Function webhookHandler

src/pages/api/webhook/index.ts:28–127

(req: NextApiRequest, res: NextApiResponse)

});

const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
  if (req.method === "POST") {
    const buf = await buffer(req);
    const sig = req.headers["stripe-signature"]!;

    let event: Stripe.Event;

    try {
      event = stripe.webhooks.constructEvent(buf.toString(), sig, webhookSecret);
    } catch (err) {
      const errorMessage = err instanceof Error ? err.message : "Unknown error";
      // On error, log and return the error message.
      if (err! instanceof Error) console.log(err);
      console.log(`❌ Error message: ${errorMessage}`);
      res.status(400).send(`Webhook Error: ${errorMessage}`);
      return;
    }

    // Cast event data to Stripe object.
    if (event.type === "payment_intent.succeeded") {
      const paymentIntent = event.data.object as Stripe.PaymentIntent;
      const charge = await stripe.charges.retrieve(paymentIntent.latest_charge as string);

      let plan;
      try {
        plan = getPlanFromPriceId(paymentIntent.metadata.price);
      } catch (err) {
        console.log(err);
        res.status(400).send(`Invalid price id: ${paymentIntent.metadata.price}`);
        return;
      }

      const customerId = paymentIntent.customer as string;
      if (customerId) {
        // Save the stripe customer id so that we can relate this customer to future payments.
        await prisma.user.update({
          where: {
            email: paymentIntent.metadata.email,
          },
          data: {
            stripeId: customerId,
          },
        });
      }

      const user = await prisma.user.findUniqueOrThrow({
        where: { email: paymentIntent.metadata.email },
      });

      const payment: Prisma.PaymentUncheckedCreateInput = {
        userId: user.id,
        email: paymentIntent.metadata.email,
        createdAt: new Date(paymentIntent.created * 1000),
        paymentId: paymentIntent.id,
        customerId: customerId || "",
        description: plan.description,
        amount: paymentIntent.amount,
        currency: paymentIntent.currency,