import * as plugins from './plugins.js';

/** Codex's canonical app_server_control_socket_path, relative to its selected home. */
export const codexLocalSocketPath = (codexHomeArg: string): string => {
  if (!plugins.path.isAbsolute(codexHomeArg) || codexHomeArg.includes('\0')) throw new Error('CODEX_HOME must be an absolute directory.');
  return plugins.path.join(codexHomeArg, 'app-server-control', 'app-server-control.sock');
};

/** Absence selects an owned server. An inaccessible or stale socket is a connection failure. */
export const findCodexLocalSocket = async (codexHomeArg: string): Promise<string | undefined> => {
  const socketPath = codexLocalSocketPath(codexHomeArg);
  let stat: plugins.fs.Stats;
  try { stat = await plugins.fs.promises.lstat(socketPath); }
  catch (error) { if ((error as NodeJS.ErrnoException).code === 'ENOENT') return undefined; throw error; }
  if (!stat.isSocket()) throw new Error('The Codex control socket path is not a Unix socket.');
  return socketPath;
};