<?php
/**
 * @class netHttp
 * @brief HTTP Client
 *
 * Features:
 *
 * - Implements a useful subset of the HTTP 1.0 and 1.1 protocols.
 * - Includes cookie support.
 * - Ability to set the user agent and referal fields.
 * - Can automatically handle redirected pages.
 * - Can be used for multiple requests, with any cookies sent by the server resent
 *   for each additional request.
 * - Support for gzip encoded content, which can dramatically reduce the amount of
 *   bandwidth used in a transaction.
 * - Object oriented, with static methods providing a useful shortcut for simple
 *   requests.
 * - The ability to only read the page headers - useful for implementing tools such
 *   as link checkers.
 * - Support for file uploads.
 *
 * This class is fully based on Simon Willison's HTTP Client in version 0.9 of
 * 6th April 2003 - http://scripts.incutio.com/httpclient/
 *
 * Changes since fork:
 *
 * - PHP5 only with Exception support
 * - Charset support in POST requests
 * - Proxy support through HTTP_PROXY_HOST and HTTP_PROXY_PORT or setProxy()
 * - SSL support (if possible)
 * - Handles redirects on other hosts
 * - Configurable output
 *
 * @package Clearbricks
 * @subpackage Network
 *
 * @copyright Olivier Meunier & Association Dotclear
 * @copyright GPL-2.0-only
 */

/** @cond ONCE */
if (class_exists('netSocket')) {
/** @endcond */

    class netHttp extends netSocket
    {
        protected $host;          ///< string Server host
        protected $port;          ///< integer Server port
        protected $path;          ///< string Query path
        protected $method;        ///< string HTTP method
        protected $postdata = ''; ///< string POST query string
        protected $post_charset;  ///< string POST charset
        protected $cookies = [];  ///< array Cookies sent
        protected $referer;       ///< string HTTP referer

        protected $accept = 'text/xml,application/xml,application/xhtml+xml,text/html,text/plain,image/png,image/jpeg,image/gif,image/webp,*/*'; ///< string HTTP accept header

        protected $accept_encoding  = 'gzip';                    ///< string HTTP accept encoding
        protected $accept_language  = 'en-us';                   ///< string HTTP accept language
        protected $user_agent       = 'Clearbricks HTTP Client'; ///< string HTTP User Agent
        protected $more_headers     = [];                        ///< array More headers to be sent
        protected $timeout          = 10;                        ///< integer Connection timeout
        protected $use_ssl          = false;                     ///< boolean Use SSL connection
        protected $use_gzip         = false;                     ///< boolean Use gzip transfert
        protected $persist_cookies  = true;                      ///< boolean Allow persistant cookies
        protected $persist_referers = true;                      ///< boolean Allow persistant referers
        protected $debug            = false;                     ///< boolean Use debug mode
        protected $handle_redirects = true;                      ///< boolean Follow redirects
        protected $max_redirects    = 5;                         ///< integer Maximum redirects to follow
        protected $headers_only     = false;                     ///< boolean Retrieve only headers
        protected $username;                                     ///< string Authentication user name
        protected $password;                                     ///< string Authentication password
        protected $proxy_host;                                   ///< string Proxy server host
        protected $proxy_port;                                   ///< integer Proxy server port

        # Response vars
        protected $status;        ///< integer HTTP Status code
        protected $status_string; ///< string HTTP Status string
        protected $headers = [];  ///< array Response headers
        protected $content = '';  ///< string Response body

        # Tracker variables
        protected $redirect_count = 0;  ///< integer Internal redirects count
        protected $cookie_host    = ''; ///< string Internal cookie host

        # Output module (null is this->content)
        protected $output   = null; ///< string Output stream name
        protected $output_h = null; ///< resource Output resource

        /**
         * Constructor.
         *
         * Takes the web server host, an optional port and timeout.
         *
         * @param string    $host            Server host
         * @param integer    $port            Server port
         * @param integer    $timeout            Connection timeout
         */
        public function __construct($host, $port = 80, $timeout = null)
        {
            $this->setHost($host, $port);

            if (defined('HTTP_PROXY_HOST') && defined('HTTP_PROXY_PORT')) {
                $this->setProxy(HTTP_PROXY_HOST, HTTP_PROXY_PORT);
            }

            if ($timeout) {
                $this->setTimeout($timeout);
            }
            $this->_timeout = &$this->timeout;
        }

        /**
         * GET Request
         *
         * Executes a GET request for the specified path. If <var>$data</var> is
         * specified, appends it to a query string as part of the get request.
         * <var>$data</var> can be an array of key value pairs, in which case a
         * matching query string will be constructed. Returns true on success.
         *
         * @param string    $path            Request path
         * @param array        $data            Request parameters
         * @return boolean
         */
        public function get($path, $data = false)
        {
            $this->path   = $path;
            $this->method = 'GET';

            if ($data) {
                $this->path .= '?' . $this->buildQueryString($data);
            }

            return $this->doRequest();
        }

        /**
         * POST Request
         *
         * Executes a POST request for the specified path. If <var>$data</var> is
         * specified, appends it to a query string as part of the get request.
         * <var>$data</var> can be an array of key value pairs, in which case a
         * matching query string will be constructed. Returns true on success.
         *
         * @param string    $path            Request path
         * @param array        $data            Request parameters
         * @param array        $charset            Request charset
         * @return boolean
         */
        public function post($path, $data, $charset = null)
        {
            if ($charset) {
                $this->post_charset = $charset;
            }
            $this->path     = $path;
            $this->method   = 'POST';
            $this->postdata = $this->buildQueryString($data);
            return $this->doRequest();
        }

        /**
         * Query String Builder
         *
         * Prepares Query String for HTTP request. <var>$data</var> is an associative
         * array of arguments.
         *
         * @param array        $data            Query data
         * @return string
         */
        protected function buildQueryString($data)
        {
            if (is_array($data)) {
                $qs = [];
                # Change data in to postable data
                foreach ($data as $key => $val) {
                    if (is_array($val)) {
                        foreach ($val as $val2) {
                            $qs[] = urlencode($key) . '=' . urlencode($val2);
                        }
                    } else {
                        $qs[] = urlencode($key) . '=' . urlencode($val);
                    }
                }
                $qs = implode('&', $qs);
            } else {
                $qs = $data;
            }

            return $qs;
        }

        /**
         * Do Request
         *
         * Sends HTTP request and stores status, headers, content object properties.
         *
         * @return boolean
         */
        protected function doRequest()
        {
            if ($this->proxy_host && $this->proxy_port) {
                $this->_host      = $this->proxy_host;
                $this->_port      = $this->proxy_port;
                $this->_transport = '';
            } else {
                $this->_host      = $this->host;
                $this->_port      = $this->port;
                $this->_transport = $this->use_ssl ? 'ssl://' : '';
            }

            #Reset all the variables that should not persist between requests
            $this->headers = [];
            $in_headers    = true;
            $this->outputOpen();

            $request = $this->buildRequest();
            $this->debug('Request', implode("\r", $request));

            $this->open();
            $this->debug('Connecting to ' . $this->_transport . $this->_host . ':' . $this->_port);
            foreach ($this->write($request) as $index => $line) {
                # Deal with first line of returned data
                if ($index == 0) {
                    $line = rtrim($line, "\r\n");
                    if (!preg_match('/HTTP\/(\\d\\.\\d)\\s*(\\d+)\\s*(.*)/', $line, $m)) {
                        throw new Exception('Status code line invalid: ' . $line);
                    }
                    $http_version        = $m[1]; # not used
                    $this->status        = $m[2];
                    $this->status_string = $m[3]; # not used
                    $this->debug($line);
                    continue;
                }

                # Read headers
                if ($in_headers) {
                    $line = rtrim($line, "\r\n");
                    if ($line == '') {
                        $in_headers = false;
                        $this->debug('Received Headers', $this->headers);
                        if ($this->headers_only) {
                            break;
                        }
                        continue;
                    }

                    if (!preg_match('/([^:]+):\\s*(.*)/', $line, $m)) {
                        # Skip to the next header
                        continue;
                    }
                    $key = strtolower(trim($m[1]));
                    $val = trim($m[2]);
                    # Deal with the possibility of multiple headers of same name
                    if (isset($this->headers[$key])) {
                        if (is_array($this->headers[$key])) {
                            $this->headers[$key][] = $val;
                        } else {
                            $this->headers[$key] = [$this->headers[$key], $val];
                        }
                    } else {
                        $this->headers[$key] = $val;
                    }
                    continue;
                }

                # We're not in the headers, so append the line to the contents
                $this->outputWrite($line);
            }
            $this->close();
            $this->outputClose();

            # If data is compressed, uncompress it
            if ($this->getHeader('content-encoding') && $this->use_gzip) {
                $this->debug('Content is gzip encoded, unzipping it');
                # See http://www.php.net/manual/en/function.gzencode.php
                $this->content = gzinflate(substr($this->content, 10));
            }

            # If $persist_cookies, deal with any cookies
            if ($this->persist_cookies && $this->getHeader('set-cookie') && $this->host == $this->cookie_host) {
                $cookies = $this->headers['set-cookie'];
                if (!is_array($cookies)) {
                    $cookies = [$cookies];
                }

                foreach ($cookies as $cookie) {
                    if (preg_match('/([^=]+)=([^;]+);/', $cookie, $m)) {
                        $this->cookies[$m[1]] = $m[2];
                    }
                }

                # Record domain of cookies for security reasons
                $this->cookie_host = $this->host;
            }

            # If $persist_referers, set the referer ready for the next request
            if ($this->persist_referers) {
                $this->debug('Persisting referer: ' . $this->getRequestURL());
                $this->referer = $this->getRequestURL();
            }

            # Finally, if handle_redirects and a redirect is sent, do that
            if ($this->handle_redirects) {
                if (++$this->redirect_count >= $this->max_redirects) {
                    $this->redirect_count = 0;
                    throw new Exception('Number of redirects exceeded maximum (' . $this->max_redirects . ')');
                }

                $location = isset($this->headers['location']) ? $this->headers['location'] : '';
                $uri      = isset($this->headers['uri']) ? $this->headers['uri'] : '';
                if ($location || $uri) {
                    if (self::readUrl($location . $uri, $r_ssl, $r_host, $r_port, $r_path, $r_user, $r_pass)) {
                        # If we try to move on another host, remove cookies, user and pass
                        if ($r_host != $this->host || $r_port != $this->port) {
                            $this->cookies = [];
                            $this->setAuthorization(null, null);
                            $this->setHost($r_host, $r_port);
                        }
                        $this->useSSL($r_ssl);
                        $this->debug('Redirect to: ' . $location . $uri);
                        return $this->get($r_path);
                    }
                }
                $this->redirect_count = 0;
            }
            return true;
        }

        /**
         * Prepare Request
         *
         * Prepares HTTP request and returns an array of HTTP headers.
         *
         * @return array
         */
        protected function buildRequest()
        {
            $headers = [];

            if ($this->proxy_host) {
                $path = $this->getRequestURL();
            } else {
                $path = $this->path;
            }

            # Using 1.1 leads to all manner of problems, such as "chunked" encoding
            $headers[] = $this->method . ' ' . $path . ' HTTP/1.0';

            $headers[] = 'Host: ' . $this->host;
            $headers[] = 'User-Agent: ' . $this->user_agent;
            $headers[] = 'Accept: ' . $this->accept;

            if ($this->use_gzip) {
                $headers[] = 'Accept-encoding: ' . $this->accept_encoding;
            }
            $headers[] = 'Accept-language: ' . $this->accept_language;

            if ($this->referer) {
                $headers[] = 'Referer: ' . $this->referer;
            }

            # Cookies
            if ($this->cookies) {
                $cookie = 'Cookie: ';
                foreach ($this->cookies as $key => $value) {
                    $cookie .= $key . '=' . $value . ';';
                }
                $headers[] = $cookie;
            }

            # X-Forwarded-For
            $xforward = [];
            if (isset($_SERVER['REMOTE_ADDR'])) {
                $xforward[] = $_SERVER['REMOTE_ADDR'];
            }
            if ($this->proxy_host && isset($_SERVER['SERVER_ADDR'])) {
                $xforward[] = $_SERVER['SERVER_ADDR'];
            }
            if (count($xforward)) {
                $headers[] = 'X-Forwarded-For: ' . implode(', ', $xforward);
            }

            # Basic authentication
            if ($this->username && $this->password) {
                $headers[] = 'Authorization: Basic ' . base64_encode($this->username . ':' . $this->password);
            }

            $headers = array_merge($headers, $this->more_headers);

            # If this is a POST, set the content type and length
            if ($this->postdata) {
                $needed = true;
                foreach ($headers as $value) {
                    if (preg_match('/^Content-Type: /', $value)) {
                        // Content-Type already set in headers, ignore
                        $needed = false;
                        break;
                    }
                }
                if ($needed) {
                    $content_type = 'Content-Type: application/x-www-form-urlencoded';
                    if ($this->post_charset) {
                        $content_type .= '; charset=' . $this->post_charset;
                    }
                    $headers[] = $content_type;
                }
                $headers[] = 'Content-Length: ' . strlen($this->postdata);
                $headers[] = '';
                $headers[] = $this->postdata;
            }

            return $headers;
        }

        /**
         * Open Output
         *
         * Initializes output handler if {@link $output} property is not null and
         * is a valid resource stream.
         */
        protected function outputOpen()
        {
            if ($this->output) {
                if (($this->output_h = @fopen($this->output, 'wb')) === false) {
                    throw new Exception('Unable to open output stream ' . $this->output);
                }
            } else {
                $this->content = '';
            }
        }

        /**
         * Close Output
         *
         * Closes output module if exists.
         */
        protected function outputClose()
        {
            if ($this->output && is_resource($this->output_h)) {
                fclose($this->output_h);
            }
        }

        /**
         * Write Output
         *
         * Writes data <var>$c</var> to output module.
         *
         * @param string    $c                Data content
         */
        protected function outputWrite($c)
        {
            if ($this->output && is_resource($this->output_h)) {
                fwrite($this->output_h, $c);
            } else {
                $this->content .= $c;
            }
        }

        /**
         * Get Status
         *
         * Returns the status code of the response - 200 means OK, 404 means file not
         * found, etc.
         *
         * @return string
         */
        public function getStatus()
        {
            return $this->status;
        }

        /**
         * Get Contet
         *
         * Returns the content of the HTTP response. This is usually an HTML document.
         *
         * @return string
         */
        public function getContent()
        {
            return $this->content;
        }

        /**
         * Response Headers
         *
         * Returns the HTTP headers returned by the server as an associative array.
         *
         * @return array
         */
        public function getHeaders()
        {
            return $this->headers;
        }

        /**
         * Response Header
         *
         * Returns the specified response header, or false if it does not exist.
         *
         * @param string    $header            Header name
         * @return string
         */
        public function getHeader($header)
        {
            $header = strtolower($header);
            if (isset($this->headers[$header])) {
                return $this->headers[$header];
            } else {
                return false;
            }
        }

        /**
         * Cookies
         *
         * Returns an array of cookies set by the server.
         *
         * @return array
         */
        public function getCookies()
        {
            return $this->cookies;
        }

        /**
         * Request URL
         *
         * Returns the full URL that has been requested.
         *
         * @return string
         */
        public function getRequestURL()
        {
            $url = 'http' . ($this->use_ssl ? 's' : '') . '://' . $this->host;
            if (!$this->use_ssl && $this->port != 80 || $this->use_ssl && $this->port != 443) {
                $url .= ':' . $this->port;
            }
            $url .= $this->path;
            return $url;
        }

        /**
         * Sets server host and port.
         *
         * @param string    $host            Server host
         * @param integer    $port            Server port
         */
        public function setHost($host, $port = 80)
        {
            $this->host = $host;
            $this->port = abs((integer) $port);
        }

        /**
         * Sets proxy host and port.
         *
         * @param string    $host                Proxy host
         * @param mixed     $port                Proxy port
         */
        public function setProxy($host, $port = '8080')
        {
            $this->proxy_host = $host;
            $this->proxy_port = abs((integer) $port);
        }

        /**
         * Sets connection timeout.
         *
         * @param integer    $t                Connection timeout
         */
        public function setTimeout($t)
        {
            $this->timeout = abs((integer) $t);
        }

        /**
         * User Agent String
         *
         * Sets the user agent string to be used in the request. Default is
         * "Clearbricks HTTP Client".
         *
         * @param string    $string            User agent string
         */
        public function setUserAgent($string)
        {
            $this->user_agent = $string;
        }

        /**
         * HTTP Authentication
         *
         * Sets the HTTP authorization username and password to be used in requests.
         * Don't forget to unset this in subsequent requests to different servers.
         *
         * @param string    $username            User name
         * @param string    $password            Password
         */
        public function setAuthorization($username, $password)
        {
            $this->username = $username;
            $this->password = $password;
        }

        /**
         * Add Header
         *
         * Sets additionnal header to be sent with the request.
         *
         * @param string    $header            Full header definition
         */
        public function setMoreHeader($header)
        {
            $this->more_headers[] = $header;
        }

        /**
         * Empty additionnal headers
         */
        public function voidMoreHeaders()
        {
            $this->more_headers = [];
        }

        /**
         * Set Cookies
         *
         * Sets the cookies to be sent in the request. Takes an array of name value
         * pairs.
         *
         * @param array        $array            Cookies array
         */
        public function setCookies($array)
        {
            $this->cookies = $array;
        }

        /**
         * Enable / Disable SSL
         *
         * Sets SSL connection usage.
         *
         * @param boolean    $boolean            Enable/Disable SSL
         */
        public function useSSL($boolean)
        {
            if ($boolean) {
                if (!in_array('ssl', stream_get_transports())) {
                    throw new Exception('SSL support is not available');
                }
                $this->use_ssl = true;
            } else {
                $this->use_ssl = false;
            }
        }

        /**
         * Use Gzip
         *
         * Specifies if the client should request gzip encoded content from the server
         * (saves bandwidth but can increase processor time). Default behaviour is
         * false.
         *
         * @param boolean    $boolean            Enable/Disable Gzip
         */
        public function useGzip($boolean)
        {
            $this->use_gzip = (boolean) $boolean;
        }

        /**
         * Persistant Cookies
         *
         * Specify if the client should persist cookies between requests. Default
         * behaviour is true.
         *
         * @param boolean    $boolean            Enable/Disable Persist Cookies
         */
        public function setPersistCookies($boolean)
        {
            $this->persist_cookies = (boolean) $boolean;
        }

        /**
         * Persistant Referrers
         *
         * Specify if the client should use the URL of the previous request as the
         * referral of a subsequent request. Default behaviour is true.
         *
         * @param boolean    $boolean            Enable/Disable Persistant Referrers
         */
        public function setPersistReferers($boolean)
        {
            $this->persist_referers = (boolean) $boolean;
        }

        /**
         * Enable / Disable Redirects
         *
         * Specify if the client should automatically follow redirected requests.
         * Default behaviour is true.
         *
         * @param boolean    $boolean            Enable/Disable Redirects
         */
        public function setHandleRedirects($boolean)
        {
            $this->handle_redirects = (boolean) $boolean;
        }

        /**
         * Maximum Redirects
         *
         * Set the maximum number of redirects allowed before the client quits
         * (mainly to prevent infinite loops) Default is 5.
         *
         * @param integer    $num                Maximum redirects value
         */
        public function setMaxRedirects($num)
        {
            $this->max_redirects = abs((integer) $num);
        }

        /**
         * Headers Only
         *
         * If true, the client only retrieves the headers from a page. This could be
         * useful for implementing things like link checkers. Defaults to false.
         *
         * @param boolean    $boolean            Enable/Disable Headers Only
         */
        public function setHeadersOnly($boolean)
        {
            $this->headers_only = (boolean) $boolean;
        }

        /**
         * Debug mode
         *
         * Should the client run in debug mode? Default behaviour is false.
         *
         * @param boolean    $boolean            Enable/Disable Debug Mode
         */
        public function setDebug($boolean)
        {
            $this->debug = (boolean) $boolean;
        }

        /**
         * Set Output
         *
         * Output module init. If <var>$out</var> is null, then output will be
         * directed to STDOUT.
         *
         * @param string|null    $out            Output stream
         */
        public function setOutput($out)
        {
            $this->output = $out;
        }

        /**
         * Quick Get
         *
         * Static method designed for running simple GET requests. Returns content or
         * false on failure.
         *
         * @param string    $url                Request URL
         * @param string    $output            Optionnal output stream
         * @return string|false
         */
        public static function quickGet($url, $output = null)
        {
            if (($client = self::initClient($url, $path)) === false) {
                return false;
            }
            $client->setOutput($output);
            $client->get($path);
            return $client->getStatus() == 200 ? $client->getContent() : false;
        }

        /**
         * Quick Post
         *
         * Static method designed for running simple POST requests. Returns content or
         * false on failure.
         *
         * @param string    $url                Request URL
         * @param string    $data            Array of parameters
         * @param string    $output            Optionnal output stream
         * @return string
         */
        public static function quickPost($url, $data, $output = null)
        {
            if (($client = self::initClient($url, $path)) === false) {
                return false;
            }
            $client->setOutput($output);
            $client->post($path, $data);
            return $client->getStatus() == 200 ? $client->getContent() : false;
        }

        /**
         * Quick Init
         *
         * Returns a new instance of the class. <var>$path</var> is an output variable.
         *
         * @param string    $url                Request URL
         * @param string    &$path            Resulting path
         * @return netHttp
         */
        public static function initClient($url, &$path)
        {
            if (!self::readUrl($url, $ssl, $host, $port, $path, $user, $pass)) {
                return false;
            }

            $client = new self($host, $port);
            $client->useSSL($ssl);
            $client->setAuthorization($user, $pass);

            return $client;
        }

        /**
         * Read URL
         *
         * Parses an URL and fills <var>$ssl</var>, <var>$host</var>, <var>$port</var>,
         * <var>$path</var>, <var>$user</var> and <var>$pass</var> variables. Returns
         * true on succes.
         *
         * @param string    $url                Request URL
         * @param boolean    &$ssl            true if HTTPS URL
         * @param string    &$host            Host name
         * @param string    &$port            Server Port
         * @param string    &$path            Path
         * @param string    &$user            Username
         * @param string    &$pass            Password
         * @return boolean
         */
        public static function readURL($url, &$ssl, &$host, &$port, &$path, &$user, &$pass)
        {
            $bits = parse_url($url);

            if (empty($bits['host'])) {
                return false;
            }

            if (empty($bits['scheme']) || !preg_match('%^http[s]?$%', $bits['scheme'])) {
                return false;
            }

            $scheme = isset($bits['scheme']) ? $bits['scheme'] : 'http';
            $host   = isset($bits['host']) ? $bits['host'] : null;
            $port   = isset($bits['port']) ? $bits['port'] : null;
            $path   = isset($bits['path']) ? $bits['path'] : '/';
            $user   = isset($bits['user']) ? $bits['user'] : null;
            $pass   = isset($bits['pass']) ? $bits['pass'] : null;

            $ssl = $scheme == 'https';

            if (!$port) {
                $port = $ssl ? 443 : 80;
            }

            if (isset($bits['query'])) {
                $path .= '?' . $bits['query'];
            }

            return true;
        }

        /**
         * Debug
         *
         * This method is the method the class calls whenever there is debugging
         * information available. $msg is a debugging message and $object is an
         * optional object to be displayed (usually an array). Default behaviour is to
         * display the message and the object in a red bordered div. If you wish
         * debugging information to be handled in a different way you can do so by
         * creating a new class that extends HttpClient and over-riding the debug()
         * method in that class.
         *
         * @param string    $msg                Debug message
         * @param mixed        $object            Variable to print_r
         */
        protected function debug($msg, $object = false)
        {
            if ($this->debug) {
                echo "-----------------------------------------------------------\n";
                echo '-- netHttp Debug: ' . $msg . "\n";
                if ($object) {
                    print_r($object);
                    echo "\n";
                }
                echo "-----------------------------------------------------------\n\n";
            }
        }
    }

/** @cond ONCE */
}
/** @endcond */

# Compatibility to Incutio HttpClient class
# This will be removed soon!

/** @cond ONCE */
if (class_exists('netHttp')) {
/** @endcond */

    class HttpClient extends netHttp
    {
        public function getError()
        {
            return;
        }
    }

/** @cond ONCE */
}
/** @endcond */
