var random = require('../number/random')

var values = require('../base/values')

/**
  * 将一个数组随机打乱，返回一个新的数组
  *
  * @param {Array} array 数组
  * @return {Array}
  */
function shuffle (array) {
  var index
  var result = []
  var list = values(array)
  var len = list.length - 1
  for (; len >= 0; len--) {
    index = len > 0 ? random(0, len) : 0
    result.push(list[index])
    list.splice(index, 1)
  }
  return result
}

module.exports = shuffle