segunolalive/helloBooks

import { BorrowedBook, User } from './models';
import { borrowingDuration } from './helpers/borrowingLimits';
import { transporter, mailOptions } from './config/mail';


const timeLimit = borrowingDuration * 1000 * 60 * 60 * 24;

/**
 * function for sending emails to defaulters
 * 
 * @returns {Promise} sends emails on resolution
 */
const cronJob = () => (
  BorrowedBook.findAll({
    where: {
      returned: false,
      updatedAt: {
        $lt: new Date(new Date() - timeLimit)
      }
    },
    attributes: ['userId']
  })
    .then((borrowedBooks) => {
      const ids = borrowedBooks.map(book => book.userId);
      return User.findAll({
        where: {
          id: { $in: ids }
        },
        attributes: ['email']
      })
        .then((users) => {
          const emails = users.map(user => user.email);
          const to = emails;
          const bcc = null;
          const subject = 'Defaut on Returning Book';
          const html = `<h3>Hello. This is to notify you that you have exceeded
          the borrowing duration for one of our books and would start getting
          billed for the book.</h3>`;
          transporter.sendMail(mailOptions(to, bcc, subject, html));
          process.exit(0);
        }, (error) => {
          process.stdout.write(error.stack);
          process.exit(0);
        });
    }).catch((error) => {
      process.stdout.write(error.stack);
      process.exit(0);
    })
);

cronJob();