From 56713931b170c07c2c944dfc8d1042593759d49c Mon Sep 17 00:00:00 2001
From: Richard Steinmetz <richard@steinmetz.cloud>
Date: Tue, 8 Aug 2023 14:51:08 +0200
Subject: [PATCH] feat(caldav): linkify location in scheduling mails

Signed-off-by: Richard Steinmetz <richard@steinmetz.cloud>
---
 apps/dav/lib/CalDAV/Schedule/IMipService.php | 37 ++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/apps/dav/lib/CalDAV/Schedule/IMipService.php b/apps/dav/lib/CalDAV/Schedule/IMipService.php
index 8596500f32009..5be414abb1241 100644
--- a/apps/dav/lib/CalDAV/Schedule/IMipService.php
+++ b/apps/dav/lib/CalDAV/Schedule/IMipService.php
@@ -6,6 +6,7 @@
  * @copyright 2022 Anna Larch <anna.larch@gmx.net>
  *
  * @author Anna Larch <anna.larch@gmx.net>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
@@ -105,6 +106,33 @@ private function generateDiffString(VEvent $vevent, VEvent $oldVEvent, string $p
 		return $newstring;
 	}
 
+	/**
+	 * Like generateDiffString() but linkifies the property values if they are urls.
+	 */
+	private function generateLinkifiedDiffString(VEvent $vevent, VEvent $oldVEvent, string $property, string $default): ?string {
+		$strikethrough = "<span style='text-decoration: line-through'>%s</span><br />%s";
+		if (!isset($vevent->$property)) {
+			return $default;
+		}
+		$newstring = $vevent->$property->getValue();
+		if (isset($oldVEvent->$property) && $oldVEvent->$property->getValue() !== $newstring) {
+			$oldstring = $oldVEvent->$property->getValue();
+			return sprintf($strikethrough, $this->linkify($oldstring) ?? $oldstring, $this->linkify($newstring) ?? $newstring);
+		}
+		return $this->linkify($newstring) ?? $newstring;
+	}
+
+	/**
+	 * Convert a given url to a html link element or return null otherwise.
+	 */
+	private function linkify(string $url): ?string {
+		if (!str_starts_with($url, 'http://') && !str_starts_with($url, 'https://')) {
+			return null;
+		}
+
+		return sprintf('<a href="%1$s">%1$s</a>', htmlspecialchars($url));
+	}
+
 	/**
 	 * @param VEvent $vEvent
 	 * @param VEvent|null $oldVEvent
@@ -121,11 +149,15 @@ public function buildBodyData(VEvent $vEvent, ?VEvent $oldVEvent): array {
 
 		$data['meeting_url_html'] = self::readPropertyWithDefault($vEvent, 'URL', $defaultVal);
 
+		if (($locationHtml = $this->linkify($data['meeting_location'])) !== null) {
+			$data['meeting_location_html'] = $locationHtml;
+		}
+
 		if(!empty($oldVEvent)) {
 			$oldMeetingWhen = $this->generateWhenString($oldVEvent);
 			$data['meeting_title_html']	= $this->generateDiffString($vEvent, $oldVEvent, 'SUMMARY', $data['meeting_title']);
 			$data['meeting_description_html'] = $this->generateDiffString($vEvent, $oldVEvent, 'DESCRIPTION', $data['meeting_description']);
-			$data['meeting_location_html'] = $this->generateDiffString($vEvent, $oldVEvent, 'LOCATION', $data['meeting_location']);
+			$data['meeting_location_html'] = $this->generateLinkifiedDiffString($vEvent, $oldVEvent, 'LOCATION', $data['meeting_location']);
 
 			$oldUrl = self::readPropertyWithDefault($oldVEvent, 'URL', $defaultVal);
 			$data['meeting_url_html'] = !empty($oldUrl) && $oldUrl !== $data['meeting_url'] ? sprintf('<a href="%1$s">%1$s</a>', $oldUrl) : $data['meeting_url'];
@@ -246,6 +278,7 @@ public function buildCancelledBodyData(VEvent $vEvent): array {
 		$newDescription = isset($vEvent->DESCRIPTION) && (string)$vEvent->DESCRIPTION !== '' ? (string)$vEvent->DESCRIPTION : $defaultVal;
 		$newUrl = isset($vEvent->URL) && (string)$vEvent->URL !== '' ? sprintf('<a href="%1$s">%1$s</a>', $vEvent->URL) : $defaultVal;
 		$newLocation = isset($vEvent->LOCATION) && (string)$vEvent->LOCATION !== '' ? (string)$vEvent->LOCATION : $defaultVal;
+		$newLocationHtml = $this->linkify($newLocation) ?? $newLocation;
 
 		$data = [];
 		$data['meeting_when_html'] = $newMeetingWhen === '' ?: sprintf($strikethrough, $newMeetingWhen);
@@ -256,7 +289,7 @@ public function buildCancelledBodyData(VEvent $vEvent): array {
 		$data['meeting_description'] = $newDescription;
 		$data['meeting_url_html'] = $newUrl !== '' ? sprintf($strikethrough, $newUrl) : '';
 		$data['meeting_url'] = isset($vEvent->URL) ? (string)$vEvent->URL : '';
-		$data['meeting_location_html'] = $newLocation !== '' ? sprintf($strikethrough, $newLocation) : '';
+		$data['meeting_location_html'] = $newLocationHtml !== '' ? sprintf($strikethrough, $newLocationHtml) : '';
 		$data['meeting_location'] = $newLocation;
 		return $data;
 	}