import type { DashboardTask, DashboardTaskAction } from './api';
import { localeTags, type Locale, type Messages } from './i18n';

const SHORT_TIME_FORMAT_OPTIONS = {
  hour: '2-digit',
  hour12: false,
  minute: '2-digit',
} as const;

const MONTH_DAY_TIME_FORMAT_OPTIONS = {
  day: 'numeric',
  hour: '2-digit',
  hour12: false,
  minute: '2-digit',
  month: 'short',
} as const;

const SHORT_TIME_FORMATTERS: Record<Locale, Intl.DateTimeFormat> = {
  en: new Intl.DateTimeFormat(localeTags.en, SHORT_TIME_FORMAT_OPTIONS),
  ja: new Intl.DateTimeFormat(localeTags.ja, SHORT_TIME_FORMAT_OPTIONS),
  ko: new Intl.DateTimeFormat(localeTags.ko, SHORT_TIME_FORMAT_OPTIONS),
  zh: new Intl.DateTimeFormat(localeTags.zh, SHORT_TIME_FORMAT_OPTIONS),
};

const MONTH_DAY_TIME_FORMATTERS: Record<Locale, Intl.DateTimeFormat> = {
  en: new Intl.DateTimeFormat(localeTags.en, MONTH_DAY_TIME_FORMAT_OPTIONS),
  ja: new Intl.DateTimeFormat(localeTags.ja, MONTH_DAY_TIME_FORMAT_OPTIONS),
  ko: new Intl.DateTimeFormat(localeTags.ko, MONTH_DAY_TIME_FORMAT_OPTIONS),
  zh: new Intl.DateTimeFormat(localeTags.zh, MONTH_DAY_TIME_FORMAT_OPTIONS),
};

export function formatDate(
  value: string | null | undefined,
  locale: Locale,
): string {
  if (!value) return '-';
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) return value;
  const now = Date.now();
  const ageMs = now - date.getTime();
  if (ageMs >= 0 && ageMs < 60_000) {
    return locale === 'ko'
      ? '방금'
      : locale === 'ja'
        ? 'たった今'
        : locale === 'zh'
          ? '刚刚'
          : 'just now';
  }
  if (ageMs >= 0 && ageMs < 3_600_000) {
    const mins = Math.floor(ageMs / 60_000);
    return locale === 'ko'
      ? `${mins}분 전`
      : locale === 'ja'
        ? `${mins}分前`
        : locale === 'zh'
          ? `${mins} 分钟前`
          : `${mins}m ago`;
  }
  const sameDay = new Date().toDateString() === date.toDateString();
  if (sameDay) {
    return SHORT_TIME_FORMATTERS[locale].format(date);
  }
  const time = SHORT_TIME_FORMATTERS[locale].format(date);
  if (locale === 'ko')
    return `${date.getMonth() + 1}월 ${date.getDate()}일 ${time}`;
  if (locale === 'ja')
    return `${date.getMonth() + 1}月${date.getDate()}日 ${time}`;
  if (locale === 'zh')
    return `${date.getMonth() + 1}月${date.getDate()}日 ${time}`;
  return MONTH_DAY_TIME_FORMATTERS[locale].format(date);
}

export function taskActionsFor(task: DashboardTask): DashboardTaskAction[] {
  if (task.status === 'active') return ['pause', 'cancel'];
  if (task.status === 'paused') return ['resume', 'cancel'];
  return [];
}

export function statusLabel(status: string, t: Messages): string {
  if (status in t.status) return t.status[status as keyof Messages['status']];
  return status;
}