'use strict'

var os = require('os')

/**
 * System states
 * @type {{hostname: *, platform: *, arch: *, release: *, cpus, uptime, memory}}
 */
var stat = module.exports = {
  /**
   * Hostname, e.g.: localhost, TjatseMacProBook.local...
   */
  hostname: os.hostname(),
  /**
   * Platform, e.g.: darwin, win32, linux...
   */
  platform: os.platform(),
  /**
   * Architecture, e.g.: 64, 32...
   */
  arch: os.arch(),
  /**
   * Ver number of system.
   */
  release: os.release(),
  /**
   * List all CPUs.
   * @returns {*}
   */
  get cpus () {
    return os.cpus()
  },
  /**
   * Uptime.
   * @returns {*}
   */
  get uptime () {
    return os.uptime()
  },
  /**
   * System memory usage.
   * @returns {{free: *, total: *, percentage: number}}
   */
  get memory () {
    return {
      free: os.freemem(),
      total: os.totalmem(),
      percentage: Math.round(100 * (1 - os.freemem() / os.totalmem()))
    }
  }
}

/**
 * System CPU usage percentage (total).
 * @param fn
 * @param context
 */
stat.cpuUsage = function (fn, context) {
  // check 1s changes
  setTimeout(function (ctx, stat1) {
    var stat2 = ctx.cpuInfo()
    var perc = 100 * (1 - (stat2.idle - stat1.idle) / (stat2.total - stat1.total))
    fn.call(context, null, perc.toFixed(2))
  }, 1000, this, this.cpuInfo())
}

/**
 * System CPU usage detail information.
 * @returns {{idle: number, total: number}}
 */
stat.cpuInfo = function () {
  var cpus = this.cpus
  var idle = 0
  var total = 0
  for (var i in cpus) {
    idle += cpus[i].times.idle
    for (var k in cpus[i].times) {
      total += cpus[i].times[k]
    }
  }
  return {
    'idle': idle,
    'total': total
  }
}