const DMS = /(\d+(?:\.\d+)?)°\s*(\d+)'\s*(\d+(?:\.\d+)?)"/;

/** Parses a degree-minute-second string such as ` 75°56'55.9"` into decimal degrees. Returns null when invalid. */
export function parseDms(text: string): number | null {
  const m = DMS.exec(String(text));
  if (!m) return null;
  const deg = Number(m[1]);
  const min = Number(m[2]);
  const sec = Number(m[3]);
  if (min >= 60 || sec >= 60) return null;
  return deg + min / 60 + sec / 3600;
}