<?php

set_time_limit(0);

class SocketService

{

    private $address  = 'localhost';

    private $port = 80;

    private $_sockets;

    public function __construct($address = '', $port='')

    {

        if(!empty($address)){

            $this->address = $address;

        }

        if(!empty($port)) {

            $this->port = $port;

        }

    }

    public function service(){

        //获取tcp协议号码。

        $tcp = getprotobyname("SOL_TCP");           # 获取与协议名称关联的协议号

        $sock = socket_create(AF_INET, SOCK_STREAM, $tcp);  # 创建一个套接字（通讯节点）

        socket_set_option($sock, SOL_SOCKET, SO_REUSEADDR, 1);  # 设置套接字选项

        if($sock < 0)

        {

            throw new Exception("failed to create socket: ".socket_strerror($sock)."\n");

        }

        socket_bind($sock, $this->address, $this->port);    # 绑定

        socket_listen($sock, $this->port);      # 监听套接字上的连接

        $this->_sockets = $sock;  

    }

    public function run(){

        $this->service();

        $clients[] = $this->_sockets;   # 数组存储 每个socket

        # 让服务器无限获取客户端传过来的信息

        while (true){

            $changes = $clients;

            $write = NULL;

            $except = NULL;

            socket_select($changes,  $write,  $except, NULL);

            foreach ($changes as $key => $_sock){

                if($this->_sockets == $_sock){  # 判断是不是新接入的socket

                    if(($newClient = socket_accept($_sock))  === false){    # 接受新的套接字上的连接   socket_accept的作用就是接受socket_bind()所绑定的主机发过来的套接流

                        die('failed to accept socket: '.socket_strerror($_sock)."\n");  # 返回描述套接字错误的字符串

                    }

                    $line = trim(socket_read($newClient, 1024));  # 读取客户端传过来的资源，并转化为字符串     socket_read的作用就是读出socket_accept()的资源并把它转化为字符串

                    $this->handshaking($newClient, $line);

                    //获取client ip

                    socket_getpeername ($newClient, $ip);                                   # 查询给定套接字的远程端，这可能导致主机/端口或UNIX文件系统路径，具体取决于其类型。

                    $clients[$ip] = $newClient;

                } else {

                    # 读取该socket的信息，注意：第二个参数是引用传参即接收数据，第三个参数是接收数据的长度

                    $lenght = socket_recv($_sock, $buffer,  2048, 0);               # 从已连接的socket接收数据   $lenght 接收到字符串长度

                    $msg = $this->message($buffer);          # 接收到的信息

                    //在这里业务代码

                    fwrite(STDOUT, 'Please input a argument:');

                    $response = trim(fgets(STDIN));

//                    $this->send($_sock, $response);                                                       # 第二个参数是获取数据    要发送的信息

                    $this->send($_sock, '在线');

                }

            }

        }

    }

    /**

     * 握手处理

     * @param $newClient socket

     * @return int  接收到的信息

     */

    public function handshaking($newClient, $line){

        $headers = array();

        $lines = preg_split("/\r\n/", $line);   # 通过一个正则表达式分隔字符串。

        foreach($lines as $line)

        {

            $line = chop($line);    # 移除字符串右端的空白字符或其他预定义字符

            if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))

            {

                $headers[$matches[1]] = $matches[2];

            }

        }

        $secKey = $headers['Sec-WebSocket-Key'];

        $secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));

        $upgrade  = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .

            "Upgrade: websocket\r\n" .

            "Connection: Upgrade\r\n" .

            "WebSocket-Origin: $this->address\r\n" .

            "WebSocket-Location: ws://$this->address:$this->port/服务器地址\r\n".

            "Sec-WebSocket-Accept:$secAccept\r\n\r\n";

        return socket_write($newClient, $upgrade, strlen($upgrade));    # socket_write的作用是向socket_create的套接流写入信息，或者向socket_accept的套接流写入信息

    }

    /**

     * 解析接收数据

     * @param $buffer

     * @return null|string

     */

    public function message($buffer){

        $len = $masks = $data = $decoded = null;

        $len = ord($buffer[1]) & 127;

        if ($len === 126)  {

            $masks = substr($buffer, 4, 4);

            $data = substr($buffer, 8);

        } else if ($len === 127)  {

            $masks = substr($buffer, 10, 4);

            $data = substr($buffer, 14);

        } else  {

            $masks = substr($buffer, 2, 4);

            $data = substr($buffer, 6);

        }

        for ($index = 0; $index < strlen($data); $index++) {

            $decoded .= $data[$index] ^ $masks[$index % 4];

        }

        return $decoded;

    }

    /**

     * 发送数据

     * @param $newClinet 新接入的socket

     * @param $msg   要发送的数据

     * @return int|string

     */

    public function send($newClinet, $msg){

        $msg = $this->frame($msg);

        socket_write($newClinet, $msg, strlen($msg));   # 写入套接字

    }

    public function frame($s) {

        $a = str_split($s, 125);    # 把字符串分割到数组中 第二个长度参数

        if (count($a) == 1) {

            return "\x81" . chr(strlen($a[0])) . $a[0];

        }

        $ns = "";

        foreach ($a as $o) {

            $ns .= "\x81" . chr(strlen($o)) . $o;

        }

        return $ns;

    }

    /**

     * 关闭socket

     */

    public function close(){

        # socket_close的作用是关闭socket_create()或者socket_accept()所建立的套接流

        return socket_close($this->_sockets);

    }

}

$sock = new SocketService();

$sock->run();