export const POST_SLUG_RE = /^[a-z0-9][a-z0-9-]{0,98}[a-z0-9]$|^[a-z0-9]$/

export function normalizePostSlugCandidate(input: string): string {
  const ascii = input
    .toLowerCase()
    .normalize('NFKD')
    .replace(/[\u0300-\u036f]/g, '')
    .replace(/['"]/g, '')
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .replace(/-{2,}/g, '-')

  const limited = ascii.slice(0, 100).replace(/-+$/g, '')
  return limited
}

export function generateRandomPostSlug(): string {
  // 输出如 post-a1b2c3d4e5，满足现有 slug 校验规则。
  const alphabet = 'abcdefghijklmnopqrstuvwxyz0123456789'
  let suffix = ''
  for (let i = 0; i < 10; i += 1) {
    const idx = Math.floor(Math.random() * alphabet.length)
    suffix += alphabet[idx]
  }
  return `post-${suffix}`
}