/// <reference types="node" />
import { WriteStream } from 'fs';
import * as moment from 'moment';
export declare class Util {
    static readonly ROOT = "__ROOT__";
    static DEFAULT_BATCH_SIZE: number;
    static batchSize: number;
    static getRef(firestore: FirebaseFirestore.Firestore, path: string): ComplexRef;
    static safeWrite(writeStream: WriteStream, chunk: string): Promise<any>;
    static batchExecutor<T>(total: number, builder: (batchSize: number) => Promise<any>[], batchSize?: number, batchDone?: () => void): Promise<T[]>;
    static getTimestamp(): string;
    static getMoment(): moment.Moment;
    static arrayChunks(array: Array<any>, chunk_size: number): Array<Array<any>>;
    static serializeSpecialTypes(data: any): any;
    static unserializeSpecialTypes(data: any): any;
    static isScalar(val: any): boolean;
}
export interface ComplexRef {
    isRoot: boolean;
    isDocument: boolean;
    isCol: boolean;
    ref: FirebaseFirestore.Firestore | FirebaseFirestore.DocumentReference | FirebaseFirestore.CollectionReference | any;
}