import { Observable } from 'rxjs/Observable';
import { GroupedObservable } from 'rxjs/operator/groupBy';
export interface SingleRequest<R extends string> {
    resource: R;
    id: string;
}
interface BatchRequest<R extends string> extends SingleRequest<R> {
    batchId: number;
    fallbackWhen: FallbackWhen;
}
export interface BatchedRequest<R extends string> {
    resource: R;
    ids: string[];
}
/**
 * 指定某一个请求在 batch service 中使用 fallback 的策略
 */
export declare const enum FallbackWhen {
    /**
     * 不使用 fallback
     */
    Never = 0,
    /**
     * 当聚合请求发生错误时，使用 fallback
     */
    Error = 1,
    /**
     * 当单个请求没有和其他请求发生聚合时，使用 fallback
     */
    Alone = 2,
    /**
     * 当聚合请求发生错误或者单个请求没有发生聚合时，都使用 fallback
     */
    Both = 3
}
export interface BatchRequestMethod<RM extends {} = {}> {
    <K extends KeyofStringOnly<RM> = KeyofStringOnly<RM>, T = RM[K]>(resourceName: K, resourceId: string, fallback?: Observable<T>, fallbackWhen?: FallbackWhen): Observable<T>;
    <R>(resourceName: string, resourceId: string, fallback?: Observable<R>, fallbackWhen?: FallbackWhen): Observable<R>;
}
export interface BatchConfig<M extends string> {
    bufferTime?: number;
    maxBufferCount?: number | ((resource: M) => number);
    bufferTimer?: (groupedRequests$: GroupedObservable<M, BatchRequest<M>>) => Observable<any>;
    maxConcurrent?: number;
}
export declare type RequestMethod<K extends string, R extends {} = {}> = (resource: K, ids: string[]) => Observable<R>;
export declare type GetMatched<RM extends {} = StringObj, R extends {} = {}> = (result: R, id: string, resource: KeyofStringOnly<RM>) => RM[typeof resource] | undefined | never;
export declare type KeyofStringOnly<T extends {}> = Extract<keyof T, string>;
declare type StringObj = {
    [key: string]: any;
};
export declare const batchService: <RM extends {} = StringObj, R extends {} = {}>(requestMethod: RequestMethod<Extract<keyof RM, string>, R>, getMatched: GetMatched<RM, R>, { bufferTime: defaultBufferTime, maxBufferCount, bufferTimer, maxConcurrent }?: BatchConfig<Extract<keyof RM, string>>) => BatchRequestMethod<RM>;
export {};