Initial commit: Holiday Travel App with resort comparison, trip management, and multi-provider search

lib/date.ts

@@ -0,0 +1,26 @@
+import { addDays, differenceInDays, parseISO, format, isBefore } from "date-fns";
+
+export function enumerateDatePairs(startISO: string, endISO: string, minNights: number, maxNights: number, maxPairs = 8) {
+  const start = parseISO(startISO);
+  const end = parseISO(endISO);
+  const pairs: {out: string, back: string, nights: number}[] = [];
+  let cursor = start;
+  while (!isBefore(end, cursor) && pairs.length < maxPairs) {
+    for (let n = minNights; n <= maxNights && pairs.length < maxPairs; n++) {
+      const back = addDays(cursor, n);
+      if (isBefore(end, back)) continue;
+      pairs.push({ out: format(cursor, "yyyyMMdd"), back: format(back, "yyyyMMdd"), nights: n });
+    }
+    cursor = addDays(cursor, Math.max(1, Math.floor((differenceInDays(end, start) || 1) / (maxPairs))));
+  }
+  if (pairs.length === 0) {
+    // fallback to exact minNights from start
+    const back = addDays(start, minNights);
+    pairs.push({ out: format(start, "yyyyMMdd"), back: format(back, "yyyyMMdd"), nights: minNights });
+  }
+  return pairs;
+}
+
+export function isoToSkyscanner(iso: string) {
+  return iso.replace(/-/g, "");
+}