import { RemoteData } from '@shared/application/remote-data';

/** The standard load-lifecycle tags an editor machine exposes. */
export type LoadLifecycle =
  { tag: 'loading' } | { tag: 'failed'; reason: string } | { tag: 'loaded' };

/**
 * Project an Elm-machine state onto `RemoteData` for the `<app-async>` seam. The machine
 * keeps owning its own domain lifecycle (draft/submitted/…); this is purely the
 * loading/failed/loaded → async mapping, which was byte-identical across BriefStore,
 * OrgTemplateStore and StamdataStore (WP-31). Wrap the call in a `computed`.
 */
export function machineRemoteData<S extends LoadLifecycle>(
  s: S,
): RemoteData<Error, Extract<S, { tag: 'loaded' }>> {
  switch (s.tag) {
    case 'loading':
      return { tag: 'Loading' };
    case 'failed':
      return { tag: 'Failure', error: new Error(s.reason) };
    default: // 'loaded'
      return { tag: 'Success', value: s as Extract<S, { tag: 'loaded' }> };
  }
}