46 add stripe product endpoint (#4133)

* Add self billing feature flag

* Add two core tables for billing

* Remove useless imports

* Remove graphql decorators

* Rename subscriptionProduct table

* WIP: Add stripe config

* Add controller to get product prices

* Add billing service

* Remove unecessary package

* Simplify stripe service

* Code review returns

* Use nestjs param

* Rename subscription to basePlan

* Rename env variable

packages/twenty-server/src/core/billing/billing.service.ts

@@ -0,0 +1,43 @@
+import { Injectable } from '@nestjs/common';
+
+import Stripe from 'stripe';
+
+import { EnvironmentService } from 'src/integrations/environment/environment.service';
+
+export type PriceData = Partial<
+  Record<Stripe.Price.Recurring.Interval, Stripe.Price>
+>;
+export enum AvailableProduct {
+  BasePlan = 'base-plan',
+}
+
+@Injectable()
+export class BillingService {
+  constructor(private readonly environmentService: EnvironmentService) {}
+
+  getProductStripeId(product: AvailableProduct) {
+    if (product === AvailableProduct.BasePlan) {
+      return this.environmentService.getBillingStripeBasePlanProductId();
+    }
+  }
+
+  formatProductPrices(prices: Stripe.Price[]) {
+    const result: PriceData = {};
+
+    prices.forEach((item) => {
+      const recurringInterval = item.recurring?.interval;
+
+      if (!recurringInterval) {
+        return;
+      }
+      if (
+        !result[recurringInterval] ||
+        item.created > (result[recurringInterval]?.created || 0)
+      ) {
+        result[recurringInterval] = item;
+      }
+    });
+
+    return result;
+  }
+}