import type express from 'express';
import prometheus from 'prom-client';
import { TypedError } from 'typed-error';
import type { AuthTestFunc, CustomParams, LabelSet, MetricsMetaMap } from './types';
export declare class MetricsGathererError extends TypedError {
}
interface Describer {
    [kind: string]: (name: string, help: string, customParams?: CustomParams) => void;
}
export declare class MetricsGatherer {
    internalErrorCount: number;
    meta: MetricsMetaMap;
    private metrics;
    describe: Describer;
    client: typeof prometheus;
    constructor();
    private initState;
    private setupDescribe;
    gauge(name: string, val: number, labels?: LabelSet): void;
    inc(name: string, val?: number, labels?: LabelSet): void;
    dec(name: string, val?: number, labels?: LabelSet): void;
    counter(name: string, val?: number, labels?: LabelSet): void;
    summary(name: string, val: number, labels?: LabelSet, customParams?: CustomParams): void;
    histogram(name: string, val: number, labels?: LabelSet, customParams?: CustomParams): void;
    histogramSummary(name: string, val: number, labels?: LabelSet): void;
    checkMetricType(name: string, kinds: string[]): boolean | undefined;
    getMetric<T extends string = string>(name: string): prometheus.Metric<T> | undefined;
    exists(name: string): boolean;
    private ensureExists;
    reset(name?: string): void;
    requestHandler(authTest?: AuthTestFunc): express.Handler;
    /**
     * Create an express request handler given an auth test function which is suitable
     * for use in a context where we're using node's `cluster` module.
     * Note: This *must* be paired with an `aggregateRequestWorker()` call on all workers
     */
    aggregateRequestHandler(authTest?: AuthTestFunc): express.Handler;
    aggregateRequestWorker(): void;
    collectDefaultMetrics(): void;
    collectAPIMetrics(app: express.Application): express.Application;
    output(): Promise<string>;
    clear(): void;
    private err;
}
export {};