Refactor billing gateway and enhance localization

Refactored the 'plan-picker' component in the billing gateway to remove unwanted line items and improve checkout session and subscription handling. Enhanced the localization support by adding translations in the plan picker and introduced a new function to check trial eligibility so that existing customers can't start a new trial period. These changes enhance the usability of the application across different regions and provide accurate trial period conditions.

packages/billing/src/create-billing-schema.ts

@@ -226,3 +226,20 @@ export function getProductPlanPair(
 
   throw new Error('Plan not found');
 }
+
+export function getProductPlanPairByVariantId(
+  config: z.infer<typeof BillingSchema>,
+  planId: string,
+) {
+  for (const product of config.products) {
+    for (const plan of product.plans) {
+      for (const lineItem of plan.lineItems) {
+        if (lineItem.id === planId) {
+          return { product, plan };
+        }
+      }
+    }
+  }
+
+  throw new Error('Plan not found');
+}

packages/billing/src/services/billing-webhook-handler.service.ts

@@ -3,26 +3,42 @@ import { Database } from '@kit/supabase/database';
 type UpsertSubscriptionParams =
   Database['public']['Functions']['upsert_subscription']['Args'];
 
+type UpsertOrderParams =
+  Database['public']['Functions']['upsert_order']['Args'];
+
 /**
- * Represents an abstract class for handling billing webhook events.
+ * @name BillingWebhookHandlerService
+ * @description Represents an abstract class for handling billing webhook events.
  */
 export abstract class BillingWebhookHandlerService {
+  // Verifies the webhook signature - should throw an error if the signature is invalid
   abstract verifyWebhookSignature(request: Request): Promise<unknown>;
 
   abstract handleWebhookEvent(
     event: unknown,
     params: {
+      // this method is called when a checkout session is completed
       onCheckoutSessionCompleted: (
-        subscription: UpsertSubscriptionParams,
+        subscription: UpsertSubscriptionParams | UpsertOrderParams,
         customerId: string,
       ) => Promise<unknown>;
 
+      // this method is called when a subscription is updated
       onSubscriptionUpdated: (
         subscription: UpsertSubscriptionParams,
         customerId: string,
       ) => Promise<unknown>;
 
+      // this method is called when a subscription is deleted
       onSubscriptionDeleted: (subscriptionId: string) => Promise<unknown>;
+
+      // this method is called when a payment is succeeded. This is used for
+      // one-time payments
+      onPaymentSucceeded: (sessionId: string) => Promise<unknown>;
+
+      // this method is called when a payment is failed. This is used for
+      // one-time payments
+      onPaymentFailed: (sessionId: string) => Promise<unknown>;
     },
   ): Promise<unknown>;
 }