From 1b7e67dd9760c159e525cd88face00e28a260d13 Mon Sep 17 00:00:00 2001
From: Meier Lukas <meierschlumpf@gmail.com>
Date: Sat, 11 Oct 2025 22:54:51 +0200
Subject: [PATCH] fix(calendar): recurring events not working (#4265)

---
 .../src/nextcloud/nextcloud.integration.ts    | 87 +++++++++++--------
 1 file changed, 52 insertions(+), 35 deletions(-)

diff --git a/packages/integrations/src/nextcloud/nextcloud.integration.ts b/packages/integrations/src/nextcloud/nextcloud.integration.ts
index 4e3dbb82e..a1f9a78e2 100644
--- a/packages/integrations/src/nextcloud/nextcloud.integration.ts
+++ b/packages/integrations/src/nextcloud/nextcloud.integration.ts
@@ -1,4 +1,7 @@
 import type { Agent } from "https";
+import dayjs from "dayjs";
+import timezone from "dayjs/plugin/timezone";
+import utc from "dayjs/plugin/utc";
 import type { RequestInit as NodeFetchRequestInit } from "node-fetch";
 import * as ical from "node-ical";
 import { DAVClient } from "tsdav";
@@ -14,6 +17,9 @@ import type { TestingResult } from "../base/test-connection/test-connection-serv
 import type { ICalendarIntegration } from "../interfaces/calendar/calendar-integration";
 import type { CalendarEvent } from "../interfaces/calendar/calendar-types";
 
+dayjs.extend(utc);
+dayjs.extend(timezone);
+
 @HandleIntegrationErrors([integrationTsdavHttpErrorHandler])
 export class NextcloudIntegration extends Integration implements ICalendarIntegration {
   protected async testingAsync(input: IntegrationTestingInput): Promise<TestingResult> {
@@ -41,47 +47,58 @@ export class NextcloudIntegration extends Integration implements ICalendarIntegr
       )
     ).flat();
 
-    return calendarEvents.map((event): CalendarEvent => {
-      // @ts-expect-error the typescript definitions for this package are wrong
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-call,@typescript-eslint/no-unsafe-member-access
-      const icalData = ical.default.parseICS(event.data) as ical.CalendarResponse;
-      const veventObject = Object.values(icalData).find((data) => data.type === "VEVENT");
+    return calendarEvents
+      .map((event) => {
+        // @ts-expect-error the typescript definitions for this package are wrong
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-call,@typescript-eslint/no-unsafe-member-access
+        const icalData = ical.default.parseICS(event.data) as ical.CalendarResponse;
+        const veventObject = Object.values(icalData).find((data) => data.type === "VEVENT");
 
-      if (!veventObject) {
-        throw new Error(`Invalid event data object: ${JSON.stringify(event.data)}. Unable to process the calendar.`);
-      }
+        if (!veventObject) {
+          throw new Error(`Invalid event data object: ${JSON.stringify(event.data)}. Unable to process the calendar.`);
+        }
 
-      logger.debug(`Converting VEVENT event to ${event.etag} from Nextcloud: ${JSON.stringify(veventObject)}`);
+        logger.debug(`Converting VEVENT event to ${event.etag} from Nextcloud: ${JSON.stringify(veventObject)}`);
 
-      const date = veventObject.start;
+        const eventUrlWithoutHost = new URL(event.url).pathname;
+        const eventSlug = Buffer.from(eventUrlWithoutHost).toString("base64url");
 
-      const eventUrlWithoutHost = new URL(event.url).pathname;
-      const dateInMillis = veventObject.start.valueOf();
+        const startDates = veventObject.rrule ? veventObject.rrule.between(start, end) : [veventObject.start];
 
-      const url = this.url(
-        `/apps/calendar/timeGridWeek/now/edit/sidebar/${Buffer.from(eventUrlWithoutHost).toString("base64url")}/${dateInMillis / 1000}`,
-      );
+        const durationMs = veventObject.end.getTime() - veventObject.start.getTime();
 
-      return {
-        title: veventObject.summary,
-        subTitle: null,
-        description: veventObject.description,
-        startDate: date,
-        endDate: veventObject.end,
-        image: null,
-        location: veventObject.location || null,
-        indicatorColor: "#ff8600",
-        links: [
-          {
-            href: url.toString(),
-            name: "Nextcloud",
-            logo: "/images/apps/nextcloud.svg",
-            color: undefined,
-            isDark: true,
-          },
-        ],
-      };
-    });
+        return startDates.map((startDate) => {
+          const timezoneOffsetMinutes = veventObject.rrule?.origOptions.tzid
+            ? dayjs(startDate).tz(veventObject.rrule.origOptions.tzid).utcOffset()
+            : 0;
+          const utcStartDate = new Date(startDate.getTime() - timezoneOffsetMinutes * 60 * 1000);
+          const endDate = new Date(utcStartDate.getTime() + durationMs);
+          const dateInMillis = utcStartDate.valueOf();
+
+          return {
+            title: veventObject.summary,
+            subTitle: null,
+            description: veventObject.description,
+            startDate: utcStartDate,
+            endDate,
+            image: null,
+            location: veventObject.location || null,
+            indicatorColor: "#ff8600",
+            links: [
+              {
+                href: this.url(
+                  `/apps/calendar/timeGridWeek/now/edit/sidebar/${eventSlug}/${dateInMillis / 1000}`,
+                ).toString(),
+                name: "Nextcloud",
+                logo: "/images/apps/nextcloud.svg",
+                color: undefined,
+                isDark: true,
+              },
+            ],
+          };
+        });
+      })
+      .flat();
   }
 
   private async createCalendarClientAsync(agent?: Agent) {