feat: Gruppen-Sichtbarkeit – genau ein designierter Kalender pro Person

Neues user_settings.group_visible_calendar_id: jedes Mitglied waehlt EINEN
lokalen Kalender, der in seinen Gruppen sichtbar ist. Die kombinierte
Ansicht ueberlagert nur diesen (statt aller) Kalender je Mitglied + den
Gruppenkalender; private Termine weiter gefiltert. Settings GET/PUT erweitert
(nullbar). Tests angepasst + ergaenzt (14 gruen).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/main.py

@@ -157,6 +157,12 @@ def _migrate():
             logging.info("Migration: added is_private to local_events")
         except Exception:
             pass
+        try:
+            conn.execute(text("ALTER TABLE user_settings ADD COLUMN group_visible_calendar_id INTEGER"))
+            conn.commit()
+            logging.info("Migration: added group_visible_calendar_id to user_settings")
+        except Exception:
+            pass
 
 _migrate()
 

backend/models.py

@@ -95,6 +95,9 @@ class UserSettings(Base):
     # How this user's private events appear to other group members:
     # 'hidden' = invisible, 'busy' = anonymous busy block (default).
     private_event_visibility = Column(String(10), default="busy")
+    # The single local calendar this user shares into all their groups
+    # (combined view shows only this calendar per member). NULL = share nothing.
+    group_visible_calendar_id = Column(Integer, nullable=True)
 
     user = relationship("User", back_populates="settings")
 

backend/routers/groups_router.py

@@ -313,16 +313,26 @@ def combined_events(
                     b = _strip_busy(b)
                 all_events.append(b)
 
-    # Each member's own local calendars (excluding the group calendar to avoid dupes).
+    # Each member shares exactly one calendar into their groups, chosen in their
+    # settings (group_visible_calendar_id). Only that calendar is overlaid.
     for m in members:
-        member_cals = (
-            db.query(models.LocalCalendar)
-            .filter(models.LocalCalendar.user_id == m.user_id)
-            .all()
+        settings = (
+            db.query(models.UserSettings)
+            .filter(models.UserSettings.user_id == m.user_id)
+            .first()
         )
-        for cal in member_cals:
-            if group_cal_id is not None and cal.id == group_cal_id:
-                continue
+        visible_id = settings.group_visible_calendar_id if settings else None
+        if visible_id is None or visible_id == group_cal_id:
+            continue
+        cal = (
+            db.query(models.LocalCalendar)
+            .filter(
+                models.LocalCalendar.id == visible_id,
+                models.LocalCalendar.user_id == m.user_id,  # must be the member's own
+            )
+            .first()
+        )
+        if cal:
             emit_calendar(cal, m.user_id, is_group=False)
 
     # The group calendar itself.

backend/routers/settings_router.py

@@ -28,6 +28,7 @@ class SettingsUpdate(BaseModel):
     line_color: Optional[str] = None
     bg_color:   Optional[str] = None
     private_event_visibility: Optional[str] = None
+    group_visible_calendar_id: Optional[int] = None
 
 
 def _settings_dict(s: models.UserSettings) -> dict:
@@ -48,6 +49,7 @@ def _settings_dict(s: models.UserSettings) -> dict:
         "line_color": s.line_color,
         "bg_color":   s.bg_color,
         "private_event_visibility": s.private_event_visibility or "busy",
+        "group_visible_calendar_id": s.group_visible_calendar_id,
     }
 
 
@@ -90,7 +92,7 @@ def update_settings(
     # For these three override colours, an explicit null is meaningful
     # ("reset to default") and must be persisted as NULL. All other fields
     # keep the previous behaviour where a null/missing value is ignored.
-    NULLABLE_OVERRIDES = {"text_color", "line_color", "bg_color"}
+    NULLABLE_OVERRIDES = {"text_color", "line_color", "bg_color", "group_visible_calendar_id"}
     update_data = data.model_dump(exclude_unset=True)
     for field, value in update_data.items():
         if field in NULLABLE_OVERRIDES:

backend/tests/test_collaboration.py

@@ -155,8 +155,9 @@ def test_combined_view_marks_owner_and_group_event(client):
     gid = group["id"]
     gcal = group["group_calendar_id"]
 
-    # Bob's own calendar + event.
+    # Bob's own calendar + event; Bob designates it as his group-visible calendar.
     b_cal = _make_calendar(client, b_tok, "Bobs Kalender")
+    client.put("/api/settings/", headers=auth(b_tok), json={"group_visible_calendar_id": b_cal})
     _make_event(client, b_tok, b_cal, "Bobs Termin")
     # A group-calendar event.
     _make_event(client, admin, gcal, "Gruppentermin")
@@ -185,6 +186,7 @@ def test_private_visibility_hidden_and_busy(client):
     gid = group["id"]
 
     b_cal = _make_calendar(client, b_tok, "Bobs Kalender")
+    client.put("/api/settings/", headers=auth(b_tok), json={"group_visible_calendar_id": b_cal})
     _make_event(client, b_tok, b_cal, "Geheimes", private=True,
                 start="2026-06-15T10:00:00+00:00", end="2026-06-15T11:00:00+00:00")
 
@@ -204,6 +206,25 @@ def test_private_visibility_hidden_and_busy(client):
     assert not any(e["start"].startswith("2026-06-15") for e in seen2)
 
 
+def test_member_calendar_hidden_until_designated(client):
+    admin = register_admin(client)
+    b_id, b_tok = create_user(client, admin, "bob")
+    group = client.post("/api/groups/", headers=auth(admin),
+                        json={"name": "Team", "member_ids": [b_id]}).json()
+    gid = group["id"]
+    b_cal = _make_calendar(client, b_tok, "Bobs Kalender")
+    _make_event(client, b_tok, b_cal, "Bobs Termin")
+
+    # Not designated yet -> admin doesn't see Bob's calendar in the combined view.
+    seen = _combined_titles(client, admin, gid)
+    assert not any(e["title"] == "Bobs Termin" for e in seen)
+
+    # After Bob designates it, it appears.
+    client.put("/api/settings/", headers=auth(b_tok), json={"group_visible_calendar_id": b_cal})
+    seen2 = _combined_titles(client, admin, gid)
+    assert any(e["title"] == "Bobs Termin" for e in seen2)
+
+
 def test_private_visibility_validation(client):
     admin = register_admin(client)
     r = client.put("/api/settings/", headers=auth(admin), json={"private_event_visibility": "bogus"})