Kalkulator PodatkowyMT5 dla Traderów

async function getNBPRate(currency, date) {
  const MAX_FALLBACK = 7;
  let current = date;
  
  for (let i = 0; i < MAX_FALLBACK; i++) {
    const rate = await fetchNBP(currency, current);
    if (rate) return rate; // ✓ Found
    current = getPreviousDay(current);
  }
  return null;
}

// Przeliczenie wg kursu NBP
const zyskPLN = roundTo(zysk * rate.mid, 2);
const swapPLN = roundTo(swap * rate.mid, 2);
 
// Agregacja do podsumowania
summary.profit += zyskPLN;
summary.swap += swapPLN;
summary.commission += prowizjaPLN;
 
return summary.profit - summary.commission;

for (const trade of trades) {
  const side = getSide(trade.kierunek);
  if (side === "unknown") continue;
  
  const key = trade.zlecenie
    ? `order:${trade.zlecenie}`
    : `sym:${trade.instrument}`;
  
  const group = groups.get(key);
  group[side].push(trade);
}

const CONCURRENT = 4;
const results = [];
 
for (let i = 0; i < trades.length; i += CONCURRENT) {
  const batch = trades.slice(i, i + CONCURRENT);
  const processed = await Promise.all(
    batch.map(t => processTradeNBP(t))
  );
  results.push(...processed);
  onProgress(i + batch.length, total);
}