<?php

define('HOST',"localhost");
define('PORT',"9000");

//Create TCP/IP sream socket
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

//reuseable port
socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);

//bind socket to specified host
socket_bind($socket, 0, PORT);

//listen to port
socket_listen($socket);

//create & add listning socket to the list
$clients = array($socket);

//start endless loop, so that our script doesn't stop
while (true) {

    //manage multipal connections
    $changed = $clients;

    //returns the socket resources in $changed array
    socket_select($changed, $null, $null, 0, 10);

    //check for new socket
    if (in_array($socket, $changed)) {
        $socket_new = socket_accept($socket); //accpet new socket
        $clients[] = $socket_new; //add socket to client array

        $header = socket_read($socket_new, 1024); //read data sent by the socket
        ** perform_handshaking($header, $socket_new, HOST, PORT); //perform websocket handshake Validation and acl etc ..

        socket_getpeername($socket_new, $ip); //get ip address of connected socket
        $response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' connected'))); //prepare json data
        send_message($response); //notify all users about new connection

        //make room for new socket
        $found_socket = array_search($socket, $changed);
        unset($changed[$found_socket]);
    }

    //loop through all connected sockets
    foreach ($changed as $changed_socket) {

        //check for any incomming data
        while(socket_recv($changed_socket, $buf, 1024, 0) >= 1)
        {
            $received_text = unmask($buf); //unmask data
            $tst_msg = json_decode($received_text); //json decode
            $user_name = $tst_msg->name; //sender name
            $user_message = $tst_msg->message; //message text
            $user_color = $tst_msg->color; //color

            //prepare data to be sent to client
            $response_text = mask(json_encode(array('type'=>'usermsg', 'name'=>$user_name, 'message'=>$user_message, 'color'=>$user_color)));
            send_message($response_text); //send data
            break 2; //exist this loop
        }

        $buf = socket_read($changed_socket, 1024, PHP_NORMAL_READ);

    // check disconnected client
        if ($buf === false) {

            // remove client for $clients array
            $found_socket = array_search($changed_socket, $clients);
            socket_getpeername($changed_socket, $ip);
            unset($clients[$found_socket]);

            //notify all users about disconnected connection
            $response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' disconnected')));
            send_message($response);
        }
    }
}

// close the listening socket
socket_close($sock);