Customer Wallets

async function refundToWallet(customerId, refundAmount, originalPaymentId) {
  await client.customers.wallets.ledgerEntries.create(customerId, {
    amount: refundAmount, // Amount in cents
    currency: 'USD',
    entry_type: 'credit',
    reason: `Refund for payment ${originalPaymentId}`,
    idempotency_key: `refund_${originalPaymentId}`
  });
}

async function addWelcomeBonus(customerId) {
  await client.customers.wallets.ledgerEntries.create(customerId, {
    amount: 1000, // $10.00 promotional balance
    currency: 'USD',
    entry_type: 'credit',
    reason: 'Welcome bonus - $10 promotional balance',
    idempotency_key: `welcome_${customerId}`
  });
}

async function deductForPurchase(customerId, purchaseAmount, purchaseId) {
  try {
    await client.customers.wallets.ledgerEntries.create(customerId, {
      amount: purchaseAmount,
      currency: 'USD',
      entry_type: 'debit',
      reason: `Manual charge for purchase ${purchaseId}`,
      idempotency_key: `charge_${purchaseId}`
    });
  } catch (error) {
    if (error.status === 400) {
      console.log('Insufficient wallet balance');
    }
  }
}

async function addFundsSafely(customerId, amount, reason, eventId) {
  // Derive the key from the event, not from the time, so retries reuse it.
  const idempotencyKey = `credit_${customerId}_${eventId}`;

  try {
    const result = await client.customers.wallets.ledgerEntries.create(customerId, {
      amount: amount,
      currency: 'USD',
      entry_type: 'credit',
      reason: reason,
      idempotency_key: idempotencyKey
    });

    // Replaying the same idempotency_key creates no duplicate entry and
    // returns the wallet, so no special duplicate handling is required.
    return { success: true, wallet: result };
  } catch (error) {
    if (error.status === 400) {
      // e.g. insufficient balance on a debit
      return { success: false, reason: 'insufficient_balance' };
    }

    throw error;
  }
}

async function checkBalanceBeforeOperation(customerId, requiredAmount) {
  const wallets = await client.customers.wallets.list(customerId);
  const usdWallet = wallets.items.find(w => w.currency === 'USD');

  if (!usdWallet || usdWallet.balance < requiredAmount) {
    throw new Error('Insufficient funds for this operation');
  }

  return usdWallet.balance;
}