export function verifyComposeInvariants(compose) {
  const services = compose?.services ?? {};

  for (const [name, service] of Object.entries(services)) {
    if (name !== 'edge' && Array.isArray(service.ports) && service.ports.length > 0) {
      throw new Error(`${name} must not define ports`);
    }
    if (service.network_mode === 'host') {
      throw new Error(`${name} must not use network_mode: host`);
    }
  }

  const edge = services.edge;
  const edgePorts = Array.isArray(edge?.ports) ? edge.ports : [];
  if (edgePorts.length !== 1) {
    throw new Error(`edge must publish exactly one port; found ${edgePorts.length}`);
  }
}