Course.js

'use strict';

const mongoose = require('mongoose');
// Import the slug package
const slug = require('mongoose-slug-updater');
// Initialize
mongoose.plugin(slug);

const courseSchema = mongoose.Schema(
  {
    title: { type: String, unique: true, index: true },
    slug: { type: String, slug: 'title', unique: true },
    user: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'User',
    },
    category: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Category',
    },
    price: { type: Number, required: true },
    video: String,
    description: String,
    content: String,
    image: String,
    lessons: [
      {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'Lesson',
      },
    ],
  },  
  { timestamps: true },
);

courseSchema.statics.list = async function (filter, skip, limit, sort) {
  const query = Course.find(filter).populate('user').populate('category');
  query.sort(sort);
  query.skip(skip);
  query.limit(limit);

  return await query.exec();
};

const Course = mongoose.model('Course', courseSchema);

module.exports = Course;

courses.js

'use strict';

const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const Category = mongoose.model('Category');
const Lesson = mongoose.model('Lesson');
const Course = mongoose.model('Course');
const User = mongoose.model('User');
const jwtAuth = require('../../lib/jwAuth');

const multer = require('multer');
const { uploadFile } = require('../../lib/s3');
const path = require('path');

const UPLOAD_FOLDER = process.env.UPLOAD_FOLDER || "public/images/";

/**
 * Configurar multer
 */
const fileExtensionRemover = originalName => {
  return originalName.split('.')[0];
};

const storage = multer.diskStorage({
  destination: function(req, file, cb) {
    cb(null, UPLOAD_FOLDER);
  },
  filename: function(req,file, cb) {
    cb(null, fileExtensionRemover(file.originalname) + '-' + Date.now() + path.extname(file.originalname))
  }
});
const upload = multer({ storage });

/**
 * POST /api/v1/courses
 * Create a new course
 */
router.post(
  '/',
  jwtAuth,
  upload.single('image'),
  async function (req, res, next) {
    try {
      // Server side validation
      const formData = { ...req.body };
      const validation = formData.title && formData.category;
      if (!validation) {
        res
          .status(400)
          .json({ message: 'Title and category are both required' });
        return;
      }

      // Inject userId in new course before saving it
      formData.user = req.apiAuthUserId;
      const course = new Course(formData);

      if (req.file) {
        // Uplaod file to S3 and add image location to course object
        const file = req.file;
        const { Location } = await uploadFile(file);
        course.image = Location;
      }

      // Save new lessons
      if (formData.lessons) {
        const lessonsToSave = JSON.parse(formData.lessons)
        course.lessons = []
        for (const key in lessonsToSave) {
          async function saveLesson() {
            const oneLessonToSave = new Lesson(lessonsToSave[key]);
            const saved = await oneLessonToSave.save()
            return saved
          }
          saveLesson().then(async saved => {
            console.log('LESSON salvada: ', saved)
            course.lessons.push(saved._id)
            console.log(course.lessons)
          })
        }
      }

      // Save new course in database
      const newCourse = await course.save();
      res.status(201).json(newCourse);
    } catch (err) {
      next(err);
    }
  },
);

Lesson.js

'use strict';

const mongoose = require('mongoose');
// Import the slug package
const slug = require('mongoose-slug-updater');
// Initialize
mongoose.plugin(slug);

const lessonSchema = mongoose.Schema(
  {
    title: { type: String },
    slug: { type: String, slug: 'title', unique: 'true' },
    image: String,
    video: String,
    description: String,
    content: String,
  },
  { timestamps: true },
);

const Lesson = mongoose.model('Lesson', lessonSchema);

module.exports = Lesson;