<?php

function program()
{
	$program = array();
	$opts = array('http' => array('timeout' => 2, 'user_agent' => 'Fahrplan'));
	$context  = stream_context_create($opts);
	$schedule = file_get_contents('http://fahrplan-31c3.mkswap.net/fahrplan?a=1', false, $context);

	// loading failed, try tmp-file
	if(!$schedule)
		$schedule = file_get_contents('/tmp/website-schedule-fallback.xml');

	// failed, too, give up
	if(!$schedule)
		return array();

	// save tmp-file (for when uplink goes down or such)
	file_put_contents('/tmp/website-schedule-fallback.xml', $schedule);
	$schedule = simplexml_load_string($schedule);
	// re-calculate day-ends
	// some schedules have long gaps before the first talk or talks that expand beyond the dayend
	// (fiffkon, i look at you)
	// so to be on the safer side we calculate our own daystart/end here
	foreach($schedule->day as $day)
	{
		$daystart = PHP_INT_MAX;
		$dayend = 0;

		foreach($day->room as $room)
		{
			foreach($room->event as $event)
			{
				$start = strtotime((string)$event->date);
				$duration = strtoduration((string)$event->duration);
				$end = $start + $duration;

				$daystart = min($daystart, $start);
				$dayend = max($dayend, $end);
			}
		}

		$day['start'] = $daystart;
		$day['end'] = $dayend;
	}

	$dayidx = 0;
	foreach($schedule->day as $day)
	{
		$dayidx++;
		$daystart = (int)$day['start'];
		$dayend = (int)$day['end'];

		$roomidx = 0;
		foreach($day->room as $room)
		{
			$roomidx++;
			$lastend = false;
			$name = (string)$room['name'];
			if(isset($GLOBALS['CONFIG']['FAHRPLAN_ROOM_MAPPING'][$name]))
				$name = $GLOBALS['CONFIG']['FAHRPLAN_ROOM_MAPPING'][$name];

			foreach($room->event as $event)
			{
				$start = strtotime((string)$event->date);
				$duration = strtoduration((string)$event->duration);
				$end = $start + $duration;

				if($lastend && $lastend < $start)
				{
					// synthesize pause event
					$pauseduration = $start - $lastend;
					$program[$name][] = array(
						'special' => 'pause',
						'title' => round($pauseduration / 60).' minutes pause',

						'fstart' => date('c', $lastend),
						'fend' => date('c', $start),

						'start' => $lastend,
						'end' => $start,
						'duration' => $pauseduration,
					);
				}
				else if(!$lastend && $daystart < $start)
				{
					$program[$name][] = array(
						'special' => 'gap',

						'fstart' => date('c', $daystart),
						'fend' => date('c', $start),

						'start' => $daystart,
						'end' => $start,
						'duration' => $start - $daystart,
					);
				}

			$personnames = array();
			foreach($event->persons->person as $person)
				$personnames[] = (string)$person;

			$program[$name][] = array(
					'title' => (string)$event->title,
					'speaker' => implode(', ', $personnames),

					'fstart' => date('c', $start),
					'fend' => date('c', $end),

					'start' => $start,
					'end' => $end,
					'duration' => $duration,
				);

				$lastend = $end;
			}

			// synthesize daychange event
			if(!$lastend) $lastend = $daystart;
			if($lastend < $dayend)
			{
				$program[$name][] = array(
					'special' => 'gap',

					'fstart' => date('c', $lastend),
					'fend' => date('c', $dayend),

					'start' => $lastend,
					'end' => $dayend,
					'duration' => $dayend - $lastend,
				);
			}

			if($dayidx < count($schedule->day))
			{
				$program[$name][] = array(
					'special' => 'daychange',
					'title' => 'Daychange from Day '.$dayidx.' to '.($dayidx+1),

					'start' => $dayend,
					'end' => (int)$schedule->day[$dayidx]['start'],
					'duration' => 60*60,
				);
			}
		}
	}

	return $program;
}