import { createIAP } from '@nossdev/iap';

const iap = createIAP({
  products: [
    { id: 'premium_monthly', type: 'subscription', androidPlanId: 'monthly-plan' },
  ],
  backend: {
    baseUrl: 'https://api.your-app.com',
    endpoints: {
      verifyApple: '/api/iap/verify/apple',
      verifyGoogle: '/api/iap/verify/google',
      entitlements: '/api/iap/entitlements',
      restore: '/api/iap/restore',
    },
    getAuthHeaders: async () => ({
      Authorization: `Bearer ${await getAuthToken()}`,
    }),
  },
});

await iap.initialize();

const result = await iap.purchase({ productId: 'premium_monthly' });
if (result.status === 'success') {
  // backend has validated; entitlements are cached
}

// (optional) Pre-attach a UUID so it travels through StoreKit/Play Billing
// and reaches your backend on both the verify response and the eventual
// webhook — eliminates the verify/webhook race for purchases where the
// user is signed in. Either pass a string you already have or an async
// fetcher that hits your backend (which mints+saves on first call,
// returns the existing UUID on subsequent calls).
await iap.purchase({
  productId: 'premium_monthly',
  appUserId: async () => {
    const r = await fetch('/api/iap/uuid', { headers: authHeaders() });
    return (await r.json()).uuid;
  },
});