backend/src/models/language.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var LanguageSchema = new Schema(
  {
    language: { type: String, unique: true },
    locale: { type: String, unique: true },
  },
  { timestamps: true },
);

/*
 *** Statics ***
 */

// Get all languages
LanguageSchema.statics.getAll = () => {
  return new Promise((resolve, reject) => {
    var query = Language.find();
    query.select('-_id language locale');
    query
      .exec()
      .then(rows => {
        resolve(rows);
      })
      .catch(err => {
        reject(err);
      });
  });
};

// Create language
LanguageSchema.statics.create = language => {
  return new Promise((resolve, reject) => {
    var query = new Language(language);
    query
      .save()
      .then(row => {
        resolve(row);
      })
      .catch(err => {
        if (err.code === 11000)
          reject({ fn: 'BadParameters', message: 'Language already exists' });
        else reject(err);
      });
  });
};

// Update languages
LanguageSchema.statics.updateAll = languages => {
  return new Promise((resolve, reject) => {
    Language.deleteMany()
      .then(row => {
        Language.insertMany(languages);
      })
      .then(row => {
        resolve('Languages updated successfully');
      })
      .catch(err => {
        reject(err);
      });
  });
};

// Delete language
LanguageSchema.statics.delete = locale => {
  return new Promise((resolve, reject) => {
    Language.deleteOne({ locale: locale })
      .then(res => {
        if (res.deletedCount === 1) resolve('Language deleted');
        else reject({ fn: 'NotFound', message: 'Language not found' });
      })
      .catch(err => {
        reject(err);
      });
  });
};

/*
 *** Methods ***
 */

var Language = mongoose.model('Language', LanguageSchema);
module.exports = Language;