import type { AstroIntegration } from "astro";
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

export default function ogImageIntegration(): AstroIntegration {
  return {
    name: "og-image-per-page",
    hooks: {
      "astro:build:done": async ({ dir, pages }) => {
        const distDir = typeof dir === "string" ? dir : fileURLToPath(dir);

        for (const page of pages) {
          const htmlPath = path.join(distDir, page.pathname, "index.html");

          if (!fs.existsSync(htmlPath)) continue;

          let html = fs.readFileSync(htmlPath, "utf-8");

          let slug = page.pathname.replace(/^\/|\/$/g, "") || "index";
          // URL-safe: replace / with - for nested paths
          const imageSlug = slug.replace(/\//g, "-");
          const ogImageUrl = `https://yasutakeyohei.com/og/${imageSlug}.png?v=2`;

          html = html.replace(
            /<meta property="og:image" content="[^"]*"/g,
            `<meta property="og:image" content="${ogImageUrl}"`,
          );
          html = html.replace(
            /<meta name="twitter:image" content="[^"]*"/g,
            `<meta name="twitter:image" content="${ogImageUrl}"`,
          );

          // Fix breadcrumb: replace directory slug with Japanese label
          html = html.replace(/>about-dyslexia</g, `>ディスレクシアについて<`);

          fs.writeFileSync(htmlPath, html, "utf-8");
        }
      },
    },
  };
}