#!/usr/local/bin/php
<?
/* a simple 'partyline' example of how to use socket_select() and co. to create
 * a multi-socket php listening daemon with multi-client support.
 *
 * modify at will. (by dave on irc.dal.net)
 */

$listen_addr = '0.0.0.0';
$listen_port = 10000;

define('STATE_NICKNAME', 1);
define('STATE_CHATTING', 2);

/* this is to be a daemon, don't want to auto-timeout and no error messages! */
set_time_limit(0);
error_reporting(0);

/* display error message */
function myerror() {
  echo '[error]: ' . socket_strerror(socket_last_error()) . "\n";
}

/* display error message and die */
function myerror_d() {
  myerror();
  die();
}

/* send a message to a socket */
function send_single($sock, $message) {
  socket_write($sock, "$message\n");
}

/* send a message to all client sockets */
function send_all($message, $state = STATE_CHATTING) {
  global $s_clients, $cdata;

  foreach ($s_clients as $sock)
    if ($cdata[$sock]['state'] == $state || $state == 0)
      send_single($sock, $message);

}

/* send a message to all client sockets except one */
function send_all_butone($sock, $message, $state = STATE_CHATTING) {
  global $s_clients, $cdata;

  foreach ($s_clients as $mysock)
    if ($mysock != $sock && $cdata[$mysock]['state'] == $state || $state == 0)
      send_single($mysock, $message);

}

/* handle incoming data */
function handle_data($sock, $read) {
  global $cdata;

  if ($cdata[$sock]['buf'] != '')
    $read = $cdata[$sock]['buf'] . $read;

  $read = str_replace("\r", '', $read);

  $cdata[$sock]['buf'] = substr(strrchr($read, "\n"), 1);
  $read = substr($read, 0, strpos($read, "\n"));

  if ($cdata[$sock]['state'] == STATE_NICKNAME)
    handle_nickname($sock, $read);
  else
    handle_chat($sock, $read);
}

/* handle nickname entry */
function handle_nickname($sock, $nick) {
  global $s_clients, $cdata;

  if (!preg_match('/^[a-zA-Z]{1,10}$/', $nick)) {
    send_single($sock, "That nick is invalid. Please choose another:");
    return;
  }

  foreach ($s_clients as $mysock)
    if (strcasecmp($cdata[$mysock]['nick'], $nick) == 0) {
      send_single($sock, "That nick is already in use. Please choose another:");
      return;
    }

  $cdata[$sock]['nick'] = $nick;
  $cdata[$sock]['state'] = STATE_CHATTING;
  on_join($sock);
}

/* handle chat text */
function handle_chat($sock, $data) {
  global $cdata;

  /* do who command */
  if ($data == '.who') {
    do_who($sock);
    return;
  }
  else if ($data[0] == '.') {
    send_single($sock, "Invalid command.");
    return;
  }

  $nick = $cdata[$sock]['nick'];
  send_all_butone($sock, "<$nick> $data");
}

/* client has joined */
function on_join($sock) {
  global $cdata;

  $nick = $cdata[$sock]['nick'];
  $addr = $cdata[$sock]['addr'];
  send_all("*** Joins: $nick ($addr)");
}

/* client has quit */
function on_quit($sock) {
  global $cdata;

  $nick = $cdata[$sock]['nick'];
  $addr = $cdata[$sock]['addr'];
  send_all_butone($sock, "*** Quits: $nick ($addr)");
}

/* who command */
function do_who($sock) {
  global $s_clients, $cdata;

  foreach ($s_clients as $mysock) {
    $state = $cdata[$mysock]['state'];

    if ($state == STATE_NICKNAME)
      send_single($sock, sprintf('[nickname] (%s)', $cdata[$mysock]['addr']));
    else
      send_single($sock, sprintf('[chatting] %10s (%s)', $cdata[$mysock]['nick'], $cdata[$mysock]['addr']));
  }
}      

/* assign listening socket */
if (!($s_listen = socket_create(AF_INET, SOCK_STREAM, 0)))
  myerror_d();

/* reuse listening socket address */
if (!socket_set_option($s_listen, SOL_SOCKET, SO_REUSEADDR, 1))
  myerror_d();

/* set socket to non-blocking */
if (!socket_set_nonblock($s_listen))
  myerror_d();

/* bind listening socket to specific address/port */
if (!socket_bind($s_listen, $listen_addr, $listen_port))
  myerror_d();

/* listen on listening socket */
if (!socket_listen($s_listen))
  myerror_d();

/* set initial vars and loop until $abort is set to true */
$s_clients = Array();
$abort = false;

while (!$abort) {
  /* sockets we want to pay attention to */
  $set = array_merge($s_listen, $s_clients);

  if (socket_select($set, $set_w = NULL, $set_e = NULL, 1, 0) > 0) {
    /* loop through sockets */
    foreach ($set as $sock) {
      /* listening socket has a connection, deal with it */
      if ($sock == $s_listen) {
        if (!($this = socket_accept($s_listen)))
          myerror();
        else {
          /* add socket to client list and announce connection */
          $s_clients[$this] = $this;
          socket_getpeername($this, $addr);
          $cdata[$this]['addr']  = $addr;
          $cdata[$this]['buf']   = '';
          $cdata[$this]['state'] = STATE_NICKNAME;

          echo "[connection]: $addr\n";
          send_single($this, 'Enter a nickname:');
        }
      }
      else {
        /* client socket has incoming data */
        if (($read = socket_read($sock, 1024)) === false || $read == '') {
          if ($read != '')
            myerror();
          else /* no error, but connection was closed, so tell everyone */
            on_quit($sock);

          /* remove client from arrays */
          unset($s_clients[$sock]);
          unset($cdata[$sock]);
        }
        else {
          /* only want data with a newline */
          if (strchr($read, "\n") === false)
            $cdata[$sock]['buf'] .= $read;
          else
            handle_data($sock, $read);
        }
      }
    }
  }
}

echo "[end]\n";

?>