type Result<T> =
  | { ok: true; value: T }
  | { ok: false; error: string };

export enum Status { Idle = 'idle', Busy = 'busy', Failed = 'failed' }

export interface FileSpec {
  readonly path: string;
  bytes: number;
  tags?: string[];
}

/** Generic angle brackets are what a JavaScript-only tokeniser trips over. */
export function unwrap<T>(r: Result<T>, fallback: T): T {
  return r.ok ? r.value : fallback;
}

export const SIZES = { small: 1024, large: 1048576 } as const;

export function describe(spec: FileSpec): string {
  const { path, bytes } = spec;
  const kind: Status = bytes > SIZES.large ? Status.Busy : Status.Idle;
  return `${path} is ${bytes} bytes (${kind})`;
}

const check = { path: 'a.txt', bytes: 12 } satisfies FileSpec;
export default check;