function toRouterPath(configuredPath, defaultApiPath) {
  const fallback = String(defaultApiPath || '/').trim() || '/';
  const raw = String(configuredPath || fallback).trim() || fallback;

  let path = raw.startsWith('/') ? raw : `/${raw}`;

  // Routers are mounted under /api in server.js, so strip an optional /api prefix.
  if (path === '/api') path = '/';
  if (path.startsWith('/api/')) path = path.slice(4);

  if (path.length > 1) path = path.replace(/\/+$/, '');
  return path || '/';
}

function getRouterPathFromApiEnv(envKey, defaultApiPath) {
  return toRouterPath(process.env[envKey], defaultApiPath);
}

module.exports = {
  toRouterPath,
  getRouterPathFromApiEnv,
};