`lib/pricing.js`

29 lines
// Retail pricing rule for Fine Art America fulfilled products on the DW Shopify
// store. Steve-selected 2026-07-16 (AskUserQuestion): the DW wallcovering
// formula — retail = cost / 0.65 / 0.85 (~1.81x the FAA fulfillment cost).
//
// "cost" here = the FAA price for the exact configuration encoded in the variant
// SKU (see lib/faa-cost.js). This guarantees Shopify retail sits safely above
// fulfillment cost so an order can never lose money the way the pre-fix prices
// did (e.g. 7"x8" framed selling at $42.22 against a ~$74 FAA cost).

const DISCOUNT_A = 0.65;
const DISCOUNT_B = 0.85;

function retailFromCost(cost, { round = 'cent' } = {}) {
  if (cost == null || isNaN(cost) || cost <= 0) return null;
  let r = cost / DISCOUNT_A / DISCOUNT_B;
  if (round === 'dollar') r = Math.ceil(r);            // round UP to whole dollar
  else if (round === '.99') r = Math.ceil(r) - 0.01;   // charm price
  else r = Math.round(r * 100) / 100;                  // 2-decimal
  return r;
}

// Margin sanity: fraction of retail that is gross profit after FAA cost.
function grossMargin(cost, retail) {
  if (!retail) return null;
  return (retail - cost) / retail;
}

module.exports = { retailFromCost, grossMargin, DISCOUNT_A, DISCOUNT_B };