var staticParseInt = require('./staticParseInt')

var helperGetHGSKeys = require('./helperGetHGSKeys')

var hasOwnProp = require('./hasOwnProp')

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

function setDeepProps (obj, key, isEnd, nextKey, value) {
  if (obj[key]) {
    if (isEnd) {
      obj[key] = value
    }
  } else {
    var index
    var rest
    var currMatchs = key ? key.match(sKeyRE) : null
    if (isEnd) {
      rest = value
    } else {
      var nextMatchs = nextKey ? nextKey.match(sKeyRE) : null
      if (nextMatchs && !nextMatchs[1]) {
        // 如果下一个属性为数组类型
        rest = new Array(staticParseInt(nextMatchs[2]) + 1)
      } else {
        rest = {}
      }
    }
    if (currMatchs) {
      if (currMatchs[1]) {
        // 如果为对象中数组
        index = staticParseInt(currMatchs[2])
        if (obj[currMatchs[1]]) {
          if (isEnd) {
            obj[currMatchs[1]][index] = rest
          } else {
            if (obj[currMatchs[1]][index]) {
              rest = obj[currMatchs[1]][index]
            } else {
              obj[currMatchs[1]][index] = rest
            }
          }
        } else {
          obj[currMatchs[1]] = new Array(index + 1)
          obj[currMatchs[1]][index] = rest
        }
      } else {
        // 如果为数组
        obj[currMatchs[2]] = rest
      }
    } else {
      // 如果为对象
      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
        }
        var isEnd = index === len - 1
        rest = setDeepProps(rest, props[index], isEnd, isEnd ? null : props[index + 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