Offline Payment API for Kiosks, Vending, Aircraft and Festivals

import fetch from 'node-fetch';

async function requestPayment(deviceId: string, cardToken: string, amount: number) {
  const intent = {
    device_id: deviceId,
    card_token: cardToken,
    amount_minor: amount,
    currency: 'USD',
    context: { location: 'KIOSK-17', vertical: 'vending' }
  };

  const online = await connectivity.isOnline();

  if (!online) {
    // Evaluate locally and queue
    const decision = localAffixio.decide('card_payment', intent);
    if (!decision.allowed) return { status: 'declined_offline' };

    await offlineQueue.append({ intent, decision });
    return { status: 'approved_offline' };
  }

  // Online: call AffixIO API directly
  const res = await fetch('https://api.affix-io.com/payments/offline/intents', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.AFFIXIO_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(intent)
  });

  const body = await res.json();
  if (body.allowed) {
    printer.dispenseProduct();
    return { status: 'approved_online', proof: body.proof };
  }

  return { status: 'declined_online', reason: body.reason };
}

// Called periodically from the device when it regains connectivity
async function syncQueuedTransactions() {
  if (!await connectivity.isOnline()) return;

  const batch = await offlineQueue.readBatch(50);
  if (!batch.length) return;

  const res = await fetch('https://api.affix-io.com/payments/offline/sync', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.AFFIXIO_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ batch })
  });

  const result = await res.json();
  await offlineQueue.applyResults(result);
}