import FormDataNode from 'form-data';
export interface UploadOptions {
    form: Record<string, string | Blob> | FormData | FormDataNode;
    url: string;
    headers?: Record<string, string>;
    withCredentials?: boolean;
}
export interface UploadResponse {
    data?: string | ArrayBuffer | Blob;
    xhr?: XMLHttpRequest;
    status?: Number;
    headers?: Record<string, string | string[] | undefined>;
}
export declare type UploadState = 'new' | 'started' | 'failed' | 'successful' | 'aborted';
export declare type UploadStateChangeEventListener = (this: Upload, state: UploadState) => void;
export declare type UploadProgressEventListener = (this: Upload, progress: number) => void;
export declare type UploadErrorEventListener = (this: Upload) => void;
export declare class Upload {
    private events;
    private form;
    private url;
    private headers?;
    private xhr?;
    private withCredentials?;
    private _uploadedBytes;
    private _totalBytes;
    private _state;
    constructor(options: UploadOptions);
    /**
     * POSTs the form.
     */
    upload(): Promise<UploadResponse>;
    abort(): void;
    get uploadedBytes(): number;
    private setUploadedBytes;
    private increaseUploadedBytes;
    get totalBytes(): number;
    private setTotalBytes;
    /**
     * Current upload progress. A float between 0 and 1.
     */
    get progress(): number;
    get state(): UploadState;
    private setState;
    /**
     * Adds a listener for a progress event.
     * @param eventType Event type. (progress)
     * @param listener Listener function.
     */
    on(eventType: 'progress', listener: UploadProgressEventListener): void;
    /**
     * Adds a listener for an error event.
     * @param eventType Event type. (error)
     * @param listener Listener function.
     */
    on(eventType: 'error', listener: UploadErrorEventListener): void;
    /**
     * Adds a listener for a state change event.
     * @param eventType Event type. (state)
     * @param listener Listener function.
     */
    on(eventType: 'state', listener: UploadStateChangeEventListener): void;
    /**
     * Removes a listener for a progress event.
     * @param eventType Event type. (progress)
     * @param listener Listener function.
     */
    off(eventType: 'progress', listener: UploadProgressEventListener): void;
    /**
     * Removes a listener for an error event.
     * @param eventType Event type. (error)
     * @param listener Listener function.
     */
    off(eventType: 'error', listener: UploadErrorEventListener): void;
    /**
     * Removes a listener for a state change event.
     * @param eventType Event type. (state)
     * @param listener Listener function.
     */
    off(eventType: 'state', listener: UploadStateChangeEventListener): void;
    private emit;
}