const http = require("node:http");

// A small multi-file app whose markup uses absolute paths, as real apps do.
const files = {
  "/style.css": ["text/css", `@import "/more.css";\n`],
  "/more.css": ["text/css", `#hi { color: rgb(1, 2, 3) }\n`],
  "/lib.js": ["text/javascript", `export const text = "from lib.js";\n`],
  "/app.js": ["text/javascript", `import { text } from "/lib.js";
document.getElementById("js").textContent = text;
fetch("/api/data").then((r) => r.json()).then((d) => { document.getElementById("api").textContent = String(d.n); });
new Worker("/w.js").onmessage = (e) => { document.getElementById("worker").textContent = "worker:" + e.data; };
`],
  "/w.js": ["text/javascript", `fetch("/api/data").then((r) => r.json()).then((d) => postMessage(d.n));\n`],
  "/api/data": ["application/json", JSON.stringify({ n: 42 })],
  "/about": ["text/html", `<h1 id="about-h">About</h1>`],
};

const server = http.createServer();
// A plain listener ahead of the async one: its throw is a true synchronous uncaught exception.
server.on("request", (req) => {
  if (req.url === "/boom") throw new Error("boom");
});
server.on("request", async (req, res) => {
  if (req.url === "/async-boom") {
    await null;
    throw new Error("async boom");
  }
  if (req.url === "/reject-string") {
    await null;
    throw "nope";
  }
  if (req.method === "POST" && req.url === "/submit") {
    let body = "";
    const dec = new TextDecoder();
    req.on("data", (chunk) => { body += dec.decode(chunk, { stream: true }); });
    req.on("end", () => {
      res.writeHead(200, { "content-type": "text/html; charset=utf-8" });
      res.end(`<p id="submitted">${body}</p>`);
    });
    return;
  }
  const file = req.method === "GET" && files[req.url];
  if (file) {
    res.writeHead(200, { "content-type": `${file[0]}; charset=utf-8` });
    res.end(file[1]);
    return;
  }
  if (req.method === "POST" && req.url.startsWith("/echo")) {
    let body = "";
    const dec = new TextDecoder();
    req.on("data", (chunk) => { body += dec.decode(chunk, { stream: true }); });
    req.on("end", () => {
      res.setHeader("x-nib", "1");
      res.writeHead(200, { "content-type": "text/plain; charset=utf-8" });
      res.end(body);
    });
    return;
  }
  if (req.url === "/bye") {
    res.writeHead(200, { "content-type": "text/plain; charset=utf-8" });
    res.end("bye\n");
    server.close(() => console.log("closed"));
    return;
  }
  res.writeHead(200, { "content-type": "text/html; charset=utf-8" });
  const hi = `<h1 id="hi">Hello from ${req.method} ${req.url}</h1>`;
  if (req.url !== "/") {
    res.end(hi);
    return;
  }
  res.end(`<!doctype html>
<link rel="stylesheet" href="/style.css">
<script type="module" src="/app.js"></script>
${hi}
<p id="js"></p><p id="api"></p><p id="worker"></p>
<a id="about" href="/about">About</a>
<form id="f" method="post" action="/submit"><input name="q" value="hello"><button>Send</button></form>`);
});
server.listen(3000, () => console.log("listening on 3000"));