fix: use @polar-sh/sdk validateEvent for webhook verification

src/app/api/payments/polar/callback/route.ts

@@ -1,10 +1,11 @@
 import { NextRequest, NextResponse } from "next/server";
+import { WebhookVerificationError } from "@polar-sh/sdk/webhooks";
 import { Query } from "node-appwrite";
 
 import { logAudit } from "@/lib/appwrite/audit";
 import { DATABASE_ID, TABLES, type SubscriptionPayment } from "@/lib/appwrite/schema";
 import { createAdminClient } from "@/lib/appwrite/server";
-import { verifyPolarWebhook } from "@/lib/payments/polar";
+import { verifyAndParsePolarWebhook } from "@/lib/payments/polar";
 
 const PRO_VALIDITY_DAYS = 30;
 
@@ -16,33 +17,30 @@ export async function POST(req: NextRequest): Promise<NextResponse> {
     return NextResponse.json({ error: "invalid body" }, { status: 400 });
   }
 
-  // Svix tüm headerları obje olarak alır
   const headers: Record<string, string> = {};
   req.headers.forEach((value, key) => { headers[key] = value; });
 
-  if (!verifyPolarWebhook(headers, rawBody)) {
-    console.error("[polar/callback] signature mismatch");
-    return NextResponse.json({ error: "signature mismatch" }, { status: 403 });
-  }
-
-  let event: { type: string; data: Record<string, unknown> };
+  let event: ReturnType<typeof verifyAndParsePolarWebhook>;
   try {
-    event = JSON.parse(rawBody) as typeof event;
-  } catch {
-    return NextResponse.json({ error: "invalid json" }, { status: 400 });
+    event = verifyAndParsePolarWebhook(headers, rawBody);
+  } catch (e) {
+    if (e instanceof WebhookVerificationError) {
+      console.error("[polar/callback] signature mismatch");
+      return NextResponse.json({ error: "signature mismatch" }, { status: 403 });
+    }
+    return NextResponse.json({ error: "invalid payload" }, { status: 400 });
   }
 
   // order.created veya checkout.updated (status=confirmed) eventlerini işle
   const isOrderCreated = event.type === "order.created";
   const isCheckoutConfirmed =
-    event.type === "checkout.updated" &&
-    (event.data as { status?: string }).status === "confirmed";
+    event.type === "checkout.updated" && event.data.status === "confirmed";
 
   if (!isOrderCreated && !isCheckoutConfirmed) {
     return new NextResponse("OK", { status: 200 });
   }
 
-  const metadata = (event.data as { metadata?: Record<string, string> }).metadata ?? {};
+  const metadata = (event.data.metadata ?? {}) as Record<string, string>;
   const crmOrderId = metadata.crm_order_id ?? "";
 
   if (!crmOrderId) {

src/lib/payments/polar.ts

@@ -1,6 +1,6 @@
 import "server-only";
 
-import { Webhook } from "svix";
+import { validateEvent, WebhookVerificationError } from "@polar-sh/sdk/webhooks";
 
 const POLAR_API_BASE = "https://api.polar.sh";
 const ACCESS_TOKEN = process.env.POLAR_ACCESS_TOKEN ?? "";
@@ -52,19 +52,11 @@ export async function createPolarCheckout(params: {
   return res.json() as Promise<PolarCheckout>;
 }
 
-// Svix kullanarak Polar webhook imzasını doğrula
-export function verifyPolarWebhook(
+// Polar resmi SDK ile webhook doğrulama ve parse
+// Hata fırlatırsa imza geçersiz demektir
+export function verifyAndParsePolarWebhook(
   headers: Record<string, string>,
   rawBody: string,
-): boolean {
-  if (!WEBHOOK_SECRET) return false;
-  try {
-    // Svix whsec_ prefix bekler; polar_whs_ → whsec_ dönüşümü
-    const secret = WEBHOOK_SECRET.replace(/^polar_whs_/, "whsec_");
-    const wh = new Webhook(secret);
-    wh.verify(rawBody, headers);
-    return true;
-  } catch {
-    return false;
-  }
+): ReturnType<typeof validateEvent> {
+  return validateEvent(rawBody, headers, WEBHOOK_SECRET);
 }