Wise Timetable to iCalendar Converter

WiseTimetableToiCalendarConverter.php

<?php
/*
 * Wise Timetable to vCalendar Converter 
 * @Author		Marko Zabreznik
 * @copyright	Marko Zabreznik
 * @license		http://www.gnu.org/licenses/gpl-3.0.html GNU/GPL
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Usage: urnik.php?c=[id][,id]...
 *        id is number of the course
 *
*/

define('LOCALE', 'Slovenian');
define('URL', 'http://feri.um.si/urniki5/courses.php');

/* */

date_default_timezone_set('UTC');
setlocale(LC_ALL, LOCALE);

// do a post request with APC caching
function do_cached_post_request($url, $data, $optional_headers = null){
	$params = array('http' => array(
		'method' => 'POST',
		'content' => $data
	));
	if ($optional_headers !== null)
		$params['http']['header'] = $optional_headers;
		
	// maybe get from APC
	$hash = md5(serialize($params));
	if (function_exists('apc_fetch') && $response = apc_fetch($hash))
		return $response;
	
	$fp = @fopen($url, 'rb', false, stream_context_create($params));
	if (!$fp)
		throw new Exception("Problem with $url, $php_errormsg");
		
	$response = @stream_get_contents($fp);
	if ($response === false) {
		throw new Exception("Problem reading data from $url, $php_errormsg");
	}
	
	//$response = iconv('Windows-1250', 'UTF-8', $response); // očitno so popravli to
	
	// store to APC
	if (function_exists('apc_add'))
		apc_add($hash, $response, 360 );
	
	return $response;
}
/* */



// get courses from url  
$courses='';
foreach(explode(',',$_GET['c']) as $course)
	if(is_numeric($course)) $courses[]=$course;
if(empty($courses)) 
	die('not enought data');

// get courses from Wise Timetable server
$data = do_cached_post_request(URL,'show_week=0&courses_values='.implode('%2C',$courses));

// get data from HTML
preg_match_all('/span class="caption">(.*?)<\/span/is', $data, $titles);
preg_match_all('/\/thead>(.*?)<\/table/is', $data, $tables);




if (!isset($_GET['debug'])) {
	header("Content-Type: text/calendar; charset=utf-8");
	header('Content-Disposition: attachment; filename="feri-' . implode('-',$courses). '.ical"');
} else {
	header("Content-Type: text/plain; charset=utf-8");
}
	


// VCalendar Header
$out = <<<EOT
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//hxcal//NONSGML Version 1//EN

EOT;

function escapeString($string) {
  return preg_replace('/([\,;])/','\\\$1', $string);
}

// parse courses
$it = 0;
foreach($tables[1] as $table) {
	$table = explode('class="data"',$table);
	$title = escapeString(mb_convert_case(trim($titles[1][$it]), MB_CASE_TITLE, 'UTF-8'));
	// parse events
	foreach($table as $trow){
		if (!preg_match_all('/td class="wholeCell">(.*?)<\/td/is', $trow, $cells))
			continue;
		$cells = $cells[1];
		$time = explode(' - ',$cells[2]);
		
		$start = strtotime($cells[1].' '.$time[0]. ' Europe/Ljubljana');
		$dtstart = date('Ymd\THis', $start);
		$end = strtotime($cells[1].' '.$time[1]. ' Europe/Ljubljana');
		$dtend = date('Ymd\THis',$end);
		$cells[6] = escapeString (mb_convert_case($cells[6], MB_CASE_TITLE, 'UTF-8'));

		$cells[3] = escapeString( $cells[3] );
		$cells[4] = escapeString( $cells[4] );
		$cells[5] = escapeString( $cells[5] );
		$cells[6] = escapeString( $cells[6] );
		
		$out.= <<<EOT
BEGIN:VEVENT
DTSTART:{$dtstart}Z
DTEND:{$dtend}Z
LOCATION:{$cells[3]}
DESCRIPTION:{$cells[4]}: {$cells[6]} za {$cells[5]} ob {$time[0]}
SUMMARY:$title
END:VEVENT

EOT;

	}
	$it++;
}

$out.=  "END:VCALENDAR".PHP_EOL;

echo str_replace("\n","\r\n",$out);

// end