dcrouter/ts/mail/delivery/smtpclient/utils/logging.ts

/**
 * SMTP Client Logging Utilities
 * Client-side logging utilities for SMTP operations
 */

import { logger } from '../../../../logger.js';
import type { ISmtpResponse, ISmtpClientOptions } from '../interfaces.js';

export interface ISmtpClientLogData {
  component: string;
  host?: string;
  port?: number;
  secure?: boolean;
  command?: string;
  response?: ISmtpResponse;
  error?: Error;
  connectionId?: string;
  messageId?: string;
  duration?: number;
  [key: string]: any;
}

/**
 * Log SMTP client connection events
 */
export function logConnection(
  event: 'connecting' | 'connected' | 'disconnected' | 'error',
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    event,
    host: options.host,
    port: options.port,
    secure: options.secure,
    ...data
  };
  
  switch (event) {
    case 'connecting':
      logger.info('SMTP client connecting', logData);
      break;
    case 'connected':
      logger.info('SMTP client connected', logData);
      break;
    case 'disconnected':
      logger.info('SMTP client disconnected', logData);
      break;
    case 'error':
      logger.error('SMTP client connection error', logData);
      break;
  }
}

/**
 * Log SMTP command execution
 */
export function logCommand(
  command: string,
  response?: ISmtpResponse,
  options?: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    command,
    response,
    host: options?.host,
    port: options?.port,
    ...data
  };
  
  if (response && response.code >= 400) {
    logger.warn('SMTP command failed', logData);
  } else {
    logger.debug('SMTP command executed', logData);
  }
}

/**
 * Log authentication events
 */
export function logAuthentication(
  event: 'start' | 'success' | 'failure',
  method: string,
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    event: `auth_${event}`,
    authMethod: method,
    host: options.host,
    port: options.port,
    ...data
  };
  
  switch (event) {
    case 'start':
      logger.debug('SMTP authentication started', logData);
      break;
    case 'success':
      logger.info('SMTP authentication successful', logData);
      break;
    case 'failure':
      logger.error('SMTP authentication failed', logData);
      break;
  }
}

/**
 * Log TLS/STARTTLS events
 */
export function logTLS(
  event: 'starttls_start' | 'starttls_success' | 'starttls_failure' | 'tls_connected',
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    event,
    host: options.host,
    port: options.port,
    ...data
  };
  
  if (event.includes('failure')) {
    logger.error('SMTP TLS operation failed', logData);
  } else {
    logger.info('SMTP TLS operation', logData);
  }
}

/**
 * Log email sending events
 */
export function logEmailSend(
  event: 'start' | 'success' | 'failure',
  recipients: string[],
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    event: `send_${event}`,
    recipientCount: recipients.length,
    recipients: recipients.slice(0, 5), // Only log first 5 recipients for privacy
    host: options.host,
    port: options.port,
    ...data
  };
  
  switch (event) {
    case 'start':
      logger.info('SMTP email send started', logData);
      break;
    case 'success':
      logger.info('SMTP email send successful', logData);
      break;
    case 'failure':
      logger.error('SMTP email send failed', logData);
      break;
  }
}

/**
 * Log performance metrics
 */
export function logPerformance(
  operation: string,
  duration: number,
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  const logData: ISmtpClientLogData = {
    component: 'smtp-client',
    operation,
    duration,
    host: options.host,
    port: options.port,
    ...data
  };
  
  if (duration > 10000) { // Log slow operations (>10s)
    logger.warn('SMTP slow operation detected', logData);
  } else {
    logger.debug('SMTP operation performance', logData);
  }
}

/**
 * Log debug information (only when debug is enabled)
 */
export function logDebug(
  message: string,
  options: ISmtpClientOptions,
  data?: Partial<ISmtpClientLogData>
): void {
  if (!options.debug) {
    return;
  }
  
  const logData: ISmtpClientLogData = {
    component: 'smtp-client-debug',
    host: options.host,
    port: options.port,
    ...data
  };
  
  logger.debug(`[SMTP Client Debug] ${message}`, logData);
}