如何在php中检测来自json响应的charset

Question

I'm trying to receive a JSON Response from a webservice using GuzzleHttp Client but I'm unable to decode the received json data with json_decode which returns null.

I noticed that on the response headers the Content-Type is application/json; charset=windows-1253

If I convert the json string using iconv from windows-1253 to utf-8 it decodes OK.

So my question is how can I reliably determine which charset the response uses in order to convert correctly and then parse it with json_decode?

For example a function

getCharsetFromResponse(\GuzzleHttp\Psr7\Response $response){
 //detect charset here
 .....
 return $charset;
}