/**
 * Message Bus - Inter-agent communication infrastructure
 *
 * Provides a publish-subscribe message bus for agent-to-agent communication
 * with support for:
 * - Topic-based messaging
 * - Request-response patterns
 * - Broadcast messaging
 * - Message persistence and replay
 */
import type { AgentMessage, MessageHandler, SubscriptionOptions, MessageBusConfig } from "../../types/index.js";
/**
 * Message Bus - Central hub for agent communication
 */
export declare class MessageBus {
    private subscriptions;
    private messageHistory;
    private pendingRequests;
    private deadLetterQueue;
    private config;
    private emitter;
    constructor(config?: MessageBusConfig);
    /**
     * Subscribe to a topic
     */
    subscribe(topic: string, subscriberId: string, handler: MessageHandler, options?: SubscriptionOptions): string;
    /**
     * Unsubscribe from a topic
     */
    unsubscribe(subscriptionId: string): boolean;
    /**
     * Unsubscribe all subscriptions for an agent
     */
    unsubscribeAll(subscriberId: string): number;
    /**
     * Publish a message to a topic
     */
    publish(topic: string, senderId: string, payload: unknown, options?: Partial<Omit<AgentMessage, "id" | "topic" | "senderId" | "payload" | "timestamp">>): Promise<void>;
    /**
     * Send a direct message to a specific agent
     */
    sendDirect(senderId: string, recipientId: string, payload: unknown, options?: Partial<Omit<AgentMessage, "id" | "senderId" | "recipientId" | "payload" | "timestamp">>): Promise<void>;
    /**
     * Send a request and wait for response
     */
    request(topic: string, senderId: string, payload: unknown, timeout?: number): Promise<AgentMessage>;
    /**
     * Reply to a request
     */
    reply(originalMessage: AgentMessage, senderId: string, payload: unknown): Promise<void>;
    /**
     * Broadcast a message to all subscribers
     */
    broadcast(senderId: string, payload: unknown, excludeTopics?: string[]): Promise<void>;
    /**
     * Deliver a message to subscribers
     */
    private deliverMessage;
    /**
     * Check if message should be delivered to subscription
     */
    private shouldDeliver;
    /**
     * Unsubscribe by topic for a specific subscriber
     */
    private unsubscribeByTopic;
    /**
     * Get message history for a topic
     */
    getHistory(topic?: string, limit?: number): AgentMessage[];
    /**
     * Get dead letter queue messages
     */
    getDeadLetterQueue(): AgentMessage[];
    /**
     * Clear dead letter queue
     */
    clearDeadLetterQueue(): void;
    /**
     * Replay messages from history
     */
    replayHistory(topic: string, subscriberId: string, since?: number): Promise<void>;
    /**
     * Get all topics
     */
    getTopics(): string[];
    /**
     * Get subscriber count for a topic
     */
    getSubscriberCount(topic: string): number;
    /**
     * Get statistics
     */
    getStats(): {
        topicCount: number;
        totalSubscriptions: number;
        historySize: number;
        deadLetterQueueSize: number;
        pendingRequests: number;
    };
    /**
     * Subscribe to bus events
     */
    on(event: string, handler: (...args: unknown[]) => void): void;
    /**
     * Unsubscribe from bus events
     */
    off(event: string, handler: (...args: unknown[]) => void): void;
    /**
     * Shutdown the message bus
     */
    shutdown(): void;
}