import { Subject, Observable, OperatorFunction } from 'rxjs';

/**
 * A factory function returning an object to handle the process of merging Observable next notifications into one
 *   Observable. This API takes away the clumsy handling of static values and Observable, reduces the number of
 *   emissions by:
 * - only merging distinct Observables
 * - only emit distinct values of the merged result
 *
 * You can next a Observable of `U` multiple times and merge them into the Observable exposed under one optimized
 *   `values$`
 *
 */
declare function coerceAllFactory<U, R = U>(subjectFactory?: () => Subject<Observable<U> | U>, flattenOperator?: OperatorFunction<Observable<U>, R>): {
    values$: Observable<R>;
    next(observable: Observable<U> | U): void;
};

/**
 * This Observable factory creates an Observable out of a static value or an Observable.
 * It forwards only distinct values from distinct incoming Observables or values.
 * This comes in handy in any environment where you handle processing of incoming dynamic values and their state.
 *
 * Optionally you can pass a flatten strategy to get find grained control of the flattening process. E.g. mergeAll, switchAll
 *
 * @param o$ - The Observable to coerce and map to a Observable with distinct values
 * @param flattenOperator - determines the flattening strategy e.g. mergeAll, concatAll, exhaust, switchAll. default is switchAll
 */
declare function coerceDistinctObservable<T>(o$: Observable<Observable<T> | T>, flattenOperator?: OperatorFunction<Observable<T>, T>): Observable<T>;

/**
 * This operator takes an Observable of values ot Observables aof values and
 * It forwards only distinct values from distinct incoming Observables or values.
 * This comes in handy in any environment where you handle processing of incoming dynamic values and their state.
 *
 * Optionally you can pass a flatten strategy to get find grained control of the flattening process. E.g. mergeAll, switchAll
 *
 * @param flattenOperator - determines the flattening strategy e.g. mergeAll, concatAll, exhaust, switchAll. default is switchAll
 *
 */
declare function coerceDistinctWith<T>(flattenOperator?: OperatorFunction<Observable<T>, T>): (o$: Observable<Observable<T> | T>) => Observable<T>;

/**
 * This Observable factory creates an Observable out of a static value or an Observable.
 *
 * @param o - the value to coerce
 */
declare function coerceObservable<T>(o: Observable<T> | T): Observable<T>;

/**
 * This operator maps an Observable out of a static value or an Observable.
 *
 */
declare function coerceObservableWith<T>(): OperatorFunction<Observable<T | null | undefined> | T | null | undefined, Observable<T | null | undefined>>;

export { coerceAllFactory, coerceDistinctObservable, coerceDistinctWith, coerceObservable, coerceObservableWith };