import fs from 'fs';
import path from 'path';
import matter from 'gray-matter';
import { remark } from 'remark';
import html from 'remark-html';

const postsDirectory = path.join(process.cwd(), 'src/posts');

export function getAllPosts() {
  const fileNames = fs.readdirSync(postsDirectory);

  return fileNames
    .map((fileName) => {
      const slug = fileName.replace(/\.md$/, '');
      const fullPath = path.join(postsDirectory, fileName);
      const fileContents = fs.readFileSync(fullPath, 'utf8');

      const { data } = matter(fileContents);

      return {
        slug,
        title: data.title,
        date: data.date,
        excerpt: data.excerpt,
      };
    })
    .sort((a, b) => (a.date < b.date ? 1 : -1));
}

export async function getPostBySlug(slug: string) {
  const fullPath = path.join(postsDirectory, `${slug}.md`);
  if (!fs.existsSync(fullPath)) {
    throw new Error(`Post not found: ${slug}`);
  }
  const fileContents = fs.readFileSync(fullPath, 'utf8');

  const { data, content } = matter(fileContents);

  const processedContent = await remark().use(html).process(content);
  const contentHtml = processedContent.toString();

  return {
    slug,
    contentHtml,
    title: data.title,
    date: data.date,
  };
}

export const getAllSlugs = () => {
  return fs.readdirSync(postsDirectory).map((fileName) => ({
    params: { slug: fileName.replace(/\.md$/, '') },
  }));
};