<?php

$start_time = time();

define( "MSG_TIMEOUT", ZM_WEB_AJAX_TIMEOUT );
define( "MSG_DATA_SIZE", 4+256 );

if ( !($_REQUEST['connkey'] && $_REQUEST['command']) ) {
  ajaxError( "Unexpected received message type '$type'" );
}

if ( !($socket = @socket_create( AF_UNIX, SOCK_DGRAM, 0 )) ) {
  ajaxError( "socket_create() failed: ".socket_strerror(socket_last_error()) );
}
$locSockFile = ZM_PATH_SOCKS.'/zms-'.sprintf("%06d",$_REQUEST['connkey']).'w.sock';
if ( file_exists( $locSockFile ) ) {
  Warning("sock file $locSockFile already exists?!  Is someone else talking to zms?");
  // They could be.  We can maybe have concurrent requests from a browser.  
} else {
  Logger::Debug("socket file does not exist, we should be good to connect.");
}
if ( !@socket_bind( $socket, $locSockFile ) ) {
  ajaxError( "socket_bind( $locSockFile ) failed: ".socket_strerror(socket_last_error()) );
} else {
  Logger::Debug("Bound to $locSockFile");
}

switch ( $_REQUEST['command'] ) {
  case CMD_VARPLAY :
    Logger::Debug( 'Varplaying to '.$_REQUEST['rate'] );
    $msg = pack( 'lcn', MSG_CMD, $_REQUEST['command'], $_REQUEST['rate']+32768 );
    break;
  case CMD_ZOOMIN :
    Logger::Debug( 'Zooming to '.$_REQUEST['x'].",".$_REQUEST['y'] );
    $msg = pack( 'lcnn', MSG_CMD, $_REQUEST['command'], $_REQUEST['x'], $_REQUEST['y'] );
    break;
  case CMD_PAN :
    Logger::Debug( 'Panning to '.$_REQUEST['x'].",".$_REQUEST['y'] );
    $msg = pack( 'lcnn', MSG_CMD, $_REQUEST['command'], $_REQUEST['x'], $_REQUEST['y'] );
    break;
  case CMD_SCALE :
    Logger::Debug( 'Scaling to '.$_REQUEST['scale'] );
    $msg = pack( 'lcn', MSG_CMD, $_REQUEST['command'], $_REQUEST['scale'] );
    break;
  case CMD_SEEK :
    Logger::Debug( 'Seeking to '.$_REQUEST['offset'] );
    $msg = pack( 'lcN', MSG_CMD, $_REQUEST['command'], $_REQUEST['offset'] );
    break;
  default :
    $msg = pack( 'lc', MSG_CMD, $_REQUEST['command'] );
    break;
}

$remSockFile = ZM_PATH_SOCKS.'/zms-'.sprintf('%06d',$_REQUEST['connkey']).'s.sock';
$max_socket_tries = 10;
// FIXME This should not exceed web_ajax_timeout
while ( !file_exists($remSockFile) && $max_socket_tries-- ) { //sometimes we are too fast for our own good, if it hasn't been setup yet give it a second.
  Logger::Debug("$remSockFile does not exist, waiting, current " . (time() - $start_time) . ' seconds' );
  usleep(200000);
}

if ( !file_exists($remSockFile) ) {
  ajaxError("Socket $remSockFile does not exist.  This file is created by zms, and since it does not exist, either zms did not run, or zms exited early.  Please check your zms logs and ensure that CGI is enabled in apache and check that the PATH_ZMS is set correctly.  Make sure that ZM is actually recording.  If you are trying to view a live stream and the capture process (zmc) is not running then zms will exit. Please go to http://zoneminder.readthedocs.io/en/latest/faq.html#why-can-t-i-see-streamed-images-when-i-can-see-stills-in-the-zone-window-etc for more information.");
} else {
  if ( !@socket_sendto( $socket, $msg, strlen($msg), 0, $remSockFile ) ) {
    ajaxError( "socket_sendto( $remSockFile ) failed: ".socket_strerror(socket_last_error()) );
  }
}

$rSockets = array( $socket );
$wSockets = NULL;
$eSockets = NULL;

$timeout = MSG_TIMEOUT - ( time() - $start_time );
Logger::Debug("TImeout is: $timeout " );

$numSockets = @socket_select( $rSockets, $wSockets, $eSockets, intval($timeout/1000), ($timeout%1000)*1000 );

if ( $numSockets === false ) {
  Error("socket_select failed: " . socket_strerror(socket_last_error()) );
  ajaxError( "socket_select failed: ".socket_strerror(socket_last_error()) );
} else if ( $numSockets < 0 ) {
  Error( "Socket closed $remSockFile"  );
  ajaxError( "Socket closed $remSockFile"  );
} else if ( $numSockets == 0 ) {
  Error( "Timed out waiting for msg $remSockFile"  );
  ajaxError( "Timed out waiting for msg $remSockFile"  );
} else if ( $numSockets > 0 ) {
  if ( count($rSockets) != 1 ) {
    Error( "Bogus return from select, ".count($rSockets).' sockets available' );
    ajaxError( "Bogus return from select, ".count($rSockets).' sockets available' );
  }
}

switch( $nbytes = @socket_recvfrom( $socket, $msg, MSG_DATA_SIZE, 0, $remSockFile ) ) {
  case -1 :
  {
    ajaxError( "socket_recvfrom( $remSockFile ) failed: ".socket_strerror(socket_last_error()) );
    break;
  }
  case 0 :
  {
    ajaxError( 'No data to read from socket' );
    break;
  }
  default :
  {
    if ( $nbytes != MSG_DATA_SIZE )
      ajaxError( "Got unexpected message size, got $nbytes, expected ".MSG_DATA_SIZE );
    break;
  }
}

$data = unpack( 'ltype', $msg );
switch ( $data['type'] ) {
  case MSG_DATA_WATCH :
  {
    $data =  unpack( "ltype/imonitor/istate/dfps/ilevel/irate/ddelay/izoom/Cdelayed/Cpaused/Cenabled/Cforced", $msg );
    Logger::Debug("FPS: " . $data['fps'] );
    $data['fps'] = round( $data['fps'], 2 );
    Logger::Debug("FPS: " . $data['fps'] );
    $data['rate'] /= RATE_BASE;
    $data['delay'] = round( $data['delay'], 2 );
    $data['zoom'] = round( $data['zoom']/SCALE_BASE, 1 );
    if ( ZM_OPT_USE_AUTH && ZM_AUTH_RELAY == 'hashed' ) {
      session_start();
      $time = time();
      // Regenerate auth hash after half the lifetime of the hash
      if ( (!isset($_SESSION['AuthHashGeneratedAt'])) or ( $_SESSION['AuthHashGeneratedAt'] < $time - (ZM_AUTH_HASH_TTL * 1800) ) ) {
        $data['auth'] = generateAuthHash( ZM_AUTH_HASH_IPS );
      } 
      session_write_close();
    }
    ajaxResponse( array( 'status'=>$data ) );
    break;
  }
  case MSG_DATA_EVENT :
  {
    $data =  unpack( "ltype/ievent/iprogress/irate/izoom/Cpaused", $msg );
    //$data['progress'] = sprintf( "%.2f", $data['progress'] );
    $data['rate'] /= RATE_BASE;
    $data['zoom'] = round( $data['zoom']/SCALE_BASE, 1 );
    if ( ZM_OPT_USE_AUTH && ZM_AUTH_RELAY == 'hashed' ) {
      session_start();
      $time = time();
      // Regenerate auth hash after half the lifetime of the hash
      if ( (!isset($_SESSION['AuthHashGeneratedAt'])) or ( $_SESSION['AuthHashGeneratedAt'] < $time - (ZM_AUTH_HASH_TTL * 1800) ) ) {
        $data['auth'] = generateAuthHash( ZM_AUTH_HASH_IPS );
      } 
      session_write_close();
    }
    ajaxResponse( array( 'status'=>$data ) );
    break;
  }
  default :
  {
    ajaxError( "Unexpected received message type '$type'" );
  }
}

ajaxError( 'Unrecognised action or insufficient permissions' );

function ajaxCleanup() {
  global $socket, $locSockFile;
  if ( !empty( $socket ) )
    @socket_close( $socket );
  if ( !empty( $locSockFile ) )
    @unlink( $locSockFile );
}
?>