export default {
  createUUID: function () {
    var _self = this
    // Loose interpretation of the specification DCE 1.1: Remote Procedure Call
    // since JavaScript doesn't allow access to internal systems, the last 48 bits 
    // of the node section is made up using a series of random numbers (6 octets long).
    //  
    var dg = new Date(1582, 10, 15, 0, 0, 0, 0)
    var dc = new Date()
    var t = dc.getTime() - dg.getTime()
    var tl = _self.getIntegerBits(t, 0, 31)
    var tm = _self.getIntegerBits(t, 32, 47)
    var thv = _self.getIntegerBits(t, 48, 59) + '1' // version 1, security version is 2
    var csar = _self.getIntegerBits(_self.rand(4095), 0, 7)
    var csl = _self.getIntegerBits(_self.rand(4095), 0, 7)
    // since detection of anything about the machine/browser is far to buggy, 
    // include some more random numbers here
    // if NIC or an IP can be obtained reliably, that should be put in
    // here instead.
    var n = _self.getIntegerBits(_self.rand(8191), 0, 7) +
			_self.getIntegerBits(_self.rand(8191), 8, 15) +
			_self.getIntegerBits(_self.rand(8191), 0, 7) +
			_self.getIntegerBits(_self.rand(8191), 8, 15) +
			_self.getIntegerBits(_self.rand(8191), 0, 15) // this last number is two octets long
    return tl + tm + thv + csar + csl + n
  },

  //Pull out only certain bits from a very large integer, used to get the time
  //code information for the first part of a UUID. Will return zero's if there 
  //aren't enough bits to shift where it needs to.
  getIntegerBits: function (val, start, end) {
    var base16 = this.returnBase(val, 16)
    var quadArray = new Array()
    var quadString = ''
    var i = 0
    for (i = 0; i < base16.length; i++) {
      quadArray.push(base16.substring(i, i + 1))
    }
    for (i = Math.floor(start / 4); i <= Math.floor(end / 4); i++) {
      if (!quadArray[i] || quadArray[i] == '')
        quadString += '0'
      else
        quadString += quadArray[i]
    }
    return quadString
  },

  //Replaced from the original function to leverage the built in methods in
  //JavaScript. Thanks to Robert Kieffer for pointing this one out
  returnBase: function (number, base) {
    return (number).toString(base).toUpperCase()
  },

  //pick a random number within a range of numbers
  //int b rand(int a); where 0 <= b <= a
  rand: function (max) {
    return Math.floor(Math.random() * (max + 1))
  },
}