import { AxiosInstance } from 'axios';
/**
 * Telegram API timeout configuration (milliseconds)
 * Centralized timeout settings for all Telegram operations
 */
/**
 * Default timeout for plain text messages (milliseconds)
 * Environment variable: TELEGRAM_TEXT_TIMEOUT
 * Default: 10 seconds
 */
export declare const TELEGRAM_TEXT_TIMEOUT: number;
/**
 * Timeout for Markdown-to-HTML conversion and sending (milliseconds)
 * Environment variable: TELEGRAM_MARKDOWN_TIMEOUT
 * Default: 10 seconds
 */
export declare const TELEGRAM_MARKDOWN_TIMEOUT: number;
/**
 * Timeout for messages with inline buttons (milliseconds)
 * Environment variable: TELEGRAM_BUTTONS_TIMEOUT
 * Default: 10 seconds
 */
export declare const TELEGRAM_BUTTONS_TIMEOUT: number;
/**
 * Timeout for photo/image uploads (milliseconds)
 * Longer than default timeout to allow for larger file uploads
 * Environment variable: TELEGRAM_PHOTO_TIMEOUT
 * Default: 15 seconds
 */
export declare const TELEGRAM_PHOTO_TIMEOUT: number;
/**
 * @deprecated Use specific timeout constants instead:
 * - TELEGRAM_TEXT_TIMEOUT for text messages
 * - TELEGRAM_MARKDOWN_TIMEOUT for markdown messages
 * - TELEGRAM_BUTTONS_TIMEOUT for button messages
 * - TELEGRAM_PHOTO_TIMEOUT for photo uploads
 */
export declare const TELEGRAM_TIMEOUT: number;
/**
 * Create configured axios instance for Telegram API
 * Optimized for WSL and cross-platform compatibility
 *
 * Connection Pool Settings:
 * - maxSockets: Maximum concurrent connections (50)
 * - maxFreeSockets: Maximum idle connections (10)
 * - timeout: Idle connection timeout (60s)
 * - keepAliveMsecs: Keep-alive interval (30s)
 */
export declare function createTelegramAxios(): AxiosInstance;
/**
 * Create axios instance for image validation (HEAD requests only)
 * Uses non-keepalive connections to avoid connection pool accumulation
 */
export declare function createImageValidatorAxios(): AxiosInstance;
/**
 * Singleton instance for Telegram API
 * Thread-safe lazy initialization with race condition prevention
 */
export declare function getTelegramAxios(): AxiosInstance;
/**
 * Singleton instance for image validation
 * Thread-safe lazy initialization with race condition prevention
 */
export declare function getImageValidatorAxios(): AxiosInstance;
/**
 * Graceful shutdown: destroy all agents
 */
export declare function destroyAxiosAgents(): void;