import { Dispatch, SetStateAction } from "react";
import { InitializerAction } from "../Hub/Hub";
import { PromiseAction } from "./usePromiseHub";
export type PromiseHubError<E> = E | null;
export type PromiseHubType<R, E> = {
    currentState: R;
    pending: boolean;
    error: PromiseHubError<E>;
};
export type PromiseListener<R, E> = Dispatch<SetStateAction<PromiseHubType<R, E>>>;
export declare class PromiseHub<R, E = Error> {
    private promiseState;
    private promiseAction;
    private onChangeListeners;
    private listeners;
    constructor(initialState: R, promiseAction: PromiseAction<R>);
    reAction(): Promise<R | undefined>;
    attachListener(listener: PromiseListener<R, E>): void;
    detachListener(listener: PromiseListener<R, E>): void;
    notifyListeners(newPromiseState: PromiseHubType<R, E>): void;
    getCurrentState(): R;
    setCurrentState(newCurrentState: R): void;
    setPendingState(pendingState: boolean): void;
    getPendingState(): boolean;
    getErrorState(): PromiseHubError<E>;
    setErrorState(error: E): void;
    onChange(callback: Function): void;
    removeOnChange(callback: Function): void;
}
/**
 * Creates a promise-based hub that manages a state and handles asynchronous actions.
 * The state is updated based on the result of the provided promise action, allowing
 * for easy state management involving async operations such as API calls.
 *
 * @template R - The type of the state managed by the promise hub.
 *
 * @param {R | InitializerAction<R>} initialState - The initial state or a function to initialize the state.
 * @param {PromiseAction<R>} promiseAction - The asynchronous function that will resolve to update the state.
 *
 * @returns {PromiseHub<R>} - Returns a PromiseHub which contains the current state, a loading flag, an error state, and a method to trigger the promise action.
 *
 * @example
 * // Example usage of `createPromiseHub`:
 * const userHub = createPromiseHub<User | undefined>(undefined, fetchUserData);
 */
export declare function createPromiseHub<R>(initialState: R | InitializerAction<R>, promiseAction: PromiseAction<R>): PromiseHub<R>;