smartmta/ts/mail/routing/classes.email.action.executor.ts

import { logger } from '../../logger.js';
import {
  SecurityLogger,
  SecurityLogLevel,
  SecurityEventType
} from '../../security/index.js';
import type { IEmailAction, IEmailContext } from './interfaces.js';
import { Email } from '../core/classes.email.js';
import { BounceManager } from '../core/classes.bouncemanager.js';
import { UnifiedDeliveryQueue } from '../delivery/classes.delivery.queue.js';
import type { ISmtpSendResult } from '../../security/classes.rustsecuritybridge.js';

/**
 * Dependencies injected from UnifiedEmailServer to avoid circular imports
 */
export interface IActionExecutorDeps {
  sendOutboundEmail: (host: string, port: number, email: Email, options?: {
    auth?: { user: string; pass: string };
    dkimDomain?: string;
    dkimSelector?: string;
    tlsOpportunistic?: boolean;
  }) => Promise<ISmtpSendResult>;
  bounceManager: BounceManager;
  deliveryQueue: UnifiedDeliveryQueue;
}

/**
 * Executes email routing actions (forward, process, deliver, reject)
 */
export class EmailActionExecutor {
  constructor(private deps: IActionExecutorDeps) {}

  async executeAction(action: IEmailAction, email: Email, context: IEmailContext): Promise<void> {
    switch (action.type) {
      case 'forward':
        await this.handleForwardAction(action, email, context);
        break;
      case 'process':
        await this.handleProcessAction(action, email, context);
        break;
      case 'deliver':
        await this.handleDeliverAction(action, email, context);
        break;
      case 'reject':
        await this.handleRejectAction(action, email, context);
        break;
      default:
        throw new Error(`Unknown action type: ${(action as any).type}`);
    }
  }

  private async handleForwardAction(action: IEmailAction, email: Email, context: IEmailContext): Promise<void> {
    if (!action.forward) {
      throw new Error('Forward action requires forward configuration');
    }

    const { host, port = 25, auth, addHeaders } = action.forward;

    logger.log('info', `Forwarding email to ${host}:${port}`);

    // Add forwarding headers
    if (addHeaders) {
      for (const [key, value] of Object.entries(addHeaders)) {
        email.headers[key] = value;
      }
    }

    // Add standard forwarding headers
    email.headers['X-Forwarded-For'] = context.session.remoteAddress || 'unknown';
    email.headers['X-Forwarded-To'] = email.to.join(', ');
    email.headers['X-Forwarded-Date'] = new Date().toISOString();

    try {
      // Send email via Rust SMTP client
      await this.deps.sendOutboundEmail(host, port, email, {
        auth: auth as { user: string; pass: string } | undefined,
      });

      logger.log('info', `Successfully forwarded email to ${host}:${port}`);

      SecurityLogger.getInstance().logEvent({
        level: SecurityLogLevel.INFO,
        type: SecurityEventType.EMAIL_FORWARDING,
        message: 'Email forwarded successfully',
        ipAddress: context.session.remoteAddress,
        details: {
          sessionId: context.session.id,
          routeName: context.session.matchedRoute?.name,
          targetHost: host,
          targetPort: port,
          recipients: email.to
        },
        success: true
      });
    } catch (error) {
      logger.log('error', `Failed to forward email: ${error.message}`);

      SecurityLogger.getInstance().logEvent({
        level: SecurityLogLevel.ERROR,
        type: SecurityEventType.EMAIL_FORWARDING,
        message: 'Email forwarding failed',
        ipAddress: context.session.remoteAddress,
        details: {
          sessionId: context.session.id,
          routeName: context.session.matchedRoute?.name,
          targetHost: host,
          targetPort: port,
          error: error.message
        },
        success: false
      });

      // Handle as bounce
      for (const recipient of email.getAllRecipients()) {
        await this.deps.bounceManager.processSmtpFailure(recipient, error.message, {
          sender: email.from,
          originalEmailId: email.headers['Message-ID'] as string
        });
      }
      throw error;
    }
  }

  private async handleProcessAction(action: IEmailAction, email: Email, context: IEmailContext): Promise<void> {
    logger.log('info', `Processing email with action options`);

    // Apply scanning if requested
    if (action.process?.scan) {
      logger.log('info', 'Content scanning requested');
    }

    // Queue for delivery
    const queue = action.process?.queue || 'normal';
    await this.deps.deliveryQueue.enqueue(email, 'process', context.session.matchedRoute!);

    logger.log('info', `Email queued for delivery in ${queue} queue`);
  }

  private async handleDeliverAction(_action: IEmailAction, email: Email, context: IEmailContext): Promise<void> {
    logger.log('info', `Delivering email locally`);

    // Queue for local delivery
    await this.deps.deliveryQueue.enqueue(email, 'mta', context.session.matchedRoute!);

    logger.log('info', 'Email queued for local delivery');
  }

  private async handleRejectAction(action: IEmailAction, _email: Email, context: IEmailContext): Promise<void> {
    const code = action.reject?.code || 550;
    const message = action.reject?.message || 'Message rejected';

    logger.log('info', `Rejecting email with code ${code}: ${message}`);

    SecurityLogger.getInstance().logEvent({
      level: SecurityLogLevel.WARN,
      type: SecurityEventType.EMAIL_PROCESSING,
      message: 'Email rejected by routing rule',
      ipAddress: context.session.remoteAddress,
      details: {
        sessionId: context.session.id,
        routeName: context.session.matchedRoute?.name,
        rejectCode: code,
        rejectMessage: message,
        from: _email.from,
        to: _email.to
      },
      success: false
    });

    // Throw error with SMTP code and message
    const error = new Error(message);
    (error as any).responseCode = code;
    throw error;
  }
}