<?php

define('CS_REST_GET', 'GET');
define('CS_REST_POST', 'POST');
define('CS_REST_PUT', 'PUT');
define('CS_REST_DELETE', 'DELETE');
define('CS_REST_SOCKET_TIMEOUT', 10);
define('CS_REST_CALL_TIMEOUT', 10);

function CS_REST_TRANSPORT_get_available($requires_ssl, $log) {
    if(function_exists('curl_init') && function_exists('curl_exec')) {
        return new CS_REST_CurlTransport($log);
    } else if(CS_REST_TRANSPORT_can_use_raw_socket($requires_ssl)) {
        return new CS_REST_SocketTransport($log);
    } else { 
        $log->log_message('No transport is available', __FUNCTION__, CS_REST_LOG_ERROR);
        trigger_error('No transport is available.'.
            ($requires_ssl ? ' Try using non-secure (http) mode or ' : ' Please ').
            'ensure the cURL extension is loaded', E_USER_ERROR);
    }    
}
function CS_REST_TRANSPORT_can_use_raw_socket($requires_ssl) {
    if(function_exists('fsockopen')) {
        if($requires_ssl) {
            return extension_loaded('openssl');
        }

        return true;
    }

    return false;
}   
class CS_REST_BaseTransport {
    
    var $_log;
    
    function CS_REST_BaseTransport($log) {
        $this->_log = $log;
    }
    
    function split_and_inflate($response, $may_be_compressed) {        
        $ra = explode("\r\n\r\n", $response);
        
        $result = array_pop($ra);
        $headers = array_pop($ra);
        
        if($may_be_compressed && preg_match('/^Content-Encoding:\s+gzip\s+$/im', $headers)) {        
            $original_length = strlen($response);
            $result = gzinflate(substr($result, 10, -8));
    
            $this->_log->log_message('Inflated gzipped response: '.$original_length.' bytes ->'.
                strlen($result).' bytes', get_class(), CS_REST_LOG_VERBOSE);
        }
        
        return array($headers, $result); 
    }
}
/**
 * Provide HTTP request functionality via cURL extensions
 *
 * @author tobyb
 * @since 1.0
 */
class CS_REST_CurlTransport extends CS_REST_BaseTransport {

    var $_curl_zlib;

    function CS_REST_CurlTransport($log) {
        $this->CS_REST_BaseTransport($log);
        
        $curl_version = curl_version();
        $this->_curl_zlib = isset($curl_version['libz_version']);
    }

    /**
     * @return string The type of transport used
     */
    function get_type() {
        return 'cURL';
    }

    function make_call($call_options) {
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $call_options['route']);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, true);
        $headers = array();
        $headers[] = 'Content-Type: '.$call_options['contentType'];
        

        if (array_key_exists('authdetails', $call_options) &&
            isset($call_options['authdetails'])) {
            if (array_key_exists('username', $call_options['authdetails']) &&
                array_key_exists('password', $call_options['authdetails'])) {
                # Authenticating using basic auth for retrieving user's API key.
                curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
                curl_setopt($ch, CURLOPT_USERPWD, $call_options['authdetails']['username'].':'.$call_options['authdetails']['password']);
            } elseif (array_key_exists('access_token', $call_options['authdetails'])) {
                # Authenticating using OAuth.
                $access_token = $call_options['authdetails']['access_token'];
                $headers[] = 'Authorization: Bearer '.$access_token;
            } elseif (array_key_exists('api_key', $call_options['authdetails'])) {
                # Authenticating using an API key.
                curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
                $api_key = $call_options['authdetails']['api_key'];
                curl_setopt($ch, CURLOPT_USERPWD, $api_key.':nopass');
            }
        }

        curl_setopt($ch, CURLOPT_USERAGENT, $call_options['userAgent']);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, CS_REST_SOCKET_TIMEOUT);
        curl_setopt($ch, CURLOPT_TIMEOUT, CS_REST_CALL_TIMEOUT);

        $inflate_response = false;
        if($this->_curl_zlib) {
            $this->_log->log_message('curl+zlib support available. Requesting gzipped response.',
                get_class($this), CS_REST_LOG_VERBOSE);
            curl_setopt($ch, CURLOPT_ENCODING, 'gzip');
        } else if(function_exists('gzinflate')) {
            $headers[] = 'Accept-Encoding: gzip';
            $inflate_response = true;
        }
        
        if($call_options['protocol'] === 'https') {
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);

            if(strlen(ini_get('curl.cainfo')) === 0) {
                curl_setopt($ch, CURLOPT_CAINFO, dirname(__FILE__).'/cacert.pem');
            }
        }

        switch($call_options['method']) {
            case CS_REST_PUT:
                curl_setopt($ch, CURLOPT_CUSTOMREQUEST, CS_REST_PUT);
                $headers[] = 'Content-Length: '.strlen($call_options['data']);
                curl_setopt($ch, CURLOPT_POSTFIELDS, $call_options['data']);
                break;
            case CS_REST_POST:
                curl_setopt($ch, CURLOPT_POST, true);
                curl_setopt($ch, CURLOPT_POSTFIELDS, isset($call_options['data']) ? $call_options['data'] : '');
                break;
            case CS_REST_DELETE:
                curl_setopt($ch, CURLOPT_CUSTOMREQUEST, CS_REST_DELETE);
                break;
        }
        
        if(count($headers) > 0) {
            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        }

        $response = curl_exec($ch);

        if(!$response && $response !== '') {
            $this->_log->log_message('Error making request with curl_error: '.curl_errno($ch),
                get_class($this), CS_REST_LOG_ERROR);
            trigger_error('Error making request with curl_error: '.curl_error($ch), E_USER_ERROR);
        }
        
        list( $headers, $result ) = $this->split_and_inflate($response, $inflate_response);
        
        $this->_log->log_message('API Call Info for '.$call_options['method'].' '.
        curl_getinfo($ch, CURLINFO_EFFECTIVE_URL).': '.curl_getinfo($ch, CURLINFO_SIZE_UPLOAD).
		    ' bytes uploaded. '.curl_getinfo($ch, CURLINFO_SIZE_DOWNLOAD).' bytes downloaded'.
		    ' Total time (seconds): '.curl_getinfo($ch, CURLINFO_TOTAL_TIME), 
        get_class($this), CS_REST_LOG_VERBOSE);

        $result = array(
			'code' => curl_getinfo($ch, CURLINFO_HTTP_CODE),
		    'response' => $result
        );

        curl_close($ch);

        return $result;
    }
}

class CS_REST_SocketWrapper {
    var $socket;

    function open($domain, $port) {
        $this->socket = fsockopen($domain, $port, $errno, $errstr, CS_REST_SOCKET_TIMEOUT);

        if(!$this->socket) {
            die('Error making request with '.$errno.': '.$errstr);
            return false;
        } else if(function_exists('stream_set_timeout')) {
            stream_set_timeout($this->socket, CS_REST_SOCKET_TIMEOUT);
        }

        return true;
    }

    function write($data) {
        fwrite($this->socket, $data);
    }

    function read() {
        ob_start();
        fpassthru($this->socket);

        return ob_get_clean();
    }

    function close() {
        fclose($this->socket);
    }
}

class CS_REST_SocketTransport extends CS_REST_BaseTransport {

    var $_socket_wrapper;

    function CS_REST_SocketTransport($log, $socket_wrapper = NULL) {
        $this->CS_REST_BaseTransport($log);

        if(is_null($socket_wrapper)) {
            $socket_wrapper = new CS_REST_SocketWrapper();
        }

        $this->_socket_wrapper = $socket_wrapper;
    }

    /**
     * @return string The type of transport used
     */
    function get_type() {
        return 'Socket';
    }

    function make_call($call_options) {
        $start_host = strpos($call_options['route'], $call_options['host']);
        $host_len = strlen($call_options['host']);

        $domain = substr($call_options['route'], $start_host, $host_len);
        $host = $domain;
        $path = substr($call_options['route'], $start_host + $host_len);
        $protocol = substr($call_options['route'], 0, $start_host);
        $port = 80;

        $this->_log->log_message('Creating socket to '.$domain.' over '.$protocol.' for request to '.$path,
            get_class($this), CS_REST_LOG_VERBOSE);

        if($protocol === 'https://') {
            $domain = 'ssl://'.$domain;
            $port = 443;
        }

        if($this->_socket_wrapper->open($domain, $port)) {
            $inflate_response = function_exists('gzinflate');
            
            $request = $this->_build_request($call_options, $host, $path, $inflate_response);
            $this->_log->log_message('Sending <pre>'.$request.'</pre> down the socket',
            get_class($this), CS_REST_LOG_VERBOSE);
             
            $this->_socket_wrapper->write($request);
            $response = $this->_socket_wrapper->read();
            $this->_socket_wrapper->close();
            	
            $this->_log->log_message('API Call Info for '.$call_options['method'].' '.
            $call_options['route'].': '.strlen($request).
	            ' bytes uploaded. '.strlen($response).' bytes downloaded', 
            get_class($this), CS_REST_LOG_VERBOSE);
            	
            list( $headers, $result ) = $this->split_and_inflate($response, $inflate_response);
                
            $this->_log->log_message('Received headers <pre>'.$headers.'</pre>',
                get_class($this), CS_REST_LOG_VERBOSE);
            	
            return array(
			    'code' => $this->_get_status_code($headers),
			    'response' => trim($result)
            );
        }
    }

    function _get_status_code($headers) {
        if (preg_match('%^\s*HTTP/1\.1 (?P<code>\d{3})%', $headers, $regs)) {
            $this->_log->log_message('Got HTTP Status Code: '.$regs['code'],
            get_class($this), CS_REST_LOG_VERBOSE);
            return $regs['code'];
        }

        $this->_log->log_message('Failed to get HTTP status code from request headers <pre>'.$headers.'</pre>',
            get_class($this), CS_REST_LOG_ERROR);
        trigger_error('Failed to get HTTP status code from request', E_USER_ERROR);        
    }

    function _build_request($call_options, $host, $path, $accept_gzip) {
        $request_auth_details = '';

        if (array_key_exists('authdetails', $call_options)) {
            if (array_key_exists('username', $call_options['authdetails']) &&
                array_key_exists('password', $call_options['authdetails'])) {
                # Authenticating using basic auth for retrieving user's API key.
                $request_auth_details .= 'Authorization: Basic '.base64_encode($call_options['authdetails']['username'].':'.$call_options['authdetails']['password'])."\n";
            } elseif (array_key_exists('access_token', $call_options['authdetails'])) {
                # Authenticating using OAuth.
                $access_token = $call_options['authdetails']['access_token'];
                $request_auth_details .= 'Authorization: Bearer '.$access_token."\n";
            } elseif (array_key_exists('api_key', $call_options['authdetails'])) {
                # Authenticating using an API key.
                $api_key = $call_options['authdetails']['api_key'];
                $request_auth_details .= 'Authorization: Basic '.base64_encode($api_key.':nopass')."\n";
            }
        }

        $request =
$call_options['method'].' '.$path." HTTP/1.1\n".
'Host: '.$host."\n".
$request_auth_details.
'User-Agent: '.$call_options['userAgent']."\n".
"Connection: Close\n".
'Content-Type: '.$call_options['contentType']."\n";

        if($accept_gzip) {
            $request .=
"Accept-Encoding: gzip\n";           
        }

        if(isset($call_options['data'])) {
            $request .=
'Content-Length: '.strlen($call_options['data'])."\n\n".
$call_options['data'];
        }

        return $request."\n\n";
    }
}