import { OnModuleDestroy } from '@nestjs/common';
/**
 * Token bucket rate limiter for email logs
 * Prevents email spam during error storms
 *
 * Similar pattern to CacheModule's LRUCacheProvider
 */
export declare class EmailLogRateLimiterService implements OnModuleDestroy {
    private readonly maxEmails;
    private readonly windowMs;
    private readonly burstSize;
    private readonly logger;
    private tokenBucket;
    private refillTimer;
    constructor(maxEmails: number, windowMs: number, burstSize: number);
    /**
     * Check if email should be sent based on rate limit
     * @param key - Rate limit key (e.g., 'error:global' or 'error:appname')
     * @returns true if allowed, false if rate limited
     */
    canSend(key: string): boolean;
    /**
     * Get current state for monitoring/debugging
     */
    getState(key: string): {
        tokens: number;
        lastRefill: number;
    } | undefined;
    /**
     * Reset rate limit for a key (admin function)
     */
    reset(key: string): void;
    /**
     * Start periodic token refill
     * Refills all buckets every second to prevent token starvation
     */
    private startRefillTimer;
    /**
     * Cleanup on module destroy
     */
    onModuleDestroy(): void;
}