from datetime import timedelta

from django.utils import timezone

from communications.models import ActiveChatSession

ACTIVE_CHAT_SESSION_TTL = timedelta(seconds=75)


def set_active_chat(*, user_id: int, chat_id: int, connection_id: str) -> None:
    now = timezone.now()
    ActiveChatSession.objects.update_or_create(
        connection_id=connection_id,
        defaults={
            "user_id": user_id,
            "chat_id": chat_id,
            "expires_at": now + ACTIVE_CHAT_SESSION_TTL,
        },
    )


def touch_active_chat(*, connection_id: str) -> None:
    now = timezone.now()
    ActiveChatSession.objects.filter(connection_id=connection_id).update(
        last_seen_at=now,
        expires_at=now + ACTIVE_CHAT_SESSION_TTL,
    )


def clear_active_chat(*, connection_id: str) -> None:
    ActiveChatSession.objects.filter(connection_id=connection_id).delete()


def user_is_viewing_chat(*, user_id: int, chat_id: int) -> bool:
    now = timezone.now()
    queryset = ActiveChatSession.objects.filter(
        user_id=user_id,
        chat_id=chat_id,
    )
    queryset.filter(expires_at__lte=now).delete()
    return queryset.filter(expires_at__gt=now).exists()