/** Outbound port: tell the user how a command went (implemented with toasts by the app). */
export abstract class Notifications {
  abstract success(message: string): void;
  abstract error(message: string): void;
  /** Done, offering to undo it for a few seconds: `undo` runs if asked. */
  abstract undoable(message: string, undo: () => void): void;
}

/** Message of a failed GraphQL/HTTP call, for the user. */
export function describeError(error: unknown): string {
  if (
    error &&
    typeof error === 'object' &&
    'errors' in error &&
    Array.isArray((error as { errors: unknown[] }).errors)
  ) {
    return (error as { errors: { message: string }[] }).errors
      .map((e) => e.message)
      .join('\n');
  }
  return error instanceof Error ? error.message : String(error);
}

/** The read model is eventually consistent: right after a command, a query may 404 for a few ms. */
export function isNotFound(error: unknown): boolean {
  return /not found/i.test(describeError(error));
}