<?php

class Server {
    protected $clients = array();
    protected $master  = array();

    function __construct($uri = 'tcp://0.0.0.0:8000') {
        $this->master = stream_socket_server($uri, $errno, $errstr);
        if (!$this->master) {
            echo "$errstr ($errno)<br />\n";
        } else {
            while (true) {
                foreach($this->select() as $client) {
                    $buffer = $client->read(2048);
                    if (!$client->handshake($buffer)) {
                        continue;
                    }
                    $this->compute($client, substr($buffer, 1, -1));
                }
            }
            fclose($this->master);
        }
    }

    function compute($clientFrom, $message) {
        echo "Received $message from $clientFrom->socket\n";
        echo count($this->clients)." connected\n";
        foreach($this->clients as $clientTo) {
            echo "Dispatching to $clientTo->socket\n";
            $clientTo->send(chr(0).$message.chr(255));
        }
    }

    function select() {
        $read    = array_map(function($client) {
            return $client->socket;
        }, $this->clients);
        $read[] = $this->master;
        $write  = null;
        $except = null;
        stream_select($read, $write, $except, 30);

        $found = array();
        foreach ($read as $current) {
            if ($current == $this->master) {
                $socket = stream_socket_accept($current);
                $client = new Client($socket, $this);
                $this->clients[(string) $socket] = $client;
                $found[] = $client;
            } else {
                $found[] = $this->clients[(string) $current];
            }
        }
        return $found;
    }

    function onClientClose($client) {
        echo "Client $client->socket closed\n";
        unset($this->clients[(string) $client->socket]);
    }

    function close() {
        foreach ($this->clients as $client) {
            $client->close();
        }
        @fclose($this->master);
    }

    function  __destruct() {
        $this->close();
    }
}

class Client {

    public    $socket;
    protected $server;
    protected $handshake = false;

    function __construct($socket, $server) {
        $this->socket = $socket;
        $this->server = $server;
    }

    function send($message) {
        echo "Sending $message to $this->socket\n";
        return stream_socket_sendto($this->socket, $message);
    }

    function read($length) {
        $message = @stream_socket_recvfrom($this->socket, $length);
        if ($message == '') {
            $this->close();
        }
        return $message;
    }

    function close() {
        $this->server->onClientClose($this);
        @fclose($this->socket);
    }

    public function handshake($buffer) {

        if ($this->handshake) {
            return true;
        }

        $x = explode("\r\n", $buffer);
        $h = array();

        for($i = 1, $m = count($x) - 3; $i <= $m; ++$i)
            $h[strtolower(substr($x[$i], 0, strpos($x[$i], ':')))] =
                trim(substr($x[$i], strpos($x[$i], ':') + 2));

        if(0 !== preg_match('#GET (.*) HTTP#', $buffer, $match))
            $h['resource'] = $match[1];

        $key1      = $h['sec-websocket-key1'];
        $key2      = $h['sec-websocket-key2'];
        $key3      = $x[count($x) - 1];
        $keynumb1  = (int) preg_replace('#[^0-9]#', '', $key1);
        $keynumb2  = (int) preg_replace('#[^0-9]#', '', $key2);

        $spaces1   = substr_count($key1, ' ');
        $spaces2   = substr_count($key2, ' ');

        $part1     = pack('N', $keynumb1 / $spaces1);
        $part2     = pack('N', $keynumb2 / $spaces2);
        $challenge = $part1 . $part2 . $key3;
        $response  = md5($challenge, true);

        $this->send(
            'HTTP/1.1 101 WebSocket Protocol Handshake' . "\r\n" .
            'Upgrade: WebSocket' . "\r\n" .
            'Connection: Upgrade' . "\r\n" .
            'Sec-WebSocket-Origin: ' . $h['origin'] . "\r\n" .
            'Sec-WebSocket-Location: ws://' . $h['host'] .
            $h['resource'] . "\r\n" .
            "\r\n" .
            $response . "\r\n"
        );

        $this->handshake = true;
        return false;
    }

    function  __destruct() {
        $this->close();
    }
}

new Server('tcp://0.0.0.0:8080');