import {mkdirSync, rmSync} from "node:fs";
import net from "node:net";

const mode = process.env.BRIDGE_MODE || "network";
const socketPath = process.env.BRIDGE_SOCKET || "/run/provider-proxy/upstream.sock";
const listenPort = Number.parseInt(process.env.LISTEN_PORT || "17897", 10);
const upstreamHost = process.env.UPSTREAM_HOST || "127.0.0.1";
const upstreamPort = Number.parseInt(process.env.UPSTREAM_PORT || "7897", 10);

if (mode === "host") {
  mkdirSync("/run/provider-proxy", {recursive: true});
  rmSync(socketPath, {force: true});
}

const server = net.createServer((client) => {
  client.pause();
  const upstream = mode === "host"
    ? net.connect({host: upstreamHost, port: upstreamPort})
    : net.connect(socketPath);
  upstream.once("connect", () => {
    client.pipe(upstream);
    upstream.pipe(client);
    client.resume();
  });
  const close = () => {
    client.destroy();
    upstream.destroy();
  };
  client.on("error", close);
  upstream.on("error", close);
});

const listenTarget = mode === "host" ? socketPath : {host: "0.0.0.0", port: listenPort};
server.listen(listenTarget, () => {
  const target = mode === "host" ? socketPath : `0.0.0.0:${listenPort}`;
  const upstream = mode === "host" ? `${upstreamHost}:${upstreamPort}` : socketPath;
  console.log(`provider proxy ${mode} bridge ${target} -> ${upstream}`);
});

function shutdown() {
  server.close(() => {
    if (mode === "host") rmSync(socketPath, {force: true});
    process.exit(0);
  });
}

process.on("SIGTERM", shutdown);
process.on("SIGINT", shutdown);