<?php
// ini_set('display_errors', 1);
// error_reporting(E_ALL);

/**
 * Very basic websocket client.
 * Supporting draft hybi-10.
 *
 * @author Simon Samtleben <web@lemmingzshadow.net>
 * @version 2011-10-18
 */

class WebSocketClient
{
    private $_host;
    private $_port;
    private $_path;
    private $_origin;
    private $_Socket = null;
    private $_connected = false;

    public function __construct() { }

    public function __destruct()
    {
        $this->disconnect();
    }

    public function sendData($data, $type = 'text', $masked = true)
    {
        if($this->_connected === false)
        {
            trigger_error("Not connected", E_USER_WARNING);
            return false;
        }

        if( !is_string($data)) {
            trigger_error("Not a string data was given.", E_USER_WARNING);
            return false;
        }
        if (strlen($data) == 0)
        {
            return false;
        }
        $res = @fwrite($this->_Socket, $this->_hybi10Encode($data, $type, $masked));

        if($res === 0 || $res === false)
        {
            return false;
        }
        //todo 駿濤。。将下面逻辑注释。不需要得到反馈
/*        $buffer = ' ';
        while($buffer !== '')
        {
            $buffer = fread($this->_Socket, 512);
        }*/
        return true;
    }

    public function connect($host, $port, $path, $origin = false)
    {
        $this->_host = $host;
        $this->_port = $port;
        $this->_path = $path;
        $this->_origin = $origin;

        $key = base64_encode($this->_generateRandomString(16, false, true));
        $header = "GET " . $path . " HTTP/1.1\r\n";
        $header.= "Host: ".$host.":".$port. "\r\n";
        $header.= "Upgrade: websocket\r\n";
        $header.= "Connection: Upgrade\r\n";
        //$header.= "Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits\r\n";
        $header.= "Sec-WebSocket-Key: " . $key . "\r\n";

        if($origin !== false)
        {
            $header.= "Sec-WebSocket-Origin: " . $origin . "\r\n";
        }
        $header.= "Sec-WebSocket-Version: 13\r\n\r\n";

        $this->_Socket = fsockopen($host, $port, $errno, $errstr, 2);
        socket_set_timeout($this->_Socket, 2, 10000);
        //socket_write($this->_Socket, $header);
        $res = @fwrite($this->_Socket, $header);
        if( $res === false ){
            //echo "fwrite false \n";
        }

        $response = @fread($this->_Socket, 1500);
        //$response = socket_read($this->_Socket);
        preg_match('#Sec-WebSocket-Accept:\s(.*)$#mU', $response, $matches);
        if ($matches) {
            $keyAccept = trim($matches[1]);
            $expectedResonse = base64_encode(pack('H*', sha1($key . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
            $this->_connected = ($keyAccept === $expectedResonse) ? true : false;
        }
        return $this->_connected;
    }

    public function checkConnection()
    {
        $this->_connected = false;

        // send ping:
        $data = 'ping?';
        @fwrite($this->_Socket, $this->_hybi10Encode($data, 'ping', true));
        $response = @fread($this->_Socket, 300);
        if(empty($response))
        {
            return false;
        }
        $response = $this->_hybi10Decode($response);
        if(!is_array($response))
        {
            return false;
        }
        if(!isset($response['type']) || $response['type'] !== 'pong')
        {
            return false;
        }
        $this->_connected = true;
        return true;
    }


    public function disconnect()
    {
        $this->_connected = false;
        is_resource($this->_Socket) and fclose($this->_Socket);
    }

    public function reconnect()
    {
        sleep(10);
        $this->_connected = false;
        fclose($this->_Socket);
        $this->connect($this->_host, $this->_port, $this->_path, $this->_origin);
    }

    private function _generateRandomString($length = 10, $addSpaces = true, $addNumbers = true)
    {
        $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"ยง$%&/()=[]{}';
        $useChars = array();
        // select some random chars:
        for($i = 0; $i < $length; $i++)
        {
            $useChars[] = $characters[mt_rand(0, strlen($characters)-1)];
        }
        // add spaces and numbers:
        if($addSpaces === true)
        {
            array_push($useChars, ' ', ' ', ' ', ' ', ' ', ' ');
        }
        if($addNumbers === true)
        {
            array_push($useChars, rand(0,9), rand(0,9), rand(0,9));
        }
        shuffle($useChars);
        $randomString = trim(implode('', $useChars));
        $randomString = substr($randomString, 0, $length);
        return $randomString;
    }

    private function _hybi10Encode($payload, $type = 'text', $masked = true)
    {
        $frameHead = array();
        $frame = '';
        $payloadLength = strlen($payload);

        switch($type)
        {
            case 'text':
                // first byte indicates FIN, Text-Frame (10000001):
                $frameHead[0] = 129;
                break;

            case 'close':
                // first byte indicates FIN, Close Frame(10001000):
                $frameHead[0] = 136;
                break;

            case 'ping':
                // first byte indicates FIN, Ping frame (10001001):
                $frameHead[0] = 137;
                break;

            case 'pong':
                // first byte indicates FIN, Pong frame (10001010):
                $frameHead[0] = 138;
                break;
        }

        // set mask and payload length (using 1, 3 or 9 bytes)
        if($payloadLength > 65535)
        {
            $payloadLengthBin = str_split(sprintf('%064b', $payloadLength), 8);
            $frameHead[1] = ($masked === true) ? 255 : 127;
            for($i = 0; $i < 8; $i++)
            {
                $frameHead[$i+2] = bindec($payloadLengthBin[$i]);
            }
            // most significant bit MUST be 0 (close connection if frame too big)
            if($frameHead[2] > 127)
            {
                $this->close(1004);
                return false;
            }
        }
        elseif($payloadLength > 125)
        {
            $payloadLengthBin = str_split(sprintf('%016b', $payloadLength), 8);
            $frameHead[1] = ($masked === true) ? 254 : 126;
            $frameHead[2] = bindec($payloadLengthBin[0]);
            $frameHead[3] = bindec($payloadLengthBin[1]);
        }
        else
        {
            $frameHead[1] = ($masked === true) ? $payloadLength + 128 : $payloadLength;
        }

        // convert frame-head to string:
        foreach(array_keys($frameHead) as $i)
        {
            $frameHead[$i] = chr($frameHead[$i]);
        }
        if($masked === true)
        {
            // generate a random mask:
            $mask = array();
            for($i = 0; $i < 4; $i++)
            {
                $mask[$i] = chr(rand(0, 255));
            }

            $frameHead = array_merge($frameHead, $mask);
        }
        $frame = implode('', $frameHead);

        // append payload to frame:
        $framePayload = array();
        for($i = 0; $i < $payloadLength; $i++)
        {
            $frame .= ($masked === true) ? $payload[$i] ^ $mask[$i % 4] : $payload[$i];
        }

        return $frame;
    }

    private function _hybi10Decode($data)
    {
        $payloadLength = '';
        $mask = '';
        $unmaskedPayload = '';
        $decodedData = array();

        // estimate frame type:
        $firstByteBinary = sprintf('%08b', ord($data[0]));
        $secondByteBinary = sprintf('%08b', ord($data[1]));
        $opcode = bindec(substr($firstByteBinary, 4, 4));
        $isMasked = ($secondByteBinary[0] == '1') ? true : false;
        $payloadLength = ord($data[1]) & 127;

        switch($opcode)
        {
            // text frame:
            case 1:
                $decodedData['type'] = 'text';
                break;

            case 2:
                $decodedData['type'] = 'binary';
                break;

            // connection close frame:
            case 8:
                $decodedData['type'] = 'close';
                break;

            // ping frame:
            case 9:
                $decodedData['type'] = 'ping';
                break;

            // pong frame:
            case 10:
                $decodedData['type'] = 'pong';
                break;

            default:
                return false;
                break;
        }

        if($payloadLength === 126)
        {
            $mask = substr($data, 4, 4);
            $payloadOffset = 8;
            $dataLength = bindec(sprintf('%08b', ord($data[2])) . sprintf('%08b', ord($data[3]))) + $payloadOffset;
        }
        elseif($payloadLength === 127)
        {
            $mask = substr($data, 10, 4);
            $payloadOffset = 14;
            $tmp = '';
            for($i = 0; $i < 8; $i++)
            {
                $tmp .= sprintf('%08b', ord($data[$i+2]));
            }
            $dataLength = bindec($tmp) + $payloadOffset;
            unset($tmp);
        }
        else
        {
            $mask = substr($data, 2, 4);
            $payloadOffset = 6;
            $dataLength = $payloadLength + $payloadOffset;
        }

        if($isMasked === true)
        {
            for($i = $payloadOffset; $i < $dataLength; $i++)
            {
                $j = $i - $payloadOffset;
                if(isset($data[$i]))
                {
                    $unmaskedPayload .= $data[$i] ^ $mask[$j % 4];
                }
            }
            $decodedData['payload'] = $unmaskedPayload;
        }
        else
        {
            $payloadOffset = $payloadOffset - 4;
            $decodedData['payload'] = substr($data, $payloadOffset);
        }

        return $decodedData;
    }
}