[locationinfo] Revert HisInOne calendar workaroundHEADmaster

The hack introduced in 87686da817dfd349c9f89a01065f799408e29f10 to work
around HisInOne returning incomplete data in ical files is obsolete, now
that HisInOne seems to have fixed this bug.

2 files changed, 7 insertions, 71 deletions

diff --git a/modules-available/locationinfo/inc/coursebackend/coursebackend_hisinone.inc.php b/modules-available/locationinfo/inc/coursebackend/coursebackend_hisinone.inc.php
index d3487f32..a559af76 100644
--- a/modules-available/locationinfo/inc/coursebackend/coursebackend_hisinone.inc.php
+++ b/modules-available/locationinfo/inc/coursebackend/coursebackend_hisinone.inc.php
@@ -55,79 +55,16 @@ class CourseBackend_HisInOne extends ICalCourseBackend
 	{
 		if (!$this->isOK())
 			return false;
-		// Unfortunately, HisInOne returns an internal server error if you pass an invalid roomId.
-		// So we just try a bunch and see if anything works. Even if this fails, using
-		// the backend should work, given the URL is actually correct.
+		// Older HisInOne versions returned an internal server error if you pass an invalid roomId.
+		// Newer ones seem to return 200 OK with an empty ical file. Nevertheless, keep this attempt
+		// with trying random room ids, in case the behavior changes again in the future.
 		foreach ([60, 100, 5, 10, 11, 12, 13, 14, 15, 50, 110, 200, 210, 250, 300, 333, 500, 1000, 2000] as $roomId) {
-			// Use parent as we don't care about the periodId shenanigans
-			if (parent::downloadIcal((string)$roomId, time() + 60) !== null)
+			if ($this->downloadIcal((string)$roomId, time() + 60) !== null)
 				return true;
 		}
 		return false;
 	}
 
-	protected function downloadIcal(string $roomId, ?int $deadline, ?string $appendToUrl = null, ?bool $limitRange = true): ?array
-	{
-		$events = parent::downloadIcal($roomId, $deadline, null, false);
-		if (empty($events))
-			return $events;
-		$periodIds = [];
-		$finalEvents = [];
-		$dtStart = strtotime('-7 days');
-		$dtEnd = strtotime('+7 days');
-		foreach ($events as $event) {
-			if (isset($event->url) && preg_match('/[&?]periodId=([0-9]+)(&|$)/', $event->url, $out)) {
-				// Collect periodIds from URLs to find more lectures. While the HisInOne help says that the periodId
-				// parameter can simply be removed, this is not true. In practice, some lectures that take place even
-				// on the current day or week might not be returned in the resulting ical file, unless you the proper
-				// current periodId. BUT WAIT THERE'S MORE: Even with the current periodId, some lectures don't get
-				// returned, so we start brute-forcing semi-random periodIds, while at the same time discovering
-				// new ones from the returned calendars.
-				$periodId = (int)$out[1];
-				for ($i = max($periodId - 2, 1); $i <= $periodId + 2; $i++) {
-					$periodIds[$i] = $i;
-				}
-			}
-			if (strtotime($event->dtstart) > $dtEnd || strtotime($event->dtend) < $dtStart)
-				continue;
-			$finalEvents[$this->hash($event)] = $event;
-		}
-		// Now re-query with all the periodIds we found
-		$dupCheck = [];
-		while (($periodId = array_pop($periodIds)) !== null) {
-			if (count($dupCheck) > 35)
-				break;
-			if (isset($dupCheck[$periodId]))
-				continue;
-			if ($deadline !== null && $deadline - time() <= 1) {
-				error_log("Timeout exceeded (" . count($finalEvents) . " events & " . count($dupCheck) . " periodIds) for $roomId");
-				break;
-			}
-			$dupCheck[$periodId] = true;
-			$events = parent::downloadIcal($roomId, $deadline, '&periodId=' . $periodId, $limitRange);
-			if (empty($events))
-				continue;
-			foreach ($events as $event) {
-				if (strtotime($event->dtstart) <= $dtEnd && strtotime($event->dtend) >= $dtStart) {
-					$finalEvents[$this->hash($event)] = $event;
-				}
-				// Collect more periodIds
-				if (isset($event->url) && preg_match('/[&?]periodId=([0-9]+)(&|$)/', $event->url, $out)) {
-					$newPeriodId = (int)$out[1];
-					for ($i = max($newPeriodId - 2, 1); $i <= $newPeriodId + 2; $i++) {
-						$periodIds[$i] = $i;
-					}
-				}
-			}
-		}
-		return array_values($finalEvents);
-	}
-
-	private function hash(ICalEvent $event): string
-	{
-		return md5($event->dtstart . $event->dtend . ($event->uid ?? $event->summary));
-	}
-
 	public function getCacheTime(): int
 	{
 		return 40 * 60;
diff --git a/modules-available/locationinfo/inc/icalcoursebackend.inc.php b/modules-available/locationinfo/inc/icalcoursebackend.inc.php
index c9113ec6..493d0008 100644
--- a/modules-available/locationinfo/inc/icalcoursebackend.inc.php
+++ b/modules-available/locationinfo/inc/icalcoursebackend.inc.php
@@ -38,17 +38,16 @@ abstract class ICalCourseBackend extends CourseBackend
 	 *
 	 * @param string $roomId The ID of the room for which iCal data is to be downloaded.
 	 * @param ?int $deadline Optional deadline timestamp for the download operation.
-	 * @param ?string $appendToUrl Optional appendage to the URL used for the download.
 	 *
 	 * @return ?ICalEvent[] An array of iCal events if successful, or null on failure.
 	 */
-	protected function downloadIcal(string $roomId, ?int $deadline, ?string $appendToUrl = null, ?bool $limitRange = true): ?array
+	protected function downloadIcal(string $roomId, ?int $deadline): ?array
 	{
 		if (!$this->isOK())
 			return null;
 
 		try {
-			$ical = new ICalParser($limitRange ? ['filterDaysBefore' => 7, 'filterDaysAfter' => 7] : []);
+			$ical = new ICalParser(['filterDaysBefore' => 7, 'filterDaysAfter' => 7]);
 		} catch (Exception $e) {
 			$this->addError('Error instantiating ICalParser: ' . $e->getMessage(), true);
 			return null;
@@ -70,7 +69,7 @@ abstract class ICalCourseBackend extends CourseBackend
 			CURLOPT_FOLLOWLOCATION => true,
 			CURLOPT_SSL_VERIFYHOST => $this->verifyHostname ? 2 : 0,
 			CURLOPT_SSL_VERIFYPEER => $this->verifyCert ? 1 : 0,
-			CURLOPT_URL => str_replace('%ID%', $roomId, $this->location . ($appendToUrl ?? '')),
+			CURLOPT_URL => str_replace('%ID%', $roomId, $this->location),
 			CURLOPT_TIMEOUT => min(20, $timeout),
 			CURLOPT_CONNECTTIMEOUT => 4,
 		];