Paginate address book contacts

src/govoplan_addresses/backend/service.py

@@ -2421,14 +2421,79 @@ def list_contacts(
     principal: ApiPrincipal,
     *,
     address_book_id: str | None = None,
+    address_list_id: str | None = None,
     query: str | None = None,
     limit: int = 200,
+    offset: int = 0,
     include_deleted: bool = False,
 ) -> list[Contact]:
+    contact_query = _filtered_contact_query(
+        session,
+        principal,
+        address_book_id=address_book_id,
+        address_list_id=address_list_id,
+        query=query,
+        include_deleted=include_deleted,
+    )
+    return (
+        contact_query.order_by(Contact.display_name.asc(), Contact.id.asc())
+        .offset(max(0, offset))
+        .limit(max(1, min(limit, 500)))
+        .all()
+    )
+
+
+def count_contacts(
+    session: Session,
+    principal: ApiPrincipal,
+    *,
+    address_book_id: str | None = None,
+    address_list_id: str | None = None,
+    query: str | None = None,
+    include_deleted: bool = False,
+) -> int:
+    contact_query = _filtered_contact_query(
+        session,
+        principal,
+        address_book_id=address_book_id,
+        address_list_id=address_list_id,
+        query=query,
+        include_deleted=include_deleted,
+    )
+    return int(
+        contact_query.order_by(None)
+        .with_entities(func.count(func.distinct(Contact.id)))
+        .scalar()
+        or 0
+    )
+
+
+def _filtered_contact_query(
+    session: Session,
+    principal: ApiPrincipal,
+    *,
+    address_book_id: str | None,
+    address_list_id: str | None,
+    query: str | None,
+    include_deleted: bool,
+):
     contact_query = _visible_contact_query(session, principal, include_deleted=include_deleted, include_deleted_books=include_deleted)
     if address_book_id:
         get_visible_address_book(session, principal, address_book_id, include_deleted=include_deleted)
         contact_query = contact_query.filter(Contact.address_book_id == address_book_id)
+    if address_list_id:
+        address_list = get_visible_address_list(
+            session,
+            principal,
+            address_list_id,
+            include_deleted=include_deleted,
+        )
+        if address_book_id and address_list.address_book_id != address_book_id:
+            raise AddressBookError("Address list does not belong to the selected address book.")
+        contact_query = contact_query.join(
+            AddressListEntry,
+            AddressListEntry.contact_id == Contact.id,
+        ).filter(AddressListEntry.address_list_id == address_list_id)
     normalized_query = _trim(query)
     if normalized_query:
         pattern = f"%{normalized_query.lower()}%"
@@ -2439,7 +2504,7 @@ def list_contacts(
                 func.lower(ContactEmail.email).like(pattern),
             )
         )
-    return contact_query.order_by(Contact.display_name.asc(), Contact.id.asc()).limit(max(1, min(limit, 500))).all()
+    return contact_query.distinct()
 
 
 def get_visible_contact(session: Session, principal: ApiPrincipal, contact_id: str, *, include_deleted: bool = False) -> Contact: