/**
 * Environment variable helpers.
 */

/**
 * Parse a staleness window from an env var string (interpreted as hours).
 * Falls back to `defaultHours` when the value is missing, non-numeric,
 * non-finite, or <= 0 — preventing NaN from silently breaking staleness checks.
 */
export function parseStalenessHours(envVar: string | undefined, defaultHours: number): number {
  const parsed = parseInt(envVar ?? "", 10);
  return Number.isFinite(parsed) && parsed > 0 ? parsed : defaultHours;
}

/**
 * Returns today's date as YYYY-MM-DD using local wall-clock time with a 3 AM
 * switchover. Before 3 AM local time we still consider it "yesterday", so the
 * calendar doesn't flip to the next day at midnight while people are still out
 * at the park.
 *
 * Important: `new Date().toISOString()` returns UTC, which causes the date to
 * advance at 8 PM EDT (UTC-4) or 7 PM EST (UTC-5) — too early. This helper
 * corrects that by using local year/month/day components and rolling back one
 * day when the local hour is before 3.
 */
export function getTodayLocal(): string {
  const now = new Date();
  if (now.getHours() < 3) {
    now.setDate(now.getDate() - 1);
  }
  const y = now.getFullYear();
  const m = String(now.getMonth() + 1).padStart(2, "0");
  const d = String(now.getDate()).padStart(2, "0");
  return `${y}-${m}-${d}`;
}

/**
 * Returns true when the current local time is within 1 hour before open
 * or 1 hour after close, based on a hoursLabel like "10am – 6pm".
 * Falls back to true when the label can't be parsed.
 */
export function isWithinOperatingWindow(hoursLabel: string): boolean {
  const m = hoursLabel.match(
    /^(\d+)(?::(\d+))?(am|pm)\s*[–-]\s*(\d+)(?::(\d+))?(am|pm)$/i
  );
  if (!m) return true;
  const toMinutes = (h: string, min: string | undefined, period: string) => {
    let hours = parseInt(h, 10);
    const minutes = min ? parseInt(min, 10) : 0;
    if (period.toLowerCase() === "pm" && hours !== 12) hours += 12;
    if (period.toLowerCase() === "am" && hours === 12) hours = 0;
    return hours * 60 + minutes;
  };
  const openMin  = toMinutes(m[1], m[2], m[3]);
  const closeMin = toMinutes(m[4], m[5], m[6]);
  const now = new Date();
  const nowMin = now.getHours() * 60 + now.getMinutes();
  return nowMin >= openMin - 60 && nowMin <= closeMin + 60;
}