import { env } from "mikro/env";
import { sleep } from "mikro/sleep";
import { deviceId } from "mikro/sys";
import { bind } from "mikro/udp";
import { wifi } from "mikro/wifi";

// IPv4 site-local discovery group. 224.0.0.251 is the mDNS group, which
// home routers almost always forward (Bonjour/AirPlay/Chromecast use it).
// Note: real mDNS is on port 5353; we use a different port to avoid
// colliding with system mDNS responders.
const GROUP = "224.0.0.251";
const PORT = 7654;
const ANNOUNCE_MS = 2000;

const ssid = env.require("WIFI_SSID");
const passphrase = env.require("WIFI_PASSPHRASE");

console.log("Connecting to %s...", ssid);
const connected = await wifi.connect({ ssid, passphrase });
if (!connected.ok) {
  console.error("WiFi connect failed:", connected.error);
} else {
  console.log("Connected. IP: %s", connected.value.ip);

  const bound = await bind({ port: PORT, family: "ipv4" });
  if (!bound.ok) {
    console.error("bind failed:", bound.error);
  } else {
    const sock = bound.value;

    const joined = sock.joinMulticastGroup({ address: GROUP });
    if (!joined.ok) {
      console.error("join failed:", joined.error);
      sock.close();
    } else {
      const me = deviceId;

      sock.onMessage.subscribe(({ msg, from }) => {
        const text = new TextDecoder().decode(msg);
        // Multicast loops back to ourselves on the same host; skip.
        if (text === me) return;
        console.log("discovered %s at %s", text, from.address);
      });

      console.log("announcing as %s on %s:%d", me, GROUP, PORT);

      while (true) {
        const sent = await sock.send(me, { address: GROUP, port: PORT, family: "ipv4" });
        if (!sent.ok) console.error("send failed:", sent.error);
        await sleep(ANNOUNCE_MS);
      }
    }
  }
}