moderation: add chat bans for groups/channels with web actions

app/chats/service.py

@@ -350,6 +350,8 @@ async def add_chat_member_for_user(
     chat, membership = await _get_chat_and_membership(db, chat_id=chat_id, user_id=actor_user_id)
     _ensure_group_or_channel(chat.type)
     _ensure_manage_permission(membership.role)
+    if await repository.is_user_banned_in_chat(db, chat_id=chat_id, user_id=target_user_id):
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="User is banned from this chat")
     if target_user_id == actor_user_id:
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail="User is already in chat")
     target_user = await get_user_by_id(db, target_user_id)
@@ -427,6 +429,45 @@ async def remove_chat_member_for_user(
     await db.commit()
 
 
+async def ban_chat_member_for_user(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    actor_user_id: int,
+    target_user_id: int,
+) -> None:
+    chat, actor_membership = await _get_chat_and_membership(db, chat_id=chat_id, user_id=actor_user_id)
+    _ensure_group_or_channel(chat.type)
+    if actor_membership.role not in {ChatMemberRole.OWNER, ChatMemberRole.ADMIN}:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Insufficient permissions")
+    if target_user_id == actor_user_id:
+        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail="Cannot ban yourself")
+    target_membership = await repository.get_chat_member(db, chat_id=chat_id, user_id=target_user_id)
+    if target_membership:
+        if target_membership.role == ChatMemberRole.OWNER:
+            raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail="Owner cannot be banned")
+        if actor_membership.role == ChatMemberRole.ADMIN and target_membership.role != ChatMemberRole.MEMBER:
+            raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin can ban only members")
+        await repository.delete_chat_member(db, target_membership)
+    await repository.upsert_chat_ban(db, chat_id=chat_id, user_id=target_user_id, banned_by_user_id=actor_user_id)
+    await db.commit()
+
+
+async def unban_chat_member_for_user(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    actor_user_id: int,
+    target_user_id: int,
+) -> None:
+    chat, actor_membership = await _get_chat_and_membership(db, chat_id=chat_id, user_id=actor_user_id)
+    _ensure_group_or_channel(chat.type)
+    if actor_membership.role not in {ChatMemberRole.OWNER, ChatMemberRole.ADMIN}:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Insufficient permissions")
+    await repository.remove_chat_ban(db, chat_id=chat_id, user_id=target_user_id)
+    await db.commit()
+
+
 async def leave_chat_for_user(db: AsyncSession, *, chat_id: int, user_id: int) -> None:
     chat, membership = await _get_chat_and_membership(db, chat_id=chat_id, user_id=user_id)
     _ensure_group_or_channel(chat.type)
@@ -514,6 +555,8 @@ async def join_public_chat_for_user(db: AsyncSession, *, chat_id: int, user_id:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Chat not found")
     if not chat.is_public or chat.type not in {ChatType.GROUP, ChatType.CHANNEL}:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Chat is not joinable")
+    if await repository.is_user_banned_in_chat(db, chat_id=chat_id, user_id=user_id):
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You are banned from this chat")
     membership = await repository.get_chat_member(db, chat_id=chat_id, user_id=user_id)
     if membership:
         return chat
@@ -650,6 +693,8 @@ async def join_chat_by_invite_for_user(
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Chat not found")
     if chat.type not in {ChatType.GROUP, ChatType.CHANNEL}:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Invite link is not valid for this chat")
+    if await repository.is_user_banned_in_chat(db, chat_id=chat.id, user_id=user_id):
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You are banned from this chat")
     membership = await repository.get_chat_member(db, chat_id=chat.id, user_id=user_id)
     if membership:
         return chat