PHP's str_ireplace in JavaScript

module.exports = functionstr_ireplace (search, replace, subject, countObj) { // eslint-disable-line camelcase
//  discuss at: https://locutus.io/php/str_ireplace/
// original by: Glen Arason (https://CanadianDomainRegistry.ca)
// bugfixed by: Mahmoud Saeed
//      note 1: Case-insensitive version of str_replace()
//      note 1: Compliant with PHP 5.0 str_ireplace() Full details at:
//      note 1: https://ca3.php.net/manual/en/function.str-ireplace.php
//      note 2: The countObj parameter (optional) if used must be passed in as a
//      note 2: object. The count will then be written by reference into it's `value` property
//   example 1: str_ireplace('M', 'e', 'name')
//   returns 1: 'naee'
//   example 2: var $countObj = {}
//   example 2: str_ireplace('M', 'e', 'name', $countObj)
//   example 2: var $result = $countObj.value
//   returns 2: 1
//   example 3: str_ireplace('', '.', 'aaa')
//   returns 3: 'aaa'
let i = 0
let j = 0
let temp = ''
let repl = ''
let sl = 0
let fl = 0
let f = ''
let r = ''
let s = ''
let ra = ''
let otemp = ''
let oi = ''
let ofjl = ''
let os = subject
const osa = Object.prototype.toString.call(os) === '[object Array]'
// var sa = ''
if (typeof (search) === 'object') {
    temp = search
    search = []
for (i = 0; i < temp.length; i += 1) {
      search[i] = temp[i].toLowerCase()
    }
  } else {
    search = search.toLowerCase()
  }
if (typeof (subject) === 'object') {
    temp = subject
    subject = []
for (i = 0; i < temp.length; i += 1) {
      subject[i] = temp[i].toLowerCase()
    }
  } else {
    subject = subject.toLowerCase()
  }
if (typeof (search) === 'object' && typeof (replace) === 'string') {
    temp = replace
    replace = []
for (i = 0; i < search.length; i += 1) {
      replace[i] = temp
    }
  }
  temp = ''
  f = [].concat(search)
  r = [].concat(replace)
  ra = Object.prototype.toString.call(r) === '[object Array]'
  s = subject
// sa = Object.prototype.toString.call(s) === '[object Array]'
  s = [].concat(s)
  os = [].concat(os)
if (countObj) {
    countObj.value = 0
  }
for (i = 0, sl = s.length; i < sl; i++) {
if (s[i] === '') {
continue
    }
for (j = 0, fl = f.length; j < fl; j++) {
if (f[j] === '') {
continue
      }
      temp = s[i] + ''
      repl = ra ? (r[j] !== undefined ? r[j] : '') : r[0]
      s[i] = (temp).split(f[j]).join(repl)
      otemp = os[i] + ''
      oi = temp.indexOf(f[j])
      ofjl = f[j].length
if (oi >= 0) {
        os[i] = (otemp).split(otemp.substr(oi, ofjl)).join(repl)
      }
if (countObj) {
        countObj.value += ((temp.split(f[j])).length - 1)
      }
    }
  }
return osa ? os : os[0]
}