Build a Ticketed Webinar Platform

Tables: events (title, description, host_id, scheduled_at, timezone, price, early_bird_price, early_bird_deadline, capacity, seats_sold, status, video_platform, video_room_url), tickets (event_id, attendee_email, attendee_name, access_token, price_paid, paystack_ref, issued_at, used_for_live, used_for_replay).

var crypto = require('crypto');

function generateAccessToken() {
  return crypto.randomBytes(24).toString('hex'); // 48-char unique token
}

async function getCurrentPrice(event) {
  if (event.early_bird_deadline && new Date() < new Date(event.early_bird_deadline)) {
    return event.early_bird_price;
  }
  return event.price;
}

async function purchaseTicket(attendeeEmail, attendeeName, eventId) {
  var event = await db.events.findById(eventId);
  if (event.status !== 'on_sale') throw new Error('Tickets not available');
  if (event.seats_sold >= event.capacity) throw new Error('Event is sold out');

  var price = await getCurrentPrice(event);
  var reference = 'WEB-' + eventId + '-' + Date.now();

  var res = await fetch('https://api.paystack.co/transaction/initialize', {
    method: 'POST',
    headers: { Authorization: 'Bearer ' + process.env.PAYSTACK_SECRET_KEY, 'Content-Type': 'application/json' },
    body: JSON.stringify({
      email: attendeeEmail,
      amount: price,
      currency: 'NGN',
      reference,
      metadata: { event_id: eventId, attendee_name: attendeeName, attendee_email: attendeeEmail },
    }),
  });
  return (await res.json()).data.authorization_url;
}

// Webhook: issue ticket with access token
if (event.event === 'charge.success') {
  var meta = event.data.metadata;
  if (!meta.event_id) return res.sendStatus(200);

  var webinarEvent = await db.events.findById(meta.event_id);
  if (webinarEvent.seats_sold >= webinarEvent.capacity) {
    // Race condition: sold out — refund
    await fetch('https://api.paystack.co/refund', { method: 'POST', headers: { Authorization: 'Bearer ' + process.env.PAYSTACK_SECRET_KEY, 'Content-Type': 'application/json' }, body: JSON.stringify({ transaction: event.data.reference }) });
    return res.sendStatus(200);
  }

  var accessToken = generateAccessToken();
  await db.tickets.create({
    event_id: meta.event_id,
    attendee_email: meta.attendee_email,
    attendee_name: meta.attendee_name,
    access_token: accessToken,
    price_paid: event.data.amount,
    paystack_ref: event.data.reference,
    issued_at: new Date(),
  });
  await db.events.increment(meta.event_id, 'seats_sold', 1);
  await sendTicketEmail(meta.attendee_email, meta.attendee_name, webinarEvent, accessToken);
}

// Attendee joins via: /join?token=abc123
async function validateAccessToken(token, eventId, accessType) {
  var ticket = await db.tickets.findByToken(token);
  if (!ticket || ticket.event_id !== parseInt(eventId)) {
    throw { status: 403, message: 'Invalid or expired ticket.' };
  }

  var webinarEvent = await db.events.findById(eventId);

  if (accessType === 'live') {
    var now = new Date();
    var startTime = new Date(webinarEvent.scheduled_at);
    var endTime = new Date(startTime.getTime() + 180 * 60000); // 3-hour window
    if (now < new Date(startTime.getTime() - 15 * 60000)) throw { status: 403, message: 'Event has not started yet. Join 15 minutes before.' };
    if (now > endTime) throw { status: 403, message: 'Live session has ended. Access the replay instead.' };
    await db.tickets.update(ticket.id, { used_for_live: true, first_joined_at: new Date() });
  }

  if (accessType === 'replay') {
    if (webinarEvent.status !== 'replay_available') throw { status: 403, message: 'Replay not yet available.' };
    await db.tickets.update(ticket.id, { used_for_replay: true });
  }

  return { valid: true, room_url: webinarEvent.video_room_url };
}

// Refund before event (admin or automated)
async function refundTicket(ticketId) {
  var ticket = await db.tickets.findById(ticketId);
  var event = await db.events.findById(ticket.event_id);
  var hoursUntilEvent = (new Date(event.scheduled_at) - new Date()) / (1000 * 60 * 60);
  if (hoursUntilEvent < 24) throw new Error('Refund window has passed — less than 24 hours to event.');

  await fetch('https://api.paystack.co/refund', {
    method: 'POST',
    headers: { Authorization: 'Bearer ' + process.env.PAYSTACK_SECRET_KEY, 'Content-Type': 'application/json' },
    body: JSON.stringify({ transaction: ticket.paystack_ref }),
  });
  await db.tickets.update(ticketId, { status: 'refunded' });
  await db.events.decrement(ticket.event_id, 'seats_sold', 1);
}

See build a cinema ticketing system for the seat reservation and QR code ticketing pattern applied to in-person events.

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