export function formatCount(value: number): string {
  const n = Number(value ?? 0);
  if (n >= 100_000) return `${Math.round(n / 10_000)}万`;
  if (n >= 10_000) return `${(n / 10_000).toFixed(1).replace(/\.0$/, '')}万`;
  if (n >= 1_000) return `${(n / 1_000).toFixed(1).replace(/\.0$/, '')}k`;
  return String(n);
}

export function formatRelativeTime(iso: string): string {
  const date = new Date(iso);
  if (Number.isNaN(date.getTime())) return '';
  const diffMs = Date.now() - date.getTime();
  const minutes = Math.floor(diffMs / 60_000);
  if (minutes < 1) return '刚刚';
  if (minutes < 60) return `${minutes} 分钟前`;
  const hours = Math.floor(minutes / 60);
  if (hours < 24) return `${hours} 小时前`;
  const days = Math.floor(hours / 24);
  if (days < 30) return `${days} 天前`;
  return date.toLocaleDateString('zh-CN');
}

export function categoryAccent(slug: string): string {
  const palette = [
    'from-emerald-700 to-teal-500',
    'from-amber-700 to-orange-500',
    'from-violet-700 to-purple-500',
    'from-sky-700 to-cyan-500',
    'from-rose-700 to-pink-500',
    'from-lime-700 to-green-500',
  ];
  let hash = 0;
  for (let i = 0; i < slug.length; i += 1) hash = (hash + slug.charCodeAt(i) * (i + 1)) % palette.length;
  return palette[hash] ?? palette[0];
}