function isSaleActive(product) {
  if (product.sale_price_cents == null) return false;
  if (product.sale_price_cents >= product.price_cents) return false;
  if (product.sale_ends_at && new Date(product.sale_ends_at) <= new Date()) return false;
  return true;
}

function getEffectivePriceCents(product) {
  return isSaleActive(product) ? product.sale_price_cents : product.price_cents;
}

function salePercent(product) {
  if (!isSaleActive(product) || !product.price_cents) return 0;
  return Math.round(
    ((product.price_cents - product.sale_price_cents) / product.price_cents) * 100
  );
}

module.exports = { isSaleActive, getEffectivePriceCents, salePercent };