/**
 * Idempotency Store for Storage Webhook Processing
 *
 * Prevents duplicate processing of webhook events
 * Supports both in-memory and external storage (Redis, DB)
 */
import type { CoreInMemoryIdempotencyAdapterConfig } from '@plyaz/types/core';
import type { LoggerInterface } from '@plyaz/types';
/**
 * Idempotency Store for Storage Webhooks
 *
 * Prevents duplicate processing of webhook events using unique keys
 */
export declare class InMemoryIdempotencyAdapter {
    private config;
    private logger;
    private store;
    private cleanupTimer?;
    private readonly defaultTTL;
    private readonly cleanupInterval;
    private readonly maxKeys;
    constructor(config?: CoreInMemoryIdempotencyAdapterConfig, logger?: LoggerInterface | undefined);
    /**
     * Check if key has been processed (idempotency check)
     *
     * @param key - Unique idempotency key
     * @returns True if already processed
     */
    has(key: string): Promise<boolean>;
    /**
     * Mark key as processed
     *
     * @param key - Unique idempotency key
     * @param ttl - Time to live in milliseconds (optional, uses default if not provided)
     * @param metadata - Additional data to store with the key
     */
    set(key: string, ttl?: number, metadata?: Record<string, unknown>): Promise<void>;
    /**
     * Remove key from store
     *
     * @param key - Idempotency key to remove
     */
    delete(key: string): Promise<void>;
    /**
     * Clear all keys (useful for testing)
     */
    clear(): Promise<void>;
    /**
     * Get store statistics
     */
    getStats(): {
        size: number;
        maxKeys: number;
        oldestKey?: {
            key: string;
            age: number;
        };
    };
    /**
     * Start automatic cleanup of expired keys
     */
    private startCleanup;
    /**
     * Stop automatic cleanup
     */
    stop(): void;
    /**
     * Clean up expired keys
     */
    private cleanup;
    /**
     * Evict oldest keys when maxKeys is exceeded
     */
    private evictOldest;
}