'use strict';
  
  const modemList = {
      by_name: {},
      by_imsi: {},
      by_msisdn: {},
  };
  
  /**
   * Objek data sebuah modem.
   * 
   * @typedef   {Object} ModemData
   * @property  {string} name - nama modem

   * @property  {string} device - modem device path

   * @property  {string} imsi - IMSI modem
   * @property  {string} msisdn - MSISDN modem

   * @property  {string} networkId - operator network id
   * @property  {string} networkName - operator network name
   * @property  {string} signalStrength - modem signal strength

   * @property  {number} uptime - modem uptime in seconds

   * @property  {string} reportIp - IP modem
   * @property  {number} reportPort - TCP port modem
   * @property  {string} reportApikey - APIKEY modem

   * @property  {string} reportPathSms - url path untuk pengiriman SMS

   */
  
  /**
   * Update data sebuah modem berdasarkan nama modem.
   * 
   * @param  {ModemData} val - objek data modem
   */
  function touchByName(val) {
      if (!val || !val.name) return;
      if (typeof val.name !== 'string') return;
      if (!val.name.trim()) return;
  
      modemList.by_name[val.name] = val;
  }
  /**
   * Update data sebuah modem berdasarkan IMSI.
   * 
   * @param  {ModemData} val - objek data modem
   */
  function touchByIMSI(val) {
      if (!val || !val.imsi) return;
      if (typeof val.imsi !== 'string') return;
      if (!val.imsi.trim()) return;

      const oldName = modemList.by_imsi[val.imsi] ? modemList.by_imsi[val.imsi].name : null;
      if (oldName && oldName !== val.name && modemList.by_name[oldName]) {
          delete modemList.by_name[oldName];
      }

      modemList.by_imsi[val.imsi] = val;
  }
  
  /**
   * Update data sebuah modem berdasarkan MSISDN.
   * 
   * @param  {ModemData} val - objek data modem
   */
  function touchByMSISDN(val) {
      if (!val || !val.msisdn) return;
      if (typeof val.msisdn !== 'string') return;
      if (!val.msisdn.trim()) return;
  
      modemList.by_msisdn[val.msisdn] = val;
  }
  
  /**
   * Update data sebuah modem.
   * 
   * @param  {ModemData} val - objek data modem
   * @see ModemData
   */
  function touch(val) {

      if (!val || typeof val !== 'object') return;
  
      val._ts = new Date();

  
      if (!val.reportIp) {
          val.reportIp = '127.0.0.1';
      }
  
      touchByName(val);
      touchByIMSI(val);
      touchByMSISDN(val);
  }
  /**
   * Ambil data sebuah modem.
   * 
   * @param  {string} selector - selector pencarian, valid jika bernilai salah satu dari: name, imsi, msisdn
   * @param  {string} keyword - kata kunci modem yang ingin diambil
   * @returns {ModemData} data modem terkait
   */
  function get(selector, keyword) {
      if (!selector || !keyword) return null;
  
      return modemList[`by_${selector}`] ? modemList[`by_${selector}`][keyword] : null;
  }

  function dump() {
      return modemList;
  }

  exports.touch = touch;
  exports.set = touch;

  exports.get = get;
  exports.dump = dump;