fix: migrate billing to RR7

packages/lib/server-only/user/create-checkout-session.ts

@@ -0,0 +1,39 @@
+import type { User } from '@prisma/client';
+
+import { getCheckoutSession } from '@documenso/ee/server-only/stripe/get-checkout-session';
+import { getStripeCustomerByUser } from '@documenso/ee/server-only/stripe/get-customer';
+import { getPortalSession } from '@documenso/ee/server-only/stripe/get-portal-session';
+import { NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
+
+import { getSubscriptionsByUserId } from '../subscription/get-subscriptions-by-user-id';
+
+export type CreateCheckoutSession = {
+  user: Pick<User, 'id' | 'customerId' | 'email' | 'name'>;
+  priceId: string;
+};
+
+export const createCheckoutSession = async ({ user, priceId }: CreateCheckoutSession) => {
+  const { stripeCustomer } = await getStripeCustomerByUser(user);
+
+  const existingSubscriptions = await getSubscriptionsByUserId({ userId: user.id });
+
+  const foundSubscription = existingSubscriptions.find(
+    (subscription) =>
+      subscription.priceId === priceId &&
+      subscription.periodEnd &&
+      subscription.periodEnd >= new Date(),
+  );
+
+  if (foundSubscription) {
+    return getPortalSession({
+      customerId: stripeCustomer.id,
+      returnUrl: `${NEXT_PUBLIC_WEBAPP_URL()}/settings/billing`,
+    });
+  }
+
+  return getCheckoutSession({
+    customerId: stripeCustomer.id,
+    priceId,
+    returnUrl: `${NEXT_PUBLIC_WEBAPP_URL()}/settings/billing`,
+  });
+};