simple class for calling a url using either curl or fopen

<?php
class EmailManager {
    var $_server;
    var $_account;

    const client_login_url = 'https://www.google.com/accounts/ClientLogin';

    function __construct($params = array())
    {
        if(!isset($params["server"])) {
            throw new Exception("Server name required.");
        }
        if(!isset($params["account"])) {
            throw new Exception("Account name required.");
        }
        $this->_account = $params["account"];
        $this->_server = $params["server"];
    }

    protected function authenticateUser($email, $password)
    {
        $postVariables = array(
            'accountType' => 'GOOGLE',
            'Email' => $email,
            'Passwd' => $password,
            'service' => 'analytics'
        );
        $response = $this->httpRequest(EmailManager::client_login_url, null, $postVariables);
    }

    protected function httpRequest($url, $get_variables=null, $post_variables=null, $headers=null)
    {
        $interface = null;
        if(function_exists('curl_exec')) {
            $interface = 'curl';
        } else {
            $interface = 'fopen';
        }
        if($interface == 'curl') {
            return $this->curlRequest($url, $get_variables, $post_variables, $headers);
        } else if($interface == 'fopen') {
            return $this->fOpenRequest($url, $get_variables, $post_variables, $headers);
        }
    }

    private function curlRequest($url, $get_variables=null, $post_variables=null, $headers=null)
    {
        $ch = curl_init();

        if(is_array($get_variables))
        {
            $get_variables = '?' . str_replace('&amp;','&',urldecode(http_build_query($get_variables)));
        }
        else
        {
            $get_variables = null;
        }

        curl_setopt($ch, CURLOPT_URL, $url . $get_variables);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); //CURL doesn't like google's cert

        if(is_array($post_variables))
        {
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $post_variables);
        }

        if(is_array($headers))
        {
            curl_setopt($ch, CURLOPT_HTTPHEADER,$headers);
        }

        $response = curl_exec($ch);
        $code = curl_getinfo($ch,CURLINFO_HTTP_CODE);

        curl_close($ch);

        return array('body'=>$response,'code'=>$code);
    }

    private function fOpenRequest($url, $get_variables=null, $post_variables=null, $headers=null)
    {
        $http_options = array('method'=>'GET','timeout'=>3);

        if(is_array($headers))
        {
            $headers = implode("\r\n",$headers) . "\r\n";
        }
        else
        {
            $headers = '';
        }

        if(is_array($get_variables))
        {
            $get_variables = '?' . str_replace('&amp;','&',urldecode(http_build_query($get_variables)));
        }
        else
        {
            $get_variables = null;
        }

        if(is_array($post_variables))
        {
            $post_variables = str_replace('&amp;','&',urldecode(http_build_query($post_variables)));
            $http_options['method'] = 'POST';
            $headers = "Content-type: application/x-www-form-urlencoded\r\n" . "Content-Length: " . strlen($post_variables) . "\r\n" . $headers;
            $http_options['header'] = $headers;
            $http_options['content'] = $post_variables;
        }
        else
        {
            $post_variables = '';
            $http_options['header'] = $headers;
        }

        $context = stream_context_create(array('http'=>$http_options));
        $response = @file_get_contents($url . $get_variables, null, $context);

        return array('body'=>$response!==false?$response:'Request failed, fopen provides no further information','code'=>$response!==false?'200':'400');
    }
}
?>