posts.ts

import fs from "node:fs";
import path from "node:path";
import matter from "gray-matter";

const POSTS_DIR = path.join(process.cwd(), "posts");

export type PostMeta = {
  slug: string;
  title: string;
  description: string;
  date: string;
};

export function getPostSlugs(): string[] {
  if (!fs.existsSync(POSTS_DIR)) return [];
  return fs
    .readdirSync(POSTS_DIR)
    .filter((file) => /\.mdx?$/.test(file))
    .map((file) => file.replace(/\.mdx?$/, ""));
}

export function getPostMeta(slug: string): PostMeta | null {
  const mdxPath = path.join(POSTS_DIR, `${slug}.mdx`);
  const mdPath = path.join(POSTS_DIR, `${slug}.md`);
  const filePath = fs.existsSync(mdxPath) ? mdxPath : mdPath;
  if (!fs.existsSync(filePath)) return null;

  const raw = fs.readFileSync(filePath, "utf8");
  const { data } = matter(raw);
  return {
    slug,
    title: String(data.title ?? slug),
    description: String(data.description ?? ""),
    date: data.date ? String(data.date) : "",
  };
}

export function getAllPostsMeta(): PostMeta[] {
  return getPostSlugs()
    .map((slug) => getPostMeta(slug))
    .filter((meta): meta is PostMeta => meta !== null)
    .sort((a, b) => (a.date < b.date ? 1 : -1));
}

export function formatDate(value: string): string {
  if (!value) return "";
  if (/^[A-Za-z]+ \d{4}$/.test(value)) return value;

  const date = new Date(value.length <= 10 ? `${value}T00:00:00` : value);
  if (Number.isNaN(date.getTime())) return value;
  return date.toLocaleDateString("en-US", {
    year: "numeric",
    month: "long",
    day: "numeric",
  });
}