<?php
/*
 *  sac-a-push - Obj/transports.phh
 *
 *  Copyright (C) 2012 Matteo Nastasi
 *                          mailto: nastasi@alternativeoutput.it 
 *                                  matteo.nastasi@milug.org
 *                          web: http://www.alternativeoutput.it
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABLILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details. You should have received a
 * copy of the GNU General Public License along with this program; if
 * not, write to the Free Software Foundation, Inc, 59 Temple Place -
 * Suite 330, Boston, MA 02111-1307, USA.
 *
 */

/*
 *  test: SO x Browser
 *  Values: Y: works, N: not works, @: continuous download,
 *          D: continuous download after first reload
 *
 *  Stream IFRAME:
 *
 * Iframe| IW | FF | Ch | Op | Ko | IE
 * ------+----+----+----+----+----+----
 *   Lnx | D  |    | @  |    | @  | x
 *   Win | x  | D  | @  | @  |    | D
 *   Mac | x  |    |    |    |    |
 *
 *
 *   XHR | IW | FF | Ch | Op | Ko | IE
 * ------+----+----+----+----+----+----
 *   Lnx | Y  |    | ^D |    | Y  | x
 *   Win | x  | Y  | Y  |    |    | N
 *   Mac | x  |    |    |    |    |
 *
 *
 * HtmlFl| IW | FF | Ch | Op | Ko | IE
 * ------+----+----+----+----+----+----
 *   Lnx | N  |    |    |    | N  |
 *   Win | x  | N  | N  |    |    | Y* (* seems delay between click and load of a new page)
 *   Mac | x  |    |    |    |    |
 *
 *
 */


class Transport_template {

    function Transport_template() {
    }

    // return string value is appended to the content of the returned page
    function init($enc, $header, &$header_out, $init_string, $base, $step)
    {
    }

    static function fini($init_string, $base, $blockerr)
    {
    }

    function chunk($step, $cont)
    {
    }

    function is_chunked()
    {
    }
}

class Transport_websocket {
    $magicGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

    function Transport_websocket() {
    }

    protected function doHandshake($user, $buffer) {
        $magicGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
        $headers = array();
        $lines = explode("\n",$buffer);
        foreach ($lines as $line) {
            if (strpos($line,":") !== false) {
                $header = explode(":",$line,2);
                $headers[strtolower(trim($header[0]))] = trim($header[1]);
            } else if (stripos($line,"get ") !== false) {
                preg_match("/GET (.*) HTTP/i", $buffer, $reqResource);
                $headers['get'] = trim($reqResource[1]);
            }
        }
        if (isset($headers['get'])) {
            $user->requestedResource = $headers['get'];
        } else {
            // todo: fail the connection
            $handshakeResponse = "HTTP/1.1 405 Method Not Allowed\r\n\r\n";			
        }
        if (!isset($headers['host']) || !$this->checkHost($headers['host'])) {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        }
        if (!isset($headers['upgrade']) || strtolower($headers['upgrade']) != 'websocket') {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        } 
        if (!isset($headers['connection']) || strpos(strtolower($headers['connection']), 'upgrade') === FALSE) {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        }
        if (!isset($headers['sec-websocket-key'])) {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        } else {
            
        }
        if (!isset($headers['sec-websocket-version']) || strtolower($headers['sec-websocket-version']) != 13) {
            $handshakeResponse = "HTTP/1.1 426 Upgrade Required\r\nSec-WebSocketVersion: 13";
        }
        if (($this->headerOriginRequired && !isset($headers['origin']) ) || ($this->headerOriginRequired && !$this->checkOrigin($headers['origin']))) {
            $handshakeResponse = "HTTP/1.1 403 Forbidden";
        }
        if (($this->headerSecWebSocketProtocolRequired && !isset($headers['sec-websocket-protocol'])) || ($this->headerSecWebSocketProtocolRequired && !$this->checkWebsocProtocol($header['sec-websocket-protocol']))) {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        }
        if (($this->headerSecWebSocketExtensionsRequired && !isset($headers['sec-websocket-extensions'])) || ($this->headerSecWebSocketExtensionsRequired && !$this->checkWebsocExtensions($header['sec-websocket-extensions']))) {
            $handshakeResponse = "HTTP/1.1 400 Bad Request";
        }
        
        // Done verifying the _required_ headers and optionally required headers.
        
        if (isset($handshakeResponse)) {
            socket_write($user->socket,$handshakeResponse,strlen($handshakeResponse));
            $this->disconnect($user->socket);
            return false;
        }
        
        $user->headers = $headers;
        $user->handshake = $buffer;
        
        $webSocketKeyHash = sha1($headers['sec-websocket-key'] . $magicGUID);
        
        $rawToken = "";
        for ($i = 0; $i < 20; $i++) {
            $rawToken .= chr(hexdec(substr($webSocketKeyHash,$i*2, 2)));
        }
        $handshakeToken = base64_encode($rawToken) . "\r\n";
        
        $subProtocol = (isset($headers['sec-websocket-protocol'])) ? $this->processProtocol($headers['sec-websocket-protocol']) : "";
        $extensions = (isset($headers['sec-websocket-extensions'])) ? $this->processExtensions($headers['sec-websocket-extensions']) : "";
        
        $handshakeResponse = "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: $handshakeToken$subProtocol$extensions\r\n";
        socket_write($user->socket,$handshakeResponse,strlen($handshakeResponse));
        $this->connected($user);
    }
    

    function init($enc, $header, &$header_out, $init_string, $base, $step)
    {
        

        $ret = sprintf("@BEGIN@ /* %s */ @END@", $init_string);
        if ($enc != 'plain')
            $header_out['Content-Encoding'] = $enc;
        $header_out['Cache-Control'] = 'no-cache, must-revalidate';     // HTTP/1.1
        $header_out['Expires']       = 'Mon, 26 Jul 1997 05:00:00 GMT'; // Date in the past
        $header_out['Content-type']  = 'application/xml; charset="utf-8"';

        return ($ret);
    }

    static function fini($init_string, $base, $blockerr)
    {
        return (sprintf('@BEGIN@ %s window.onbeforeunload = null; window.onunload = null; document.location.assign("%sindex.php"); @END@',  ($blockerr ? 'xstm.stop(); ' : ''), $base));
        return ("");
    }

    function chunk($step, $cont)
    {
        return ("@BEGIN@".$cont."@END@");
    }
}

class Transport_xhr {

    function Transport_xhr() {
    }

    function init($enc, $header, &$header_out, $init_string, $base, $step)
    {
        $ret = sprintf("@BEGIN@ /* %s */ @END@", $init_string);
        if ($enc != 'plain')
            $header_out['Content-Encoding'] = $enc;
        $header_out['Cache-Control'] = 'no-cache, must-revalidate';     // HTTP/1.1
        $header_out['Expires']       = 'Mon, 26 Jul 1997 05:00:00 GMT'; // Date in the past
        $header_out['Content-type']  = 'application/xml; charset="utf-8"';

        return ($ret);
    }

    static function fini($init_string, $base, $blockerr)
    {
        return (sprintf('@BEGIN@ %s window.onbeforeunload = null; window.onunload = null; document.location.assign("%sindex.php"); @END@',  ($blockerr ? 'xstm.stop(); ' : ''), $base));
        return ("");
    }

    function chunk($step, $cont)
    {
        return ("@BEGIN@".$cont."@END@");
    }

    function is_chunked()
    {
        return TRUE;
    }
}

class Transport_iframe {

    function Transport_iframe() {
    }

    function init($enc, $header, &$header_out, $init_string, $base, $step)
    {
        $ret = "";

        if ($enc != 'plain')
            $header_out['Content-Encoding'] = $enc;
        $header_out['Cache-Control'] = 'no-cache, must-revalidate';     // HTTP/1.1
        $header_out['Expires']       = 'Mon, 26 Jul 1997 05:00:00 GMT'; // Date in the past
        $header_out['Content-type']  = 'text/html; charset="utf-8"';
        
        $ret .= sprintf("<html>
<head>
<script type=\"text/javascript\" src=\"%scommons.js\"></script>
<script type=\"text/javascript\" src=\"%sxynt-streaming-ifra.js\"></script>
<script type=\"text/javascript\">
var xynt_streaming = \"ready\";", $base, $base);
        if ($step > 0)
            $ret .= sprintf("last_clean = %d;\n", ($step-1));
        $ret .= sprintf("
window.onload = function () { try { if (xynt_streaming != \"ready\") { xynt_streaming.transp.stopped = true; } } catch(e) { /* console.log(\"catcha\"); */ } };
</script> 
</head>
<body>");
        $ret .= sprintf("<!-- \n%s -->\n", $init_string);

        return ($ret);
    }

    static function fini($init_string, $base, $blockerr)
    {
        $ret = "";
        $ret .= sprintf("<html>
<head>
<script type=\"text/javascript\" src=\"%scommons.js\"></script>
<script type=\"text/javascript\" src=\"%sxynt-streaming-ifra.js\"></script>
<script type=\"text/javascript\">
var xynt_streaming = \"ready\";", $base, $base);
        $ret .= sprintf("
window.onload = function () { try { if (xynt_streaming != \"ready\") { xynt_streaming.reload(); } } catch(e) { /* console.log(\"catcha\"); */ } };
</script>
</head>
<body>");
        $ret .= sprintf("<!-- \n%s -->\n", $init_string);
        $ret .= sprintf("<script id='hs%d' type='text/javascript'><!--
push(\"%s\");
// -->
</script>", 0, escpush($blockerr) );
        return ($ret);
    }

    function chunk($step, $cont)
    {
        if ($cont == NULL) {
            return sprintf("<script id='hs%d' type='text/javascript'><!--
push(null);\n// -->\n</script>", $step);
        }
        else {
            return sprintf("<script id='hs%d' type='text/javascript'><!--
push(\"%s\");\n// -->\n</script>", $step, escpush($cont) );
        }
    }

    function is_chunked()
    {
        return TRUE;
    }
}

class Transport_htmlfile extends Transport_iframe {
}

class Transport {
    function Transport()
    {
    }

    static function create($transp)
    {
        if ($transp == 'xhr') {
            return new Transport_xhr();
        }
        else if ($transp == 'htmlfile') {
            return new Transport_htmlfile();
        }
        else  {
            return new Transport_iframe();
        }
    }
    static function gettype($transp)
    {
        if ($transp == 'xhr' || $transp == 'htmlfile') {
            return "Transport_".$transp;
        }
        else {
            return 'Transport_iframe';
        }
    }
}
?>