from rest_framework import permissions
from django_filters.rest_framework import DjangoFilterBackend


def get_user_club(user):
    """Helper to get club from user, checking profile.club first."""
    if hasattr(user, 'profile') and user.profile and user.profile.club:
        return user.profile.club
    if hasattr(user, 'club') and user.club:
        return user.club
    return None


class ClubFilterBackend(DjangoFilterBackend):
    """
    Filter backend that automatically filters queries by the authenticated user's club.
    """

    def filter_queryset(self, request, queryset, view):
        user = request.user

        if not user.is_authenticated:
            return queryset.none()

        club = get_user_club(user)
        if club is None:
            return queryset.none()

        if hasattr(queryset.model, 'club'):
            return queryset.filter(club=club)

        if hasattr(queryset.model, 'wrestler') and hasattr(queryset.model, 'training'):
            return queryset.filter(training__club=club)

        if hasattr(queryset.model, 'homework'):
            return queryset.filter(homework__club=club)

        return queryset


class ClubLevelPermission(permissions.BasePermission):
    """
    Permission class that ensures users can only access their own club's data.
    """

    def has_permission(self, request, view):
        if not request.user or not request.user.is_authenticated:
            return False

        club = get_user_club(request.user)
        if club is None:
            return False

        return True

    def has_object_permission(self, request, view, obj):
        if not request.user or not request.user.is_authenticated:
            return False

        club = get_user_club(request.user)
        if club is None:
            return False

        obj_club = getattr(obj, 'club', None)

        if obj_club is None and hasattr(obj, 'training'):
            obj_club = getattr(obj.training, 'club', None)

        if obj_club is None and hasattr(obj, 'homework'):
            obj_club = getattr(obj.homework, 'club', None)

        if obj_club is None and hasattr(obj, 'wrestler'):
            obj_club = getattr(obj.wrestler, 'club', None)

        return obj_club == club