Network+whichOperator.swift

import CoreTelephony

// Under iOS 12
func isThailandOperator() -> Bool {
  let networkInfo = CTTelephonyNetworkInfo()
  guard let carrier = networkInfo.subscriberCellularProvider else {
    return false
  }
  
  guard let mcc = carrier.mobileCountryCode else {
    throw ReachabilityError.cannotGetMobileCountryCode
  }

  // 520 is Thailand
  guard mcc == "520" else {
    throw ReachabilityError.countryCodeIsNotThailand
  }

  guard let mnc = carrier.mobileNetworkCode else {
    throw ReachabilityError.cannotGetMobileNetwork
  }
  
  let networkList = [
    "00": "TruemoveH",
    "03": "AIS",
    "05": "dtac",
  ]

  return networkList.contains(where: { key, _ -> Bool in
    return key == mnc
  })
}