text: const mongoose = require('mongoose');
  const Schema = mongoose.Schema;
  
  const NavSchema = new Schema({ list1: [String] , list2: [String] });
  
  const Navigation= new Schema({
      phone: String,
      time: String,
      email:String,
      kr_logo: String,
      jp_logo: String,
      eng_logo: String,
      kr_website: String,
      jp_website: String,
      eng_website: String,
      quick_link: {
          links: [{
              first: String,
              second: String,
              third: String,
            }]
      },
      nav_logo: String,
      first_nav: {
          links: [NavSchema],
      },
      second_nav: {
          links: [NavSchema],
      },
      third_nav: {
          links: [NavSchema],
      },
      forth_nav: {
          links: [NavSchema],
      },
      fifth_nav: {
          links: [NavSchema],
      },
      sixth_nav: {
          links: [NavSchema],
      },
      seventh_nav: {
          links: [NavSchema],
      },
      eighth_nav: {
          links: [NavSchema],
      },
      //footer
      footer_logo: String,
      footer_content: String,
      footer_findmore: String,
      footer_social_media:{
          type: [{
              fb: String,
              ig: String,
              youtube: String,
              twitter: String,
              skype: String,
              line: String,
              wechat: String,
              whatsapp: String,
          }]
      },
      footer_course: {
          image_first: String,
          cname_first: String,
          cdate_first: String,
  
          cname_second: String,
          cdate_first: String,
          image_second: String,
  
          cname_third: String,
          cdate_first: String,
          image_third: String,
  
          cname_forth: String,
          cdate_first: String,
          image_forth: String,
      },
      footer_links: {
          first:  String,
          second: String,
          third:  String,
          forth:  String,
          fifth:  String,
      },
      footer_about: {
          phone:  String,
          email:  String,
          address:  String,
      },
      createdAt:{ type: Date, default:Date.now },
  });
  
  function arrayLimit(val) {
      return val.length <= 10;
  };
  
  // the third argment students(optional) => for mongodb name
  const Kr_Nav= mongoose.model('Navigation', Navigation, 'Kr_Nav');
  module.exports= Kr_Nav;