/**
 * Adaptive SMTP Logging System
 * Automatically switches between logging modes based on server load (active connections)
 * to maintain performance during high-concurrency scenarios
 */
import * as plugins from '../../../../plugins.js';
import { SecurityLogLevel, SecurityEventType } from '../constants.js';
import type { ISmtpSession } from '../interfaces.js';
import type { LogLevel, ISmtpLogOptions } from './logging.js';
/**
 * Log modes based on server load
 */
export declare enum LogMode {
    VERBOSE = "VERBOSE",// < 20 connections: Full detailed logging
    REDUCED = "REDUCED",// 20-40 connections: Limited command/response logging, full error logging
    MINIMAL = "MINIMAL"
}
/**
 * Configuration for adaptive logging thresholds
 */
export interface IAdaptiveLogConfig {
    verboseThreshold: number;
    reducedThreshold: number;
    aggregationInterval: number;
    maxAggregatedEntries: number;
}
/**
 * Connection metadata for aggregation tracking
 */
interface IConnectionTracker {
    activeConnections: number;
    peakConnections: number;
    totalConnections: number;
    connectionsPerSecond: number;
    lastConnectionTime: number;
}
/**
 * Adaptive SMTP Logger that scales logging based on server load
 */
export declare class AdaptiveSmtpLogger {
    private static instance;
    private currentMode;
    private config;
    private aggregatedEntries;
    private aggregationTimer;
    private connectionTracker;
    private constructor();
    /**
     * Get singleton instance
     */
    static getInstance(config?: Partial<IAdaptiveLogConfig>): AdaptiveSmtpLogger;
    /**
     * Update active connection count and adjust log mode if needed
     */
    updateConnectionCount(activeConnections: number): void;
    /**
     * Track new connection for rate calculation
     */
    trackConnection(): void;
    /**
     * Get current logging mode
     */
    getCurrentMode(): LogMode;
    /**
     * Get connection statistics
     */
    getConnectionStats(): IConnectionTracker;
    /**
     * Log a message with adaptive behavior
     */
    log(level: LogLevel, message: string, options?: ISmtpLogOptions): void;
    /**
     * Log command with adaptive behavior
     */
    logCommand(command: string, socket: plugins.net.Socket | plugins.tls.TLSSocket, session?: ISmtpSession): void;
    /**
     * Log response with adaptive behavior
     */
    logResponse(response: string, socket: plugins.net.Socket | plugins.tls.TLSSocket): void;
    /**
     * Log connection event with adaptive behavior
     */
    logConnection(socket: plugins.net.Socket | plugins.tls.TLSSocket, eventType: 'connect' | 'close' | 'error', session?: ISmtpSession, error?: Error): void;
    /**
     * Log security event (always logged regardless of mode)
     */
    logSecurityEvent(level: SecurityLogLevel, type: SecurityEventType, message: string, details: Record<string, any>, ipAddress?: string, domain?: string, success?: boolean): void;
    /**
     * Determine appropriate log mode based on connection count
     */
    private determineLogMode;
    /**
     * Switch to a new log mode
     */
    private switchLogMode;
    /**
     * Add entry to aggregation buffer
     */
    private aggregateEntry;
    /**
     * Start the aggregation timer
     */
    private startAggregationTimer;
    /**
     * Flush aggregated entries to logs
     */
    private flushAggregatedEntries;
    /**
     * Cleanup resources
     */
    destroy(): void;
}
/**
 * Default instance for easy access
 */
export declare const adaptiveLogger: AdaptiveSmtpLogger;
export {};