Automate Store Inventory Pricing

const API_BASE = "https://api.tcgapi.dev/v1";
const API_KEY = "tcg_live_your_key_here";
const headers = { "X-API-Key": API_KEY };

// Your inventory: an array of items from your POS or database
const inventory = [
  { sku: "PKM-001", cardId: 512842, printing: "Foil", quantity: 3 },
  { sku: "PKM-002", cardId: 510033, printing: "Normal", quantity: 12 },
  { sku: "MTG-001", cardId: 301455, printing: "Normal", quantity: 1 },
  // ... thousands more
];

// Tiered margin rules based on market price
function calculateSellPrice(marketPrice, change7d) {
  if (marketPrice === null || marketPrice <= 0) return null;

  let margin;
  if (marketPrice >= 50)       margin = 1.10;  // 10% on high-value cards
  else if (marketPrice >= 10)  margin = 1.15;  // 15% on mid-range
  else if (marketPrice >= 1)   margin = 1.25;  // 25% on budget singles
  else                         margin = 1.50;  // 50% on bulk (floor $0.25)

  // Increase margin on trending cards (up 10%+ in 7 days)
  if (change7d > 10) margin += 0.05;

  const raw = marketPrice * margin;
  // Round to nearest $0.25 for pricing labels
  return Math.max(0.25, Math.ceil(raw * 4) / 4);
}

// Calculate buy price (what you'd offer for the card)
function calculateBuyPrice(marketPrice, lowPrice) {
  if (!marketPrice || marketPrice < 0.50) return 0;
  const basePrice = lowPrice || marketPrice;
  // Offer 40-60% of low price depending on value
  const buyRate = marketPrice >= 20 ? 0.60 : 0.40;
  return Math.floor(basePrice * buyRate * 100) / 100;
}

// Batch pricing: fetch by set for efficiency
async function priceBySet(setId) {
  const res = await fetch(
    `${API_BASE}/sets/${setId}/prices`,
    { headers }
  );
  return await res.json();
}

// Price individual cards not covered by set batches
async function priceSingleCard(cardId) {
  const res = await fetch(
    `${API_BASE}/cards/${cardId}/prices`,
    { headers }
  );
  return await res.json();
}

// Generate updated price list
async function updatePrices(inventory) {
  const updates = [];

  for (const item of inventory) {
    const priceData = await priceSingleCard(item.cardId);

    const marketPrice = item.printing === "Foil"
      ? priceData.foil_market_price
      : priceData.market_price;

    const lowPrice = item.printing === "Foil"
      ? priceData.foil_low_price
      : priceData.low_price;

    const sellPrice = calculateSellPrice(marketPrice, priceData.change_7d || 0);
    const buyPrice = calculateBuyPrice(marketPrice, lowPrice);

    updates.push({
      sku: item.sku,
      card_name: priceData.card_name,
      market_price: marketPrice,
      sell_price: sellPrice,
      buy_price: buyPrice,
      change_7d: priceData.change_7d,
    });
  }

  return updates;
}

// Run and output results
const priceUpdates = await updatePrices(inventory);
console.log("SKU | Card | Market | Sell | Buy | 7d Change");
console.log("-".repeat(60));
priceUpdates.forEach(u => {
  console.log(
    `${u.sku} | ${u.card_name} | $${u.market_price?.toFixed(2) ?? "N/A"}` +
    ` | $${u.sell_price?.toFixed(2) ?? "N/A"} | $${u.buy_price?.toFixed(2) ?? "0.00"}` +
    ` | ${u.change_7d?.toFixed(1) ?? "—"}%`
  );
});