server.js

const express = require("express");
const app = express();
const { resolve } = require("path");
// Copy the .env.example in the root into a .env file in this folder
const env = require("dotenv").config({ path: "./.env" });
const stripe = require("stripe")(process.env.STRIPE_SECRET_KEY);

app.use(express.static(process.env.STATIC_DIR));
app.use(
  express.json({
    // We need the raw body to verify webhnook signatures.
    // Let's compute it only when hitting the Stripe webhook endpoint.
    verify: function(req, res, buf) {
      if (req.originalUrl.startsWith("/webhook")) {
        req.rawBody = buf.toString();
      }
    }
  })
);

app.get("/", (req, res) => {
  const path = resolve(process.env.STATIC_DIR + "/index.html");
  res.sendFile(path);
});

app.get("/custom", (req, res) => {
  const path = resolve(process.env.STATIC_DIR + "/custom.html");
  res.sendFile(path);
});

app.get("/config", (req, res) => {
  res.send({
    publicKey: process.env.STRIPE_PUBLISHABLE_KEY,
    currency: process.env.CURRENCY
  });
});

// Fetch the Checkout Session to display the JSON result on the success page
app.get("/checkout-session", async (req, res) => {
  const { sessionId } = req.query;
  const session = await stripe.checkout.sessions.retrieve(sessionId);
  res.send(session);
});

app.post("/create-checkout-session", async (req, res) => {
  const domainURL = process.env.DOMAIN;
  const { cart } = req.body;
  console.log(cart)
  // Create new Checkout Session for the order
  // Other optional params include:
  // [billing_address_collection] - to display billing address details on the page
  // [customer] - if you have an existing Stripe Customer ID
  // [payment_intent_data] - lets capture the payment later
  // [customer_email] - lets you prefill the email input in the form
  // For full details see https://stripe.com/docs/api/checkout/sessions/create
  session = await stripe.checkout.sessions.create({
    billing_address_collection: 'required',
    payment_method_types: ["card"],
    line_items: cart,
    // ?session_id={CHECKOUT_SESSION_ID} means the redirect will have the session ID set as a query param
    success_url: `${domainURL}/success.html?session_id={CHECKOUT_SESSION_ID}`,
    cancel_url: `${domainURL}/canceled.html`
  });

  res.send({
    sessionId: session.id
  });
});

// Webhook handler for asynchronous events.
app.post("/webhook", async (req, res) => {
  let data;
  let eventType;
  // Check if webhook signing is configured.
  if (process.env.STRIPE_WEBHOOK_SECRET) {
    // Retrieve the event by verifying the signature using the raw body and secret.
    let event;
    let signature = req.headers["stripe-signature"];

    try {
      event = stripe.webhooks.constructEvent(
        req.rawBody,
        signature,
        process.env.STRIPE_WEBHOOK_SECRET
      );
    } catch (err) {
      console.log(`⚠️  Webhook signature verification failed.`);
      return res.sendStatus(400);
    }
    // Extract the object from the event.
    data = event.data;
    eventType = event.type;
  } else {
    // Webhook signing is recommended, but if the secret is not configured in `config.js`,
    // retrieve the event data directly from the request body.
    data = req.body.data;
    eventType = req.body.type;
  }

  if (eventType === "checkout.session.completed") {
    console.log(`🔔  Payment received!`);
  }

  res.sendStatus(200);
});
const port = process.env.PORT || 4242;
app.listen(port, () => console.log(`Node server listening on port ${port}!`));