import fs from "node:fs";
import type { IncomingMessage, ServerResponse } from "node:http";
import path from "node:path";
import type { Connect, Plugin, ViteDevServer } from "vite";

export function mp3DownloaderPlugin(): Plugin {
  return {
    name: "mp3-downloader",
    configureServer(server: ViteDevServer) {
      // Vite dev server middlewares are connect-style: (req, res, next)
      server.middlewares.use(async (req, res, next) => {
        const reqUrl = req.url;
        if (!reqUrl || !reqUrl.startsWith("/uploads/")) return next();
        if (!reqUrl.endsWith(".mp3")) return next();

        try {
          await mp3Downloader(req, res, next);
        } catch (e) {
          console.error(e, reqUrl);
          next();
        }
      });
    },
  };
}

async function mp3Downloader(
  req: Connect.IncomingMessage,
  res: ServerResponse<IncomingMessage>,
  next: Connect.NextFunction,
) {
  const url = new URL(`https://www.howtostudykorean.com/wp-content${req.url}`);

  const segs = req.url!.slice(1).split("/");
  const filename = segs.pop()!;
  const saveroot = "docs/public";
  const saveto = path.join(saveroot, ...segs, filename);

  if (fs.existsSync(saveto)) {
    return next();
  }

  fs.mkdirSync(path.join(saveroot, ...segs), { recursive: true });

  const r = await fetch(url, { redirect: "follow" });
  if (!r.ok) {
    console.error(r);
    return next();
  }

  fs.writeFileSync(saveto, Buffer.from(await r.arrayBuffer()));
  // console.log(fs.statSync(saveto));
  console.log("saved to", saveto);

  res.setHeader("Content-Type", "audio/mpeg");
  fs.createReadStream(saveto).pipe(res);
}