from django.utils import timezone


class LastSeenMiddleware:
    """Lightweight 'last active' tracker stored on the session — no extra DB writes per request."""

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        response = self.get_response(request)
        if request.user.is_authenticated:
            request.session["last_seen"] = timezone.now().isoformat()
        return response