<?php
require_once ROOT.'/environment/classes/event/parse_ics.php';

class CalFormatUtilities {
	
	function decode_ical_file($filename) {
		$parsed_data = parse_ical($filename);
		
		if (isset($parsed_data[0]['tzoffsetfrom']))
			$tz_diff = logged_user()->getTimezone() - ($parsed_data[0]['tzoffsetfrom'] / 100);
		else
			$tz_diff = logged_user()->getTimezone();
		unset($parsed_data[0]);
		$events_data = CalFormatUtilities::build_events_data($parsed_data, $tz_diff);
		return $events_data;
	}
	
	function build_events_data($ical_events_data, $tz_diff) {
		$result = array();
		
		foreach($ical_events_data as $ical_ev) {
			$data = array();
			$data['subject'] = substr_utf(array_var($ical_ev, 'summary', 'No Subject'), 0, 100);
			$data['description'] = array_var($ical_ev, 'description', '');
			$data['subject'] = html_entity_decode($data['subject']);
			$data['subject'] = str_replace('<br />', "\n", $data['subject']);
			$data['description'] = html_entity_decode($data['description']);
			$data['description'] = str_replace('<br />', "\n", $data['description']);
			$data['type_id'] = array_var($ical_ev, 'all_day', 0) == 0 ? 1 : 2;
			
			$data['start'] = date('Y-m-d H:i:s', array_var($ical_ev, 'start_unix') - $tz_diff * 3600);
			$data['duration'] = date('Y-m-d H:i:s', array_var($ical_ev, 'end_unix') - $tz_diff * 3600);
			
			$data['repeat_num'] = 0;
			$data['repeat_h'] = 0;
			$data['repeat_d'] = 0;
			$data['repeat_m'] = 0;
			$data['repeat_y'] = 0;
			$data['repeat_forever'] = 0;
			$data['repeat_end'] =  0;
			
			$rrule = array_var($ical_ev, 'rrule', null);
			if ($rrule != null) {
				$data['repeat_end'] = isset($rrule['until_unix']) ? date('Y-m-d', array_var($rrule, 'until_unix')) : 0;
				$data['repeat_num'] = array_var($rrule, 'count', 0);
				$freq = array_var($rrule, 'freq', null);
				$jump = array_var($rrule, 'interval', 1);
				if ($freq != null) {
					switch ($freq) {
						case 'DAILY': $data['repeat_d'] = $jump; break;
						case 'WEEKLY': $data['repeat_d'] = 7 * $jump; break;
						case 'MONTHLY': $data['repeat_m'] = $jump; break;
						case 'YEARLY': $data['repeat_y'] = $jump; break;
					}					
				}
				if ($data['repeat_end'] == 0 && $data['repeat_num'] == 0) $data['repeat_forever'] = 1;
			}
			$data['users_to_invite'] = array();
			$data['users_to_invite'][logged_user()->getId()] = 1; 

			$status = array_var($ical_ev, 'status', 'CONFIRMED');
			switch ($status) {
				case 'CONFIRMED': $data['confirmAttendance'] = 1; break;
				case 'CANCELLED': $data['confirmAttendance'] = 2; break;
				case 'TENTATIVE': $data['confirmAttendance'] = 3; break;
			}
			
			$result[] = $data;
		}
		
		return $result;
	}
	
	function generateICalInfo($events, $calendar_name, $user = null) {
		if ($user == null) $user = logged_user();
		$ical_info = '';
		$ical_info .= "BEGIN:VCALENDAR\r\n";
		$ical_info .= "VERSION:2.0\r\n";
		$ical_info .= "PRODID:PHP\r\n";
		$ical_info .= "METHOD:REQUEST\r\n";
		$ical_info .= "X-WR-CALNAME:$calendar_name\r\n";
		
		// timezone info
		$tz = ($user->getTimezone() < 0 ? "-":"").str_pad(abs($user->getTimezone())*100, 4, '0', STR_PAD_LEFT);
		$tz_desc = $user->getTimezone() > 0 ? lang("timezone gmt +".$user->getTimezone()) : lang("timezone gmt ".$user->getTimezone());
		$ical_info .= "BEGIN:VTIMEZONE\r\n";
		$ical_info .= "TZID:$tz_desc\r\n";
		$ical_info .= "BEGIN:STANDARD\r\n";
		$ical_info .= "TZOFFSETFROM:$tz\r\n";
		$ical_info .= "TZOFFSETTO:$tz\r\n";
		$ical_info .= "END:STANDARD\r\n";
		$ical_info .= "END:VTIMEZONE\r\n";
		
		foreach ($events as $event) {
			$ical_info .= "BEGIN:VEVENT\r\n";
			
			$event_start = new DateTimeValue($event->getStart()->getTimestamp() + 3600 * $user->getTimezone());
			$event_duration = new DateTimeValue($event->getDuration()->getTimestamp() + 3600 * $user->getTimezone());
			
			$startNext = new DateTimeValue($event_start->getTimestamp());
			$startNext->add('d', 1);
			if ($event->getTypeId() == 2) $ical_info .= "DTSTART;VALUE=DATE:" . $event_start->format('Ymd') ."\r\n";
			else $ical_info .= "DTSTART:" . $event_start->format('Ymd') ."T". $event_start->format('His') ."\r\n";
			if ($event->getTypeId() == 2) $ical_info .= "DTEND;VALUE=DATE:" . $startNext->format('Ymd') ."\r\n";
			else $ical_info .= "DTEND:" . $event_duration->format('Ymd') ."T". $event_duration->format('His') ."\r\n";

			$uid = $event->getId() . "@";
			$url = str_replace('http://', '', ROOT_URL);
			$uid .= str_replace('www.', '', $url);
			
			$description = str_replace(array(chr(13).chr(10), chr(13), chr(10)),'\n', $event->getDescription());
			$ical_info .= "DESCRIPTION:$description\r\n";
            $ical_info .= "SUMMARY:" . $event->getSubject() . "\r\n";
		    $ical_info .= "UID:$uid\r\n";
		    $ical_info .= "SEQUENCE:0\r\n";
		    $ical_info .= "DTSTAMP:".$event->getCreatedOn()->format('Ymd').'T'.$event->getCreatedOn()->format('His')."\r\n";
			
		    $invitations = $event->getInvitations();
			if ($invitations != null && is_array($invitations) && $invitations[logged_user()->getId()] != null) {
				$inv = $invitations[logged_user()->getId()];
		    	$inv->getInvitationState();
		    	if ($inv->getInvitationState() == 1) $ical_info .= "STATUS:CONFIRMED\r\n"; 
		    	else if ($inv->getInvitationState() == 2) $ical_info .= "STATUS:CANCELLED\r\n";
		    	else $ical_info .= "STATUS:TENTATIVE\r\n";
			}
			$rrule = '';
			if ($event->getRepeatD() > 0 || $event->getRepeatM() > 0 || $event->getRepeatY() > 0 || $event->getRepeatForever() > 0) {
				$rrule_ok = true;
				if ($event->getRepeatD() > 0) {
					if ($event->getRepeatD() % 7 == 0) {
						$freq = "FREQ=WEEKLY;";
						$interval = "INTERVAL=".($event->getRepeatD() / 7);
					} else {
						$freq = "FREQ=DAILY;";
						$interval = "INTERVAL=".$event->getRepeatD();
					}
				} else if ($event->getRepeatM() > 0) {
					$freq = "FREQ=MONTHLY;";
					$interval = "INTERVAL=".$event->getRepeatM();
				} else if ($event->getRepeatY() > 0) {
					$freq = "FREQ=YEARLY;";
					$interval = "INTERVAL=".$event->getRepeatY();
				} else {
					$rrule_ok = false;
				}
				$until = '';
				$count = '';
				if (!$event->getRepeatForever() && $event->getRepeatNum() > 0) $count = ";COUNT=".$event->getRepeatNum();
				else if (!$event->getRepeatForever() && $event->getRepeatEnd()) $until = ";UNTIL=".$event->getRepeatEnd()->format('Ymd').'T'.$event->getRepeatEnd()->format('His');
				
				if ($rrule_ok) $rrule = "RRULE:$freq$interval$count$until\r\n";
			}
		    $ical_info .= $rrule;
		    
		    $ical_info .= "END:VEVENT\r\n";
		}
		
		$ical_info .= "END:VCALENDAR\r\n";
		
		return $ical_info;
	}

}

?>