feat: add blog (#320)

utils/blog.ts

@@ -0,0 +1,70 @@
+import fs from 'node:fs'
+import path from 'node:path'
+
+import type { MDXRemoteSerializeResult } from 'next-mdx-remote'
+import { serialize } from 'next-mdx-remote/serialize'
+import remarkGfm from 'remark-gfm'
+import remarkPrism from 'remark-prism'
+import matter from 'gray-matter'
+
+export const postsPath = path.join(process.cwd(), 'posts')
+
+export type MDXSource = MDXRemoteSerializeResult<Record<string, unknown>>
+
+export interface FrontMatter {
+  title: string
+  description: string
+  isPublished: boolean
+  publishedOn: string
+}
+
+export interface PostMetadata {
+  frontmatter: FrontMatter
+  slug: string
+  content: string
+}
+
+export interface Post extends PostMetadata {
+  source: MDXSource
+}
+
+export const getPosts = async (): Promise<PostMetadata[]> => {
+  const posts = await fs.promises.readdir(postsPath)
+  const postsWithTime = await Promise.all(
+    posts.map(async (postFilename) => {
+      const [slug] = postFilename.split('.')
+      const blogPostPath = path.join(postsPath, `${slug}.mdx`)
+      const blogPostContent = await fs.promises.readFile(blogPostPath, {
+        encoding: 'utf8'
+      })
+      const { data, content } = matter(blogPostContent) as any
+      const date = new Date(data.publishedOn)
+      return {
+        slug,
+        content,
+        frontmatter: data,
+        time: date.getTime()
+      }
+    })
+  )
+  const postsWithTimeSorted = postsWithTime
+    .filter((post) => post.frontmatter.isPublished)
+    .sort((a, b) => b.time - a.time)
+  return postsWithTimeSorted
+}
+
+export const getPostBySlug = async (
+  slug?: string | string[]
+): Promise<Post | undefined> => {
+  const posts = await getPosts()
+  const post = posts.find((post) => post.slug === slug)
+  if (post == null) {
+    return undefined
+  }
+  const source = await serialize(post.content, {
+    mdxOptions: {
+      remarkPlugins: [remarkGfm as any, remarkPrism]
+    }
+  })
+  return { ...post, source }
+}