import pino from 'pino';
import type { EmailLogTransportService } from '../services/email-log-transport.service';
import type { EmailLogOptions } from '../interfaces';
import { PinoEmailTransport } from '../transports/pino-email.transport';
/**
 * Pino multistream target interface
 */
export interface PinoMultiStreamTarget {
    level: string | number;
    stream: NodeJS.WritableStream;
}
/**
 * Create a Pino transport stream for email logging
 * This function creates a writable stream that can be used with Pino
 *
 * @param options Email log options
 * @returns A Pino transport configuration
 *
 * @example
 * ```typescript
 * import { createEmailTransport } from '@nest-omni/core';
 * import pino from 'pino';
 *
 * const transport = createEmailTransport({
 *   enabled: true,
 *   to: ['admin@example.com'],
 *   from: 'noreply@example.com',
 *   smtpHost: 'smtp.example.com',
 * });
 *
 * const logger = pino(transport);
 * ```
 */
export declare function createEmailTransport(options: EmailLogOptions): PinoEmailTransport;
/**
 * Create a Pino multistream configuration that includes email transport
 *
 * @param options Email log options
 * @param emailTransport The email transport service instance or PinoEmailTransport
 * @returns Pino multistream targets array
 *
 * @example
 * ```typescript
 * import { createPinoMultistream } from '@nest-omni/core';
 * import pino from 'pino';
 *
 * const streams = createPinoMultistream(options, emailTransport);
 * const logger = pino(pino.multistream(streams));
 * ```
 */
export declare function createPinoMultistream(options: EmailLogOptions, emailTransport: EmailLogTransportService | PinoEmailTransport): PinoMultiStreamTarget[];
/**
 * Create a Pino logger with email transport already configured
 * This is the simplest way to get started with email logging
 *
 * @param options Email log options
 * @param baseLogger Optional base Pino logger to extend
 * @returns Pino logger with email transport
 *
 * @example
 * ```typescript
 * import { createPinoEmailLogger } from '@nest-omni/core';
 *
 * const logger = createPinoEmailLogger({
 *   enabled: true,
 *   to: ['admin@example.com'],
 *   from: 'noreply@example.com',
 *   smtpHost: 'smtp.example.com',
 * });
 *
 * logger.error('Something went wrong!', { userId: '123' });
 * // This will log to console AND send an email
 * ```
 */
export declare function createPinoEmailLogger(options: EmailLogOptions, baseLogger?: pino.Logger): pino.Logger;
/**
 * Manually attach email transport to an existing Pino logger
 * Use this if you want to add email logging to a specific logger instance
 *
 * @param logger The Pino logger instance
 * @param options Email log options
 * @param emailTransport The email transport service instance
 *
 * @example
 * ```typescript
 * import { attachEmailTransportToLogger } from '@nest-omni/core';
 *
 * attachEmailTransportToLogger(myLogger, options, emailTransport);
 * ```
 */
export declare function attachEmailTransportToLogger(logger: pino.Logger, options: EmailLogOptions, emailTransport: EmailLogTransportService | PinoEmailTransport): void;
/**
 * Create a child logger with email context
 * Useful for adding consistent metadata to all logs from a module
 *
 * @param parentLogger The parent Pino logger
 * @param context Context object to include in all logs
 * @returns Child Pino logger
 *
 * @example
 * ```typescript
 * import { createPinoEmailLogger, createPinoEmailChildLogger } from '@nest-omni/core';
 *
 * const baseLogger = createPinoEmailLogger(options);
 * const userServiceLogger = createPinoEmailChildLogger(baseLogger, {
 *   module: 'UserService',
 *   version: '1.0.0',
 * });
 *
 * userServiceLogger.error('User creation failed', { userId: '123' });
 * // Email will include: module, version, userId in context
 * ```
 */
export declare function createPinoEmailChildLogger(parentLogger: pino.Logger, context: Record<string, any>): pino.Logger;
/**
 * Configure Pino email transport from environment variables
 * This is a convenience function that reads from process.env
 *
 * @returns PinoEmailTransport instance or null if not configured
 *
 * @example
 * ```typescript
 * import { createEmailTransportFromEnv } from '@nest-omni/core';
 * import pino from 'pino';
 *
 * const emailTransport = createEmailTransportFromEnv();
 * const logger = emailTransport
 *   ? pino(pino.multistream([
 *       { level: 'trace', stream: process.stdout },
 *       { level: 'error', stream: emailTransport },
 *     ]))
 *   : pino();
 * ```
 */
export declare function createEmailTransportFromEnv(): PinoEmailTransport | null;