feat(invites): add group/channel invite links and join by token

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, ChatMember, ChatMemberRole, ChatNotificationSetting, ChatType, ChatUserSetting
+from app.chats.models import Chat, ChatInviteLink, ChatMember, ChatMemberRole, ChatNotificationSetting, ChatType, ChatUserSetting
 from app.messages.models import Message, MessageHidden, MessageReceipt
 
 
@@ -320,3 +320,25 @@ async def upsert_chat_pinned_setting(
     db.add(setting)
     await db.flush()
     return setting
+
+
+async def create_chat_invite_link(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    creator_user_id: int,
+    token: str,
+) -> ChatInviteLink:
+    link = ChatInviteLink(chat_id=chat_id, creator_user_id=creator_user_id, token=token, is_active=True)
+    db.add(link)
+    await db.flush()
+    return link
+
+
+async def get_active_chat_invite_by_token(db: AsyncSession, *, token: str) -> ChatInviteLink | None:
+    result = await db.execute(
+        select(ChatInviteLink)
+        .where(ChatInviteLink.token == token, ChatInviteLink.is_active.is_(True))
+        .limit(1)
+    )
+    return result.scalar_one_or_none()