server.mjs

import { createReadStream } from "node:fs";
import { stat } from "node:fs/promises";
import { createServer } from "node:http";
import { extname, resolve, sep } from "node:path";
import { fileURLToPath } from "node:url";

import { handleApiRequest } from "./src/http.js";
import { createIncidentService } from "./src/service.js";
import { createMemoryStore } from "./src/store.js";

const root = resolve(fileURLToPath(new URL(".", import.meta.url)));
const port = Number(process.env.PORT || 4174);
const store = createMemoryStore();
const types = {
  ".css": "text/css; charset=utf-8",
  ".html": "text/html; charset=utf-8",
  ".js": "text/javascript; charset=utf-8",
  ".json": "application/json; charset=utf-8",
  ".png": "image/png",
  ".svg": "image/svg+xml",
  ".webp": "image/webp",
};

async function webRequest(request) {
  const chunks = [];
  for await (const chunk of request) chunks.push(chunk);
  const body = chunks.length ? Buffer.concat(chunks) : undefined;
  return new Request(`http://${request.headers.host}${request.url}`, {
    method: request.method,
    headers: request.headers,
    body,
  });
}

async function sendWebResponse(response, webResponse) {
  response.writeHead(webResponse.status, Object.fromEntries(webResponse.headers));
  response.end(Buffer.from(await webResponse.arrayBuffer()));
}

createServer(async (request, response) => {
  const pathname = new URL(request.url, `http://${request.headers.host}`).pathname;
  if (pathname.startsWith("/api/")) {
    const webResponse = await handleApiRequest(await webRequest(request), (storageKey) =>
      createIncidentService(store, storageKey),
    );
    await sendWebResponse(response, webResponse);
    return;
  }

  const requested = pathname === "/" ? "index.html" : pathname.slice(1);
  const path = resolve(root, requested);
  if (path !== root && !path.startsWith(`${root}${sep}`)) {
    response.writeHead(403).end("Forbidden");
    return;
  }

  try {
    const metadata = await stat(path);
    if (!metadata.isFile()) throw new Error("Not a file");
    response.writeHead(200, {
      "Content-Type": types[extname(path)] || "application/octet-stream",
      "Cache-Control": "no-store",
      "Permissions-Policy": "tools=(self)",
      "X-Content-Type-Options": "nosniff",
    });
    createReadStream(path).pipe(response);
  } catch {
    response.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" }).end("Not found");
  }
}).listen(port, "127.0.0.1", () => {
  console.log(`Arrastra Relay prototype: http://127.0.0.1:${port}`);
});