import { Socket } from 'net';
import { EventEmitter } from 'events';
import { MessageBuffer } from '../config/protocol';
import { TCPResponse } from '../types/protocol.types';
import { AuthenticatedUser } from '../../config/Interfaces/Auth/auth.interface';
/**
 * Connection metadata
 */
interface ConnectionInfo {
    socket: Socket;
    buffer: MessageBuffer;
    connectedAt: number;
    lastActivity: number;
    requestCount: number;
    /** Remote IP this connection came in on - kept for removeConnection() to clean up connectionsByIp. */
    remoteAddress: string;
    /** Set once a successful AUTHENTICATE command has run on this connection. Lives for the socket's lifetime. */
    authUser?: AuthenticatedUser;
}
/** Reason `addConnection` rejected a new socket, so the caller can send an accurate error response. */
export declare enum ConnectionRejectReason {
    SERVER_OVERLOAD = "SERVER_OVERLOAD",
    IP_LIMIT_EXCEEDED = "IP_LIMIT_EXCEEDED",
    RATE_LIMITED = "RATE_LIMITED"
}
/** Result of `addConnection` - either the new connection's id, or why it was rejected. */
export type ConnectionAddResult = {
    connectionId: string;
} | {
    rejected: ConnectionRejectReason;
};
/**
 * Connection Manager - Manages all active TCP connections
 */
export declare class ConnectionManager extends EventEmitter {
    private connections;
    /** Connection ids grouped by remote IP, so addConnection can enforce MAX_CONNECTIONS_PER_IP in O(1). */
    private connectionsByIp;
    private connectionCounter;
    constructor();
    /**
     * Add new connection
     */
    addConnection(socket: Socket): ConnectionAddResult;
    /**
     * Remove connection
     */
    removeConnection(connectionId: string): void;
    /**
     * Send response to client
     */
    sendResponse(connectionId: string, response: TCPResponse): boolean;
    /**
     * Get connection info
     */
    getConnection(connectionId: string): ConnectionInfo | undefined;
    /**
     * Mark a connection as authenticated, following a successful AUTHENTICATE command.
     */
    setAuthUser(connectionId: string, authUser: AuthenticatedUser): void;
    /**
     * Get the authenticated identity for a connection, if AUTHENTICATE has succeeded.
     */
    getAuthUser(connectionId: string): AuthenticatedUser | undefined;
    /**
     * Clears the cached authenticated identity for every connection belonging to a
     * given username, following a role change, password reset, or account deletion
     * elsewhere (see AuthEvents). The connection itself is left open - the next
     * command on it will simply be treated as unauthenticated again, mirroring how a
     * revoked GUI session cookie stops working without forcibly closing the browser tab.
     */
    revokeAuthForUser(username: string): void;
    /**
     * Get total active connections
     */
    get activeConnections(): number;
    /**
     * Get all connection IDs
     */
    getAllConnectionIds(): string[];
    /**
     * Close all connections gracefully
     */
    closeAll(): void;
    /**
     * Setup socket event handlers
     */
    private setupSocketHandlers;
    /**
     * Generate unique connection ID
     */
    private generateConnectionId;
    /**
     * Get connection statistics
     */
    getStats(): Record<string, any>;
}
export {};