export interface ProgressState {
    percentage: number;
    message?: string;
    eta?: number | null;
}
declare class Progress {
    private _message;
    private _bar;
    private _lastLine;
    /**
     * @summary Create a CLI Progress Bar
     * @name Progress
     * @class
     * @public
     * @memberof visuals
     *
     * @param {String} message - message
     * @returns {Progress} progress bar instance
     *
     * @throws Will throw if no message.
     *
     * @example
     * progress = new visuals.Progress('Hello World')
     */
    constructor(message: string);
    /**
     * @summary Get progress string from a state
     * @name visuals.Progress#_tick
     * @method
     * @private
     *
     * @param {Object} state - progress state
     * @param {Number} state.percentage - percentage
     * @param {String} [state.message] - message
     * @param {Number} [state.eta] - eta in seconds
     *
     * @throws Will throw if no percentage.
     * @throws Will throw if no eta.
     *
     * @returns {String} progress string
     *
     *	@example
     * progress = new visuals.Progress('Hello World')
     * string = progress._tick(percentage: 49, eta: 300)
     * console.log(string)
     */
    _tick(state: ProgressState): string;
    /**
     * @summary Erase last printed line
     * @name visuals.Progress#_eraseLastLine
     * @method
     * @private
     *
     * @example
     * progress = new visuals.Progress('Hello World')
     * progress._eraseLastLine()
     */
    _eraseLastLine(): boolean | undefined;
    /**
     * @summary Update the progress bar
     * @name visuals.Progress#update
     * @method
     * @public
     *
     * @param {Object} state - progress state
     * @param {Number} state.percentage - percentage
     * @parm  {String} [state.message] - message
     * @param {Number} [state.eta] - eta in seconds
     *
     * @example
     * progress = new visuals.Progress('Hello World')
     * progress.update(percentage: 49, eta: 300)
     */
    update(state: ProgressState): boolean;
}
export default Progress;