/src/Symfony/Component/HttpFoundation/Request.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpFoundation;

use Symfony\Component\HttpFoundation\Session\SessionInterface;

/**
 * Request represents an HTTP request.
 *
 * The methods dealing with URL accept / return a raw path (% encoded):
 *   * getBasePath
 *   * getBaseUrl
 *   * getPathInfo
 *   * getRequestUri
 *   * getUri
 *   * getUriForPath
 *
 * @author Fabien Potencier <fabien@symfony.com>
 *
 * @api
 */
class Request
{
    const HEADER_CLIENT_IP    = 'client_ip';
    const HEADER_CLIENT_HOST  = 'client_host';
    const HEADER_CLIENT_PROTO = 'client_proto';
    const HEADER_CLIENT_PORT  = 'client_port';

    protected static $trustProxy = false;

    protected static $trustedProxies = array();

    /**
     * Names for headers that can be trusted when
     * using trusted proxies.
     *
     * The default names are non-standard, but widely used
     * by popular reverse proxies (like Apache mod_proxy or Amazon EC2).
     */
    protected static $trustedHeaders = array(
        self::HEADER_CLIENT_IP    => 'X_FORWARDED_FOR',
        self::HEADER_CLIENT_HOST  => 'X_FORWARDED_HOST',
        self::HEADER_CLIENT_PROTO => 'X_FORWARDED_PROTO',
        self::HEADER_CLIENT_PORT  => 'X_FORWARDED_PORT',
    );

    protected static $httpMethodParameterOverride = false;

    /**
     * @var \Symfony\Component\HttpFoundation\ParameterBag
     *
     * @api
     */
    public $attributes;

    /**
     * @var \Symfony\Component\HttpFoundation\ParameterBag
     *
     * @api
     */
    public $request;

    /**
     * @var \Symfony\Component\HttpFoundation\ParameterBag
     *
     * @api
     */
    public $query;

    /**
     * @var \Symfony\Component\HttpFoundation\ServerBag
     *
     * @api
     */
    public $server;

    /**
     * @var \Symfony\Component\HttpFoundation\FileBag
     *
     * @api
     */
    public $files;

    /**
     * @var \Symfony\Component\HttpFoundation\ParameterBag
     *
     * @api
     */
    public $cookies;

    /**
     * @var \Symfony\Component\HttpFoundation\HeaderBag
     *
     * @api
     */
    public $headers;

    /**
     * @var string
     */
    protected $content;

    /**
     * @var array
     */
    protected $languages;

    /**
     * @var array
     */
    protected $charsets;

    /**
     * @var array
     */
    protected $acceptableContentTypes;

    /**
     * @var string
     */
    protected $pathInfo;

    /**
     * @var string
     */
    protected $requestUri;

    /**
     * @var string
     */
    protected $baseUrl;

    /**
     * @var string
     */
    protected $basePath;

    /**
     * @var string
     */
    protected $method;

    /**
     * @var string
     */
    protected $format;

    /**
     * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
     */
    protected $session;

    /**
     * @var string
     */
    protected $locale;

    /**
     * @var string
     */
    protected $defaultLocale = 'en';

    /**
     * @var array
     */
    protected static $formats;

    /**
     * Constructor.
     *
     * @param array  $query      The GET parameters
     * @param array  $request    The POST parameters
     * @param array  $attributes The request attributes (parameters parsed from the PATH_INFO, ...)
     * @param array  $cookies    The COOKIE parameters
     * @param array  $files      The FILES parameters
     * @param array  $server     The SERVER parameters
     * @param string $content    The raw body data
     *
     * @api
     */
    public function __construct(array $query = array(), array $request = array(), array $attributes = array(), array $cookies = array(), array $files = array(), array $server = array(), $content = null)
    {
        $this->initialize($query, $request, $attributes, $cookies, $files, $server, $content);
    }

    /**
     * Sets the parameters for this request.
     *
     * This method also re-initializes all properties.
     *
     * @param array  $query      The GET parameters
     * @param array  $request    The POST parameters
     * @param array  $attributes The request attributes (parameters parsed from the PATH_INFO, ...)
     * @param array  $cookies    The COOKIE parameters
     * @param array  $files      The FILES parameters
     * @param array  $server     The SERVER parameters
     * @param string $content    The raw body data
     *
     * @api
     */
    public function initialize(array $query = array(), array $request = array(), array $attributes = array(), array $cookies = array(), array $files = array(), array $server = array(), $content = null)
    {
        $this->request = new ParameterBag($request);
        $this->query = new ParameterBag($query);
        $this->attributes = new ParameterBag($attributes);
        $this->cookies = new ParameterBag($cookies);
        $this->files = new FileBag($files);
        $this->server = new ServerBag($server);
        $this->headers = new HeaderBag($this->server->getHeaders());

        $this->content = $content;
        $this->languages = null;
        $this->charsets = null;
        $this->acceptableContentTypes = null;
        $this->pathInfo = null;
        $this->requestUri = null;
        $this->baseUrl = null;
        $this->basePath = null;
        $this->method = null;
        $this->format = null;
    }

    /**
     * Creates a new request with values from PHP's super globals.
     *
     * @return Request A new request
     *
     * @api
     */
    public static function createFromGlobals()
    {
        $request = new static($_GET, $_POST, array(), $_COOKIE, $_FILES, $_SERVER);

        if (0 === strpos($request->headers->get('CONTENT_TYPE'), 'application/x-www-form-urlencoded')
            && in_array(strtoupper($request->server->get('REQUEST_METHOD', 'GET')), array('PUT', 'DELETE', 'PATCH'))
        ) {
            parse_str($request->getContent(), $data);
            $request->request = new ParameterBag($data);
        }

        return $request;
    }

    /**
     * Creates a Request based on a given URI and configuration.
     *
     * The information contained in the URI always take precedence
     * over the other information (server and parameters).
     *
     * @param string $uri        The URI
     * @param string $method     The HTTP method
     * @param array  $parameters The query (GET) or request (POST) parameters
     * @param array  $cookies    The request cookies ($_COOKIE)
     * @param array  $files      The request files ($_FILES)
     * @param array  $server     The server parameters ($_SERVER)
     * @param string $content    The raw body data
     *
     * @return Request A Request instance
     *
     * @api
     */
    public static function create($uri, $method = 'GET', $parameters = array(), $cookies = array(), $files = array(), $server = array(), $content = null)
    {
        $server = array_replace(array(
            'SERVER_NAME'          => 'localhost',
            'SERVER_PORT'          => 80,
            'HTTP_HOST'            => 'localhost',
            'HTTP_USER_AGENT'      => 'Symfony/2.X',
            'HTTP_ACCEPT'          => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
            'HTTP_ACCEPT_LANGUAGE' => 'en-us,en;q=0.5',
            'HTTP_ACCEPT_CHARSET'  => 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
            'REMOTE_ADDR'          => '127.0.0.1',
            'SCRIPT_NAME'          => '',
            'SCRIPT_FILENAME'      => '',
            'SERVER_PROTOCOL'      => 'HTTP/1.1',
            'REQUEST_TIME'         => time(),
        ), $server);

        $server['PATH_INFO'] = '';
        $server['REQUEST_METHOD'] = strtoupper($method);

        $components = parse_url($uri);
        if (isset($components['host'])) {
            $server['SERVER_NAME'] = $components['host'];
            $server['HTTP_HOST'] = $components['host'];
        }

        if (isset($components['scheme'])) {
            if ('https' === $components['scheme']) {
                $server['HTTPS'] = 'on';
                $server['SERVER_PORT'] = 443;
            } else {
                unset($server['HTTPS']);
                $server['SERVER_PORT'] = 80;
            }
        }

        if (isset($components['port'])) {
            $server['SERVER_PORT'] = $components['port'];
            $server['HTTP_HOST'] = $server['HTTP_HOST'].':'.$components['port'];
        }

        if (isset($components['user'])) {
            $server['PHP_AUTH_USER'] = $components['user'];
        }

        if (isset($components['pass'])) {
            $server['PHP_AUTH_PW'] = $components['pass'];
        }

        if (!isset($components['path'])) {
            $components['path'] = '/';
        }

        switch (strtoupper($method)) {
            case 'POST':
            case 'PUT':
            case 'DELETE':
                if (!isset($server['CONTENT_TYPE'])) {
                    $server['CONTENT_TYPE'] = 'application/x-www-form-urlencoded';
                }
            case 'PATCH':
                $request = $parameters;
                $query = array();
                break;
            default:
                $request = array();
                $query = $parameters;
                break;
        }

        if (isset($components['query'])) {
            parse_str(html_entity_decode($components['query']), $qs);
            $query = array_replace($qs, $query);
        }
        $queryString = http_build_query($query, '', '&');

        $server['REQUEST_URI'] = $components['path'].('' !== $queryString ? '?'.$queryString : '');
        $server['QUERY_STRING'] = $queryString;

        return new static($query, $request, array(), $cookies, $files, $server, $content);
    }

    /**
     * Clones a request and overrides some of its parameters.
     *
     * @param array $query      The GET parameters
     * @param array $request    The POST parameters
     * @param array $attributes The request attributes (parameters parsed from the PATH_INFO, ...)
     * @param array $cookies    The COOKIE parameters
     * @param array $files      The FILES parameters
     * @param array $server     The SERVER parameters
     *
     * @return Request The duplicated request
     *
     * @api
     */
    public function duplicate(array $query = null, array $request = null, array $attributes = null, array $cookies = null, array $files = null, array $server = null)
    {
        $dup = clone $this;
        if ($query !== null) {
            $dup->query = new ParameterBag($query);
        }
        if ($request !== null) {
            $dup->request = new ParameterBag($request);
        }
        if ($attributes !== null) {
            $dup->attributes = new ParameterBag($attributes);
        }
        if ($cookies !== null) {
            $dup->cookies = new ParameterBag($cookies);
        }
        if ($files !== null) {
            $dup->files = new FileBag($files);
        }
        if ($server !== null) {
            $dup->server = new ServerBag($server);
            $dup->headers = new HeaderBag($dup->server->getHeaders());
        }
        $dup->languages = null;
        $dup->charsets = null;
        $dup->acceptableContentTypes = null;
        $dup->pathInfo = null;
        $dup->requestUri = null;
        $dup->baseUrl = null;
        $dup->basePath = null;
        $dup->method = null;
        $dup->format = null;

        return $dup;
    }

    /**
     * Clones the current request.
     *
     * Note that the session is not cloned as duplicated requests
     * are most of the time sub-requests of the main one.
     */
    public function __clone()
    {
        $this->query      = clone $this->query;
        $this->request    = clone $this->request;
        $this->attributes = clone $this->attributes;
        $this->cookies    = clone $this->cookies;
        $this->files      = clone $this->files;
        $this->server     = clone $this->server;
        $this->headers    = clone $this->headers;
    }

    /**
     * Returns the request as a string.
     *
     * @return string The request
     */
    public function __toString()
    {
        return
            sprintf('%s %s %s', $this->getMethod(), $this->getRequestUri(), $this->server->get('SERVER_PROTOCOL'))."\r\n".
            $this->headers."\r\n".
            $this->getContent();
    }

    /**
     * Overrides the PHP global variables according to this request instance.
     *
     * It overrides $_GET, $_POST, $_REQUEST, $_SERVER, $_COOKIE.
     * $_FILES is never override, see rfc1867
     *
     * @api
     */
    public function overrideGlobals()
    {
        $_GET = $this->query->all();
        $_POST = $this->request->all();
        $_SERVER = $this->server->all();
        $_COOKIE = $this->cookies->all();

        foreach ($this->headers->all() as $key => $value) {
            $key = strtoupper(str_replace('-', '_', $key));
            if (in_array($key, array('CONTENT_TYPE', 'CONTENT_LENGTH'))) {
                $_SERVER[$key] = implode(', ', $value);
            } else {
                $_SERVER['HTTP_'.$key] = implode(', ', $value);
            }
        }

        $request = array('g' => $_GET, 'p' => $_POST, 'c' => $_COOKIE);

        $requestOrder = ini_get('request_order') ?: ini_get('variable_order');
        $requestOrder = preg_replace('#[^cgp]#', '', strtolower($requestOrder)) ?: 'gp';

        $_REQUEST = array();
        foreach (str_split($requestOrder) as $order) {
            $_REQUEST = array_merge($_REQUEST, $request[$order]);
        }
    }

    /**
     * Sets a list of trusted proxies.
     *
     * You should only list the reverse proxies that you manage directly.
     *
     * @param array $proxies A list of trusted proxies
     *
     * @api
     */
    public static function setTrustedProxies(array $proxies)
    {
        self::$trustedProxies = $proxies;
        self::$trustProxy = $proxies ? true : false;
    }

    /**
     * Gets the list of trusted proxies.
     *
     * @return array An array of trusted proxies.
     */
    public static function getTrustedProxies()
    {
        return self::$trustedProxies;
    }

    /**
     * Sets the name for trusted headers.
     *
     * The following header keys are supported:
     *
     *  * Request::HEADER_CLIENT_IP:    defaults to X-Forwarded-For   (see getClientIp())
     *  * Request::HEADER_CLIENT_HOST:  defaults to X-Forwarded-Host  (see getClientHost())
     *  * Request::HEADER_CLIENT_PORT:  defaults to X-Forwarded-Port  (see getClientPort())
     *  * Request::HEADER_CLIENT_PROTO: defaults to X-Forwarded-Proto (see getScheme() and isSecure())
     *
     * Setting an empty value allows to disable the trusted header for the given key.
     *
     * @param string $key   The header key
     * @param string $value The header name
     *
     * @throws \InvalidArgumentException
     */
    public static function setTrustedHeaderName($key, $value)
    {
        if (!array_key_exists($key, self::$trustedHeaders)) {
            throw new \InvalidArgumentException(sprintf('Unable to set the trusted header name for key "%s".', $key));
        }

        self::$trustedHeaders[$key] = $value;
    }

    /**
     * Normalizes a query string.
     *
     * It builds a normalized query string, where keys/value pairs are alphabetized,
     * have consistent escaping and unneeded delimiters are removed.
     *
     * @param string $qs Query string
     *
     * @return string A normalized query string for the Request
     */
    public static function normalizeQueryString($qs)
    {
        if ('' == $qs) {
            return '';
        }

        $parts = array();
        $order = array();

        foreach (explode('&', $qs) as $param) {
            if ('' === $param || '=' === $param[0]) {
                // Ignore useless delimiters, e.g. "x=y&".
                // Also ignore pairs with empty key, even if there was a value, e.g. "=value", as such nameless values cannot be retrieved anyway.
                // PHP also does not include them when building _GET.
                continue;
            }

            $keyValuePair = explode('=', $param, 2);

            // GET parameters, that are submitted from a HTML form, encode spaces as "+" by default (as defined in enctype application/x-www-form-urlencoded).
            // PHP also converts "+" to spaces when filling the global _GET or when using the function parse_str. This is why we use urldecode and then normalize to
            // RFC 3986 with rawurlencode.
            $parts[] = isset($keyValuePair[1]) ?
                rawurlencode(urldecode($keyValuePair[0])).'='.rawurlencode(urldecode($keyValuePair[1])) :
                rawurlencode(urldecode($keyValuePair[0]));
            $order[] = urldecode($keyValuePair[0]);
        }

        array_multisort($order, SORT_ASC, $parts);

        return implode('&', $parts);
    }

    /**
     * Enables support for the _method request parameter to determine the intended HTTP method.
     *
     * Be warned that enabling this feature might lead to CSRF issues in your code.
     * Check that you are using CSRF tokens when required.
     *
     * The HTTP method can only be overridden when the real HTTP method is POST.
     */
    public static function enableHttpMethodParameterOverride()
    {
        self::$httpMethodParameterOverride = true;
    }

    /**
     * Checks whether support for the _method request parameter is enabled.
     *
     * @return Boolean True when the _method request parameter is enabled, false otherwise
     */
    public static function getHttpMethodParameterOverride()
    {
        return self::$httpMethodParameterOverride;
    }

    /**
     * Gets a "parameter" value.
     *
     * This method is mainly useful for libraries that want to provide some flexibility.
     *
     * Order of precedence: GET, PATH, POST
     *
     * Avoid using this method in controllers:
     *
     *  * slow
     *  * prefer to get from a "named" source
     *
     * It is better to explicitly get request parameters from the appropriate
     * public property instead (query, attributes, request).
     *
     * @param string  $key     the key
     * @param mixed   $default the default value
     * @param Boolean $deep    is parameter deep in multidimensional array
     *
     * @return mixed
     */
    public function get($key, $default = null, $deep = false)
    {
        return $this->query->get($key, $this->attributes->get($key, $this->request->get($key, $default, $deep), $deep), $deep);
    }

    /**
     * Gets the Session.
     *
     * @return SessionInterface|null The session
     *
     * @api
     */
    public function getSession()
    {
        return $this->session;
    }

    /**
     * Whether the request contains a Session which was started in one of the
     * previous requests.
     *
     * @return Boolean
     *
     * @api
     */
    public function hasPreviousSession()
    {
        // the check for $this->session avoids malicious users trying to fake a session cookie with proper name
        return $this->hasSession() && $this->cookies->has($this->session->getName());
    }

    /**
     * Whether the request contains a Session object.
     *
     * This method does not give any information about the state of the session object,
     * like whether the session is started or not. It is just a way to check if this Request
     * is associated with a Session instance.
     *
     * @return Boolean true when the Request contains a Session object, false otherwise
     *
     * @api
     */
    public function hasSession()
    {
        return null !== $this->session;
    }

    /**
     * Sets the Session.
     *
     * @param SessionInterface $session The Session
     *
     * @api
     */
    public function setSession(SessionInterface $session)
    {
        $this->session = $session;
    }

    /**
     * Returns the client IP address.
     *
     * This method can read the client IP address from the "X-Forwarded-For" header
     * when trusted proxies were set via "setTrustedProxies()". The "X-Forwarded-For"
     * header value is a comma+space separated list of IP addresses, the left-most
     * being the original client, and each successive proxy that passed the request
     * adding the IP address where it received the request from.
     *
     * If your reverse proxy uses a different header name than "X-Forwarded-For",
     * ("Client-Ip" for instance), configure it via "setTrustedHeaderName()" with
     * the "client-ip" key.
     *
     * @return string The client IP address
     *
     * @see http://en.wikipedia.org/wiki/X-Forwarded-For
     *
     * @api
     */
    public function getClientIp()
    {
        $ip = $this->server->get('REMOTE_ADDR');

        if (!self::$trustProxy) {
            return $ip;
        }

        if (!self::$trustedHeaders[self::HEADER_CLIENT_IP] || !$this->headers->has(self::$trustedHeaders[self::HEADER_CLIENT_IP])) {
            return $ip;
        }

        $clientIps = array_map('trim', explode(',', $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_IP])));
        $clientIps[] = $ip;

        $trustedProxies = self::$trustProxy && !self::$trustedProxies ? array($ip) : self::$trustedProxies;
        $clientIps = array_diff($clientIps, $trustedProxies);

        return array_pop($clientIps);
    }

    /**
     * Returns current script name.
     *
     * @return string
     *
     * @api
     */
    public function getScriptName()
    {
        return $this->server->get('SCRIPT_NAME', $this->server->get('ORIG_SCRIPT_NAME', ''));
    }

    /**
     * Returns the path being requested relative to the executed script.
     *
     * The path info always starts with a /.
     *
     * Suppose this request is instantiated from /mysite on localhost:
     *
     *  * http://localhost/mysite              returns an empty string
     *  * http://localhost/mysite/about        returns '/about'
     *  * http://localhost/mysite/enco%20ded   returns '/enco%20ded'
     *  * http://localhost/mysite/about?var=1  returns '/about'
     *
     * @return string The raw path (i.e. not urldecoded)
     *
     * @api
     */
    public function getPathInfo()
    {
        if (null === $this->pathInfo) {
            $this->pathInfo = $this->preparePathInfo();
        }

        return $this->pathInfo;
    }

    /**
     * Returns the root path from which this request is executed.
     *
     * Suppose that an index.php file instantiates this request object:
     *
     *  * http://localhost/index.php         returns an empty string
     *  * http://localhost/index.php/page    returns an empty string
     *  * http://localhost/web/index.php     returns '/web'
     *  * http://localhost/we%20b/index.php  returns '/we%20b'
     *
     * @return string The raw path (i.e. not urldecoded)
     *
     * @api
     */
    public function getBasePath()
    {
        if (null === $this->basePath) {
            $this->basePath = $this->prepareBasePath();
        }

        return $this->basePath;
    }

    /**
     * Returns the root url from which this request is executed.
     *
     * The base URL never ends with a /.
     *
     * This is similar to getBasePath(), except that it also includes the
     * script filename (e.g. index.php) if one exists.
     *
     * @return string The raw url (i.e. not urldecoded)
     *
     * @api
     */
    public function getBaseUrl()
    {
        if (null === $this->baseUrl) {
            $this->baseUrl = $this->prepareBaseUrl();
        }

        return $this->baseUrl;
    }

    /**
     * Gets the request's scheme.
     *
     * @return string
     *
     * @api
     */
    public function getScheme()
    {
        return $this->isSecure() ? 'https' : 'http';
    }

    /**
     * Returns the port on which the request is made.
     *
     * This method can read the client port from the "X-Forwarded-Port" header
     * when trusted proxies were set via "setTrustedProxies()".
     *
     * The "X-Forwarded-Port" header must contain the client port.
     *
     * If your reverse proxy uses a different header name than "X-Forwarded-Port",
     * configure it via "setTrustedHeaderName()" with the "client-port" key.
     *
     * @return string
     *
     * @api
     */
    public function getPort()
    {
        if (self::$trustProxy && self::$trustedHeaders[self::HEADER_CLIENT_PORT] && $port = $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_PORT])) {
            return $port;
        }

        return $this->server->get('SERVER_PORT');
    }

    /**
     * Returns the user.
     *
     * @return string|null
     */
    public function getUser()
    {
        return $this->server->get('PHP_AUTH_USER');
    }

    /**
     * Returns the password.
     *
     * @return string|null
     */
    public function getPassword()
    {
        return $this->server->get('PHP_AUTH_PW');
    }

    /**
     * Gets the user info.
     *
     * @return string A user name and, optionally, scheme-specific information about how to gain authorization to access the server
     */
    public function getUserInfo()
    {
        $userinfo = $this->getUser();

        $pass = $this->getPassword();
        if ('' != $pass) {
           $userinfo .= ":$pass";
        }

        return $userinfo;
    }

    /**
     * Returns the HTTP host being requested.
     *
     * The port name will be appended to the host if it's non-standard.
     *
     * @return string
     *
     * @api
     */
    public function getHttpHost()
    {
        $scheme = $this->getScheme();
        $port   = $this->getPort();

        if (('http' == $scheme && $port == 80) || ('https' == $scheme && $port == 443)) {
            return $this->getHost();
        }

        return $this->getHost().':'.$port;
    }

    /**
     * Returns the requested URI.
     *
     * @return string The raw URI (i.e. not urldecoded)
     *
     * @api
     */
    public function getRequestUri()
    {
        if (null === $this->requestUri) {
            $this->requestUri = $this->prepareRequestUri();
        }

        return $this->requestUri;
    }

    /**
     * Gets the scheme and HTTP host.
     *
     * If the URL was called with basic authentication, the user
     * and the password are not added to the generated string.
     *
     * @return string The scheme and HTTP host
     */
    public function getSchemeAndHttpHost()
    {
        return $this->getScheme().'://'.$this->getHttpHost();
    }

    /**
     * Generates a normalized URI for the Request.
     *
     * @return string A normalized URI for the Request
     *
     * @see getQueryString()
     *
     * @api
     */
    public function getUri()
    {
        if (null !== $qs = $this->getQueryString()) {
            $qs = '?'.$qs;
        }

        return $this->getSchemeAndHttpHost().$this->getBaseUrl().$this->getPathInfo().$qs;
    }

    /**
     * Generates a normalized URI for the given path.
     *
     * @param string $path A path to use instead of the current one
     *
     * @return string The normalized URI for the path
     *
     * @api
     */
    public function getUriForPath($path)
    {
        return $this->getSchemeAndHttpHost().$this->getBaseUrl().$path;
    }

    /**
     * Generates the normalized query string for the Request.
     *
     * It builds a normalized query string, where keys/value pairs are alphabetized
     * and have consistent escaping.
     *
     * @return string|null A normalized query string for the Request
     *
     * @api
     */
    public function getQueryString()
    {
        $qs = static::normalizeQueryString($this->server->get('QUERY_STRING'));

        return '' === $qs ? null : $qs;
    }

    /**
     * Checks whether the request is secure or not.
     *
     * This method can read the client port from the "X-Forwarded-Proto" header
     * when trusted proxies were set via "setTrustedProxies()".
     *
     * The "X-Forwarded-Proto" header must contain the protocol: "https" or "http".
     *
     * If your reverse proxy uses a different header name than "X-Forwarded-Proto"
     * ("SSL_HTTPS" for instance), configure it via "setTrustedHeaderName()" with
     * the "client-proto" key.
     *
     * @return Boolean
     *
     * @api
     */
    public function isSecure()
    {
        if (self::$trustProxy && self::$trustedHeaders[self::HEADER_CLIENT_PROTO] && $proto = $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_PROTO])) {
            return in_array(strtolower($proto), array('https', 'on', '1'));
        }

        return 'on' == strtolower($this->server->get('HTTPS')) || 1 == $this->server->get('HTTPS');
    }

    /**
     * Returns the host name.
     *
     * This method can read the client port from the "X-Forwarded-Host" header
     * when trusted proxies were set via "setTrustedProxies()".
     *
     * The "X-Forwarded-Host" header must contain the client host name.
     *
     * If your reverse proxy uses a different header name than "X-Forwarded-Host",
     * configure it via "setTrustedHeaderName()" with the "client-host" key.
     *
     * @return string
     *
     * @throws \UnexpectedValueException when the host name is invalid
     *
     * @api
     */
    public function getHost()
    {
        if (self::$trustProxy && self::$trustedHeaders[self::HEADER_CLIENT_HOST] && $host = $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_HOST])) {
            $elements = explode(',', $host);

            $host = $elements[count($elements) - 1];
        } elseif (!$host = $this->headers->get('HOST')) {
            if (!$host = $this->server->get('SERVER_NAME')) {
                $host = $this->server->get('SERVER_ADDR', '');
            }
        }

        // trim and remove port number from host
        // host is lowercase as per RFC 952/2181
        $host = strtolower(preg_replace('/:\d+$/', '', trim($host)));

        // as the host can come from the user (HTTP_HOST and depending on the configuration, SERVER_NAME too can come from the user)
        // check that it does not contain forbidden characters (see RFC 952 and RFC 2181)
        if ($host && !preg_match('/^\[?(?:[a-zA-Z0-9-:\]_]+\.?)+$/', $host)) {
            throw new \UnexpectedValueException('Invalid Host');
        }

        return $host;
    }

    /**
     * Sets the request method.
     *
     * @param string $method
     *
     * @api
     */
    public function setMethod($method)
    {
        $this->method = null;
        $this->server->set('REQUEST_METHOD', $method);
    }

    /**
     * Gets the request "intended" method.
     *
     * If the X-HTTP-Method-Override header is set, and if the method is a POST,
     * then it is used to determine the "real" intended HTTP method.
     *
     * The _method request parameter can also be used to determine the HTTP method,
     * but only if enableHttpMethodParameterOverride() has been called.
     *
     * The method is always an uppercased string.
     *
     * @return string The request method
     *
     * @api
     *
     * @see getRealMethod
     */
    public function getMethod()
    {
        if (null === $this->method) {
            $this->method = strtoupper($this->server->get('REQUEST_METHOD', 'GET'));

            if ('POST' === $this->method) {
                if ($method = $this->headers->get('X-HTTP-METHOD-OVERRIDE')) {
                    $this->method = strtoupper($method);
                } elseif (self::$httpMethodParameterOverride) {
                    $this->method = strtoupper($this->request->get('_method', $this->query->get('_method', 'POST')));
                }
            }
        }

        return $this->method;
    }

    /**
     * Gets the "real" request method.
     *
     * @return string The request method
     *
     * @see getMethod
     */
    public function getRealMethod()
    {
        return strtoupper($this->server->get('REQUEST_METHOD', 'GET'));
    }

    /**
     * Gets the mime type associated with the format.
     *
     * @param string $format The format
     *
     * @return string The associated mime type (null if not found)
     *
     * @api
     */
    public function getMimeType($format)
    {
        if (null === static::$formats) {
            static::initializeFormats();
        }

        return isset(static::$formats[$format]) ? static::$formats[$format][0] : null;
    }

    /**
     * Gets the format associated with the mime type.
     *
     * @param string $mimeType The associated mime type
     *
     * @return string|null The format (null if not found)
     *
     * @api
     */
    public function getFormat($mimeType)
    {
        if (false !== $pos = strpos($mimeType, ';')) {
            $mimeType = substr($mimeType, 0, $pos);
        }

        if (null === static::$formats) {
            static::initializeFormats();
        }

        foreach (static::$formats as $format => $mimeTypes) {
            if (in_array($mimeType, (array) $mimeTypes)) {
                return $format;
            }
        }

        return null;
    }

    /**
     * Associates a format with mime types.
     *
     * @param string       $format    The format
     * @param string|array $mimeTypes The associated mime types (the preferred one must be the first as it will be used as the content type)
     *
     * @api
     */
    public function setFormat($format, $mimeTypes)
    {
        if (null === static::$formats) {
            static::initializeFormats();
        }

        static::$formats[$format] = is_array($mimeTypes) ? $mimeTypes : array($mimeTypes);
    }

    /**
     * Gets the request format.
     *
     * Here is the process to determine the format:
     *
     *  * format defined by the user (with setRequestFormat())
     *  * _format request parameter
     *  * $default
     *
     * @param string $default The default format
     *
     * @return string The request format
     *
     * @api
     */
    public function getRequestFormat($default = 'html')
    {
        if (null === $this->format) {
            $this->format = $this->get('_format', $default);
        }

        return $this->format;
    }

    /**
     * Sets the request format.
     *
     * @param string $format The request format.
     *
     * @api
     */
    public function setRequestFormat($format)
    {
        $this->format = $format;
    }

    /**
     * Gets the format associated with the request.
     *
     * @return string|null The format (null if no content type is present)
     *
     * @api
     */
    public function getContentType()
    {
        return $this->getFormat($this->headers->get('CONTENT_TYPE'));
    }

    /**
     * Sets the default locale.
     *
     * @param string $locale
     *
     * @api
     */
    public function setDefaultLocale($locale)
    {
        $this->defaultLocale = $locale;

        if (null === $this->locale) {
            $this->setPhpDefaultLocale($locale);
        }
    }

    /**
     * Sets the locale.
     *
     * @param string $locale
     *
     * @api
     */
    public function setLocale($locale)
    {
        $this->setPhpDefaultLocale($this->locale = $locale);
    }

    /**
     * Get the locale.
     *
     * @return string
     */
    public function getLocale()
    {
        return null === $this->locale ? $this->defaultLocale : $this->locale;
    }

    /**
     * Checks if the request method is of specified type.
     *
     * @param string $method Uppercase request method (GET, POST etc).
     *
     * @return Boolean
     */
    public function isMethod($method)
    {
        return $this->getMethod() === strtoupper($method);
    }

    /**
     * Checks whether the method is safe or not.
     *
     * @return Boolean
     *
     * @api
     */
    public function isMethodSafe()
    {
        return in_array($this->getMethod(), array('GET', 'HEAD'));
    }

    /**
     * Returns the request body content.
     *
     * @param Boolean $asResource If true, a resource will be returned
     *
     * @return string|resource The request body content or a resource to read the body stream.
     *
     * @throws \LogicException
     */
    public function getContent($asResource = false)
    {
        if (false === $this->content || (true === $asResource && null !== $this->content)) {
            throw new \LogicException('getContent() can only be called once when using the resource return type.');
        }

        if (true === $asResource) {
            $this->content = false;

            return fopen('php://input', 'rb');
        }

        if (null === $this->content) {
            $this->content = file_get_contents('php://input');
        }

        return $this->content;
    }

    /**
     * Gets the Etags.
     *
     * @return array The entity tags
     */
    public function getETags()
    {
        return preg_split('/\s*,\s*/', $this->headers->get('if_none_match'), null, PREG_SPLIT_NO_EMPTY);
    }

    /**
     * @return Boolean
     */
    public function isNoCache()
    {
        return $this->headers->hasCacheControlDirective('no-cache') || 'no-cache' == $this->headers->get('Pragma');
    }

    /**
     * Returns the preferred language.
     *
     * @param array $locales An array of ordered available locales
     *
     * @return string|null The preferred locale
     *
     * @api
     */
    public function getPreferredLanguage(array $locales = null)
    {
        $preferredLanguages = $this->getLanguages();

        if (empty($locales)) {
            return isset($preferredLanguages[0]) ? $preferredLanguages[0] : null;
        }

        if (!$preferredLanguages) {
            return $locales[0];
        }

        $extendedPreferredLanguages = array();
        foreach ($preferredLanguages as $language) {
            $extendedPreferredLanguages[] = $language;
            if (false !== $position = strpos($language, '_')) {
                $superLanguage = substr($language, 0, $position);
                if (!in_array($superLanguage, $preferredLanguages)) {
                    $extendedPreferredLanguages[] = $superLanguage;
                }
            }
        }

        $preferredLanguages = array_values(array_intersect($extendedPreferredLanguages, $locales));

        return isset($preferredLanguages[0]) ? $preferredLanguages[0] : $locales[0];
    }

    /**
     * Gets a list of languages acceptable by the client browser.
     *
     * @return array Languages ordered in the user browser preferences
     *
     * @api
     */
    public function getLanguages()
    {
        if (null !== $this->languages) {
            return $this->languages;
        }

        $languages = AcceptHeader::fromString($this->headers->get('Accept-Language'))->all();
        $this->languages = array();
        foreach (array_keys($languages) as $lang) {
            if (strstr($lang, '-')) {
                $codes = explode('-', $lang);
                if ($codes[0] == 'i') {
                    // Language not listed in ISO 639 that are not variants
                    // of any listed language, which can be registered with the
                    // i-prefix, such as i-cherokee
                    if (count($codes) > 1) {
                        $lang = $codes[1];
                    }
                } else {
                    for ($i = 0, $max = count($codes); $i < $max; $i++) {
                        if ($i == 0) {
                            $lang = strtolower($codes[0]);
                        } else {
                            $lang .= '_'.strtoupper($codes[$i]);
                        }
                    }
                }
            }

            $this->languages[] = $lang;
        }

        return $this->languages;
    }

    /**
     * Gets a list of charsets acceptable by the client browser.
     *
     * @return array List of charsets in preferable order
     *
     * @api
     */
    public function getCharsets()
    {
        if (null !== $this->charsets) {
            return $this->charsets;
        }

        return $this->charsets = array_keys(AcceptHeader::fromString($this->headers->get('Accept-Charset'))->all());
    }

    /**
     * Gets a list of content types acceptable by the client browser
     *
     * @return array List of content types in preferable order
     *
     * @api
     */
    public function getAcceptableContentTypes()
    {
        if (null !== $this->acceptableContentTypes) {
            return $this->acceptableContentTypes;
        }

        return $this->acceptableContentTypes = array_keys(AcceptHeader::fromString($this->headers->get('Accept'))->all());
    }

    /**
     * Returns true if the request is a XMLHttpRequest.
     *
     * It works if your JavaScript library set an X-Requested-With HTTP header.
     * It is known to work with common JavaScript frameworks:
     * @link http://en.wikipedia.org/wiki/List_of_Ajax_frameworks#JavaScript
     *
     * @return Boolean true if the request is an XMLHttpRequest, false otherwise
     *
     * @api
     */
    public function isXmlHttpRequest()
    {
        return 'XMLHttpRequest' == $this->headers->get('X-Requested-With');
    }

    /*
     * The following methods are derived from code of the Zend Framework (1.10dev - 2010-01-24)
     *
     * Code subject to the new BSD license (http://framework.zend.com/license/new-bsd).
     *
     * Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
     */

    protected function prepareRequestUri()
    {
        $requestUri = '';

        if ($this->headers->has('X_ORIGINAL_URL') && false !== stripos(PHP_OS, 'WIN')) {
            // IIS with Microsoft Rewrite Module
            $requestUri = $this->headers->get('X_ORIGINAL_URL');
            $this->headers->remove('X_ORIGINAL_URL');
        } elseif ($this->headers->has('X_REWRITE_URL') && false !== stripos(PHP_OS, 'WIN')) {
            // IIS with ISAPI_Rewrite
            $requestUri = $this->headers->get('X_REWRITE_URL');
            $this->headers->remove('X_REWRITE_URL');
        } elseif ($this->server->get('IIS_WasUrlRewritten') == '1' && $this->server->get('UNENCODED_URL') != '') {
            // IIS7 with URL Rewrite: make sure we get the unencoded url (double slash problem)
            $requestUri = $this->server->get('UNENCODED_URL');
            $this->server->remove('UNENCODED_URL');
            $this->server->remove('IIS_WasUrlRewritten');
        } elseif ($this->server->has('REQUEST_URI')) {
            $requestUri = $this->server->get('REQUEST_URI');
            // HTTP proxy reqs setup request uri with scheme and host [and port] + the url path, only use url path
            $schemeAndHttpHost = $this->getSchemeAndHttpHost();
            if (strpos($requestUri, $schemeAndHttpHost) === 0) {
                $requestUri = substr($requestUri, strlen($schemeAndHttpHost));
            }
        } elseif ($this->server->has('ORIG_PATH_INFO')) {
            // IIS 5.0, PHP as CGI
            $requestUri = $this->server->get('ORIG_PATH_INFO');
            if ('' != $this->server->get('QUERY_STRING')) {
                $requestUri .= '?'.$this->server->get('QUERY_STRING');
            }
            $this->server->remove('ORIG_PATH_INFO');
        }

        // normalize the request URI to ease creating sub-requests from this request
        $this->server->set('REQUEST_URI', $requestUri);

        return $requestUri;
    }

    /**
     * Prepares the base URL.
     *
     * @return string
     */
    protected function prepareBaseUrl()
    {
        $filename = basename($this->server->get('SCRIPT_FILENAME'));

        if (basename($this->server->get('SCRIPT_NAME')) === $filename) {
            $baseUrl = $this->server->get('SCRIPT_NAME');
        } elseif (basename($this->server->get('PHP_SELF')) === $filename) {
            $baseUrl = $this->server->get('PHP_SELF');
        } elseif (basename($this->server->get('ORIG_SCRIPT_NAME')) === $filename) {
            $baseUrl = $this->server->get('ORIG_SCRIPT_NAME'); // 1and1 shared hosting compatibility
        } else {
            // Backtrack up the script_filename to find the portion matching
            // php_self
            $path    = $this->server->get('PHP_SELF', '');
            $file    = $this->server->get('SCRIPT_FILENAME', '');
            $segs    = explode('/', trim($file, '/'));
            $segs    = array_reverse($segs);
            $index   = 0;
            $last    = count($segs);
            $baseUrl = '';
            do {
                $seg     = $segs[$index];
                $baseUrl = '/'.$seg.$baseUrl;
                ++$index;
            } while (($last > $index) && (false !== ($pos = strpos($path, $baseUrl))) && (0 != $pos));
        }

        // Does the baseUrl have anything in common with the request_uri?
        $requestUri = $this->getRequestUri();

        if ($baseUrl && false !== $prefix = $this->getUrlencodedPrefix($requestUri, $baseUrl)) {
            // full $baseUrl matches
            return $prefix;
        }

        if ($baseUrl && false !== $prefix = $this->getUrlencodedPrefix($requestUri, dirname($baseUrl))) {
            // directory portion of $baseUrl matches
            return rtrim($prefix, '/');
        }

        $truncatedRequestUri = $requestUri;
        if (($pos = strpos($requestUri, '?')) !== false) {
            $truncatedRequestUri = substr($requestUri, 0, $pos);
        }

        $basename = basename($baseUrl);
        if (empty($basename) || !strpos(rawurldecode($truncatedRequestUri), $basename)) {
            // no match whatsoever; set it blank
            return '';
        }

        // If using mod_rewrite or ISAPI_Rewrite strip the script filename
        // out of baseUrl. $pos !== 0 makes sure it is not matching a value
        // from PATH_INFO or QUERY_STRING
        if ((strlen($requestUri) >= strlen($baseUrl)) && ((false !== ($pos = strpos($requestUri, $baseUrl))) && ($pos !== 0))) {
            $baseUrl = substr($requestUri, 0, $pos + strlen($baseUrl));
        }

        return rtrim($baseUrl, '/');
    }

    /**
     * Prepares the base path.
     *
     * @return string base path
     */
    protected function prepareBasePath()
    {
        $filename = basename($this->server->get('SCRIPT_FILENAME'));
        $baseUrl = $this->getBaseUrl();
        if (empty($baseUrl)) {
            return '';
        }

        if (basename($baseUrl) === $filename) {
            $basePath = dirname($baseUrl);
        } else {
            $basePath = $baseUrl;
        }

        if ('\\' === DIRECTORY_SEPARATOR) {
            $basePath = str_replace('\\', '/', $basePath);
        }

        return rtrim($basePath, '/');
    }

    /**
     * Prepares the path info.
     *
     * @return string path info
     */
    protected function preparePathInfo()
    {
        $baseUrl = $this->getBaseUrl();

        if (null === ($requestUri = $this->getRequestUri())) {
            return '/';
        }

        $pathInfo = '/';

        // Remove the query string from REQUEST_URI
        if ($pos = strpos($requestUri, '?')) {
            $requestUri = substr($requestUri, 0, $pos);
        }

        if ((null !== $baseUrl) && (false === ($pathInfo = substr($requestUri, strlen($baseUrl))))) {
            // If substr() returns false then PATH_INFO is set to an empty string
            return '/';
        } elseif (null === $baseUrl) {
            return $requestUri;
        }

        return (string) $pathInfo;
    }

    /**
     * Initializes HTTP request formats.
     */
    protected static function initializeFormats()
    {
        static::$formats = array(
            'html' => array('text/html', 'application/xhtml+xml'),
            'txt'  => array('text/plain'),
            'js'   => array('application/javascript', 'application/x-javascript', 'text/javascript'),
            'css'  => array('text/css'),
            'json' => array('application/json', 'application/x-json'),
            'xml'  => array('text/xml', 'application/xml', 'application/x-xml'),
            'rdf'  => array('application/rdf+xml'),
            'atom' => array('application/atom+xml'),
            'rss'  => array('application/rss+xml'),
        );
    }

    /**
     * Sets the default PHP locale.
     *
     * @param string $locale
     */
    private function setPhpDefaultLocale($locale)
    {
        // if either the class Locale doesn't exist, or an exception is thrown when
        // setting the default locale, the intl module is not installed, and
        // the call can be ignored:
        try {
            if (class_exists('Locale', false)) {
                \Locale::setDefault($locale);
            }
        } catch (\Exception $e) {
        }
    }

    /*
     * Returns the prefix as encoded in the string when the string starts with
     * the given prefix, false otherwise.
     *
     * @param string $string The urlencoded string
     * @param string $prefix The prefix not encoded
     *
     * @return string|false The prefix as it is encoded in $string, or false
     */
    private function getUrlencodedPrefix($string, $prefix)
    {
        if (0 !== strpos(rawurldecode($string), $prefix)) {
            return false;
        }

        $len = strlen($prefix);

        if (preg_match("#^(%[[:xdigit:]]{2}|.){{$len}}#", $string, $match)) {
            return $match[0];
        }

        return false;
    }
}