/**
 * Turning a failed request into a sentence somebody can act on.
 *
 * The three that matter are genuinely different problems and send you to different places: nothing is
 * configured yet, fofos cannot be reached, or fofos refused the token. A panel that says "something
 * went wrong" for all three is the reason people restart servers that were fine.
 */

export type ApiFailure = {
  error?: string;
  /** No connection stored. A setup step, not a fault. */
  unconfigured?: boolean;
  /** fofos never answered — down, wrong URL, no route to it. */
  unreachable?: boolean;
};

/** What the client throws carries the parsed body on `.body` when there was one. */
export const failureOf = (error: unknown): ApiFailure => {
  const body = (error as { body?: unknown })?.body;
  if (body && typeof body === 'object') return body as ApiFailure;
  return { error: error instanceof Error ? error.message : String(error) };
};

export const readableError = (error: unknown): string => {
  const failure = failureOf(error);

  if (failure.unconfigured) return 'No fofos connection is set up yet.';
  if (failure.unreachable) return failure.error ?? 'fofos did not answer.';

  return failure.error ?? 'That did not work, and the server did not say why.';
};