#!/usr/bin/env node
import fs from 'fs'
import path from 'path'
import walk from 'walk-sync'
import frontmatter from '../../lib/read-frontmatter.js'
import getDocumentType from '../../lib/get-document-type.js'
import languages from '../../lib/languages.js'
import ExtendedMarkdown from '../../lib/liquid-tags/extended-markdown.js'

const extendedMarkdownTags = Object.keys(ExtendedMarkdown.tags)

const linkString = /{% [^}]*?link.*? (\/.*?) ?%}/m
const linksArray = new RegExp(linkString.source, 'gm')

// This script turns `{% link /<link> %} style content into children: [ -/<link> ] frontmatter arrays.
//
// It MUST be run after script/content-migrations/remove-map-topics.js.
//
// NOTE: The results won't work with the TOC handling currently in production, so the results must NOT
// be committed until the updated handling is in place.

const walkOpts = {
  includeBasePath: true,
  directories: false,
}

const fullDirectoryPaths = Object.values(languages).map((langObj) =>
  path.join(process.cwd(), langObj.dir, 'content')
)
const indexFiles = fullDirectoryPaths
  .map((fullDirectoryPath) => walk(fullDirectoryPath, walkOpts))
  .flat()
  .filter((file) => file.endsWith('index.md'))

const englishHomepageData = {
  children: '',
  externalProducts: '',
}

indexFiles.forEach((indexFile) => {
  const relativePath = indexFile.replace(/^.+\/content\//, '')
  const documentType = getDocumentType(relativePath)

  const { data, content } = frontmatter(fs.readFileSync(indexFile, 'utf8'))

  // Save the English homepage frontmatter props...
  if (documentType === 'homepage' && !indexFile.includes('/translations/')) {
    englishHomepageData.children = data.children
    englishHomepageData.externalProducts = data.externalProducts
  }

  // ...and reuse them in the translated homepages, in case the translated files are out of date
  if (documentType === 'homepage' && indexFile.includes('/translations/')) {
    data.children = englishHomepageData.children
    data.externalProducts = englishHomepageData.externalProducts
  }

  const linkItems = content.match(linksArray)
  if (!linkItems) return

  // Turn the `{% link /<link> %}` list into an array of /<link> items
  if (documentType === 'product' || documentType === 'mapTopic') {
    data.children = getLinks(linkItems)
  }

  if (documentType === 'category') {
    const childMapTopics = linkItems.filter((item) => item.includes('topic_'))

    data.children = childMapTopics.length ? getLinks(childMapTopics) : getLinks(linkItems)
  }

  // Fix this one weird file
  if (relativePath === 'discussions/guides/index.md') {
    data.children = [
      '/best-practices-for-community-conversations-on-github',
      '/finding-your-discussions',
      '/granting-higher-permissions-to-top-contributors',
    ]
  }

  // Remove the Table of Contents section and leave any body text before it.
  let newContent = content
    .replace(/^#*? Table of contents[\s\S]*/im, '')
    .replace('<div hidden>', '')
    .replace(linksArray, '')

  const linesArray = newContent.split('\n')

  const newLinesArray = linesArray
    .filter(
      (line, index) =>
        /\S/.test(line) ||
        extendedMarkdownTags.find(
          (tag) =>
            (linesArray[index - 1] && linesArray[index - 1].includes(tag)) ||
            (linesArray[index + 1] && linesArray[index + 1].includes(tag))
        )
    )
    .filter((line) => !/^<!--\s+?-->$/m.test(line))

  newContent = newLinesArray.join('\n')

  // Index files should no longer have body content, so we write an empty string
  fs.writeFileSync(indexFile, frontmatter.stringify(newContent, data, { lineWidth: 10000 }))
})

function getLinks(linkItemArray) {
  // do a oneoff replacement while mapping
  return linkItemArray.map((item) =>
    item.match(linkString)[1].replace('/discussions-guides', '/guides')
  )
}