import m from 'mdast-builder'
import remarkWikiLink from 'remark-wiki-link'
import { SKIP, visit } from 'unist-util-visit'

export interface WikiLink {
  value: string
  alias?: string
}

export interface Link {
  value: string
  uri: string
  title?: string
}

export type ToLink = (wikiLink: WikiLink) => Link | string

export const remarkObsidianLink = function (opts?: { toLink?: ToLink }) {
  const toLink: ToLink = opts?.toLink || (({ value, alias }) => alias || value)

  this.use(remarkWikiLink, { aliasDivider: '|' })

  return (tree) => {
    visit(tree, 'wikiLink', (node, index, parent) => {
      const wValue = node.value
      const wAlias = node.data.alias
      const wikiLink: WikiLink = {
        value: wValue.trim(),
        alias: wAlias === wValue ? undefined : wAlias.trim(),
      }

      const link = toLink(wikiLink)

      const newNode =
        typeof link == 'string'
          ? m.text(link)
          : m.link(link.uri, link.title, [m.text(link.value)])

      parent.children.splice(index, 1, newNode)

      return [SKIP, index]
    })
  }
}