/**
  * CentralAuthSilentLoginRedirect hook handler
  * Points redirects from CentralAuth wiki to mobile domain if user has logged in from it
  * @see SpecialCentralLogin in CentralAuth extension
  * @param CentralAuthUser $centralUser
  * @param string $url to redirect to
  * @param array $info token information
  *
  * @return bool
  */
 public static function onCentralAuthSilentLoginRedirect($centralUser, &$url, $info)
 {
     if (isset($info['mobileServer'])) {
         $mobileUrlParsed = wfParseUrl($info['mobileServer']);
         $urlParsed = wfParseUrl($url);
         $urlParsed['host'] = $mobileUrlParsed['host'];
         $url = wfAssembleUrl($urlParsed);
     }
     return true;
 }

/**
 * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 * is correct.
 *
 * The meaning of the PROTO_* constants is as follows:
 * PROTO_HTTP: Output a URL starting with http://
 * PROTO_HTTPS: Output a URL starting with https://
 * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 *    on which protocol was used for the current incoming request
 * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 *
 * @todo this won't work with current-path-relative URLs
 * like "subdir/foo.html", etc.
 *
 * @param string $url Either fully-qualified or a local path + query
 * @param string $defaultProto One of the PROTO_* constants. Determines the
 *    protocol to use if $url or $wgServer is protocol-relative
 * @return string Fully-qualified URL, current-path-relative URL or false if
 *    no valid URL can be constructed
 */
function wfExpandUrl($url, $defaultProto = PROTO_CURRENT)
{
    global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest, $wgHttpsPort;
    if ($defaultProto === PROTO_CANONICAL) {
        $serverUrl = $wgCanonicalServer;
    } elseif ($defaultProto === PROTO_INTERNAL && $wgInternalServer !== false) {
        // Make $wgInternalServer fall back to $wgServer if not set
        $serverUrl = $wgInternalServer;
    } else {
        $serverUrl = $wgServer;
        if ($defaultProto === PROTO_CURRENT) {
            $defaultProto = $wgRequest->getProtocol() . '://';
        }
    }
    // Analyze $serverUrl to obtain its protocol
    $bits = wfParseUrl($serverUrl);
    $serverHasProto = $bits && $bits['scheme'] != '';
    if ($defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL) {
        if ($serverHasProto) {
            $defaultProto = $bits['scheme'] . '://';
        } else {
            // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
            // This really isn't supposed to happen. Fall back to HTTP in this
            // ridiculous case.
            $defaultProto = PROTO_HTTP;
        }
    }
    $defaultProtoWithoutSlashes = substr($defaultProto, 0, -2);
    if (substr($url, 0, 2) == '//') {
        $url = $defaultProtoWithoutSlashes . $url;
    } elseif (substr($url, 0, 1) == '/') {
        // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
        // otherwise leave it alone.
        $url = ($serverHasProto ? '' : $defaultProtoWithoutSlashes) . $serverUrl . $url;
    }
    $bits = wfParseUrl($url);
    // ensure proper port for HTTPS arrives in URL
    // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
    if ($defaultProto === PROTO_HTTPS && $wgHttpsPort != 443) {
        $bits['port'] = $wgHttpsPort;
    }
    if ($bits && isset($bits['path'])) {
        $bits['path'] = wfRemoveDotSegments($bits['path']);
        return wfAssembleUrl($bits);
    } elseif ($bits) {
        # No path to expand
        return $url;
    } elseif (substr($url, 0, 1) != '/') {
        # URL is a relative path
        return wfRemoveDotSegments($url);
    }
    # Expanded URL is not valid.
    return false;
}

 /**
  * @dataProvider provideURLParts
  */
 public function testWfAssembleUrl($parts, $output)
 {
     $partsDump = print_r($parts, true);
     $this->assertEquals($output, wfAssembleUrl($parts), "Testing {$partsDump} assembles to {$output}");
 }

/**
 * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 * is correct.
 *
 * The meaning of the PROTO_* constants is as follows:
 * PROTO_HTTP: Output a URL starting with http://
 * PROTO_HTTPS: Output a URL starting with https://
 * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 *
 * @todo this won't work with current-path-relative URLs
 * like "subdir/foo.html", etc.
 *
 * @param $url String: either fully-qualified or a local path + query
 * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 *                             protocol to use if $url or $wgServer is
 *                             protocol-relative
 * @return string Fully-qualified URL, current-path-relative URL or false if
 *                no valid URL can be constructed
 */
function wfExpandUrl($url, $defaultProto = PROTO_CURRENT)
{
    global $wgServer, $wgCanonicalServer, $wgInternalServer;
    $serverUrl = $wgServer;
    if ($defaultProto === PROTO_CANONICAL) {
        $serverUrl = $wgCanonicalServer;
    }
    // Make $wgInternalServer fall back to $wgServer if not set
    if ($defaultProto === PROTO_INTERNAL && $wgInternalServer !== false) {
        $serverUrl = $wgInternalServer;
    }
    if ($defaultProto === PROTO_CURRENT) {
        $defaultProto = WebRequest::detectProtocol() . '://';
    }
    // Analyze $serverUrl to obtain its protocol
    $bits = wfParseUrl($serverUrl);
    $serverHasProto = $bits && $bits['scheme'] != '';
    if ($defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL) {
        if ($serverHasProto) {
            $defaultProto = $bits['scheme'] . '://';
        } else {
            // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
            // Fall back to HTTP in this ridiculous case
            $defaultProto = PROTO_HTTP;
        }
    }
    $defaultProtoWithoutSlashes = substr($defaultProto, 0, -2);
    if (substr($url, 0, 2) == '//') {
        $url = $defaultProtoWithoutSlashes . $url;
    } elseif (substr($url, 0, 1) == '/') {
        // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
        $url = ($serverHasProto ? '' : $defaultProtoWithoutSlashes) . $serverUrl . $url;
    }
    $bits = wfParseUrl($url);
    if ($bits && isset($bits['path'])) {
        $bits['path'] = wfRemoveDotSegments($bits['path']);
        return wfAssembleUrl($bits);
    } elseif ($bits) {
        # No path to expand
        return $url;
    } elseif (substr($url, 0, 1) != '/') {
        # URL is a relative path
        return wfRemoveDotSegments($url);
    }
    # Expanded URL is not valid.
    return false;
}

 /**
  * Take a URL and return a copy that removes any mobile tokens
  * @param string $url
  * @return string
  */
 public function getDesktopUrl($url)
 {
     $parsedUrl = wfParseUrl($url);
     $this->updateDesktopUrlHost($parsedUrl);
     $this->updateDesktopUrlQuery($parsedUrl);
     $desktopUrl = wfAssembleUrl($parsedUrl);
     return $desktopUrl;
 }

 public function testUpdateMobileUrlPath()
 {
     $this->setMwGlobals(array('wgScriptPath' => '/wiki', 'wgMobileUrlTemplate' => "/mobile/%p"));
     $updateMobileUrlHost = self::getMethod("updateMobileUrlPath");
     // check for constructing a templated URL
     $parsedUrl = wfParseUrl("http://en.wikipedia.org/wiki/Gustavus_Airport");
     $updateMobileUrlHost->invokeArgs($this->makeContext(), array(&$parsedUrl));
     $this->assertEquals("http://en.wikipedia.org/wiki/mobile/Gustavus_Airport", wfAssembleUrl($parsedUrl));
     // check for maintaining an already templated URL
     $parsedUrl = wfParseUrl("http://en.wikipedia.org/wiki/mobile/Gustavus_Airport");
     $updateMobileUrlHost->invokeArgs($this->makeContext(), array(&$parsedUrl));
     $this->assertEquals("http://en.wikipedia.org/wiki/mobile/Gustavus_Airport", wfAssembleUrl($parsedUrl));
 }