import type { _InternalHttpMethods, DedupeRule, DeduplicationConfig, RequestSerializer, RequestKeyOptions } from '../types.ts';
import type { FetchPlugin } from '../engine/types.ts';
import { ResiliencePolicy } from './base.ts';
/**
 * Deduplication policy for preventing duplicate concurrent requests.
 *
 * When multiple identical requests are made concurrently, deduplication
 * ensures only one actual network request is made. All callers share
 * the same in-flight promise.
 *
 * @template S - Instance state type
 * @template H - Headers type
 * @template P - Params type
 */
export declare class DedupePolicy<S = unknown, H = unknown, P = unknown> extends ResiliencePolicy<DeduplicationConfig<S, H, P>, DedupeRule<S, H, P>, S, H, P> {
    /**
     * Get the default serializer for deduplication.
     */
    protected getDefaultSerializer(): RequestSerializer<S, H, P>;
    /**
     * Get the default HTTP methods for deduplication.
     */
    protected getDefaultMethods(): _InternalHttpMethods[];
    /**
     * Merge a matched rule with policy defaults.
     */
    protected mergeRuleWithDefaults(rule: DedupeRule<S, H, P> | null): DedupeRule<S, H, P>;
    /**
     * Resolve deduplication configuration for a request.
     */
    resolveForRequest(method: string, path: string, ctx: RequestKeyOptions<S, H, P>): DedupeRule<S, H, P> | null;
}
/**
 * Factory function that creates a dedupe plugin for FetchEngine.
 *
 * The plugin maintains a local `Map<string, Promise>` for in-flight tracking
 * and installs an `execute` (pipe) hook at priority `-30`.
 *
 * @param config - Deduplication configuration
 * @returns FetchPlugin that can be installed via `engine.use()` or `plugins` config
 *
 * @example
 *     const api = new FetchEngine({
 *         baseUrl: 'https://api.example.com',
 *         plugins: [dedupePlugin(true)]
 *     });
 */
export declare function dedupePlugin<H = unknown, P = unknown, S = unknown>(config: boolean | DeduplicationConfig<S, H, P>): FetchPlugin<H, P, S> & {
    inflightCount(): number;
};