short_polling_server.ts

short_polling_server.ts

let powerstatus = "0";
let lastPowerstatus = "0";

const waitForChange = (timeout: number) => {
  return new Promise<string>((resolve) => {
    const start = Date.now();
    const interval = 100;

    const check = () => {
      if (powerstatus !== lastPowerstatus) {
        lastPowerstatus = powerstatus;
        resolve(lastPowerstatus);
      } else if (Date.now() - start >= timeout) {
        resolve(lastPowerstatus);
      } else {
        setTimeout(check, interval);
      }
    };

    check();
  });
};

const server = Bun.serve({
  port: 12000,
  async fetch(request, server) {
    const url = new URL(request.url);
    console.log("URL:", url.href);

    if (url.pathname === "/ask/powerstatus") {
      if (request.method === "GET") {
        const value = await waitForChange(10000);
        return new Response(value);
      } else if (request.method === "PUT") {
        const content = await request.text();
        if (content === "1" || content === "0") {
          powerstatus = content;
          return new Response(content);
        }
      }
    }

    return Response.redirect("https://www.nasa.gov", 302);
  },
});

console.log(`Listening on ${server.url}`);