/**
 * 微信小程序基础库无 Intl。业务代码已避免依赖，此处仅作兜底，
 * 防止旧包 / 依赖偶发 `new Intl.DateTimeFormat` 直接白屏。
 */
function pad(n: number) {
  return String(n).padStart(2, '0');
}

function shanghaiParts(date: Date) {
  const sh = new Date(date.getTime() + 8 * 60 * 60 * 1000);
  return {
    year: String(sh.getUTCFullYear()),
    month: pad(sh.getUTCMonth() + 1),
    day: pad(sh.getUTCDate()),
    hour: pad(sh.getUTCHours()),
    minute: pad(sh.getUTCMinutes()),
    second: pad(sh.getUTCSeconds()),
  };
}

function installIntlStub() {
  const root = (typeof globalThis !== 'undefined'
    ? globalThis
    : typeof global !== 'undefined'
      ? global
      : typeof wx !== 'undefined'
        ? wx
        : {}) as typeof globalThis & { Intl?: typeof Intl };

  if (typeof root.Intl !== 'undefined' && typeof root.Intl.DateTimeFormat === 'function') {
    return;
  }

  class MiniDateTimeFormat {
    // eslint-disable-next-line @typescript-eslint/no-unused-vars
    constructor(_locales?: string | string[], _options?: Record<string, unknown>) {}

    format(date?: Date | number) {
      const d = date instanceof Date ? date : new Date(date ?? Date.now());
      if (Number.isNaN(d.getTime())) return '';
      const p = shanghaiParts(d);
      return `${p.year}-${p.month}-${p.day} ${p.hour}:${p.minute}:${p.second}`;
    }

    formatToParts(date?: Date | number) {
      const d = date instanceof Date ? date : new Date(date ?? Date.now());
      if (Number.isNaN(d.getTime())) return [];
      const p = shanghaiParts(d);
      return [
        { type: 'year', value: p.year },
        { type: 'literal', value: '-' },
        { type: 'month', value: p.month },
        { type: 'literal', value: '-' },
        { type: 'day', value: p.day },
        { type: 'literal', value: ' ' },
        { type: 'hour', value: p.hour },
        { type: 'literal', value: ':' },
        { type: 'minute', value: p.minute },
        { type: 'literal', value: ':' },
        { type: 'second', value: p.second },
      ];
    }
  }

  root.Intl = {
    DateTimeFormat: MiniDateTimeFormat,
  } as unknown as typeof Intl;
}

installIntlStub();

export {};