nextcloud/apps/calendar/ajax/import/import.php

<?php
/**
 * Copyright (c) 2012 Georg Ehrke <ownclouddev at georgswebsite dot de>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */
//check for calendar rights or create new one
ob_start();

OCP\JSON::checkLoggedIn();
OCP\App::checkAppEnabled('calendar');
session_write_close();

$nl="\r\n";
$comps = array('VEVENT'=>true, 'VTODO'=>true, 'VJOURNAL'=>true);

global $progresskey;
$progresskey = 'calendar.import-' . $_POST['progresskey'];

if (isset($_POST['progress']) && $_POST['progress']) {
	echo OC_Cache::get($progresskey);
	die;
}

function writeProgress($pct) {
	global $progresskey;
	OC_Cache::set($progresskey, $pct, 300);
}
writeProgress('10');
$file = OC_Filesystem::file_get_contents($_POST['path'] . '/' . $_POST['file']);
if($_POST['method'] == 'new'){
	$id = OC_Calendar_Calendar::addCalendar(OCP\USER::getUser(), $_POST['calname']);
	OC_Calendar_Calendar::setCalendarActive($id, 1);
}else{
	$calendar = OC_Calendar_App::getCalendar($_POST['id']);
	if($calendar['userid'] != OCP\USER::getUser()){
		OCP\JSON::error();
		exit();
	}
	$id = $_POST['id'];
}
writeProgress('20');
// normalize the newlines
$file = str_replace(array("\r","\n\n"), array("\n","\n"), $file);
$lines = explode("\n", $file);
unset($file);
writeProgress('30');
// analyze the file, group components by uid, and keep refs to originating calendar object
// $cals is array calendar objects, keys are 1st line# $cal, ie array( $cal => $caldata )
//   $caldata is array( 'first' => 1st component line#, 'last' => last comp line#, 'end' => end line# )
//   $caldata is used to create prefix/suffix strings when building import text
// $uids is array of component arrays, keys are $uid, ie array( $uid => array( $beginlineno => $component ) )
//   $component is array( 'end' => end line#, 'cal'=> $cal )
$comp=$uid=$cal=false;
$cals=$uids=array();
$i = 0;
foreach($lines as $line) {

	if(strpos($line, ':')!==false) {
		list($attr, $val) = explode(':', strtoupper($line));
		if ($attr == 'BEGIN' && $val == 'VCALENDAR') {
			$cal = $i;
			$cals[$cal] = array('first'=>$i,'last'=>$i,'end'=>$i);
		} elseif ($attr =='BEGIN' && $cal!==false && isset($comps[$val])) {
			$comp = $val;
			$beginNo = $i;
		} elseif ($attr == 'END' && $cal!==false && $val == 'VCALENDAR') {
			if($comp!==false) {
				unset($cals[$cal]); // corrupt calendar, unset it
			} else {
				$cals[$cal]['end'] = $i;
			}
			$comp=$uid=$cal=false; // reset calendar
		} elseif ($attr == 'END' && $comp!==false && $val == $comp) {
			if(! $uid) {
				$uid = OC_Calendar_Object::createUID();
			}
			$uids[$uid][$beginNo] = array('end'=>$i, 'cal'=>$cal);
			if ($cals[$cal]['first'] == $cal) {
				$cals[$cal]['first'] = $beginNo;
			}
			$cals[$cal]['last'] = $i;
			$comp=$uid=false; // reset component
		} elseif ($attr =="UID" && $comp!==false) {
			list($attr, $uid) = explode(':', $line);
		}
	}
	$i++;
}
// import the calendar
writeProgress('60');
foreach($uids as $uid) {
	
	$prefix=$suffix=$content=array();
	foreach($uid as $begin=>$details) {
		
		$cal = $details['cal'];
		if(!isset($cals[$cal])) {
			continue; // from corrupt/incomplete calendar
		}
		$cdata = $cals[$cal];
		// if we have multiple components from different calendar objects,
		// we should really merge their elements (enhancement?) -- 1st one wins for now.
		if(! count($prefix)) {
			$prefix = array_slice($lines, $cal, $cdata['first'] - $cal);
		}
		if(! count($suffix)) {
			$suffix = array_slice($lines, $cdata['last']+1, $cdata['end'] - $cdata['last']);
		}
		$content = array_merge($content, array_slice($lines, $begin, $details['end'] - $begin + 1));
	}
	if(count($content)) {
		$import = join($nl, array_merge($prefix, $content, $suffix)) . $nl;
		OC_Calendar_Object::add($id, $import);
	}
}
// finished import
writeProgress('100');
sleep(3);
OC_Cache::remove($progresskey);
OCP\JSON::success();