From 028d4d2b07c50f2854d3cfc06f05855fa358ead3 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 19 Jan 2021 14:59:13 +0100
Subject: [locationinfo] Add generic ical backend

Closes #3824
---
 .../locationinfo/inc/icalcoursebackend.inc.php     | 151 +++++++++++++++++++++
 1 file changed, 151 insertions(+)
 create mode 100644 modules-available/locationinfo/inc/icalcoursebackend.inc.php

(limited to 'modules-available/locationinfo/inc/icalcoursebackend.inc.php')

diff --git a/modules-available/locationinfo/inc/icalcoursebackend.inc.php b/modules-available/locationinfo/inc/icalcoursebackend.inc.php
new file mode 100644
index 00000000..fba0866c
--- /dev/null
+++ b/modules-available/locationinfo/inc/icalcoursebackend.inc.php
@@ -0,0 +1,151 @@
+<?php
+
+abstract class ICalCourseBackend extends CourseBackend
+{
+
+	/** @var string */
+	private $location;
+	/** @var string */
+	private $authMethod;
+	/** @var string */
+	private $user;
+	/** @var string */
+	private $pass;
+	/** @var bool */
+	private $verifyHostname;
+	/** @var bool */
+	private $verifyCert;
+	/** @var bool|resource */
+	private $curlHandle = false;
+
+	/**
+	 * Initialize values
+	 *
+	 * @param string $location
+	 * @param bool $verifyCert
+	 * @param bool $verifyHostname
+	 * @param string $authMethod
+	 * @param string $user
+	 * @param string $pass
+	 */
+	protected function init($location, $verifyCert, $verifyHostname,
+		$authMethod = 'NONE', $user = '', $pass = '')
+	{
+		$this->verifyCert = $verifyCert;
+		$this->verifyHostname = $verifyHostname;
+		if (strpos($location, '%ID%') === false) {
+			$location .= '%ID%';
+		}
+		$this->location = $location;
+		$this->authMethod = $authMethod;
+		$this->user = $user;
+		$this->pass = $pass;
+	}
+
+	/**
+	 * @param int $roomId room id
+	 * @param callable $errorFunc
+	 * @return ICalEvent[]|null all events for this room in the range -7 days to +7 days, or NULL on error
+	 */
+	protected function downloadIcal($roomId)
+	{
+		if (!$this->isOK())
+			return null;
+		if ($this->curlHandle === false) {
+			$this->curlHandle = curl_init();
+		}
+
+		$ical = new ICalParser(['filterDaysBefore' => 7, 'filterDaysAfter' => 7]);
+		$options = [
+			CURLOPT_WRITEFUNCTION => function ($ch, $data) use ($ical) {
+				$ical->feedData($data);
+				return strlen($data);
+			},
+			CURLOPT_FOLLOWLOCATION => true,
+			CURLOPT_SSL_VERIFYHOST => $this->verifyHostname ? 2 : 0,
+			CURLOPT_SSL_VERIFYPEER => $this->verifyCert ? 1 : 0,
+			CURLOPT_URL => str_replace('%ID%', $roomId, $this->location),
+			CURLOPT_TIMEOUT => 60,
+			CURLOPT_CONNECTTIMEOUT => 4,
+		];
+		if ($this->authMethod !== 'NONE' && defined('CURLAUTH_' . $this->authMethod)) {
+			$options[CURLOPT_HTTPAUTH] = constant('CURLAUTH_' . $this->authMethod);
+			$options[CURLOPT_USERPWD] = $this->user;
+			if (!empty($this->pass)) {
+				$options[CURLOPT_USERPWD] .= ':' . $this->pass;
+			}
+		}
+
+		curl_setopt_array($this->curlHandle, $options);
+
+		$curlRet = curl_exec($this->curlHandle);
+		if (!$curlRet) {
+			$this->addError('Curl error: ' . curl_error($this->curlHandle) . ' for ' . $roomId, false);
+		}
+		$ical->finish();
+		if (!$ical->isValid()) {
+			if ($curlRet) {
+				$this->addError("Did not find a VCALENDAR in returned data for $roomId", false);
+			}
+			return null;
+		}
+		return $ical->events();
+	}
+
+	public function fetchSchedulesInternal($requestedRoomIds): array
+	{
+		if (empty($requestedRoomIds) || !$this->isOK()) {
+			return array();
+		}
+		$tTables = [];
+		foreach ($requestedRoomIds as $roomId) {
+			$data = $this->downloadIcal($roomId);
+			if ($data === null) {
+				$this->addError("Downloading ical for $roomId failed", false);
+				continue;
+			}
+			foreach ($data as $event) {
+				$tTables[$roomId][] = array(
+					'title' => $this->toTitle($event),
+					'start' => $event->dtstart,
+					'end' => $event->dtend,
+					'cancelled' => false, // ??? How
+				);
+			}
+		}
+		return $tTables;
+	}
+
+	/**
+	 * Get a usable title from either SUMMARY or DESCRIPTION
+	 * @param ICalEvent $event
+	 */
+	private function toTitle($event): string
+	{
+		$title = $event->summary;
+		if (empty($title)) {
+			$title = $event->description;
+		}
+		if (empty($title)) {
+			$title = 'Unknown';
+		}
+		return (string)preg_replace([',(\s*<br\s*/?>\s*|\r|\n|\\\r|\\\n)+,', '/\\\\([,;:])/'], ["\n", '$1'], $title);
+	}
+
+	protected function isOK(): bool
+	{
+		if (empty($this->location)) {
+			$this->addError("Credentials are not set", true);
+			return false;
+		}
+		return true;
+	}
+
+	public function __destruct()
+	{
+		if ($this->curlHandle !== false) {
+			curl_close($this->curlHandle);
+		}
+	}
+
+}
\ No newline at end of file
-- 
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