import { ValidationError } from '../error';

async function paginate(cursor: import('mongodb').Cursor, page: number, pageSize: number): Promise<[any[], number, number]> {
    if (page <= 0) throw new ValidationError('page');
    const [count, pageDocs] = await Promise.all([
        cursor.count(),
        cursor.skip((page - 1) * pageSize).limit(pageSize).toArray(),
    ]);
    const numPages = Math.floor((count + pageSize - 1) / pageSize);
    return [pageDocs, numPages, count];
}

global.Hydro.lib.paginate = paginate;
export default paginate;