import { createReadStream } from "node:fs";
import { stat } from "node:fs/promises";
import { createServer } from "node:http";
import { extname, join, normalize } from "node:path";
import { fileURLToPath } from "node:url";
import startServer from "./dist/server/server.js";

const root = fileURLToPath(new URL(".", import.meta.url));
const clientDir = join(root, "dist", "client");
const host = process.env.HOST ?? process.env.WEBSITE_LISTEN_ADDRESS ?? "127.0.0.1";
const port = Number(process.env.PORT ?? process.env.WEBSITE_LISTEN_PORT ?? "3002");

const contentTypes = new Map([
  [".css", "text/css; charset=utf-8"],
  [".html", "text/html; charset=utf-8"],
  [".ico", "image/x-icon"],
  [".js", "text/javascript; charset=utf-8"],
  [".json", "application/json; charset=utf-8"],
  [".png", "image/png"],
  [".svg", "image/svg+xml"],
  [".txt", "text/plain; charset=utf-8"],
  [".woff", "font/woff"],
]);

function writeResponse(res, response) {
  res.writeHead(response.status, Object.fromEntries(response.headers));
  if (!response.body) {
    res.end();
    return;
  }
  response.body.pipeTo(
    new WritableStream({
      write(chunk) {
        res.write(chunk);
      },
      close() {
        res.end();
      },
      abort(error) {
        res.destroy(error);
      },
    }),
  );
}

async function tryServeStatic(req, res, pathname) {
  if (pathname === "/" || !extname(pathname)) return false;

  const decoded = decodeURIComponent(pathname);
  const normalized = normalize(decoded).replace(/^\.\.(\/|$)/, "");
  const filePath = join(clientDir, normalized);

  if (!filePath.startsWith(clientDir)) return false;

  try {
    const fileStat = await stat(filePath);
    if (!fileStat.isFile()) return false;
  } catch {
    return false;
  }

  res.writeHead(200, {
    "Content-Type": contentTypes.get(extname(filePath)) ?? "application/octet-stream",
    "Cache-Control": filePath.includes("/assets/")
      ? "public, max-age=31536000, immutable"
      : "no-store",
  });
  createReadStream(filePath).pipe(res);
  return true;
}

createServer(async (req, res) => {
  try {
    const origin = `http://${req.headers.host ?? `${host}:${port}`}`;
    const url = new URL(req.url ?? "/", origin);

    if (req.method === "GET" || req.method === "HEAD") {
      const served = await tryServeStatic(req, res, url.pathname);
      if (served) return;
    }

    const request = new Request(url, {
      method: req.method,
      headers: req.headers,
      body: req.method === "GET" || req.method === "HEAD" ? undefined : req,
      duplex: "half",
    });
    const response = await startServer.fetch(request);
    writeResponse(res, response);
  } catch (error) {
    console.error(error);
    res.writeHead(500, { "Content-Type": "text/plain; charset=utf-8" });
    res.end("Internal Server Error");
  }
}).listen(port, host, () => {
  console.log(`Listening on http://${host}:${port}`);
});