feat: add heading extraction and wip flag to posts

lib/posts.ts

@@ -5,6 +5,12 @@ import readingTime from 'reading-time';
 
 const postsDirectory = path.join(process.cwd(), 'posts');
 
+export interface Heading {
+  level: number;
+  text: string;
+  slug: string;
+}
+
 export interface PostData {
   id: string;
   date: string;
@@ -12,6 +18,8 @@ export interface PostData {
   description: string;
   content: string;
   readingTime: string;
+  headings: Heading[];
+  wip?: boolean;
 }
 
 export interface PostMeta {
@@ -20,6 +28,22 @@ export interface PostMeta {
   title: string;
   description: string;
   readingTime: string;
+  wip?: boolean;
+}
+
+function extractHeadings(content: string): Heading[] {
+  const regex = /^(#{2,3})\s+(.+)$/gm;
+  const headings: Heading[] = [];
+  let match;
+  while ((match = regex.exec(content)) !== null) {
+    const text = match[2].trim();
+    const slug = text
+      .toLowerCase()
+      .replace(/[^a-z0-9]+/g, '-')
+      .replace(/(^-|-$)/g, '');
+    headings.push({ level: match[1].length, text, slug });
+  }
+  return headings;
 }
 
 export function getSortedPostsData(): PostMeta[] {
@@ -40,6 +64,7 @@ export function getSortedPostsData(): PostMeta[] {
           title: matterResult.data.title as string,
           description: matterResult.data.description as string,
           readingTime: stats.text,
+          wip: matterResult.data.wip ?? false,
         };
       });
 
@@ -76,5 +101,7 @@ export async function getPostData(id: string): Promise<PostData> {
     title: matterResult.data.title,
     description: matterResult.data.description,
     readingTime: stats.text,
+    headings: extractHeadings(matterResult.content),
+    wip: matterResult.data.wip ?? false,
   };
-}
+}