const subscription = await lettr.billing.getSubscription();

console.log({
  plan: subscription.plan,
  status: subscription.status,
  currentPeriodEnd: subscription.currentPeriodEnd,
  emailsUsed: subscription.usage.emails,
  emailsLimit: subscription.limits.emails
});

await lettr.billing.updateSubscription({
  plan: 'pro'
});

await lettr.billing.addPaymentMethod({
  type: 'card',
  token: 'tok_xxx'  // From Stripe.js
});

const methods = await lettr.billing.listPaymentMethods();

methods.forEach(method => {
  console.log({
    id: method.id,
    type: method.type,
    last4: method.card.last4,
    expiry: `${method.card.expMonth}/${method.card.expYear}`,
    isDefault: method.isDefault
  });
});

await lettr.billing.setDefaultPaymentMethod('pm_xxx');

const invoices = await lettr.billing.listInvoices();

invoices.forEach(invoice => {
  console.log({
    id: invoice.id,
    amount: invoice.amount,
    status: invoice.status,
    pdfUrl: invoice.pdfUrl,
    createdAt: invoice.createdAt
  });
});

const pdf = await lettr.billing.downloadInvoice('inv_xxx');

const usage = await lettr.billing.getUsage();

console.log({
  emails: {
    used: usage.emails.used,
    limit: usage.emails.limit,
    percentage: usage.emails.percentage
  },
  resetDate: usage.resetDate
});

const history = await lettr.billing.getUsageHistory({
  months: 6
});

history.forEach(month => {
  console.log(`${month.period}: ${month.emails} emails`);
});

await lettr.billing.updateAlerts({
  emailUsageThreshold: 80,  // Alert at 80% usage
  notifyEmails: ['billing@company.com']
});

await lettr.billing.cancelSubscription({
  reason: 'No longer needed',
  feedback: 'Optional feedback'
});

const portalUrl = await lettr.billing.createPortalSession();
// Redirect user to portalUrl