prep for the nook

src/routes/api/the-nook/webhooks/stripe.ts

@@ -0,0 +1,126 @@
+import type { APIEvent } from "@solidjs/start/server";
+import { env } from "~/env/server";
+import { NookConnectionFactory } from "~/server/db-connections";
+import { nookSchemaBootstrap, issueLicense } from "~/server/nook";
+import { json } from "../_lib";
+import { createHmac, timingSafeEqual } from "node:crypto";
+
+/**
+ * POST /api/the-nook/webhooks/stripe
+ *
+ * Verifies the Stripe webhook signature manually (no `stripe` npm package),
+ * handles `checkout.session.completed`: issues a license row (idempotent via
+ * the UNIQUE `stripe_session_id`) and emails the key to the buyer.
+ *
+ * Email failure is a logged warning, never a purchase failure — the license
+ * row is written before emailing, and the success page can still fetch the
+ * key via by-session.
+ */
+
+interface StripeSessionCompleted {
+  id: string;
+  type: string;
+  customer_details?: { email?: string };
+}
+
+function verifyStripeSignature(rawBody: string, signatureHeader: string): boolean {
+  const params = new Map<string, string>();
+  for (const pair of signatureHeader.split(",")) {
+    const eq = pair.indexOf("=");
+    if (eq > 0) params.set(pair.slice(0, eq), pair.slice(eq + 1));
+  }
+  const t = params.get("t");
+  const v1 = params.get("v1");
+  if (!t || !v1) return false;
+
+  const now = Math.floor(Date.now() / 1000);
+  const ts = Number(t);
+  if (!Number.isFinite(ts) || Math.abs(now - ts) > 300) return false;
+
+  const expected = createHmac("sha256", env.NOOK_STRIPE_WEBHOOK_SECRET)
+    .update(`${t}.${rawBody}`)
+    .digest("hex");
+  const provided = Buffer.from(v1, "hex");
+  const expectedBuffer = Buffer.from(expected, "hex");
+  if (provided.length !== expectedBuffer.length) return false;
+  return timingSafeEqual(provided, expectedBuffer);
+}
+
+async function emailLicenseKey(to: string, licenseKey: string): Promise<void> {
+  try {
+    await fetch("https://api.brevo.com/v3/smtp/email", {
+      method: "POST",
+      headers: {
+        "api-key": env.SENDINBLUE_KEY,
+        "content-type": "application/json",
+        accept: "application/json"
+      },
+      body: JSON.stringify({
+        sender: { email: env.EMAIL_FROM },
+        to: [{ email: to }],
+        subject: "Your The Nook license key",
+        textContent:
+          `Your The Nook license key is:\n\n${licenseKey}\n\n` +
+          `Open The Nook, go to Settings, and enter this key to activate.\n` +
+          `You can activate up to 3 devices.\n\n— The Nook`
+      })
+    });
+  } catch (error) {
+    // Purchase must not fail because email delivery did.
+    console.error("Failed to email The Nook license key:", error);
+  }
+}
+
+export async function POST(event: APIEvent) {
+  const rawBody = await event.request.text();
+  const signatureHeader = event.request.headers.get("Stripe-Signature");
+  if (!signatureHeader) {
+    return json({ error: "Missing signature" }, 400);
+  }
+  if (!verifyStripeSignature(rawBody, signatureHeader)) {
+    return json({ error: "Invalid signature" }, 400);
+  }
+
+  let payload: unknown;
+  try {
+    payload = JSON.parse(rawBody);
+  } catch {
+    return json({ error: "Invalid JSON" }, 400);
+  }
+
+  const body = payload as StripeSessionCompleted;
+  if (body.type !== "checkout.session.completed") {
+    // Unknown event types are acknowledged, not retried.
+    return json({ received: true });
+  }
+
+  const sessionId = body.id;
+  const email = body.customer_details?.email;
+  if (!sessionId || !email) {
+    console.error("checkout.session.completed missing id or email:", rawBody);
+    return json({ received: true });
+  }
+
+  await nookSchemaBootstrap;
+  const conn = NookConnectionFactory();
+
+  // Idempotency: a session that already produced a license is acknowledged
+  // without re-issuing or re-emailing.
+  const existing = await conn.execute({
+    sql: "SELECT id FROM licenses WHERE stripe_session_id = ?",
+    args: [sessionId]
+  });
+  if (existing.rows.length > 0) {
+    return json({ received: true });
+  }
+
+  try {
+    const { key } = await issueLicense(email, sessionId);
+    await emailLicenseKey(email, key);
+  } catch (error) {
+    // UNIQUE stripe_session_id conflict from a racing duplicate delivery.
+    console.error("Failed to issue The Nook license (webhook):", error);
+  }
+
+  return json({ received: true });
+}