var Promise = require("bluebird");
var Imap = require('imap'),
  inspect = require('util').inspect;
let buffer = '';
let OTPCode = '';
let OTPRegex = /\d{8,}/;

var imap = new Imap({
  user: "example@gmail.com",
  password: "etc",
  host: "mail.google.net",
  port: 993,
  tls: true,
  connTimeout: 10000, // Default by node-imap
  authTimeout: 5000, // Default by node-imap,
  debug: null, // Or your custom function with only one incoming argument. Default: null
  tlsOptions: { rejectUnauthorized: false },
  mailbox: "INBOX", // mailbox to monitor
  searchFilter: ["UNSEEN", "FLAGGED"], // the search filter being used after an IDLE notification has been retrieved
  markSeen: true,
  fetchUnreadOnStart: false,
  mailParserOptions: { streamAttachments: false },
  attachments: false,
  attachmentOptions: { directory: "attachments/" }
});

function openInbox(cb) {
  imap.openBox('INBOX', false, cb);
}

imap.once('ready', function () {
  openInbox(function (err, box) {
    if (err) throw err;
    imap.search(['UNSEEN', ['SUBJECT', 'Requested LexisNexis(R) One-Time Passcode (OTP)']], function (err, results) {
      if (err) throw err;
      var f = imap.fetch(results, { bodies: '1', markSeen: true });
      f.on('message', function (msg, seqno) {
        msg.on('body', function (stream, info) {
          stream.on('data', function (chunk) {
            buffer += chunk.toString('utf8');
          });
          stream.once('end', function () {
            if (info.which === '1') {
            var res = buffer.match(OTPRegex);
            OTPCode = res[0];
            console.log(OTPCode);
            }
          });
        });
        msg.once('attributes', function (attrs) {
        });
        msg.once('end', function () {
        });
      });
      f.once('error', function (err) {
        console.log('Fetch error.');
      });
      f.once('end', function () {
        console.log('Done fetching OTP codes.');
        imap.end();
      });
    });
  });
});

imap.once('error', function (err) {
  console.log('An error occured fetching the OTP code.');
});

imap.once('end', function () {
  console.log('Connection terminated.');
});


module.exports = {
  fetchOTP: async function() {
    imap.connect();
    return OTPCode.toString();

  }
}