From 2170f4a7b1f9702b6a8a68611596f7ae135c8a5a Mon Sep 17 00:00:00 2001
From: Stefan Hacker <duffy@debian-linux-terminal.local>
Date: Sun, 12 Apr 2026 13:10:54 +0200
Subject: [PATCH] feat: Kalender-Ansicht aktualisiert sich live via SSE

Backend:
Neuer Event-Typ 'calendar' im Broadcaster. Wird bei Event-CRUD,
Serien-Ausnahmen, Freigaben hinzufuegen/entfernen und beim
Loeschen ganzer Kalender emittiert. Empfaenger: Eigentuemer +
alle User mit CalendarShare auf dem jeweiligen Kalender.

Frontend:
CalendarView oeffnet beim Mount eine EventSource zu
/api/sync/events und reloaded Kalenderliste + Events bei jedem
'calendar'-Event (300ms debounced). Damit sehen beteiligte
Nutzer Aenderungen in praktisch Echtzeit - kein F5 mehr noetig.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 backend/app/api/calendar.py         | 23 +++++++++++++++++++++++
 backend/app/services/events.py      | 13 +++++++++++++
 frontend/src/views/CalendarView.vue | 29 ++++++++++++++++++++++++++++-
 3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/backend/app/api/calendar.py b/backend/app/api/calendar.py
index 9ff6c69..903ab15 100644
--- a/backend/app/api/calendar.py
+++ b/backend/app/api/calendar.py
@@ -9,6 +9,11 @@ from app.api.auth import token_required
 from app.extensions import db, bcrypt
 from app.models.calendar import Calendar, CalendarEvent, CalendarShare
 from app.models.user import User
+from app.services.events import notify_calendar_change
+
+
+def _calendar_recipients(cal: Calendar):
+    return [s.shared_with_id for s in CalendarShare.query.filter_by(calendar_id=cal.id).all()]
 
 
 def _redact_if_private(event_dict: dict, is_owner: bool) -> dict:
@@ -149,8 +154,12 @@ def delete_calendar(cal_id):
     if not cal or cal.owner_id != user.id:
         return jsonify({'error': 'Nicht gefunden oder keine Berechtigung'}), 404
 
+    recipients = _calendar_recipients(cal)
+    owner_id = cal.owner_id
+    cal_id = cal.id
     db.session.delete(cal)
     db.session.commit()
+    notify_calendar_change(owner_id, cal_id, 'deleted', shared_with=recipients)
     return jsonify({'message': 'Kalender geloescht'}), 200
 
 
@@ -235,6 +244,8 @@ def create_event(cal_id):
     )
     db.session.add(event)
     db.session.commit()
+    notify_calendar_change(cal.owner_id, cal.id, 'event',
+                           shared_with=_calendar_recipients(cal))
     return jsonify(event.to_dict()), 201
 
 
@@ -281,6 +292,8 @@ def update_event(event_id):
     )
     event.updated_at = datetime.now(timezone.utc)
     db.session.commit()
+    notify_calendar_change(cal.owner_id, cal.id, 'event',
+                           shared_with=_calendar_recipients(cal))
     return jsonify(event.to_dict()), 200
 
 
@@ -369,8 +382,12 @@ def delete_event(event_id):
     if err:
         return err
 
+    cal = db.session.get(Calendar, event.calendar_id)
     db.session.delete(event)
     db.session.commit()
+    if cal:
+        notify_calendar_change(cal.owner_id, cal.id, 'event',
+                               shared_with=_calendar_recipients(cal))
     return jsonify({'message': 'Event geloescht'}), 200
 
 
@@ -418,6 +435,9 @@ def share_calendar(cal_id):
         except Exception:
             pass
 
+    notify_calendar_change(cal.owner_id, cal.id, 'share',
+                           shared_with=[target.id, *_calendar_recipients(cal)])
+
     return jsonify({'message': f'Kalender mit {username} geteilt'}), 200
 
 
@@ -450,8 +470,11 @@ def remove_calendar_share(cal_id, share_id):
     if not share or share.calendar_id != cal_id:
         return jsonify({'error': 'Freigabe nicht gefunden'}), 404
 
+    target_id = share.shared_with_id
     db.session.delete(share)
     db.session.commit()
+    notify_calendar_change(cal.owner_id, cal.id, 'share',
+                           shared_with=[target_id, *_calendar_recipients(cal)])
     return jsonify({'message': 'Freigabe entfernt'}), 200
 
 
diff --git a/backend/app/services/events.py b/backend/app/services/events.py
index 92f95d5..6552de5 100644
--- a/backend/app/services/events.py
+++ b/backend/app/services/events.py
@@ -79,3 +79,16 @@ def notify_file_change(owner_id: int, file_id: int | None, change: str,
         'change': change,  # 'created' | 'updated' | 'deleted' | 'locked' | 'unlocked'
         'file_id': file_id,
     })
+
+
+def notify_calendar_change(owner_id: int, calendar_id: int, change: str,
+                           shared_with: Iterable[int] = ()) -> None:
+    """Emit a calendar-level change event (event added/changed/deleted or
+    share membership changed). Sent to owner + all users the calendar is
+    shared with."""
+    recipients = [owner_id, *shared_with]
+    broadcaster.publish(recipients, {
+        'type': 'calendar',
+        'change': change,  # 'event'|'share'|'deleted'
+        'calendar_id': calendar_id,
+    })
diff --git a/frontend/src/views/CalendarView.vue b/frontend/src/views/CalendarView.vue
index 7baa8ae..3983db9 100644
--- a/frontend/src/views/CalendarView.vue
+++ b/frontend/src/views/CalendarView.vue
@@ -260,7 +260,7 @@
 </template>
 
 <script setup>
-import { ref, computed, onMounted, reactive, watch } from 'vue'
+import { ref, computed, onMounted, onUnmounted, reactive, watch } from 'vue'
 import { useToast } from 'primevue/usetoast'
 import { useAuthStore } from '../stores/auth'
 import apiClient from '../api/client'
@@ -858,9 +858,36 @@ watch(() => eventForm.value.all_day, (allDay) => {
   eventForm.value.dtend = fix(eventForm.value.dtend)
 })
 
+// Live updates via SSE: refresh calendar list + events when anything
+// relevant changes (own or shared).
+let eventSource = null
+let reloadTimer = null
+
+function scheduleReload() {
+  if (reloadTimer) return
+  reloadTimer = setTimeout(async () => {
+    reloadTimer = null
+    await loadCalendars()
+    refreshEvents()
+  }, 300)
+}
+
 onMounted(async () => {
   await loadCalendars()
   refreshEvents()
+  if (auth.accessToken) {
+    try {
+      eventSource = new EventSource(`/api/sync/events?token=${encodeURIComponent(auth.accessToken)}`)
+      eventSource.addEventListener('calendar', scheduleReload)
+      eventSource.addEventListener('message', scheduleReload)
+      eventSource.onerror = () => { /* auto-reconnects */ }
+    } catch { /* ignore */ }
+  }
+})
+
+onUnmounted(() => {
+  if (reloadTimer) { clearTimeout(reloadTimer); reloadTimer = null }
+  if (eventSource) { eventSource.close(); eventSource = null }
 })
 </script>