dcrouter/ts/mail/core/classes.rulemanager.ts

import * as plugins from '../../plugins.js';
import { EmailService } from '../services/classes.emailservice.js';
import { logger } from '../../logger.js';
import { Email, type IEmailOptions } from './classes.email.js';

export class RuleManager {
  public emailRef: EmailService;
  public smartruleInstance = new plugins.smartrule.SmartRule<Email>();

  constructor(emailRefArg: EmailService) {
    this.emailRef = emailRefArg;
    
    // Register handler for incoming emails if email server is enabled
    if (this.emailRef.unifiedEmailServer) {
      this.setupIncomingHandler();
    }
  }

  /**
   * Set up handler for incoming emails via the UnifiedEmailServer
   */
  private setupIncomingHandler() {
    // Use UnifiedEmailServer events for incoming emails
    const incomingDir = './received';
    
    // The UnifiedEmailServer raises events for incoming emails
    // For backward compatibility, also watch the directory
    this.watchIncomingEmails(incomingDir);
  }

  /**
   * Watch directory for incoming emails (conceptual implementation)
   */
  private watchIncomingEmails(directory: string) {
    console.log(`Watching for incoming emails in: ${directory}`);
    
    // Conceptual - in a real implementation, set up proper file watching
    // or use UnifiedEmailServer events for incoming emails
    
    /*
    // Example using a file watcher:
    const watcher = plugins.fs.watch(directory, async (eventType, filename) => {
      if (eventType === 'rename' && filename.endsWith('.eml')) {
        const filePath = plugins.path.join(directory, filename);
        await this.handleIncomingEmail(filePath);
      }
    });
    */
    
    // Set up event listener on UnifiedEmailServer if available
    if (this.emailRef.unifiedEmailServer) {
      this.emailRef.unifiedEmailServer.on('emailProcessed', (email: Email, mode, rule) => {
        // Process email through rule system
        this.smartruleInstance.makeDecision(email);
      });
    }
  }

  /**
   * Handle incoming email received via email server
   */
  public async handleIncomingEmail(emailPath: string) {
    try {
      // Process the email file using direct file access or access through UnifiedEmailServer
      // For compatibility with existing code, we'll make a basic assumption about structure
      const emailContent = await plugins.fs.promises.readFile(emailPath, 'utf8');
      // Parse the email content into proper format
      const parsedContent = await plugins.mailparser.simpleParser(emailContent);
      
      // Create an Email object with the parsed content
      const fromAddress = Array.isArray(parsedContent.from) 
        ? parsedContent.from[0]?.text || 'unknown@example.com'
        : parsedContent.from?.text || 'unknown@example.com';
      
      const toAddress = Array.isArray(parsedContent.to)
        ? parsedContent.to[0]?.text || 'unknown@example.com'
        : parsedContent.to?.text || 'unknown@example.com';
        
      const fetchedEmail = new Email({
        from: fromAddress,
        to: toAddress,
        subject: parsedContent.subject || '',
        text: parsedContent.text || '',
        html: parsedContent.html || undefined
      });
      
      console.log('=======================');
      console.log('Received a mail:');
      console.log(`From: ${fetchedEmail.from}`);
      console.log(`Subject: ${fetchedEmail.subject}`);
      console.log('^^^^^^^^^^^^^^^^^^^^^^^');

      logger.log(
        'info',
        `email from ${fetchedEmail.from} with subject '${fetchedEmail.subject}'`,
        {
          eventType: 'receivedEmail',
          provider: 'unified',
          email: {
            from: fetchedEmail.from,
            subject: fetchedEmail.subject,
          },
        }
      );

      // Process with rules
      this.smartruleInstance.makeDecision(fetchedEmail);
    } catch (error) {
      logger.log('error', `Failed to process incoming email: ${error.message}`, {
        eventType: 'emailError',
        provider: 'unified',
        error: error.message
      });
    }
  }

  public async init() {
    // Setup email rules
    await this.createForwards();
  }

  /**
   * creates the default forwards
   */
  public async createForwards() {
    const forwards: { originalToAddress: string[]; forwardedToAddress: string[] }[] = [];
    console.log(`${forwards.length} forward rules configured:`);
    for (const forward of forwards) {
      console.log(forward);
    }

    for (const forward of forwards) {
      this.smartruleInstance.createRule(
        10,
        async (emailArg: Email) => {
          const matched = forward.originalToAddress.reduce<boolean>((prevValue, currentValue) => {
            return emailArg.to.some(to => to.includes(currentValue)) || prevValue;
          }, false);
          if (matched) {
            console.log('Forward rule matched');
            console.log(forward);
            return 'apply-continue';
          } else {
            return 'continue';
          }
        },
        async (emailArg: Email) => {
          forward.forwardedToAddress.map(async (toArg) => {
            const forwardedEmail = new Email({
              from: 'forwarder@mail.lossless.one',
              to: toArg,
              subject: `Forwarded mail for '${emailArg.to.join(', ')}'`,
              html:
                `
              <div style="background: #CCC; padding: 10px; border-radius: 3px;">
                <div><b>Original Sender:</b></div>
                <div>${emailArg.from}</div>
                <div><b>Original Recipient:</b></div>
                <div>${emailArg.to.join(', ')}</div>
                <div><b>Forwarded to:</b></div>
                <div>${forward.forwardedToAddress.reduce<string>((pVal, cVal) => {
                  return `${pVal ? pVal + ', ' : ''}${cVal}`;
                }, null)}</div>
                <div><b>Subject:</b></div>
                <div>${emailArg.getSubject()}</div>
                <div><b>The original body can be found below.</b></div>
              </div>
              ` + emailArg.getBody(true),
              text: `Forwarded mail from ${emailArg.from} to ${emailArg.to.join(', ')}\n\n${emailArg.getBody()}`,
              attachments: emailArg.attachments
            });
            
            // Use the EmailService's sendEmail method to send with the appropriate provider
            await this.emailRef.sendEmail(forwardedEmail);
            
            console.log(`forwarded mail to ${toArg}`);
            logger.log(
              'info',
              `email from ${emailArg.from} to ${toArg} with subject '${emailArg.getSubject()}'`,
              {
                eventType: 'forwardedEmail',
                email: {
                  from: emailArg.from,
                  to: emailArg.to.join(', '),
                  forwardedTo: toArg,
                  subject: emailArg.subject,
                },
              }
            );
          });
        }
      );
    }
  }
}