// Extract a human-readable message from an unknown thrown value.
//
// `String(err)` on a non-Error object yields the useless "[object Object]",
// which is exactly what surfaced when native modules (whisper.rn, the audio
// decoder, file system) reject with a plain `{ message, code }`-shaped object
// instead of an `Error`. This pulls the most useful text out of whatever was
// thrown so the UI shows something actionable.
export function errorMessage(err: unknown): string {
  if (err instanceof Error) return err.message;
  if (typeof err === 'string') return err;
  if (err && typeof err === 'object') {
    const o = err as { message?: unknown; reason?: unknown; code?: unknown };
    const parts = [o.message, o.reason, o.code]
      .filter((x) => x != null && x !== '')
      .map(String);
    if (parts.length > 0) return parts.join(' — ');
    try {
      return JSON.stringify(err);
    } catch {
      /* fall through to String() for circular/unserializable objects */
    }
  }
  return String(err);
}