State Lifecycles

async function waitForCompletion(transactionId, maxAttempts = 30) {
  const terminalStates = ['completed', 'failed', 'canceled', 'reversed', 'rejected', 'invalid', 'timed_out'];

  for (let i = 0; i < maxAttempts; i++) {
    const response = await fetch(`https://api.platform.dakota.xyz/auto-transactions/${transactionId}`, {
      headers: { 'x-api-key': API_KEY }
    });
    const transaction = await response.json();

    if (terminalStates.includes(transaction.status)) {
      return transaction;
    }

    // Wait before next poll (exponential backoff)
    await new Promise(r => setTimeout(r, Math.min(1000 * Math.pow(2, i), 30000)));
  }

  throw new Error('Transaction did not complete within expected time');
}

// Webhook handler for transaction status changes
app.post('/webhooks/dakota', (req, res) => {
  const event = req.body;

  if (event.type === 'transaction.status_changed') {
    const { transaction_id, old_status, new_status } = event.data;

    console.log(`Transaction ${transaction_id}: ${old_status} → ${new_status}`);

    // Handle terminal states
    if (['completed', 'failed', 'canceled'].includes(new_status)) {
      // Update your database, notify user, etc.
    }
  }

  res.status(200).send('OK');
});