import { createConnection } from "net";

export const name = "Internet";
export const url  = null;

// TCP connect to Google DNS port 53 — more reliable than ICMP ping in
// managed Windows environments where outbound ICMP may be blocked.
const CHECK_HOST = "8.8.8.8";
const CHECK_PORT = 53;
const TIMEOUT_MS = 5000;

function tcpCheck(host, port) {
  return new Promise((resolve) => {
    const start  = Date.now();
    const socket = createConnection({ host, port }, () => {
      const latencyMs = Date.now() - start;
      socket.destroy();
      resolve({ reachable: true, latencyMs });
    });
    socket.setTimeout(TIMEOUT_MS);
    socket.on("timeout", () => { socket.destroy(); resolve({ reachable: false, latencyMs: null }); });
    socket.on("error",   () => {                   resolve({ reachable: false, latencyMs: null }); });
  });
}

export async function checkStatus() {
  const { reachable, latencyMs } = await tcpCheck(CHECK_HOST, CHECK_PORT);

  if (!reachable) {
    return {
      name,
      status:      "outage",
      message:     `No response from ${CHECK_HOST}:${CHECK_PORT} — internet may be down.`,
      lastUpdated: new Date().toISOString(),
    };
  }

  const status  = latencyMs >= 100 ? "degraded" : "operational";
  const message = latencyMs >= 100
    ? `High latency to ${CHECK_HOST}: ${latencyMs}ms.`
    : `Internet reachable — ${CHECK_HOST} responded in ${latencyMs}ms.`;

  return {
    name,
    status,
    message,
    lastUpdated: new Date().toISOString(),
  };
}