feat(chats): add per-user pinned chats and pinned sorting

app/chats/models.py

@@ -85,6 +85,8 @@ class ChatUserSetting(Base):
     chat_id: Mapped[int] = mapped_column(ForeignKey("chats.id", ondelete="CASCADE"), nullable=False, index=True)
     user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
     archived: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    pinned: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    pinned_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True),
         server_default=func.now(),

app/chats/repository.py

@@ -70,7 +70,11 @@ def _user_chats_query(user_id: int, query: str | None = None) -> Select[tuple[Ch
                 Chat.type.cast(String).ilike(q),
             )
         )
-    return stmt.order_by(Chat.id.desc())
+    return stmt.order_by(
+        func.coalesce(ChatUserSetting.pinned, False).desc(),
+        ChatUserSetting.pinned_at.desc().nullslast(),
+        Chat.id.desc(),
+    )
 
 
 async def list_user_chats(
@@ -103,7 +107,11 @@ async def list_archived_user_chats(
             (ChatUserSetting.chat_id == Chat.id) & (ChatUserSetting.user_id == user_id),
         )
         .where(ChatMember.user_id == user_id, ChatUserSetting.archived.is_(True))
-        .order_by(Chat.id.desc())
+        .order_by(
+            func.coalesce(ChatUserSetting.pinned, False).desc(),
+            ChatUserSetting.pinned_at.desc().nullslast(),
+            Chat.id.desc(),
+        )
         .limit(limit)
     )
     if before_id is not None:
@@ -287,3 +295,28 @@ async def upsert_chat_archived_setting(
     db.add(setting)
     await db.flush()
     return setting
+
+
+async def upsert_chat_pinned_setting(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    user_id: int,
+    pinned: bool,
+) -> ChatUserSetting:
+    setting = await get_chat_user_setting(db, chat_id=chat_id, user_id=user_id)
+    if setting:
+        setting.pinned = pinned
+        setting.pinned_at = func.now() if pinned else None
+        await db.flush()
+        return setting
+    setting = ChatUserSetting(
+        chat_id=chat_id,
+        user_id=user_id,
+        archived=False,
+        pinned=pinned,
+        pinned_at=func.now() if pinned else None,
+    )
+    db.add(setting)
+    await db.flush()
+    return setting

app/chats/router.py

@@ -33,6 +33,7 @@ from app.chats.service import (
     serialize_chat_for_user,
     serialize_chats_for_user,
     set_chat_archived_for_user,
+    set_chat_pinned_for_user,
     update_chat_member_role_for_user,
     update_chat_notification_settings_for_user,
     update_chat_title_for_user,
@@ -257,3 +258,23 @@ async def unarchive_chat(
 ) -> ChatRead:
     chat = await set_chat_archived_for_user(db, chat_id=chat_id, user_id=current_user.id, archived=False)
     return await serialize_chat_for_user(db, user_id=current_user.id, chat=chat)
+
+
+@router.post("/{chat_id}/pin-chat", response_model=ChatRead)
+async def pin_chat(
+    chat_id: int,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> ChatRead:
+    chat = await set_chat_pinned_for_user(db, chat_id=chat_id, user_id=current_user.id, pinned=True)
+    return await serialize_chat_for_user(db, user_id=current_user.id, chat=chat)
+
+
+@router.post("/{chat_id}/unpin-chat", response_model=ChatRead)
+async def unpin_chat(
+    chat_id: int,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+) -> ChatRead:
+    chat = await set_chat_pinned_for_user(db, chat_id=chat_id, user_id=current_user.id, pinned=False)
+    return await serialize_chat_for_user(db, user_id=current_user.id, chat=chat)

app/chats/schemas.py

@@ -18,6 +18,7 @@ class ChatRead(BaseModel):
     is_public: bool = False
     is_saved: bool = False
     archived: bool = False
+    pinned: bool = False
     unread_count: int = 0
     pinned_message_id: int | None = None
     members_count: int | None = None

app/chats/service.py

@@ -64,6 +64,7 @@ async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat)
     unread_count = await repository.get_unread_count_for_chat(db, chat_id=chat.id, user_id=user_id)
     user_setting = await repository.get_chat_user_setting(db, chat_id=chat.id, user_id=user_id)
     archived = bool(user_setting and user_setting.archived)
+    pinned = bool(user_setting and user_setting.pinned)
 
     return ChatRead.model_validate(
         {
@@ -77,6 +78,7 @@ async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat)
             "is_public": chat.is_public,
             "is_saved": chat.is_saved,
             "archived": archived,
+            "pinned": pinned,
             "unread_count": unread_count,
             "pinned_message_id": chat.pinned_message_id,
             "members_count": members_count,
@@ -501,3 +503,17 @@ async def set_chat_archived_for_user(
     await db.commit()
     await db.refresh(chat)
     return chat
+
+
+async def set_chat_pinned_for_user(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    user_id: int,
+    pinned: bool,
+) -> Chat:
+    chat, _membership = await _get_chat_and_membership(db, chat_id=chat_id, user_id=user_id)
+    await repository.upsert_chat_pinned_setting(db, chat_id=chat_id, user_id=user_id, pinned=pinned)
+    await db.commit()
+    await db.refresh(chat)
+    return chat