let cache = {}
const re = /[\u2000-\u206F\u2E00-\u2E7F\\'!"#$%&()*+,.\/:;<=>?@\[\]^`{|}~]/g

export function slugify (str) {
  if (typeof str !== 'string') return ''

  let slug = str.toLowerCase().trim()
    .replace(/<[^>\d]+>/g, '')
    .replace(re, '')
    .replace(/\s/g, '-')
    .replace(/-+/g, '-')
    .replace(/^(\d)/, '_$1')
  let count = cache[slug]

  count = cache.hasOwnProperty(slug) ? (count + 1) : 0
  cache[slug] = count

  if (count) {
    slug = slug + '-' + count
  }

  return slug
}

slugify.clear = function () {
  cache = {}
}