export function isoToSql(iso: string): string | null {
  const date = new Date(iso);
  if (Number.isNaN(date.getTime())) return null;
  return date.toISOString().slice(0, 23).replace("T", " ");
}

export function sqlDateToIso(value: unknown): string | null {
  if (value === null || value === undefined) return null;
  if (value instanceof Date) {
    if (Number.isNaN(value.getTime())) return null;
    return value.toISOString();
  }
  const raw = String(value).trim();
  if (!raw) return null;
  if (/[zZ]$/.test(raw) || /[+-]\d{2}:?\d{2}$/.test(raw)) {
    const date = new Date(raw);
    if (Number.isNaN(date.getTime())) return null;
    return date.toISOString();
  }
  const normalized = raw.includes("T") ? raw : raw.replace(" ", "T");
  const withMs = /\.\d{1,3}$/.test(normalized) ? normalized : `${normalized}.000`;
  const date = new Date(`${withMs}Z`);
  if (Number.isNaN(date.getTime())) return null;
  return date.toISOString();
}