contentlayer.config.ts

import { writeFileSync } from 'fs'
import path from 'path'
import { Post as PostType } from 'contentlayer/generated'
import {
  ComputedFields,
  defineDocumentType,
  makeSource,
} from 'contentlayer2/source-files'
import { slug } from 'github-slugger'
import readingTime from 'reading-time'
// Rehype packages
import rehypeAutolinkHeadings from 'rehype-autolink-headings'
import rehypeCodeTitles from 'rehype-code-titles'
import rehypeKatex from 'rehype-katex'
// import rehypeMermaid from 'rehype-mermaid'
import rehypePresetMinify from 'rehype-preset-minify'
import rehypePrismPlus from 'rehype-prism-plus'
import rehypeSlug from 'rehype-slug'
// Remark packages
import remarkGfm from 'remark-gfm'
import { remarkAlert } from 'remark-github-blockquote-alert'
import remarkMath from 'remark-math'

import siteMetadata from './data/siteMetadata'
import { allCoreContent, sortPosts } from './utils/contentlayer.js'

const isProduction = process.env.NODE_ENV === 'production'

const computedFields: ComputedFields = {
  slug: {
    type: 'string',
    resolve: (doc) => doc._raw.flattenedPath.replace(/^.+?(\/)/, ''),
  },
  path: {
    type: 'string',
    resolve: (doc) => doc._raw.flattenedPath,
  },
  filePath: {
    type: 'string',
    resolve: (doc) => doc._raw.sourceFilePath,
  },
  readingTime: { type: 'json', resolve: (doc) => readingTime(doc.body.raw) },
}

/**
 * Count the occurrences of all tags across blog posts and write to json file
 */
function createTagCount(allBlogs: PostType[]) {
  const tagCount: Record<string, number> = {}
  allBlogs.forEach((file) => {
    if (file.tags && (!isProduction || file.draft !== true)) {
      file.tags.forEach((tag) => {
        const formattedTag = slug(tag)
        if (formattedTag in tagCount) {
          tagCount[formattedTag] += 1
        } else {
          tagCount[formattedTag] = 1
        }
      })
    }
  })
  writeFileSync('./app/tag-data.json', JSON.stringify(tagCount))
}

function createSearchIndex(allBlogs: PostType[]) {
  if (
    siteMetadata?.search?.provider === 'kbar' &&
    siteMetadata.search.kbarConfig.searchDocumentsPath
  ) {
    writeFileSync(
      `public/${path.basename(siteMetadata.search.kbarConfig.searchDocumentsPath)}`,
      JSON.stringify(allCoreContent(sortPosts(allBlogs)))
    )
    console.log('Local search index generated...')
  }
}

export const Post = defineDocumentType(() => ({
  name: 'Post',
  filePathPattern: 'posts/**/*.mdx',
  contentType: 'mdx',
  fields: {
    title: {
      type: 'string',
      required: true,
    },
    date: {
      type: 'string',
      required: true,
    },
    tags: { type: 'list', of: { type: 'string' }, default: [] },
    lastmod: { type: 'date' },
    draft: { type: 'boolean' },
    summary: { type: 'string' },
    images: { type: 'json' },
    layout: { type: 'string' },
    bibliography: { type: 'string' },
    canonicalUrl: { type: 'string' },
  },
  computedFields: {
    ...computedFields,
    structuredData: {
      type: 'json',
      resolve: (doc) => ({
        '@context': 'https://schema.org',
        '@type': 'BlogPosting',
        author: {
          '@type': 'Person',
          name: siteMetadata.author,
        },
        headline: doc.title,
        datePublished: doc.date,
        dateModified: doc.lastmod || doc.date,
        description: doc.summary,
        image: doc.images ? doc.images[0] : siteMetadata.socialBanner,
        url: `${siteMetadata.siteUrl}/${doc._raw.flattenedPath}`,
      }),
    },
  },
}))

export const Author = defineDocumentType(() => ({
  name: 'Author',
  filePathPattern: 'authors/**/*.mdx',
  contentType: 'mdx',
  fields: {
    name: { type: 'string', required: true },
    avatar: { type: 'string' },
    occupation: { type: 'string' },
    company: { type: 'string' },
    email: { type: 'string' },
    twitter: { type: 'string' },
    linkedin: { type: 'string' },
    github: { type: 'string' },
    layout: { type: 'string' },
  },
  computedFields,
}))

export default makeSource({
  contentDirPath: 'data',
  documentTypes: [Post, Author],
  mdx: {
    remarkPlugins: [remarkGfm, remarkMath, remarkAlert],
    rehypePlugins: [
      rehypeSlug,
      rehypeCodeTitles,
      [rehypePrismPlus, { ignoreMissing: true }],
      rehypeKatex,
      // FIXME: Ask author
      // rehypeMermaid,
      [
        rehypeAutolinkHeadings,
        {
          properties: {
            className: ['anchor'],
          },
        },
      ],
      rehypePresetMinify,
    ],
  },
  onSuccess: async (importData) => {
    const { allPosts } = await importData()
    createTagCount(allPosts)
    createSearchIndex(allPosts)
  },
})