feat: integrate Stripe payment module with API + UI components

api/payments/session-status.js

@@ -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' });
+    }
+}