CampaignMonitor::doCall PHP Method

    private function doCall($url, array $parameters = null, $method = 'GET', $secure = false, $expectJSON = true, $returnHeaders = false)
    {
        // allowed methods
        $allowedMethods = array('GET', 'POST', 'DELETE', 'PUT');
        // add HTTP authentication. The call to retrieve the apikey works slightly different
        switch ($url) {
            case 'apikey':
                $options[CURLOPT_USERPWD] = $this->username . ':' . $this->password;
                $options[CURLOPT_HTTPAUTH] = CURLAUTH_BASIC;
                break;
            default:
                $options[CURLOPT_USERPWD] = $this->apiKey . ':' . md5(sha1(time()));
                $options[CURLOPT_HTTPAUTH] = CURLAUTH_ANY;
        }
        // redefine
        $url = (string) $url . '.' . $this->responseFormat;
        $parameters = (array) $parameters;
        $method = (string) $method;
        $expectJSON = (bool) $expectJSON;
        // validate method
        if (!in_array($method, $allowedMethods)) {
            throw new CampaignMonitorException('Unknown method (' . $method . '). Allowed methods are: ' . implode(', ', $allowedMethods));
        }
        // set the expect header to avoid connection fails
        $headers = array();
        $headers[] = 'Expect:';
        // based on the method, we should handle the parameters in a different way
        switch ($method) {
            case 'DELETE':
                $options[CURLOPT_CUSTOMREQUEST] = 'DELETE';
                break;
            case 'GET':
                // add the parameters into the querystring
                if (!empty($parameters)) {
                    $url .= '?' . http_build_query($parameters, null, '&', PHP_QUERY_RFC3986);
                }
                break;
            case 'POST':
                // set postfields, repair forward slash bug
                $options[CURLOPT_POSTFIELDS] = str_replace('\\/', '/', json_encode($parameters));
                // enable post
                $options[CURLOPT_POST] = true;
                // set content-type to JSON
                $headers[] = 'Content-Type: application/json';
                break;
            case 'PUT':
                // set postfields, repair forward slash bug
                $options[CURLOPT_POSTFIELDS] = str_replace('\\/', '/', json_encode($parameters));
                // enable put
                $options[CURLOPT_CUSTOMREQUEST] = 'PUT';
                // set content-type to JSON
                $headers[] = 'Content-Type: application/json';
                break;
        }
        // set options
        $options[CURLOPT_URL] = self::API_URL . '/' . $url;
        $options[CURLOPT_PORT] = self::API_PORT;
        $options[CURLOPT_USERAGENT] = $this->getUserAgent();
        if (ini_get('open_basedir') == '' && ini_get('safe_mode' == 'Off')) {
            $options[CURLOPT_FOLLOWLOCATION] = true;
        }
        $options[CURLOPT_RETURNTRANSFER] = true;
        $options[CURLOPT_TIMEOUT] = (int) $this->getTimeOut();
        $options[CURLOPT_SSL_VERIFYPEER] = false;
        $options[CURLOPT_SSL_VERIFYHOST] = false;
        $options[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_1_1;
        $options[CURLOPT_HTTPHEADER] = $headers;
        // init
        if ($this->curl == null) {
            $this->curl = curl_init();
        }
        // set options
        curl_setopt_array($this->curl, $options);
        // execute
        $response = curl_exec($this->curl);
        $headers = curl_getinfo($this->curl);
        // fetch errors
        $errorNumber = curl_errno($this->curl);
        $errorMessage = curl_error($this->curl);
        // return the headers
        if ($returnHeaders) {
            return $headers;
        }
        // we don't expext JSON, return the response
        if (!$expectJSON) {
            return $response;
        }
        // replace ids with their string values, added because some PHP-versions can't handle these large values
        $response = preg_replace('/id":(\\d+)/', 'id":"\\1"', $response);
        /*
        	This is a tricky one. Apparently PHP 5.2 does not decode strings, but returns NULL instead. 5.2.1x has no issues with this.
        	So we can assume that, if the response is not empty, and it is not a json array or object, it is a string, and we return it
        	without the double quotes, and without json_decode().
        
        	I am aware this is somewhat dirty, but if it lets you use 5.2 without issues than I can live with it.
        */
        $json = $response != '' && strpos($response, '{') === false && strpos($response, '[') === false ? str_replace('"', '', $response) : json_decode($response, true);
        // 200 OK means everything went well, 201 OK means a resource just got created with a POST request.
        if ($headers['http_code'] !== 200 && $headers['http_code'] !== 201 && !isset($json['ResultData'])) {
            // should we provide debug information
            if (self::DEBUG) {
                // make it output proper
                echo '<pre>';
                // dump the header-information
                var_dump($headers);
                // dump the raw response
                var_dump($response);
                // end proper format
                echo '</pre>';
            }
            // throw exception
            throw new CampaignMonitorException($headers['http_code'] . ': ' . $json['Message']);
        }
        // if we did a delete request, return true at this point
        if ($method === 'DELETE' && $json === null) {
            return true;
        }
        // return
        return $json;
    }