/* =============================================================================
 * common_util_time_kst.ts
 * 서버 UTC 시각(DB 세션 time_zone +00:00) → 화면 KST(UTC+9) 글자 — 서버 값은 UTC 그대로.
 * ========================================================================== */

const KST_OFFSET_MS = 9 * 3600 * 1000;

/** "YYYY-MM-DD HH:MM:SS" · ISO(UTC) → "YYYY-MM-DD HH:MM" KST · 빈 값 = "—" · 못 읽으면 원글 */
export function kstText(utc: string | null | undefined): string {
  if (!utc) return "—";
  const iso = utc.trim().replace(" ", "T");
  const ms = Date.parse(/(Z|[+-]\d\d:?\d\d)$/.test(iso) ? iso : `${iso}Z`);
  if (Number.isNaN(ms)) return utc;
  return new Date(ms + KST_OFFSET_MS).toISOString().slice(0, 16).replace("T", " ");
}