import remarkGfm from "remark-gfm"
import smartypants from 'remark-smartypants'
import { QuartzTransformerPlugin } from "../types"
import rehypeSlug from "rehype-slug"
import rehypeAutolinkHeadings from "rehype-autolink-headings"

export interface Options {
  enableSmartyPants: boolean
  linkHeadings: boolean
}

const defaultOptions: Options = {
  enableSmartyPants: true,
  linkHeadings: true
}

export const GitHubFlavoredMarkdown: QuartzTransformerPlugin<Partial<Options> | undefined> = (userOpts) => {
  const opts = { ...defaultOptions, ...userOpts }
  return {
    name: "GitHubFlavoredMarkdown",
    markdownPlugins() {
      return opts.enableSmartyPants ? [remarkGfm, smartypants] : [remarkGfm]
    },
    htmlPlugins() {
      if (opts.linkHeadings) {
        return [rehypeSlug, [rehypeAutolinkHeadings, {
          behavior: 'append', content: {
            type: 'text',
            value: ' §',
          }
        }]]
      } else {
        return []
      }
    }
  }
}