index.js

/**@module mail-listener-type
 * @author Patrick Chaves <patrick095@gmail.com>
 * @version 2.2.1
 * @date 18 may 2023
 */

// Require statements
var Imap = require('node-imap');
var EventEmitter = require('events').EventEmitter;
var simpleParser = require('mailparser').simpleParser;
var fs = require('fs');
var async = require('async');

class MailListener extends EventEmitter {
  constructor(options) {
    super();
    this.markSeen = !!options.markSeen;
    this.mailbox = options.mailbox || 'INBOX';
    if ('string' === typeof options.searchFilter) {
      this.searchFilter = [options.searchFilter];
    }
    else {
      this.searchFilter = options.searchFilter || ['UNSEEN'];
    }
    this.fetchUnreadOnStart = !!options.fetchUnreadOnStart;
    this.mailParserOptions = options.mailParserOptions || {};
    if (options.attachments && options.attachmentOptions && options.attachmentOptions.stream) {
      this.mailParserOptions.streamAttachments = true;
    }
    this.attachmentOptions = options.attachmentOptions || {};
    this.attachments = options.attachments || false;
    this.attachmentOptions.directory = (this.attachmentOptions.directory ? this.attachmentOptions.directory : '');
    this.imap = new Imap({
      xoauth2: options.xoauth2,
      user: options.username,
      password: options.password,
      host: options.host,
      port: options.port,
      tls: options.tls,
      autotls: options.autotls || true,
      tlsOptions: options.tlsOptions || { rejectUnauthorized: false },
      connTimeout: options.connTimeout || null,
      authTimeout: options.authTimeout || null,
      debug: options.debug || null,
      keepalive: options.keepalive || null,
    });
    this.imap.once('ready', this.imapReady.bind(this));
    this.imap.once('close', this.imapClose.bind(this));
    this.imap.on('error', this.imapError.bind(this));
  }

  start() {
    this.imap.connect();
  }

  stop() {
    this.imap.end();
  }

  imapReady() {
    this.imap.openBox(this.mailbox, false, (error, mailbox) => {
      if (error) {
        this.emit('error', error);
      }
      else {
        this.emit('server:connected');
        this.emit('mailbox', mailbox);
        if (this.fetchUnreadOnStart) {
          this.parseUnread.call(this);
        }
        let listener = this.imapMail.bind(this);
        this.imap.on('mail', listener);
        this.imap.on('update', listener);
      }
    });
  }

  imapClose() {
    this.emit('server:disconnected');
  }

  imapError(error) {
    if (error) {
      this.emit('error', error);
    }
  }

  imapMail() {
    this.parseUnread.call(this);
  }

  parseUnread() {
    let self = this;
    self.imap.search(self.searchFilter, (error, results) => {
      if (error) {
        self.emit('error', error);
      }
      else if (results.length > 0) {
        async.each(results, (result, callback) => {
          let f = self.imap.fetch(result, {
            bodies: '',
            markSeen: self.markSeen
          });
          f.on('message', (msg, seqno) => {
            let attrs;
            msg.on('attributes', (a) => {
              attrs = a;
            });
            msg.on('body', async (stream, info) => {
              let parsed = await simpleParser(stream);
              self.emit('mail', parsed, seqno, attrs);
              self.emit('headers', parsed.headers, seqno, attrs);
              self.emit('body', { html: parsed.html, text: parsed.text, textAsHtml: parsed.textAsHtml }, seqno, attrs);
              if (parsed.attachments.length > 0) {
                for (let att of parsed.attachments) {
                  if (self.attachments) {
                    await fs.writeFile(`${self.attachmentOptions.directory}${att.filename}`, att.content, (error) => {
                      if (error) {
                        self.emit('error', error);
                      }
                    });
                    self.emit('attachment', att, `${self.attachmentOptions.directory}${att.filename}`, seqno, attrs);
                  }
                  else {
                    self.emit('attachment', att, null, seqno, attrs);
                  }
                }
              }
            });
          });
          f.once('error', (error) => {
            if (error) {
              self.emit('error', error);
            }
          });
        }, (error) => {
          if (error) {
            self.emit('error', error);
          }
        });
      }
    });
  }
};
module.exports.MailListener = MailListener;