/**
 * Update Deduplication
 *
 * Prevents processing duplicate Telegram updates.
 * Telegram may occasionally send the same update multiple times.
 */
export interface DedupeCacheOptions {
    /** Time-to-live in milliseconds */
    ttlMs?: number;
    /** Maximum cache size */
    maxSize?: number;
}
export declare class DedupeCache {
    private cache;
    private ttlMs;
    private maxSize;
    constructor(options?: DedupeCacheOptions);
    /**
     * Check if key exists and is not expired
     */
    has(key: string): boolean;
    /**
     * Add key to cache
     */
    add(key: string): void;
    /**
     * Check and add atomically - returns true if was already seen
     */
    checkAndAdd(key: string): boolean;
    /**
     * Clean up expired entries
     */
    private cleanup;
    /**
     * Clear all entries
     */
    clear(): void;
    /**
     * Get cache stats
     */
    getStats(): {
        size: number;
        maxSize: number;
        ttlMs: number;
    };
}
/**
 * Build a unique key for a Telegram update
 */
export declare function buildTelegramUpdateKey(ctx: {
    update?: {
        update_id?: number;
        message?: {
            message_id?: number;
            chat?: {
                id?: number;
            };
        };
    };
    callbackQuery?: {
        id?: string;
    };
}): string | undefined;
export declare const telegramUpdateDedupe: DedupeCache;