function proxyHostFromHeader(hostHeader) {
  const raw = String(hostHeader || "").trim();
  if (!raw) return "";
  if (raw.startsWith("[")) {
    const end = raw.indexOf("]");
    return end > 0 ? raw.slice(1, end) : "";
  }
  return raw.split(":")[0];
}

export function buildSharedProxyInfo({
  appMode,
  proxyPort,
  running,
  hostHeader,
  sharedProxyHost,
}) {
  const host = String(sharedProxyHost || "").trim() || proxyHostFromHeader(hostHeader);
  const port = Number.parseInt(proxyPort, 10);
  const available =
    appMode === "gateway" &&
    Boolean(running) &&
    host &&
    Number.isInteger(port) &&
    port > 0 &&
    port <= 65535;

  const proxy = available
    ? {
        host,
        port,
        protocol: "socks5",
        httpUrl: `http://${host}:${port}`,
        socksUrl: `socks5://${host}:${port}`,
      }
    : null;

  return {
    success: true,
    available,
    mode: appMode,
    proxy,
  };
}