Webhook Events and Scenarios

const handleWebhookEvent = async (event) => {
  const { type, data } = event;
 
  switch (type) {
    case 'payment.completed':
      await handlePaymentCompleted(data);
      break;
 
    case 'subscription.created':
      await handleSubscriptionCreated(data);
      break;
 
    case 'subscription.updated':
      await handleSubscriptionUpdated(data);
      break;
 
    case 'subscription.cancelled':
      await handleSubscriptionCancelled(data);
      break;
 
    case 'refund.created':
      await handleRefundCreated(data);
      break;
 
    default:
      console.log(`Unhandled event type: ${type}`);
  }
};
 
// Handler implementations
const handlePaymentCompleted = async (data) => {
  const { payment, price, user, customer } = data;
 
  if (price.interval === 'lifetime') {
    // Grant lifetime access
    await grantLifetimeAccess(user.id);
    console.log(`Lifetime access granted to user ${user.id}`);
  } else {
    // Handle one-time payment
    await processOneTimePayment(payment.id, user.id);
  }
 
  // Send confirmation email
  await sendPaymentConfirmation(customer.email, price.unit_amount);
};
 
const handleSubscriptionCreated = async (data) => {
  const { subscription, user, customer } = data;
 
  if (subscription.status === 'trialing') {
    // Start trial period
    await startTrialPeriod(user.id, subscription.trial_period_end);
    console.log(`Trial started for user ${user.id}`);
  } else if (subscription.status === 'active') {
    // Activate subscription immediately
    await activateSubscription(user.id, subscription.id);
    console.log(`Subscription activated for user ${user.id}`);
  }
 
  // Send welcome email
  await sendWelcomeEmail(customer.email, subscription.status);
};

const handleEventWithOrder = async (event) => {
  const lastProcessedTime = await getLastProcessedTime(event.data.user.id);
 
  if (new Date(event.created_at) < lastProcessedTime) {
    console.log('Out of order event, handling carefully...');
    // Handle out-of-order event logic
  }
 
  await processEvent(event);
  await updateLastProcessedTime(event.data.user.id, event.created_at);
};

const processedEvents = new Set();
 
const handleIdempotentEvent = async (event) => {
  if (processedEvents.has(event.id)) {
    console.log(`Event ${event.id} already processed`);
    return;
  }
 
  await processEvent(event);
  processedEvents.add(event.id);
};