Multilingual schema mongoose plugin

i18n.js

import mongoose from 'mongoose'
import traverse from 'traverse'

const bodyToLocalized = (body, fields, lang = 'en') => {
  fields.forEach(field => {
    if (field in body) {
      body[field + '.' + lang] = body[field]
      delete body[field]
    }
  })
  return body
}

const localizedToBody = (body, fields, lang = 'en') => {
  fields.forEach(field => {
    if (field in body) {
      if (lang in body[field]) {
        body[field] = body[field][lang]
      } else {
        body[field] = '' // ?? if array?
      }
    }
  })
  return body
}

const toLocalized = (obj, lang) => {
  traverse(obj).forEach(function (item) {
    if (this.key === lang) {
      this.parent.update(item)
    }
  })
  return obj
}

const toLocalized2 = (obj, fields, lang) => {
  console.log('paths', traverse(obj).paths())
}

const I18n = (Schema, options) => {

  const i18nObject = (languages) => {
    let obj = {}

    languages.map(lang => obj[lang] = String)

    return obj
  }

  const megaMap = (Schema, startPath = '') => {
    Schema.eachPath((path, schema) => {

      if (schema instanceof mongoose.Schema.Types.DocumentArray) {
        if (schema.options.i18n) {
          delete schema.options.i18n
          Schema.remove(path)

          let langObject = {}
          options.languages.map(lang => {
            langObject[lang] = schema.options
          })

          Schema.add({ [path]: langObject })
        } else {
          megaMap(schema.schema, path)
        }
      } else if (schema instanceof mongoose.Schema.Types.Array) {
        //console.log(path, 'Array')
      } else if (schema instanceof mongoose.Schema.Types.String) {
        //console.log(path, 'String')
        if (schema.options.i18n) {
          //let fullPath = (startPath) ? startPath + '.' + path : path
          //console.log(fullPath, 'String', 'i18n')
          //console.log('pathname:options', Schema.paths[path].options)
          delete schema.options.i18n

          Schema.remove(path)
          Schema.add({
            [path]: i18nObject(options.languages)
          })
          //console.log('path', path);

        }
      } else if (schema instanceof mongoose.Schema.Types.Number) {
        //console.log(path, 'Number')
      } else if (schema instanceof mongoose.Schema.Types.Date) {
        //console.log(path, 'Date')
      } else {
        //console.log(path, 'Other')
      }
    })
  }

  const setLang = (Obj, key, lang = 'en') => {
    if (Array.isArray(Obj)) {
      Obj.map((key) => setLang(Obj[key], key, lang))
    } else if (typeof Obj === 'object') {
      //Object.keys(Obj).map((key) => setLang(Obj[key], key, lang))
      console.log(Obj[lang], key)
    }
  }

  megaMap(Schema)

  // setLang(Schema, 'ru')

  //console.log(Schema.paths);

  Schema.methods.toJSONLocalized = function() {
    setLang(this, null, 'en')
    console.log(this);
  }

  //console.log('obj', Schema.paths.included.schema.paths);
}

export {
  I18n,
  toLocalized,
  toLocalized2,
  bodyToLocalized,
  localizedToBody
}