server/webhooks/stripe.ts

import Stripe from 'stripe';
import { Request, Response } from 'express';
import { ENV } from '../_core/env';

const stripe = new Stripe(ENV.stripeSecretKey);

/**
 * Handle Stripe webhook events
 * This endpoint receives events from Stripe when payments are processed
 */
export async function handleStripeWebhook(req: Request, res: Response) {
  const sig = req.headers['stripe-signature'] as string;

  let event: Stripe.Event;

  try {
    event = stripe.webhooks.constructEvent(
      req.body,
      sig,
      ENV.stripeWebhookSecret
    );
  } catch (err) {
    console.error('[Stripe Webhook] Signature verification failed:', err);
    return res.status(400).send(`Webhook Error: ${err}`);
  }

  // Handle test events
  if (event.id.startsWith('evt_test_')) {
    console.log('[Stripe Webhook] Test event detected, returning verification response');
    return res.json({
      verified: true,
    });
  }

  try {
    switch (event.type) {
      case 'checkout.session.completed': {
        const session = event.data.object as Stripe.Checkout.Session;
        console.log('[Stripe Webhook] Checkout session completed:', session.id);
        
        // Extract metadata
        const userId = session.metadata?.user_id;
        const productId = session.metadata?.product_id;
        const customerEmail = session.customer_email;

        console.log('[Stripe Webhook] Order details:', {
          sessionId: session.id,
          userId,
          productId,
          customerEmail,
          amount: session.amount_total,
          currency: session.currency,
        });

        // TODO: Update database with order information
        // - Save order record
        // - Update user subscription status if applicable
        // - Send confirmation email
        // - Trigger fulfillment workflow

        break;
      }

      case 'payment_intent.succeeded': {
        const paymentIntent = event.data.object as Stripe.PaymentIntent;
        console.log('[Stripe Webhook] Payment intent succeeded:', paymentIntent.id);
        
        // TODO: Handle payment success
        // - Update order status
        // - Send receipt email
        // - Trigger fulfillment

        break;
      }

      case 'payment_intent.payment_failed': {
        const paymentIntent = event.data.object as Stripe.PaymentIntent;
        console.log('[Stripe Webhook] Payment intent failed:', paymentIntent.id);
        
        // TODO: Handle payment failure
        // - Update order status
        // - Send failure notification
        // - Trigger retry logic

        break;
      }

      case 'customer.subscription.created': {
        const subscription = event.data.object as Stripe.Subscription;
        console.log('[Stripe Webhook] Subscription created:', subscription.id);
        
        // TODO: Handle subscription creation
        // - Save subscription record
        // - Grant access to features
        // - Send welcome email

        break;
      }

      case 'customer.subscription.updated': {
        const subscription = event.data.object as Stripe.Subscription;
        console.log('[Stripe Webhook] Subscription updated:', subscription.id);
        
        // TODO: Handle subscription update
        // - Update subscription record
        // - Adjust feature access if plan changed

        break;
      }

      case 'customer.subscription.deleted': {
        const subscription = event.data.object as Stripe.Subscription;
        console.log('[Stripe Webhook] Subscription deleted:', subscription.id);
        
        // TODO: Handle subscription cancellation
        // - Mark subscription as cancelled
        // - Revoke access to features
        // - Send cancellation confirmation

        break;
      }

      case 'invoice.paid': {
        const invoice = event.data.object as Stripe.Invoice;
        console.log('[Stripe Webhook] Invoice paid:', invoice.id);
        
        // TODO: Handle invoice payment
        // - Update invoice status
        // - Send receipt
        // - Trigger renewal logic

        break;
      }

      case 'invoice.payment_failed': {
        const invoice = event.data.object as Stripe.Invoice;
        console.log('[Stripe Webhook] Invoice payment failed:', invoice.id);
        
        // TODO: Handle invoice payment failure
        // - Update invoice status
        // - Send retry notification
        // - Trigger dunning process

        break;
      }

      default:
        console.log('[Stripe Webhook] Unhandled event type:', event.type);
    }

    // Acknowledge receipt of event
    res.json({ received: true });
  } catch (error) {
    console.error('[Stripe Webhook] Error processing event:', error);
    res.status(500).json({ error: 'Webhook processing failed' });
  }
}