var staticParseInt = require('./staticParseInt')

var helperGetHGSKeys = require('./helperGetHGSKeys')

var hasOwnProp = require('./hasOwnProp')

var sKeyRE = /(.+)\[(\d+)\]$/

function setDeepProps (obj, key, isSet, value) {
  if (obj[key]) {
    if (isSet) {
      obj[key] = value
    }
  } else {
    var index
    var matchs = key ? key.match(sKeyRE) : null
    var rest = isSet ? value : {}
    if (matchs) {
      index = staticParseInt(matchs[2])
      if (obj[matchs[1]]) {
        obj[matchs[1]][index] = rest
      } else {
        obj[matchs[1]] = new Array(index + 1)
        obj[matchs[1]][index] = rest
      }
    } else {
      obj[key] = rest
    }
    return rest
  }
  return obj[key]
}

/**
 * 设置对象属性上的值。如果属性不存在则创建它
 * @param {Object/Array} obj 对象
 * @param {String/Function} property 键、路径
 * @param {Object} value 值
 */
function set (obj, property, value) {
  if (obj) {
    if ((obj[property] || hasOwnProp(obj, property)) && !isPrototypePolluted(property)) {
      obj[property] = value
    } else {
      var rest = obj
      var props = helperGetHGSKeys(property)
      var len = props.length
      for (var index = 0; index < len; index++) {
        if (isPrototypePolluted(props[index])) continue
        rest = setDeepProps(rest, props[index], index === len - 1, value)
      }
    }
  }
  return obj
}

/**
 * Blacklist certain keys to prevent Prototype Pollution
 * @param {string} key
 */
function isPrototypePolluted(key) {
  return key === '__proto__' || key === 'constructor' || key === 'prototype'
}

module.exports = set