fix: calculate stay totals

server.js

@@ -22,6 +22,8 @@ const DEFAULT_PRICE_HISTORY_FILE = path.join(__dirname, 'price-watch', 'history.
 const PRICE_HISTORY_FILE = process.env.PRICE_HISTORY_FILE
   ? path.resolve(process.env.PRICE_HISTORY_FILE)
   : DEFAULT_PRICE_HISTORY_FILE;
+const TRIP_CHECK_IN = process.env.TRIP_CHECK_IN || '2027-02-03';
+const TRIP_CHECK_OUT = process.env.TRIP_CHECK_OUT || '2027-02-07';
 
 app.use(cors());
 app.use(express.json());
@@ -67,6 +69,15 @@ function normalizeSourceLabel(value) {
   return String(value || 'Unknown source').trim() || 'Unknown source';
 }
 
+function formatCurrencyValue(value, currency = 'USD') {
+  if (typeof value !== 'number' || !Number.isFinite(value)) return '';
+  return new Intl.NumberFormat('en-US', {
+    style: 'currency',
+    currency,
+    maximumFractionDigits: value >= 100 ? 0 : 2,
+  }).format(value);
+}
+
 function normalizeBookingType(value) {
   const normalized = normalizeKey(value || '');
   if (['package', 'standalone', 'calculated'].includes(normalized)) return normalized;
@@ -274,6 +285,42 @@ function inferPriceBasis(point, defaults = {}) {
   return null;
 }
 
+function getTripNightCount() {
+  const checkInMs = Date.parse(`${TRIP_CHECK_IN}T00:00:00Z`);
+  const checkOutMs = Date.parse(`${TRIP_CHECK_OUT}T00:00:00Z`);
+  if (Number.isNaN(checkInMs) || Number.isNaN(checkOutMs) || checkOutMs <= checkInMs) return 1;
+  return Math.max(1, Math.round((checkOutMs - checkInMs) / (24 * 60 * 60 * 1000)));
+}
+
+function isStayUnitPrice(priceBasis) {
+  const normalized = normalizeKey(priceBasis);
+  return ['pernight', 'perday', 'nightly', 'daily'].includes(normalized);
+}
+
+function normalizeTripPrice({ price, priceBasis, currency, displayPrice }) {
+  if (!isStayUnitPrice(priceBasis)) {
+    return {
+      price,
+      unitPrice: price,
+      tripTotalPrice: price,
+      displayPrice,
+      tripNights: null,
+    };
+  }
+
+  const tripNights = getTripNightCount();
+  const tripTotalPrice = Number((price * tripNights).toFixed(2));
+  const unitLabel = displayPrice || `${formatCurrencyValue(price, currency)}/night`;
+
+  return {
+    price: tripTotalPrice,
+    unitPrice: price,
+    tripTotalPrice,
+    displayPrice: `${formatCurrencyValue(tripTotalPrice, currency)} stay total (${unitLabel} x ${tripNights} nights)`,
+    tripNights,
+  };
+}
+
 function loadPriceHistoryState() {
   const runs = readJsonLines(PRICE_HISTORY_FILE)
     .map((entry, index) => {
@@ -304,19 +351,34 @@ function loadPriceHistoryState() {
     });
 
     if (!key || price === null) return;
+    const currency = point.currency || defaults.currency || 'USD';
+    const priceBasis = inferPriceBasis(point, defaults);
+    const rawDisplayPrice = point.displayPrice || point.priceLabel || point.displayLabel || point.label || defaults.displayPrice || null;
+    const tripPrice = normalizeTripPrice({
+      price,
+      priceBasis,
+      currency,
+      displayPrice: rawDisplayPrice,
+    });
 
     const nextPoint = {
       checkedAt: run.checkedAt,
       checkedAtMs: run.checkedAtMs,
       runIndex: run.runIndex,
-      price,
-      currency: point.currency || defaults.currency || 'USD',
-      displayPrice: point.displayPrice || point.priceLabel || point.displayLabel || point.label || defaults.displayPrice || null,
+      price: tripPrice.price,
+      unitPrice: tripPrice.unitPrice,
+      tripTotalPrice: tripPrice.tripTotalPrice,
+      tripNights: tripPrice.tripNights,
+      tripCheckIn: tripPrice.tripNights ? TRIP_CHECK_IN : null,
+      tripCheckOut: tripPrice.tripNights ? TRIP_CHECK_OUT : null,
+      currency,
+      displayPrice: tripPrice.displayPrice,
+      unitDisplayPrice: rawDisplayPrice,
       source: normalizeSourceLabel(point.source || point.sourceLabel || point.vendor || defaults.source || null),
       sourceKey: normalizeKey(point.sourceKey || point.sourceId || point.source || point.sourceLabel || point.vendor || defaults.sourceKey || 'unknown-source'),
       sourceUrl: point.sourceUrl || point.url || defaults.sourceUrl || null,
       bookingType: normalizeBookingType(inferBookingType(point, defaults)),
-      priceBasis: inferPriceBasis(point, defaults),
+      priceBasis,
       includedComponents: toTextList(point.includedComponents || point.includesComponents || point.componentsIncluded || defaults.includedComponents),
       excludedComponents: toTextList(point.excludedComponents || point.componentsExcluded || defaults.excludedComponents),
       origin: point.origin || point.originAirport || defaults.origin || null,