/**
 * The rule for a saved view's name, and the only copy of it.
 *
 * Both places a name can be set consult this: **Create New View**
 * (`CreateScreenPopup`) and **Rename** on a row (`ViewItem`). They are the same
 * field with the same constraint, and a second copy would have been a second
 * constraint the moment one of them changed — the class of drift the
 * `getCustomViewFields` and `operatorNeedsValue` helpers exist to prevent.
 *
 * Client-side this covers only what the user can be told immediately. The
 * server owns **uniqueness**, and answers a duplicate with HTTP 422; both
 * callers map that to a message rather than trying to pre-empt it, because the
 * list they would check against is per-user and already stale by the time it is
 * rendered.
 */
export const VIEW_NAME_MAX_LENGTH = 25;

/** `""` when the name is usable, otherwise the message to show under the field. */
export const validateViewName = (value: string): string => {
  if (!value.trim()) return "Required";
  if (value.length > VIEW_NAME_MAX_LENGTH)
    return `Maximum ${VIEW_NAME_MAX_LENGTH} characters allowed`;
  return "";
};