import { readdir } from "node:fs/promises";
import { YAML } from "bun";
import metadata from "./metadata.json";
import templateRaw from "./templates/post.html" with { type: "text" };
const templateStr = templateRaw as unknown as string;
const template = templateStr
  .replaceAll("[[SITE]]", metadata.title)
  .replaceAll("[[NAME]]", metadata.name)
  .replaceAll("[[TIMEZONE]]", metadata.timezone)
  .replaceAll("[[YEAR]]", new Date().getFullYear().toString());
const posts = await readdir("./posts");

const defaultFrontmatter = {
  title: "Untitled",
  desc: "",
  date: "0000-00-00", // YYYY-MM-DD
  tags: [] as never[],
  draft: true,
};

function fetchFrontmatter(raw?: string) {
  try {
    if (!raw) throw new Error("No frontmatter found.");
    const parsed = { ...defaultFrontmatter, ...(YAML.parse(raw) as typeof defaultFrontmatter) };
    return { ...parsed, date: new Date(parsed.date) };
  } catch {
    console.warn("Failed to parse frontmatter. Using default values.");
    return { ...defaultFrontmatter, date: new Date(NaN) };
  }
}

posts.forEach(async (post) => {
  console.log(`Processing ${post}...`);
  const raw = (await Bun.file(`./posts/${post}`).text()).split("^---");

  const content = raw.at(-1) || "No content";
  
  const frontmatter = fetchFrontmatter(raw.at(0));
  
  const html = Bun.markdown.html(content, {
    autolinks: true,
    headings: true,
    underline: true,
    latexMath: true,
    tagFilter: true,
  });
  const render = template
    .replaceAll("[[TITLE]]", `${metadata.title} - ${frontmatter.title}`)
    .replaceAll("[[POST_TITLE]]", frontmatter.title)
    .replaceAll("[[DATE]]", frontmatter.date.toDateString())
    .replaceAll("[[REVISIONS]]", `https://git.satr14.my.id/satr14/ssg.md/commits/branch/main/posts/${post}`)
    .replaceAll("[[DESC]]", frontmatter.desc)
    .replace("[[CONTENT]]", html);
  
  await Bun.write(`./dist/posts/${post.replace(".md", ".html")}`, render);
});