymentProvider, external_id: str
):
AppUser.objects.filter(
uid=uid,
subscription__payment_provider=provider,
subscription__external_id=external_id,
).update(
subscription=None,
)

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