from .models import UserSessionYear
from rest_framework.authtoken.models import Token
from django.db.models import Q
# def get_user_session_year(user):
#     """
#     Logged-in user ke current token ke basis par session_year return karega.
#     Agar mapping nahi mili to None return karega.
#     """
#     try:
#         token = user.auth_token  # DRF resolve automatically token for authenticated user 
#         session_obj = UserSessionYear.objects.filter(user=user, token=token).last()
#         return session_obj.session_year if session_obj else None
#     except Exception:
#         return None
    


# class SessionYearMixin:
#     def get_queryset(self):
#         queryset = super().get_queryset()
#         user = self.request.user

#         # if user is authenticated, get session_year from user
#         if user.is_authenticated:
#             session_year = get_user_session_year(user)
#         else:
#             # otherwise, try to get session_year from token in request headers
#             auth_header = self.request.headers.get("Authorization")
#             session_year = None
#             if auth_header and auth_header.startswith("Token "):
#                 token_key = auth_header.split(" ")[1]
#                 try:
#                     token = Token.objects.get(key=token_key)
#                     session_year = get_user_session_year(token.user)
#                 except Token.DoesNotExist:
#                     pass
#         if session_year:
#             model_name=queryset.model.__name__
#             # Special case models with optional session_year
#             if model_name in ["MillersEntrymodel"]:
#                 return queryset.filter(Q(session_year=session_year) | Q(session_year__isnull=True))
#             # All other models → strict session filter
#             return queryset.filter(session_year=session_year)
#         return queryset.none()


def get_user_session_year(user, request=None):
    try:
        token = None
        if request and hasattr(request, "auth") and request.auth:
            token = request.auth
        elif hasattr(user, "auth_token"):
            token = user.auth_token
        if not token:
            return None

        session_obj = UserSessionYear.objects.filter(user=user, token=token).last()
        return session_obj.session_year if session_obj else None
    except Exception as e:
        print(f"[get_user_session_year] Error: {e}")
        return None


class SessionYearMixin:
    def get_queryset(self):
        queryset = super().get_queryset()
        request = self.request
        user = getattr(request, "user", None)
        token = getattr(request, "auth", None)

        session_year = None
        if user and token:
            session_year = get_user_session_year(user, request)
        elif token:
            session_year = get_user_session_year(token.user, request)

        if session_year:
            model_name = queryset.model.__name__
            if model_name in ["MillersEntrymodel","Dealersmodel"]:
                return queryset.filter(Q(session_year=session_year) | Q(session_year__isnull=True))
            return queryset.filter(session_year=session_year)

        return queryset.none()