export type SortDir = 'ASC' | 'DESC';

/**
 * Returns a new array of documents sorted by documentDate.
 * Documents without a date are always placed last, regardless of direction.
 */
export function sortDocumentsByDate<T extends { documentDate?: string | null }>(
	docs: T[],
	dir: SortDir
): T[] {
	return [...docs].sort((a, b) => {
		const da = a.documentDate ?? '';
		const db = b.documentDate ?? '';
		if (!da && !db) return 0;
		if (!da) return 1;
		if (!db) return -1;
		return dir === 'DESC' ? db.localeCompare(da) : da.localeCompare(db);
	});
}