PHP Curl Forwarder

request.php

<?php

$data = json_decode(file_get_contents('php://input'));
$url = null;
if($data){
	$request_type = 'JSON';
	$url = isset($data->target_url)?$data->target_url:null;
}elseif(isset($_POST)){
	$request_type = 'POST';
	$data = isset($_POST)?$_POST:null;
	if(isset($data['target_url'])){
		$url = $data['target_url'];
		unset($data['target_url']);
	}
}else{
	$request_type = 'GET';
	$data = isset($_GET)?$_GET:null;
	if(isset($data['target_url'])){
		$url = $data['target_url'];
		unset($data['target_url']);
	}
}

if(!filter_var($url, FILTER_VALIDATE_URL)){
	die('url target not valid');
}


$option = array(
  CURLOPT_URL => $url,
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => $request_type=='GET'?'GET':'POST',
);
$headers = [];
if($request_type=='POST' && !empty($data)){
	$option[CURLOPT_POSTFIELDS]=http_build_query($data);
}elseif($request_type=='JSON' ){
	if(!empty($data)){
		
	}
	$headers[] ='Content-Type: application/json';
}

$allheaders = getRequestHeaders();

foreach ($allheaders as $header => $value) {
	$headers[] = "$header:$value";
}
if($headers){
	$option[CURLOPT_HTTPHEADER]=$headers;
}

$curl = curl_init();

curl_setopt_array($curl, $option);

$response = curl_exec($curl);

curl_close($curl);
echo $response;


function getRequestHeaders() {
    $headers = array();
    foreach($_SERVER as $key => $value) {
        if (substr($key, 0, 5) <> 'HTTP_') {
            continue;
        }
        $header = str_replace(' ', '-', ucwords(str_replace('_', ' ', strtolower(substr($key, 5)))));
        $headers[$header] = $value;
    }
    return $headers;
}