feat: iCloud-Kontaktgruppen synchronisieren und API-Endpunkte hinzufügen

Erkennt iCloud-Gruppen (vCards mit X-ADDRESSBOOKSERVER-KIND:group) beim
CardDAV-Sync und speichert sie separat in den neuen Tabellen groups und
group_members statt als Kontakte in die contacts-Tabelle.

Änderungen:
- sql/schema.sql: Neue Tabellen groups + group_members (FK CASCADE)
- src/vcard_parser.py: is_group_vcard() + parse_group() Funktionen
- src/db.py: DB-Funktionen für Gruppen (upsert, delete, replace, get)
- src/sync.py: _classify_vcards() trennt Gruppen von Kontakten
- src/api/schemas.py: Pydantic-Modelle für Gruppen-Responses
- src/api/main.py: 3 neue Endpunkte (/api/groups, /{id}, /{id}/members)
- src/api/templates/contact.html: Gruppen-Section im Kontakt-Detail
- README.md + SPEC.md: Dokumentation aktualisiert

README.md

@@ -148,6 +148,24 @@ python3 mailer.py
   aus MariaDB entfernt, ohne Archiv.
 - Nur iCloud als Quelle, Google/Microsoft sind nicht Teil dieses Repos.
 
+## Kontaktruppen
+
+iCloud-Länder speichern Gruppen als eigene vCards mit
+`X-ADDRESSBOOKSERVER-KIND:group`. Diese werden beim Sync automatisch
+erkannt und separat in den Tabellen `groups` und `group_members`
+gespeichert (nicht als Kontakte).
+
+Gruppen sind über die API abrufbar:
+
+- `GET /api/groups` — Alle Gruppen mit Member-Anzahl
+- `GET /api/groups/{id}` — Gruppe mit aufgelösten Members
+- `GET /api/groups/{id}/members` — Nur Members einer Gruppe
+- `GET /api/contacts/{id}` — Enthält `groups`-Feld mit Gruppennamen
+
+Wird ein Kontakt gelöscht, wird die Mitgliedschaft in Gruppen
+automatisch entfernt (`ON DELETE CASCADE`). Die Gruppe selbst bleibt
+erhalten.
+
 ## 11. Web-Ansicht und API (interner Zugriff über Authelia)
 
 Läuft als zweiter Service aus demselben Image, aber mit anderem
@@ -206,13 +224,16 @@ Zugriff ohne den Reverse-Proxy ist damit nicht möglich.
 |---------|------|--------------|
 | `GET` | `/` | Dashboard mit Kontaktdaten-Übersicht, letzten Sync-Status und Geburtstagen der nächsten 7 Tage (HTML) |
 | `GET` | `/search` | Web-UI -- Suchfunktion, zeigt Kontakte des eingeloggten Users |
-| `GET` | `/contacts/{id}` | Web-UI -- Detailseite eines einzelnen Kontakts |
+| `GET` | `/contacts/{id}` | Web-UI -- Detailseite eines einzelnen Kontakts (inkl. Gruppen) |
 | `GET` | `/api/health` | Health Check (`{"status": "ok"}`), kein Login nötig |
 | `GET` | `/api/contacts` | Kontaktsuche mit Pagination (`?q=...&limit=...&offset=...`) |
-| `GET` | `/api/contacts/{id}` | Einzelnen Kontakt per ID abrufen |
+| `GET` | `/api/contacts/{id}` | Einzelnen Kontakt per ID abrufen (inkl. `groups`-Feld) |
 | `GET` | `/api/contacts/count` | Anzahl der Kontakte des eingeloggten Users |
 | `GET` | `/api/contacts/birthdays/today` | Heutige Geburtstage |
 | `GET` | `/api/contacts/birthdays/upcoming` | Geburtstage der nächsten N Tage (`?days=7`, Default 7) |
+| `GET` | `/api/groups` | Gruppenliste mit Member-Anzahl |
+| `GET` | `/api/groups/{id}` | Einzelne Gruppe mit aufgelösten Members |
+| `GET` | `/api/groups/{id}/members` | Members einer Gruppe (Kontaktdaten) |
 | `GET` | `/api/sync-runs` | Letzte 50 Sync-Runs (Status, Zeitstempel, Fehler) |
 
 Alle Endpunkte (außer `/api/health`) erfordern eine Authentifizierung

SPEC.md

@@ -92,6 +92,11 @@ Siehe `sql/schema.sql`. Wichtigste Änderungen gegenüber v1:
 - Neue Tabelle `birthday_mail_log`: ein Datensatz pro Tag, an dem
   erfolgreich eine Geburtstagsmail versendet wurde, verhindert
   Doppelversand bei mehrfachem Container-Neustart am selben Tag.
+- Neue Tabellen `groups` und `group_members`: Speichert
+  iCloud-Kontaktgruppen (vCards mit `X-ADDRESSBOOKSERVER-KIND:group`)
+  und deren Mitgliedschaften. Gruppen werden beim Sync erkannt und
+  nicht als Kontakte in die `contacts`-Tabelle geschrieben.
+  `group_members` referenziert `groups(id)` mit `ON DELETE CASCADE`.
 
 ## 6. Geburtstags-Mailer
 
@@ -247,10 +252,13 @@ geteilt wird. Getrennt ist nur die **Rolle**, in der der Container läuft.
 | `GET /contacts/{id}` | HTML-Detailseite eines einzelnen Kontakts (Jinja2-Template) |
 | `GET /api/health` | Health-Check ohne Auth-Anforderung |
 | `GET /api/contacts` | Kontaktliste, Filter `q` (Freitext), Pagination `limit`/`offset` |
-| `GET /api/contacts/{id}` | Einzelner Kontakt (JSON) |
+| `GET /api/contacts/{id}` | Einzelner Kontakt (JSON), inklusive `groups`-Feld mit zugehörigen Gruppennamen |
 | `GET /api/contacts/count` | Anzahl der Kontakte des zugeordneten Accounts |
 | `GET /api/contacts/birthdays/today` | Heutige Geburtstage (kontospezifisch bzw. global für Admins) |
 | `GET /api/contacts/birthdays/upcoming` | Geburtstage der nächsten N Tage (Parameter `days`, Default 7) |
+| `GET /api/groups` | Gruppenliste mit `member_count`, Pagination `limit`/`offset` |
+| `GET /api/groups/{id}` | Einzelne Gruppe mit aufgelösten Members (Name + UID) |
+| `GET /api/groups/{id}/members` | Nur Members einer Gruppe (Kontaktdaten aufgelöst) |
 | `GET /api/sync-runs` | Sync-Historie (kontospezifisch bzw. global für Admins) |
 
 ### 12.5 Netzwerkkontext

sql/schema.sql

@@ -57,6 +57,29 @@ CREATE TABLE IF NOT EXISTS sync_runs (
     error_message   TEXT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
+-- iCloud-Kontaktgruppen (vCards mit X-ADDRESSBOOKSERVER-KIND:group)
+CREATE TABLE IF NOT EXISTS `groups` (
+    id              INT AUTO_INCREMENT PRIMARY KEY,
+    account         VARCHAR(100) NOT NULL,
+    uid             VARCHAR(255) NOT NULL,
+    etag            VARCHAR(255) NULL,
+    name            VARCHAR(512) NULL,
+    raw_vcard       LONGTEXT NOT NULL,
+    created_at      TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at      TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    last_synced_at  TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    sync_run_id     VARCHAR(64) NULL,
+    UNIQUE KEY uq_groups_account_uid (account, uid)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+CREATE TABLE IF NOT EXISTS group_members (
+    id          INT AUTO_INCREMENT PRIMARY KEY,
+    group_id    INT NOT NULL,
+    member_uid  VARCHAR(255) NOT NULL,
+    FOREIGN KEY (group_id) REFERENCES `groups`(id) ON DELETE CASCADE,
+    UNIQUE KEY uq_group_member (group_id, member_uid)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
 -- Protokoll der Geburtstags-Mails, verhindert Doppelversand am selben Tag.
 CREATE TABLE IF NOT EXISTS birthday_mail_log (
     id              INT AUTO_INCREMENT PRIMARY KEY,

src/api/main.py

@@ -21,7 +21,13 @@ from starlette.middleware.sessions import SessionMiddleware
 
 import db
 from api.auth import get_current_user, resolve_account_for_user
-from api.schemas import ContactListResponse, ContactOut, SyncRunOut
+from api.schemas import (
+    ContactListResponse,
+    ContactOut,
+    GroupDetailOut,
+    GroupListResponse,
+    SyncRunOut,
+)
 from config import Config
 from mailer import build_message, fetch_birthdays_for_date, send_message
 from utils import fmt_birthday_age, fmt_birthday_short, is_unknown_year
@@ -48,7 +54,7 @@ def _fmt_ts(dt) -> str | None:
     return dt.astimezone(Config.TIMEZONE).strftime("%d.%m.%Y %H:%M:%S")
 
 
-def _row_to_contact_out(row: dict) -> dict:
+def _row_to_contact_out(row: dict, group_names: list[str] | None = None) -> dict:
     row = dict(row)
     for field in ["emails", "phones", "addresses", "urls", "social_profiles", "categories"]:
         raw = row.get(field)
@@ -56,6 +62,7 @@ def _row_to_contact_out(row: dict) -> dict:
     if not row.get("full_name"):
         row["full_name"] = db._build_full_name(row)
     row["updated_at"] = _fmt_ts(row["updated_at"])
+    row["groups"] = group_names if group_names is not None else []
     return row
 
 
@@ -135,7 +142,11 @@ def get_contact(contact_id: int, current_user: str = Depends(get_current_user)):
 
         if not row:
             return {}
-    return _row_to_contact_out(row)
+
+        groups = db.get_groups_for_contact(conn, row["account"], row["uid"])
+        group_names = [g["name"] for g in groups if g.get("name")]
+
+    return _row_to_contact_out(row, group_names=group_names)
 
 
 @app.get("/api/contacts/birthdays/today", response_model=list[ContactOut])
@@ -202,6 +213,108 @@ def list_sync_runs(current_user: str = Depends(get_current_user)):
     return rows
 
 
+@app.get("/api/groups", response_model=GroupListResponse)
+def list_groups(
+    request: Request,
+    limit: int = Query(default=50, le=200),
+    offset: int = Query(default=0, ge=0),
+    current_user: str = Depends(get_current_user),
+):
+    account_name, is_admin = resolve_account_for_user(current_user)
+
+    with db.get_connection() as conn:
+        where_clause, params = _account_filter_clause(account_name)
+        with conn.cursor() as cur:
+            cur.execute(f"SELECT COUNT(*) AS total FROM `groups` {where_clause}", params)
+            total = cur.fetchone()["total"]
+
+            cur.execute(
+                f"""SELECT g.id, g.account, g.uid, g.name, g.updated_at,
+                           (SELECT COUNT(*) FROM group_members gm WHERE gm.group_id = g.id) AS member_count
+                    FROM `groups` g {where_clause}
+                    ORDER BY g.name
+                    LIMIT %s OFFSET %s""",
+                params + [limit, offset],
+            )
+            rows = cur.fetchall()
+
+    for r in rows:
+        r["updated_at"] = _fmt_ts(r["updated_at"])
+    return {"total": total, "items": rows}
+
+
+@app.get("/api/groups/{group_id}", response_model=GroupDetailOut)
+def get_group(group_id: int, current_user: str = Depends(get_current_user)):
+    account_name, is_admin = resolve_account_for_user(current_user)
+
+    with db.get_connection() as conn:
+        where_clause, params = _account_filter_clause(account_name)
+        id_clause = "AND g.id = %s" if where_clause else "WHERE g.id = %s"
+        with conn.cursor() as cur:
+            cur.execute(
+                f"""SELECT g.id, g.account, g.uid, g.name, g.updated_at,
+                           (SELECT COUNT(*) FROM group_members gm WHERE gm.group_id = g.id) AS member_count
+                    FROM `groups` g {where_clause} {id_clause}""",
+                params + [group_id],
+            )
+            group_row = cur.fetchone()
+
+            if not group_row:
+                return {}
+
+            cur.execute(
+                """SELECT gm.member_uid, c.id, c.full_name, c.given_name, c.family_name
+                   FROM group_members gm
+                   LEFT JOIN contacts c ON c.account = g.account AND c.uid = gm.member_uid
+                   CROSS JOIN `groups` g
+                   WHERE g.id = %s AND gm.group_id = g.id""",
+                (group_id,),
+            )
+            members = cur.fetchall()
+
+    for m in members:
+        if not m.get("full_name"):
+            m["full_name"] = db._build_full_name(m) if any(m.get(k) for k in ("given_name", "family_name")) else None
+
+    group_row["updated_at"] = _fmt_ts(group_row["updated_at"])
+    group_row["members"] = [
+        {"member_uid": m["member_uid"], "full_name": m["full_name"], "id": m["id"]}
+        for m in members
+    ]
+    return group_row
+
+
+@app.get("/api/groups/{group_id}/members")
+def get_group_members(group_id: int, current_user: str = Depends(get_current_user)):
+    account_name, is_admin = resolve_account_for_user(current_user)
+
+    with db.get_connection() as conn:
+        where_clause, params = _account_filter_clause(account_name)
+        with conn.cursor() as cur:
+            cur.execute(
+                f"""SELECT g.id FROM `groups` g {where_clause}
+                    {"AND" if where_clause else "WHERE"} g.id = %s""",
+                params + [group_id],
+            )
+            if not cur.fetchone():
+                return {}
+
+            cur.execute(
+                """SELECT gm.member_uid, c.id, c.full_name, c.given_name, c.family_name,
+                          c.organization, c.birthday, c.photo_url
+                   FROM group_members gm
+                   LEFT JOIN contacts c ON c.uid = gm.member_uid
+                   WHERE gm.group_id = %s""",
+                (group_id,),
+            )
+            rows = cur.fetchall()
+
+    for r in rows:
+        if not r.get("full_name"):
+            r["full_name"] = db._build_full_name(r) if any(r.get(k) for k in ("given_name", "family_name")) else None
+    return {"group_id": group_id, "members": rows}
+
+
 @app.get("/", response_class=HTMLResponse)
 def web_dashboard(
     request: Request,
@@ -466,7 +579,10 @@ def web_contact(
             from fastapi.responses import RedirectResponse
             return RedirectResponse(url="/search", status_code=303)
 
-    contact = _row_to_contact_out(row)
+        groups = db.get_groups_for_contact(conn, row["account"], row["uid"])
+        group_names = [g["name"] for g in groups if g.get("name")]
+
+    contact = _row_to_contact_out(row, group_names=group_names)
 
     homecity = ""
     workcity = ""

src/api/schemas.py

@@ -23,6 +23,7 @@ class ContactOut(BaseModel):
     urls: list
     social_profiles: list
     categories: list
+    groups: list[str] = []
     updated_at: str
 
     class Config:
@@ -44,3 +45,30 @@ class SyncRunOut(BaseModel):
     contacts_upserted: int | None
     contacts_deleted: int | None
     error_message: str | None
+
+
+class GroupMemberOut(BaseModel):
+    member_uid: str
+    full_name: str | None
+    id: int | None = None
+
+
+class GroupOut(BaseModel):
+    id: int
+    account: str
+    uid: str
+    name: str | None
+    member_count: int
+    updated_at: str
+
+    class Config:
+        from_attributes = True
+
+
+class GroupDetailOut(GroupOut):
+    members: list[GroupMemberOut]
+
+
+class GroupListResponse(BaseModel):
+    total: int
+    items: list[GroupOut]

src/api/templates/contact.html

@@ -422,6 +422,17 @@
                 </div>
                 {% endif %}
 
+                {% if contact.groups %}
+                <div class="section">
+                    <div class="section-title">Gruppen</div>
+                    <div class="tags">
+                        {% for group_name in contact.groups %}
+                        <span class="tag">{{ group_name }}</span>
+                        {% endfor %}
+                    </div>
+                </div>
+                {% endif %}
+
                 {% if contact.notes %}
                 <div class="section">
                     <div class="section-title">Notizen</div>

src/db.py

@@ -279,3 +279,81 @@ def replace_all_contacts_for_account(conn, account: str, contacts: list[dict], r
                 raise
     conn.commit()
     logger.info("Voller Re-Sync für Account %s abgeschlossen: %d Kontakte", account, len(contacts))
+
+
+def upsert_groups(conn, groups: list[dict], run_id: str):
+    if not groups:
+        return
+    now = datetime.now(timezone.utc)
+    with conn.cursor() as cur:
+        for g in groups:
+            g["sync_run_id"] = run_id
+            g["last_synced_at"] = now
+            member_uids = g.pop("member_uids", [])
+            cols = [k for k in g if k != "member_uids"]
+            placeholders = ", ".join(["%s"] * len(cols))
+            update_clause = ", ".join(f"{col}=VALUES({col})" for col in cols if col not in ("account", "uid"))
+            sql = (
+                f"INSERT INTO `groups` ({', '.join(cols)}) VALUES ({placeholders}) "
+                f"ON DUPLICATE KEY UPDATE {update_clause}"
+            )
+            try:
+                cur.execute(sql, [g[c] for c in cols])
+            except Exception as exc:
+                logger.error("INSERT Gruppe fehlgeschlagen für UID %s: %s", g.get("uid"), exc)
+                raise
+            cur.execute("SELECT id FROM `groups` WHERE account = %s AND uid = %s", (g["account"], g["uid"]))
+            row = cur.fetchone()
+            if not row:
+                logger.error("Konnte Gruppen-ID nicht ermitteln für UID %s", g.get("uid"))
+                continue
+            group_id = row["id"]
+            cur.execute("DELETE FROM group_members WHERE group_id = %s", (group_id,))
+            if member_uids:
+                member_values = [(group_id, uid) for uid in member_uids]
+                cur.executemany(
+                    "INSERT INTO group_members (group_id, member_uid) VALUES (%s, %s)",
+                    member_values,
+                )
+    conn.commit()
+
+
+def delete_groups_by_uids(conn, account: str, uids: list[str]):
+    if not uids:
+        return
+    with conn.cursor() as cur:
+        placeholders = ", ".join(["%s"] * len(uids))
+        cur.execute(
+            f"DELETE FROM `groups` WHERE account = %s AND uid IN ({placeholders})",
+            [account] + uids,
+        )
+    conn.commit()
+
+
+def replace_all_groups_for_account(conn, account: str, groups: list[dict], run_id: str):
+    with conn.cursor() as cur:
+        cur.execute("DELETE FROM `groups` WHERE account = %s", (account,))
+    conn.commit()
+    if groups:
+        upsert_groups(conn, groups, run_id)
+    logger.info("Gruppen-Re-Sync für Account %s abgeschlossen: %d Gruppen", account, len(groups))
+
+
+def get_groups_for_contact(conn, account: str, member_uid: str) -> list[dict]:
+    with conn.cursor() as cur:
+        cur.execute(
+            """SELECT g.id, g.name, g.uid
+               FROM `groups` g
+               JOIN group_members gm ON gm.group_id = g.id
+               WHERE g.account = %s AND gm.member_uid = %s
+               ORDER BY g.name""",
+            (account, member_uid),
+        )
+        return cur.fetchall()
+
+
+def get_group_count(conn, account: str | None) -> int:
+    where_clause, params = _account_filter_clause(account)
+    with conn.cursor() as cur:
+        cur.execute(f"SELECT COUNT(*) AS total FROM `groups` {where_clause}", params)
+        return cur.fetchone()["total"]

src/sync.py

@@ -12,12 +12,30 @@ import sys
 import db
 from carddav_client import ICLOUD_BASE_URL, CardDAVClient, SyncTokenInvalid
 from config import Config
-from vcard_parser import parse_vcard
+from vcard_parser import is_group_vcard, parse_group, parse_vcard
 
 logging.basicConfig(level=Config.LOG_LEVEL, format="%(asctime)s [%(levelname)s] %(message)s")
 logger = logging.getLogger("sync")
 
 
+def _classify_vcards(raw_vcards, raw_etags, account_name):
+    contacts, groups = [], []
+    for v, etag in zip(raw_vcards, raw_etags):
+        if is_group_vcard(v):
+            g = parse_group(v, account_name, etag=etag)
+            if g:
+                groups.append(g)
+            else:
+                logger.warning("[%s] Gruppen-vCard konnte nicht geparst werden, überspringe", account_name)
+        else:
+            c = parse_vcard(v, account_name, etag=etag)
+            if c:
+                contacts.append(c)
+            else:
+                logger.warning("[%s] vCard konnte nicht geparst werden, überspringe", account_name)
+    return contacts, groups
+
+
 def sync_account(conn, account, href_to_uid_cache: dict):
     client = CardDAVClient(ICLOUD_BASE_URL, account.apple_email, account.apple_app_password)
     collection_url = client.discover_collection()
@@ -30,19 +48,14 @@ def sync_account(conn, account, href_to_uid_cache: dict):
         if not stored_token:
             logger.info("[%s] Kein sync-token vorhanden, führe initialen Full-Sync aus", account.name)
             raw_vcards, raw_etags = client.fetch_all_vcards(collection_url)
-            contacts = []
+            contacts, groups = _classify_vcards(raw_vcards, raw_etags, account.name)
-            for v, etag in zip(raw_vcards, raw_etags):
-                c = parse_vcard(v, account.name, etag=etag)
-                if c:
-                    contacts.append(c)
-                else:
-                    logger.warning("[%s] vCard konnte nicht geparst werden, überspringe", account.name)
             db.replace_all_contacts_for_account(conn, account.name, contacts, run_id)
+            db.replace_all_groups_for_account(conn, account.name, groups, run_id)
             _, _, _, new_token = client.sync_collection(collection_url, None, fetch_missing=False)
             if new_token:
                 db.save_sync_token(conn, account.name, new_token)
             db.finish_sync_run(conn, run_id, "success", upserted=len(contacts), deleted=0)
-            logger.info("[%s] Initialer Sync abgeschlossen: %d Kontakte", account.name, len(contacts))
+            logger.info("[%s] Initialer Sync abgeschlossen: %d Kontakte, %d Gruppen", account.name, len(contacts), len(groups))
             return
 
         try:
@@ -51,29 +64,19 @@ def sync_account(conn, account, href_to_uid_cache: dict):
             logger.warning("[%s] sync-token vom Server abgelehnt, führe vollen Re-Sync aus", account.name)
             db.clear_sync_token(conn, account.name)
             raw_vcards, raw_etags = client.fetch_all_vcards(collection_url)
-            contacts = []
+            contacts, groups = _classify_vcards(raw_vcards, raw_etags, account.name)
-            for v, etag in zip(raw_vcards, raw_etags):
-                c = parse_vcard(v, account.name, etag=etag)
-                if c:
-                    contacts.append(c)
-                else:
-                    logger.warning("[%s] vCard konnte nicht geparst werden, überspringe", account.name)
             db.replace_all_contacts_for_account(conn, account.name, contacts, run_id)
+            db.replace_all_groups_for_account(conn, account.name, groups, run_id)
             _, _, _, new_token = client.sync_collection(collection_url, None, fetch_missing=False)
             if new_token:
                 db.save_sync_token(conn, account.name, new_token)
             db.finish_sync_run(conn, run_id, "success", upserted=len(contacts), deleted=0)
-            logger.info("[%s] Re-Sync abgeschlossen: %d Kontakte", account.name, len(contacts))
+            logger.info("[%s] Re-Sync abgeschlossen: %d Kontakte, %d Gruppen", account.name, len(contacts), len(groups))
             return
 
-        contacts = []
+        contacts, groups = _classify_vcards(changed_vcards, etags, account.name)
-        for v, etag in zip(changed_vcards, etags):
-            c = parse_vcard(v, account.name, etag=etag)
-            if c:
-                contacts.append(c)
-            else:
-                logger.warning("[%s] vCard konnte nicht geparst werden, überspringe", account.name)
         db.upsert_contacts(conn, contacts, run_id)
+        db.upsert_groups(conn, groups, run_id)
 
         deleted_uids = []
         for href in deleted_hrefs:
@@ -83,14 +86,15 @@ def sync_account(conn, account, href_to_uid_cache: dict):
             else:
                 logger.warning("[%s] Konnte UID nicht aus href extrahieren: %s", account.name, href)
         db.delete_contacts_by_href_uids(conn, account.name, deleted_uids)
+        db.delete_groups_by_uids(conn, account.name, deleted_uids)
 
         if new_token:
             db.save_sync_token(conn, account.name, new_token)
 
         db.finish_sync_run(conn, run_id, "success", upserted=len(contacts), deleted=len(deleted_uids))
         logger.info(
-            "[%s] Delta-Sync abgeschlossen: %d geändert/neu, %d gelöscht",
+            "[%s] Delta-Sync abgeschlossen: %d geändert/neu, %d gelöscht (%d Gruppen geändert)",
-            account.name, len(contacts), len(deleted_uids),
+            account.name, len(contacts), len(deleted_uids), len(groups),
         )
     except Exception as exc:
         logger.exception("[%s] Sync-Lauf %s fehlgeschlagen", account.name, run_id)

src/vcard_parser.py

@@ -33,6 +33,48 @@ def _type_str(obj) -> str:
     return "other"
 
 
+_GROUP_MARKER = "X-ADDRESSBOOKSERVER-KIND:group"
+_MEMBER_PREFIX = "urn:uuid:"
+
+
+def is_group_vcard(raw_text: str) -> bool:
+    return _GROUP_MARKER in raw_text
+
+
+def parse_group(raw_text: str, account: str, etag: str | None = None) -> dict | None:
+    try:
+        vcard = vobject.readOne(raw_text)
+    except Exception as exc:
+        logger.warning("Gruppen-vCard konnte nicht geparst werden: %s", exc)
+        return None
+
+    uid = _get(vcard, "uid")
+    if not uid:
+        logger.warning("Gruppen-vCard ohne UID übersprungen")
+        return None
+
+    member_uids = []
+    for member in vcard.contents.get("x-addressbookserver-member", []):
+        value = member.value if hasattr(member, "value") else str(member)
+        if value.startswith(_MEMBER_PREFIX):
+            member_uids.append(value[len(_MEMBER_PREFIX):])
+        else:
+            member_uids.append(value)
+
+    if not member_uids:
+        logger.debug("Gruppe %s hat keine Members, überspringe", uid)
+        return None
+
+    return {
+        "account": account,
+        "uid": uid,
+        "etag": etag,
+        "name": _scalar(_get(vcard, "fn")),
+        "raw_vcard": raw_text,
+        "member_uids": member_uids,
+    }
+
+
 def parse_vcard(raw_text: str, account: str, etag: str | None = None) -> dict | None:
     try:
         vcard = vobject.readOne(raw_text)