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

app/chats/repository.py

@@ -2,7 +2,7 @@ from sqlalchemy import Select, String, func, or_, select
 from sqlalchemy.orm import aliased
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.chats.models import Chat, ChatInviteLink, ChatMember, ChatMemberRole, ChatNotificationSetting, ChatType, ChatUserSetting
+from app.chats.models import Chat, ChatBan, ChatInviteLink, ChatMember, ChatMemberRole, ChatNotificationSetting, ChatType, ChatUserSetting
 from app.messages.models import Message, MessageHidden, MessageReceipt
 
 
@@ -401,3 +401,31 @@ async def get_active_chat_invite_by_token(db: AsyncSession, *, token: str) -> Ch
         .limit(1)
     )
     return result.scalar_one_or_none()
+
+
+async def get_chat_ban(db: AsyncSession, *, chat_id: int, user_id: int) -> ChatBan | None:
+    result = await db.execute(select(ChatBan).where(ChatBan.chat_id == chat_id, ChatBan.user_id == user_id))
+    return result.scalar_one_or_none()
+
+
+async def is_user_banned_in_chat(db: AsyncSession, *, chat_id: int, user_id: int) -> bool:
+    result = await db.execute(select(ChatBan.id).where(ChatBan.chat_id == chat_id, ChatBan.user_id == user_id).limit(1))
+    return result.scalar_one_or_none() is not None
+
+
+async def upsert_chat_ban(db: AsyncSession, *, chat_id: int, user_id: int, banned_by_user_id: int) -> ChatBan:
+    existing = await get_chat_ban(db, chat_id=chat_id, user_id=user_id)
+    if existing:
+        existing.banned_by_user_id = banned_by_user_id
+        await db.flush()
+        return existing
+    ban = ChatBan(chat_id=chat_id, user_id=user_id, banned_by_user_id=banned_by_user_id)
+    db.add(ban)
+    await db.flush()
+    return ban
+
+
+async def remove_chat_ban(db: AsyncSession, *, chat_id: int, user_id: int) -> None:
+    ban = await get_chat_ban(db, chat_id=chat_id, user_id=user_id)
+    if ban:
+        await db.delete(ban)