function formatDateTime(iso) {
  if (!iso || typeof iso !== 'string') return '-';
  // expected format: 2026-03-30T12:34:56
  const s = iso.replace('T', ' ').replace('Z', '');
  if (s.length > 19) return s.slice(0, 19);
  return s;
}

function eventStatusText(status) {
  // EventStatus enum: Enrolling=0, Ongoing=1, Ended=2
  const map = {
    0: '报名中',
    1: '比赛中',
    2: '已结束'
  };
  return map[status] || `状态${status}`;
}

module.exports = {
  formatDateTime,
  eventStatusText
};