import { EventEmitter } from 'events';
export interface RateLimitConfig {
    windowMs: number;
    maxRequests: number;
    skipSuccessfulRequests?: boolean;
    skipFailedRequests?: boolean;
    keyGenerator?: (endpoint: string, clientId?: string) => string;
    onLimitReached?: (key: string) => void;
    enableBackoff?: boolean;
    backoffMultiplier?: number;
    maxBackoffMs?: number;
    enableDynamicLimits?: boolean;
    burstLimit?: number;
    burstWindowMs?: number;
}
export interface RateLimitInfo {
    limit: number;
    remaining: number;
    resetTime: number;
    retryAfter?: number;
}
export interface RateLimitResult {
    allowed: boolean;
    info: RateLimitInfo;
    backoffMs?: number;
}
export declare class APIRateLimiter extends EventEmitter {
    private config;
    private requests;
    private backoffStates;
    private dynamicLimits;
    private logger;
    private cleanupInterval;
    constructor(config: RateLimitConfig);
    checkLimit(endpoint: string, clientId?: string): Promise<RateLimitResult>;
    recordRequest(endpoint: string, success: boolean, responseTime?: number, clientId?: string): Promise<void>;
    getStatus(endpoint: string, clientId?: string): RateLimitInfo;
    getMetrics(): {
        activeKeys: number;
        totalRequests: number;
        rateLimitedRequests: number;
        averageResponseTime: number;
        backoffStates: number;
        topEndpoints: Array<{
            endpoint: string;
            requests: number;
            avgTime: number;
        }>;
    };
    reset(endpoint?: string, clientId?: string): void;
    getSecurityEvents(): Array<{
        timestamp: number;
        type: 'rate_limit_exceeded' | 'burst_limit_exceeded' | 'backoff_entered' | 'suspicious_activity';
        key: string;
        endpoint: string;
        metadata?: any;
    }>;
    detectSuspiciousActivity(endpoint: string, clientId?: string): boolean;
    private cleanup;
    private getKey;
    private getValidRequests;
    private getEffectiveLimit;
    private getResetTime;
    private getRetryAfter;
    private isInBackoff;
    private enterBackoff;
    private resetBackoff;
    private calculateBackoffTime;
    private updateDynamicLimit;
    destroy(): void;
}
export declare class RateLimiterFactory {
    static createAPILimiter(config?: Partial<RateLimitConfig>): APIRateLimiter;
    static createStrictLimiter(config?: Partial<RateLimitConfig>): APIRateLimiter;
    static createDevelopmentLimiter(config?: Partial<RateLimitConfig>): APIRateLimiter;
}
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