astro.config.mjs

import fs from "fs";
import dayjs from "dayjs";
import tailwind from "@astrojs/tailwind";

import { defineConfig } from "astro/config";
import { parse } from "node-html-parser";
import { SITE } from "./src/config";
import rehypeCustomizeImageSrc from "./rehype-customize-image-src.js";

const DEFAULT_FORMAT = "YYYY/MM/DD";
const WEEKLY_REPO_NAME = "tw93/weekly";
const START_DATE = "2022-10-10";

function formatDate(date) {
  return dayjs(date).format(DEFAULT_FORMAT);
}

function getFileCreateDate(filePath) {
  return formatDate(fs.statSync(filePath).birthtime);
}

function getWeeklyDate(num) {
  return num < 100
    ? formatDate(dayjs(START_DATE).subtract(100 - num, "week"))
    : getFileCreateDate(filePath);
}

function getTwitterImage(num) {
  return num >= 110 ? `https://weekly.tw93.fun/assets/${num}.jpg` : undefined;
}

function defaultLayoutPlugin() {
  return function (tree, file) {
    const filePath = file.history[0];
    const { frontmatter } = file.data.astro;
    frontmatter.layout = "@layouts/post.astro";

    if (tree.children[0]?.value && !frontmatter.pic) {
      const imageElement = parse(tree.children[0].value).querySelector("img");
      frontmatter.pic = imageElement.getAttribute("src");
    }

    if (tree.children[1]?.children[1]?.value) {
      frontmatter.desc = tree.children[1].children[1].value;
    }

    frontmatter.desc = frontmatter.desc || SITE.description;
    frontmatter.pic = frontmatter.pic || SITE.pic;

    if (!frontmatter.date) {
      const postNumber = filePath.split("/posts/")[1].split("-")[0];
      frontmatter.date =
        SITE.repo === WEEKLY_REPO_NAME
          ? getWeeklyDate(postNumber)
          : getFileCreateDate(filePath);
    }

    if (SITE.repo === WEEKLY_REPO_NAME) {
      const postNumber = filePath.split("/posts/")[1].split("-")[0];
      frontmatter.twitterImg = getTwitterImage(postNumber);
    }
  };
}

export default defineConfig({
  prefetch: true,
  integrations: [tailwind()],
  markdown: {
    remarkPlugins: [defaultLayoutPlugin],
    rehypePlugins: [rehypeCustomizeImageSrc],
  },
});