<?php
define('X', 0);
define('Y', 1);
class PvsGenerator
{
public static function generate()
{
if (!Module::isAvailable('locations')) {
die('sorry, but the locations module is required');
}
/* get all rooms */
$rooms = array();
$ret = Database::simpleQuery(
'SELECT l.locationid, l.locationname, lr.managerip, lr.tutoruuid, m.clientip as tutorip '
. 'FROM location l '
. 'INNER JOIN location_roomplan lr ON (l.locationid = lr.locationid)'
. 'LEFT JOIN machine m ON (lr.tutoruuid = m.machineuuid)');
while ($row = $ret->fetch(PDO::FETCH_ASSOC)) {
if (Location::isLeaf($row['locationid'])) { // TODO: This creates extra queries, optimize?
$row['locationname'] = str_replace(',', ';', $row['locationname']); // comma probably not the best sep here
$rooms[] = $row;
}
}
/* collect names and build room blocks - filter empty rooms while at it */
$roomNames = array();
$roomBlocks = '';
foreach ($rooms as $room) {
$roomBlock = PvsGenerator::generateRoomBlock($room);
if ($roomBlock === false)
continue; // Room nonexistent or empty
$roomNames[] = $room['locationname'];
$roomBlocks .= $roomBlock;
}
/* output room plus [General]-block */
return "[General]\n"
. 'rooms=' . implode(', ', $roomNames) . "\n"
. "allowClientQuit=False\n" // TODO: configurable
. "showLockDesktopButton=True\n" // TODO: Make this configurable (or not)
. "\n\n"
. $roomBlocks;
}
/**
* Generate .ini section for specific room.
*
* @param $room array room/location data as fetched from db
* @return string|bool .ini section for room, or false if room is empty
*/
private static function generateRoomBlock($room)
{
$out = '[' . $room['locationname'] . "]\n";
/* find all clients in that room */
$machines = PvsGenerator::getMachines($room['locationid']);
if (empty($machines))
return false;
/* manager */
$mgr = $room['managerip'];
$tutor = $room['tutorip'];
if ($mgr) {
$out .= 'mgrIP=' . $mgr . "\n";
}
/* tutor */
if ($tutor) {
$out .= 'tutorIP=' . $tutor . "\n";
}
/* grid */
$out .= PvsGenerator::generateGrid($machines);
return $out . "\n";
}
/**
* Generate grid size information and client position data for given clients.
*
* @param $machines array list of clients
* @return string grid and position data as required for a room's .ini section
*/
private static function generateGrid($machines)
{
$out = "";
/* this is a virtual grid, we first need this to do some optimizations */
$grid = array();
/* add each contained client with position and ip */
foreach ($machines as $machine) {
$grid[$machine['clientip']] = [$machine['gridCol'], $machine['gridRow']];
}
/* find bounding box */
PvsGenerator::boundingBox($grid, $minX, $minY, $maxX, $maxY);
$clientSizeX = 4; /* TODO: optimize */
$clientSizeY = 4; /* TODO: optimize */
$sizeX = max($maxX - $minX + $clientSizeX, 1); /* never negative */
$sizeY = max($maxY - $minY + $clientSizeY, 1); /* and != 0 to avoid divide-by-zero in pvsmgr */
/* zoom all clients into bounding box */
foreach ($grid as $ip => $pos) {
$newX = $grid[$ip][X] - $minX;
$newY = $grid[$ip][Y] - $minY;
$grid[$ip] = [$newX, $newY];
}
$out .= "gridSize=@Size($sizeX $sizeY)\n";
$out .= "clientSize=@Size($clientSizeX $clientSizeY)\n";
$out .= "client\\size=" . count($grid) . "\n";
$i = 1;
foreach ($grid as $ip => $pos) {
$out .= "client\\" . $i . "\\ip=$ip\n";
$out .= "client\\" . $i++ . "\\pos=@Point(" . $pos[X] . ' ' . $pos[Y] . ")\n";
}
return $out;
}
/**
* Get all clients for given room with IP and position.
*
* @param $roomid int locationid of room
* @return array
*/
private static function getMachines($roomid)
{
$ret = Database::simpleQuery(
'SELECT clientip, position FROM machine WHERE locationid = :locationid',
['locationid' => $roomid]);
$machines = array();
while ($row = $ret->fetch(PDO::FETCH_ASSOC)) {
$position = json_decode($row['position'], true);
$machine = array();
$machine['clientip'] = $row['clientip'];
$machine['gridRow'] = $position['gridRow'];
$machine['gridCol'] = $position['gridCol'];
$machine['tutor'] = false; /* TODO: find out if machine is default tutor */
$machine['manager'] = false; /* TODO: find out if machine is manager */
$machines[] = $machine;
}
return $machines;
}
private static function boundingBox($grid, &$minX, &$minY, &$maxX, &$maxY)
{
$minX = PHP_INT_MAX; /* PHP_INT_MIN is only avaiable since PHP 7 */
$maxX = ~PHP_INT_MAX;
$minY = PHP_INT_MAX;
$maxY = ~PHP_INT_MAX;
foreach ($grid as $pos) {
$minX = min($minX, $pos[X]);
$maxX = max($maxX, $pos[X]);
$minY = min($minY, $pos[Y]);
$maxY = max($maxY, $pos[Y]);
}
}
}
