php make multipart/form-data upload file

Multipart

class Multipart {
    const EOL = "\r\n";

    private $_data = '';
    private $_mime_boundary;

    public function __construct() {
        $this->_mime_boundary = md5(microtime(true));
    }

    private function _addPartHeader() {
        $this->_data .= '--' . $this->_mime_boundary . self::EOL;
    }

    public function addArray($data, $prefix='') {
        foreach($data as $key=>$value) {
            if(is_array($value)) {
                if($prefix)
                    $this->addArray($value, $prefix.'['.$key.']');
                else
                    $this->addArray($value, $key);
            } else {
                if($prefix)
                    $this->addPart($prefix.'['.(is_numeric($key) ? '' : $key).']', $value);
                else
                    $this->addPart($key, $value);
            }
        }
    }

    public function addPart($key, $value) {
        $this->_addPartHeader();
        $this->_data .= 'Content-Disposition: form-data; name="' . $key . '"' . self::EOL;
        $this->_data .= self::EOL;
        $this->_data .= $value . self::EOL;
    }

    public function addFile($key, $filename, $type) {
        $this->_addPartHeader();
        $this->_data .= 'Content-Disposition: form-data; name="' . $key . '"; filename="' . basename($filename) . '"' . self::EOL;
        $this->_data .= 'Content-Type: ' . $type . self::EOL;
        $this->_data .= 'Content-Transfer-Encoding: binary' . self::EOL;
        $this->_data .= self::EOL;
        $this->_data .= file_get_contents($filename) . self::EOL;
    }

    public function contentType() {
        return 'multipart/form-data; boundary=' . $this->_mime_boundary;
    }

    public function data() {
        // add the final content boundary
        return $this->_data .= '--' . $this->_mime_boundary . '--' . self::EOL . self::EOL;
    }
}

// usage 
        $filedata = [
            'sex' => '1' ,
            'name' => 'mrjnamei'
        ];
        $url = 'http://localhost/upload.php'; // where url you upload or another program 
        $file = $_FILES['file'];
        $multipart = new Multipart();
        // your params 
        $multipart->addArray($filedata);
        // key , file_path , file mime-type 
        $multipart->addFile('file',$file['tmp_name'],$file['type']);
        // make http request 
        $ch = curl_init($url);
        curl_setopt($ch,CURLOPT_POST,true);
        curl_setopt($ch,CURLOPT_POSTFIELDS ,$multipart->data());
        curl_setopt($ch,CURLOPT_HTTPHEADER,['Content-type: ' . $multipart->contentType()]);
        $response = curl_exec($ch);
        return $response ;