License Keys

// app/api/webhooks/dodo/route.ts
import { NextRequest, NextResponse } from 'next/server';
import DodoPayments from 'dodopayments';

const client = new DodoPayments({
  bearerToken: process.env.DODO_PAYMENTS_API_KEY,
  webhookKey: process.env.DODO_PAYMENTS_WEBHOOK_KEY,
  environment: process.env.DODO_PAYMENTS_ENVIRONMENT === 'live_mode' ? 'live_mode' : 'test_mode',
});

export async function POST(req: NextRequest) {
  try {
    const body = await req.text();
    const event = client.webhooks.unwrap(body, {
      headers: {
        'webhook-id': req.headers.get('webhook-id') || '',
        'webhook-signature': req.headers.get('webhook-signature') || '',
        'webhook-timestamp': req.headers.get('webhook-timestamp') || '',
      },
    });

    if (
      (event.type === 'entitlement_grant.created' || event.type === 'entitlement_grant.delivered') &&
      event.data.status === 'Delivered' &&
      event.data.license_key // other entitlement types (and Pending manual grants) have no key
    ) {
      // Dodo emails the key to the customer itself, so there is no email to send here.
      await mirrorGrant(event.data, 'active');
    }

    if (event.type === 'entitlement_grant.revoked') {
      // Dodo already disabled the key (cancellation, expiry, refund, on_hold,
      // pause, plan change, or manual revoke). Mirror it locally.
      await mirrorGrant(event.data, 'revoked');
    }

    return NextResponse.json({ received: true });
  } catch (error) {
    console.error('Webhook error:', error);
    return NextResponse.json({ error: 'Invalid signature' }, { status: 401 });
  }
}

type Grant = DodoPayments.Entitlements.EntitlementGrant;

// Webhooks can arrive out of order and be retried concurrently. Apply a grant
// only when it is newer than the stored copy (by the grant's own updated_at),
// using a conditional UPDATE so a stale "delivered" can never overwrite a newer
// "revoked". If no row exists yet - including a revocation that arrives before
// the delivery - insert one; the unique externalId keeps concurrent inserts
// safe, and the loser retries the conditional update so the newest grant wins.
async function mirrorGrant(grant: Grant, status: 'active' | 'revoked') {
  const grantUpdatedAt = new Date(grant.updated_at);
  const fields = {
    customerId: grant.customer_id,
    status,
    grantUpdatedAt,
    ...(grant.license_key && {
      key: grant.license_key.key,
      expiresAt: grant.license_key.expires_at ? new Date(grant.license_key.expires_at) : null,
      activationsLimit: grant.license_key.activations_limit,
    }),
  };

  const applyIfNewer = () =>
    prisma.license.updateMany({
      where: { externalId: grant.id, grantUpdatedAt: { lt: grantUpdatedAt } },
      data: fields,
    });

  const updated = await applyIfNewer();
  if (updated.count > 0) return;

  // Either no row yet, or the stored copy is already as new or newer.
  const inserted = await prisma.license.createMany({
    data: [{ externalId: grant.id, ...fields }],
    skipDuplicates: true,
  });
  if (inserted.count === 0) {
    // A concurrent webhook inserted the row first. It may hold an OLDER grant,
    // so re-run the conditional update; it is a no-op if the row is newer.
    await applyIfNewer();
  }
}

// Bad: validate once
if (await validateLicense(key)) {
  store.set('trusted', true);
}

// Good: validate on each startup
const isValid = await validateLicense(key);
if (!isValid) {
  // Fail closed
  process.exit(1);
}

try {
  await client.licenses.activate({ license_key: key, name: deviceName });
} catch (error: any) {
  if (error.status === 422) {
    // Show UI: "You've reached your activation limit. Deactivate a device first."
    // Provide a list of active instances so they can choose which to remove.
  }
}

// Bad: trust the client
if (localStorage.getItem('license_valid')) {
  showPremiumFeature();
}

// Good: validate server-side
const response = await fetch('/api/validate-license', {
  method: 'POST',
  body: JSON.stringify({ licenseKey }),
});
const { valid } = await response.json();
if (valid) {
  showPremiumFeature();
}

// Bad
const LICENSE_KEY = 'PRO-AAAA-BBBB-CCCC-DDDD';

// Good
const licenseKey = process.env.DODO_LICENSE_KEY;
// or read from user input / secure storage

// Bad: only store the key
store.set('license_key', key);

// Good: store both
store.set('license', {
  key,
  instanceId: response.id,
  activatedAt: new Date().toISOString(),
  lastValidatedAt: new Date().toISOString(),
});

// Bad: assume valid if offline
try {
  const valid = await validateLicense(key);
  return valid;
} catch {
  return true; // WRONG: grants access on error
}

// Good: fail closed, with optional grace period
try {
  const valid = await validateLicense(key);
  return valid;
} catch {
  // Only trust local cache if within grace period
  const lastValidated = store.get('last_validated_at');
  const daysSince = (Date.now() - lastValidated) / (1000 * 60 * 60 * 24);
  return daysSince < 30;
}