import { BehaviorSubject, Subscription, Observable } from "rxjs";
import * as i0 from "@angular/core";
export type Key = string | object | symbol;
export interface IGetLoadingOptions {
    /** Which loading "thing" do you want to track? */
    key?: Key;
}
export interface IAddLoadingOptions {
    /** Used to track the loading of different things */
    key?: Key | Key[];
    /**
     * The first time you call IsLoadingService#add() with
     * the "unique" option, it's the same as without it.
     * The second time you call add() with the "unique" option,
     * the IsLoadingService will see if
     * an active loading indicator with the same "unique" ID
     * already exists.
     * If it does, it will remove that indicator and replace
     * it with this one (ensuring that calling add() with a
     * unique key multiple times in a row only adds a single
     * loading indicator to the stack). Example:
     *
     * ```ts
     * this.isLoadingService.isLoading(); // false
     * this.isLoadingService.add({ unique: 'test' });
     * this.isLoadingService.add({ unique: 'test' });
     * this.isLoadingService.isLoading(); // true
     * this.isLoadingService.remove();
     * this.isLoadingService.isLoading(); // false
     * ```
     */
    unique?: Key;
}
export interface IRemoveLoadingOptions {
    key?: Key | Key[];
}
export declare class LoadingService {
    protected defaultKey: string;
    errorMessage: any;
    private loadingSubjects;
    isSetLoading$: BehaviorSubject<boolean>;
    private loadingStacks;
    private loadingKeyIndex;
    constructor();
    isLoading$(args?: IGetLoadingOptions): Observable<boolean>;
    /**
     * Same as `isLoading$()` except a boolean is returned,
     * rather than an observable.
     *
     * @param args.key optionally specify the key to check
     */
    isLoading(args?: IGetLoadingOptions): boolean;
    setLoading(observable: Observable<any>, key: any): void;
    add(): void;
    add(options: IAddLoadingOptions): void;
    add<T extends Subscription | Promise<unknown> | Observable<unknown>>(sub: T, options?: IAddLoadingOptions): T;
    remove(a?: Subscription | Promise<unknown> | IRemoveLoadingOptions, b?: IRemoveLoadingOptions, param?: any): void;
    private normalizeKeys;
    private indexKeys;
    private deIndexKey;
    private updateLoadingStatus;
    private _updateLoadingStatus;
    static ɵfac: i0.ɵɵFactoryDeclaration<LoadingService, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<LoadingService>;
}