/**
 * 后台统一按北京时间展示。
 *
 * 后端返回的是 ISO 字符串（UTC，带 Z），直接切片会显示成 UTC——
 * 中午 13:23 会显示成 05:23。所有时间展示都走这里。不要再用 slice。
 */
const TIME_ZONE = 'Asia/Shanghai';

function partsOf(value: unknown) {
  const date = new Date(String(value));
  if (Number.isNaN(date.getTime())) return null;
  const parts = new Intl.DateTimeFormat('zh-CN', {
    timeZone: TIME_ZONE,
    year: 'numeric',
    month: '2-digit',
    day: '2-digit',
    hour: '2-digit',
    minute: '2-digit',
    hourCycle: 'h23',
  }).formatToParts(date);
  const pick = (type: string) => parts.find((p) => p.type === type)?.value ?? '';
  return { y: pick('year'), m: pick('month'), d: pick('day'), h: pick('hour'), mi: pick('minute') };
}

/** ISO → 2026-09-30 13:23 */
export function formatDateTime(value: unknown): string {
  if (value === null || value === undefined || value === '') return '—';
  const p = partsOf(value);
  return p ? `${p.y}-${p.m}-${p.d} ${p.h}:${p.mi}` : String(value).slice(0, 16).replace('T', ' ');
}

/** ISO → 2026-09-30 */
export function formatDate(value: unknown): string {
  if (value === null || value === undefined || value === '') return '—';
  const p = partsOf(value);
  return p ? `${p.y}-${p.m}-${p.d}` : String(value).slice(0, 10);
}