import {unified} from 'unified'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import rehypeStringify from 'rehype-stringify'

export default function (config) {

  return async function ({ lineData, ended, next }) {
    if (ended) return ''
    const blockLevel = lineData.level

    let md = ''

    function finalize() {
      return unified()
      .use(remarkParse)
      .use(remarkRehype)
      .use(rehypeStringify)
      .process(md)
    }

    async function markdownContents({ line, lineData, ended }) {
      if (ended || lineData.level <= blockLevel) {
        const final = String(await finalize())
        return final
      }

      md += line.slice(blockLevel + 1) + '\n'
      return markdownContents(await next())
    }

    return markdownContents(await next())
  }
}