// src/utils/time.js

// Same logic as apiFetch and KillSwitchManagement
export function getUserTimezone() {
  try {
    return Intl.DateTimeFormat().resolvedOptions().timeZone || 'Asia/Kuala_Lumpur';
  } catch {
    return 'Asia_Kuala_Lumpur';
  }
}

// utcValue can be: "2025-11-03 16:30:00", ISO string, or Date
export function formatUtcToLocal(utcValue, options = {}) {
  if (!utcValue) return '';

  const tz = options.timeZone || getUserTimezone();
  const locale = options.locale || 'en-MY';

  let d;

  if (utcValue instanceof Date) {
    d = utcValue;
  } else if (typeof utcValue === 'string') {
    // Normalize: DB gives "YYYY-MM-DD HH:mm:ss" (UTC) – turn into ISO UTC
    let iso = utcValue;
    if (!iso.endsWith('Z')) {
      if (iso.includes('T')) {
        iso = iso + 'Z';
      } else {
        iso = iso.replace(' ', 'T') + 'Z';
      }
    }
    d = new Date(iso);
  } else if (typeof utcValue === 'number') {
    d = new Date(utcValue);
  } else {
    return '';
  }

  return d.toLocaleString(locale, {
    timeZone: tz,
    year: options.year ?? 'numeric',
    month: options.month ?? '2-digit',
    day: options.day ?? '2-digit',
    hour: options.hour ?? '2-digit',
    minute: options.minute ?? '2-digit',
    second: options.second ?? '2-digit',
    hour12: options.hour12 ?? false,
  });
}