feat: integrate Stripe payment module with API + UI components

2026-06-09 21:10:57 +05:30
parent 944a745892
commit 5eb06b2809
25 changed files with 1434 additions and 1 deletions
@@ -0,0 +1,85 @@
+/**
+ * Stripe — Create Checkout Session
+ * --------------------------------
+ * Creates a Stripe-hosted Checkout Session and returns its URL so the frontend
+ * can redirect the customer to Stripe's secure payment page. We never see or
+ * store card details — that is the whole point of using hosted Checkout.
+ *
+ * Flow:  Pay Now → POST here → Stripe Session → redirect to session.url →
+ *        Stripe hosted page → success_url / cancel_url back to the app.
+ *
+ * Env (set in Vercel project settings, and .env locally for `vercel dev`):
+ *   STRIPE_SECRET_KEY      sk_live_… / sk_test_…   (server only — never exposed)
+ *
+ * If STRIPE_SECRET_KEY is missing we return 503 with a clear message instead of
+ * crashing, so the module degrades gracefully until credentials are provided.
+ */
+
+// Server-side source of truth for invoice amounts. Prices are resolved HERE,
+// never trusted from the client, so a tampered request can't change the amount.
+// In production this would be a DB/CRM lookup; mirrors src/modules/payments/data/invoices.js.
+const INVOICES = {
+    'INV-2041': { title: 'Roof Repair — Leak Detection & Shingle Replacement', amount: 184500, currency: 'usd' },
+    'INV-2039': { title: 'Full Roof Inspection & Storm Damage Report',        amount: 32500,  currency: 'usd' },
+    'INV-2012': { title: 'Gutter Cleaning & Maintenance Plan (Q1)',            amount: 14900,  currency: 'usd' },
+};
+
+export default async function handler(req, res) {
+    if (req.method !== 'POST') {
+        return res.status(405).json({ error: 'Method not allowed' });
+    }
+
+    const secretKey = (process.env.STRIPE_SECRET_KEY || '').trim();
+    if (!secretKey) {
+        return res.status(503).json({
+            error: 'Stripe is not configured. Set STRIPE_SECRET_KEY to enable payments.',
+            code: 'stripe_not_configured',
+        });
+    }
+
+    try {
+        const { invoiceId, customerEmail } = req.body || {};
+        const invoice = INVOICES[invoiceId];
+        if (!invoice) {
+            return res.status(404).json({ error: `Unknown invoice: ${invoiceId}` });
+        }
+
+        // Lazy import keeps the module out of the cold-start path when unconfigured.
+        const Stripe = (await import('stripe')).default;
+        const stripe = new Stripe(secretKey, { apiVersion: '2024-06-20' });
+
+        // Where Stripe sends the customer back. Derive the app origin from the
+        // request so this works across local/preview/production without config.
+        const origin =
+            req.headers.origin ||
+            (req.headers.host ? `https://${req.headers.host}` : '');
+
+        const session = await stripe.checkout.sessions.create({
+            mode: 'payment',
+            payment_method_types: ['card'],
+            line_items: [
+                {
+                    quantity: 1,
+                    price_data: {
+                        currency: invoice.currency,
+                        unit_amount: invoice.amount, // integer, in cents
+                        product_data: {
+                            name: invoice.title,
+                            metadata: { invoiceId },
+                        },
+                    },
+                },
+            ],
+            ...(customerEmail ? { customer_email: customerEmail } : {}),
+            // Echoed back on the session + every webhook event for reconciliation.
+            metadata: { invoiceId },
+            success_url: `${origin}/payments/success?session_id={CHECKOUT_SESSION_ID}`,
+            cancel_url: `${origin}/payments/cancel?invoice=${encodeURIComponent(invoiceId)}`,
+        });
+
+        return res.status(200).json({ id: session.id, url: session.url });
+    } catch (err) {
+        console.error('[create-checkout-session] error:', err.message);
+        return res.status(500).json({ error: err.message || 'Failed to create checkout session' });
+    }
+}
@@ -0,0 +1,55 @@
+/**
+ * Stripe — Retrieve Checkout Session status
+ * -----------------------------------------
+ * The success return page calls this with the `session_id` Stripe appended to
+ * the success_url. We retrieve the session server-side (using the secret key)
+ * and return a trimmed, safe status object the UI can render and record.
+ *
+ * Returning here does NOT replace the webhook — the webhook is the authoritative
+ * record of truth (it fires even if the customer closes the tab). This endpoint
+ * just gives the returning customer immediate, verified confirmation.
+ *
+ * Env:  STRIPE_SECRET_KEY
+ */
+
+export default async function handler(req, res) {
+    if (req.method !== 'GET') {
+        return res.status(405).json({ error: 'Method not allowed' });
+    }
+
+    const secretKey = (process.env.STRIPE_SECRET_KEY || '').trim();
+    if (!secretKey) {
+        return res.status(503).json({
+            error: 'Stripe is not configured.',
+            code: 'stripe_not_configured',
+        });
+    }
+
+    const sessionId = req.query?.session_id;
+    if (!sessionId) {
+        return res.status(400).json({ error: 'session_id is required' });
+    }
+
+    try {
+        const Stripe = (await import('stripe')).default;
+        const stripe = new Stripe(secretKey, { apiVersion: '2024-06-20' });
+
+        const session = await stripe.checkout.sessions.retrieve(sessionId);
+
+        return res.status(200).json({
+            id: session.id,
+            // status: open | complete | expired
+            status: session.status,
+            // payment_status: paid | unpaid | no_payment_required
+            paymentStatus: session.payment_status,
+            amountTotal: session.amount_total,
+            currency: session.currency,
+            customerEmail: session.customer_details?.email || null,
+            invoiceId: session.metadata?.invoiceId || null,
+            created: session.created ? session.created * 1000 : null,
+        });
+    } catch (err) {
+        console.error('[session-status] error:', err.message);
+        return res.status(500).json({ error: err.message || 'Failed to retrieve session' });
+    }
+}
@@ -0,0 +1,27 @@
+/**
+ * Stripe — Transaction history
+ * ----------------------------
+ * Returns the payment records written by the webhook (the server-side source of
+ * truth). Reads from Vercel KV when connected; returns an empty list otherwise
+ * so the frontend degrades gracefully and falls back to its local record.
+ *
+ * GET /api/payments/transactions  ->  { transactions: [...] }
+ */
+
+export default async function handler(req, res) {
+    if (req.method !== 'GET') {
+        return res.status(405).json({ error: 'Method not allowed' });
+    }
+
+    try {
+        const { kv } = await import('@vercel/kv');
+        const raw = await kv.lrange('payments:transactions', 0, 199);
+        const transactions = (raw || []).map((item) =>
+            typeof item === 'string' ? JSON.parse(item) : item
+        );
+        return res.status(200).json({ transactions });
+    } catch {
+        // KV not configured — the frontend will use its local record instead.
+        return res.status(200).json({ transactions: [] });
+    }
+}
@@ -0,0 +1,125 @@
+/**
+ * Stripe — Webhook receiver
+ * -------------------------
+ * The authoritative record of truth for payments. Stripe POSTs events here;
+ * we verify the signature, then react to payment lifecycle events. This fires
+ * server-to-server even if the customer closes their browser, so the
+ * transaction record must be written here (not only on the success page).
+ *
+ * Configure in the Stripe Dashboard → Developers → Webhooks:
+ *   Endpoint URL:  https://<your-app>.vercel.app/api/payments/webhook
+ *   Events:        checkout.session.completed,
+ *                  checkout.session.async_payment_succeeded,
+ *                  checkout.session.async_payment_failed,
+ *                  checkout.session.expired
+ *
+ * Env:
+ *   STRIPE_SECRET_KEY        sk_…       (to construct the Stripe client)
+ *   STRIPE_WEBHOOK_SECRET    whsec_…    (to verify the signature)
+ *
+ * Local testing:  `stripe listen --forward-to localhost:5173/api/payments/webhook`
+ *
+ * Persistence uses Vercel KV when connected (same optional pattern as
+ * api/hail-webhook.js); without KV it logs the event and ack's 200.
+ */
+
+// Stripe requires the *raw* request body to verify the signature, so the
+// default JSON body parser must be disabled for this route.
+export const config = { api: { bodyParser: false } };
+
+async function readRawBody(req) {
+    const chunks = [];
+    for await (const chunk of req) {
+        chunks.push(typeof chunk === 'string' ? Buffer.from(chunk) : chunk);
+    }
+    return Buffer.concat(chunks);
+}
+
+/** Persist a payment record (best-effort; no-op without Vercel KV). */
+async function recordPayment(record) {
+    try {
+        const { kv } = await import('@vercel/kv');
+        // Keep a capped, newest-first list of transactions.
+        await kv.lpush('payments:transactions', JSON.stringify(record));
+        await kv.ltrim('payments:transactions', 0, 199);
+        if (record.invoiceId && record.status === 'paid') {
+            await kv.set(`payments:invoice:${record.invoiceId}`, 'paid');
+        }
+        console.log('[payments/webhook] recorded in KV:', record.id);
+    } catch {
+        console.log('[payments/webhook] KV unavailable — event received but not persisted:', record);
+    }
+}
+
+export default async function handler(req, res) {
+    if (req.method !== 'POST') {
+        return res.status(405).json({ error: 'Method not allowed' });
+    }
+
+    const secretKey = (process.env.STRIPE_SECRET_KEY || '').trim();
+    const webhookSecret = (process.env.STRIPE_WEBHOOK_SECRET || '').trim();
+    if (!secretKey || !webhookSecret) {
+        return res.status(503).json({ error: 'Stripe webhook is not configured.' });
+    }
+
+    let event;
+    try {
+        const Stripe = (await import('stripe')).default;
+        const stripe = new Stripe(secretKey, { apiVersion: '2024-06-20' });
+
+        const rawBody = await readRawBody(req);
+        const signature = req.headers['stripe-signature'];
+        event = stripe.webhooks.constructEvent(rawBody, signature, webhookSecret);
+    } catch (err) {
+        // Signature verification failed — reject (could be a forged request).
+        console.error('[payments/webhook] signature verification failed:', err.message);
+        return res.status(400).send(`Webhook Error: ${err.message}`);
+    }
+
+    try {
+        switch (event.type) {
+            case 'checkout.session.completed':
+            case 'checkout.session.async_payment_succeeded': {
+                const s = event.data.object;
+                await recordPayment({
+                    id: s.id,
+                    invoiceId: s.metadata?.invoiceId || null,
+                    amount: s.amount_total,
+                    currency: s.currency,
+                    customerEmail: s.customer_details?.email || null,
+                    status: s.payment_status === 'paid' ? 'paid' : s.payment_status,
+                    eventType: event.type,
+                    createdAt: new Date().toISOString(),
+                });
+                break;
+            }
+            case 'checkout.session.async_payment_failed': {
+                const s = event.data.object;
+                await recordPayment({
+                    id: s.id,
+                    invoiceId: s.metadata?.invoiceId || null,
+                    amount: s.amount_total,
+                    currency: s.currency,
+                    status: 'failed',
+                    eventType: event.type,
+                    createdAt: new Date().toISOString(),
+                });
+                break;
+            }
+            case 'checkout.session.expired': {
+                const s = event.data.object;
+                console.log('[payments/webhook] checkout session expired/cancelled:', s.id);
+                break;
+            }
+            default:
+                // Unhandled event types are acknowledged so Stripe stops retrying.
+                console.log('[payments/webhook] unhandled event:', event.type);
+        }
+    } catch (err) {
+        console.error('[payments/webhook] handler error:', err.message);
+        // Still 200 below if we got a valid event — returning 500 makes Stripe
+        // retry, which is only desirable for transient persistence failures.
+    }
+
+    return res.status(200).json({ received: true });
+}