from functools import wraps

from django.utils.decorators import classonlymethod
from rest_framework.viewsets import ViewSetMixin

try:
    from django_scopes import scope
except ImportError:
    from xenua.decorators import no_op as scope

try:
    from rest_framework import APIView
except ImportError:
    APIView = None


class ScopedViewMixin:
    def dispatch(self, request, *args, **kwargs):
        for method_name in self.http_method_names:
            if (method := getattr(self, method_name, None)) is not None:
                wrapped_method = wraps(method)(self.apply_scopes(method, method_name))
                setattr(self, method_name, wrapped_method)

        return super().dispatch(request, *args, **kwargs)

    def apply_scopes(self, to: callable, http_method):
        def wrapper(request, *args, **kwargs):
            with scope(**self.get_scopes(request, *args, **kwargs)):
                return to(request, *args, **kwargs)

        return wrapper

    def get_scopes(self, request, *args, **kwargs):
        return {}


class UserScopedViewMixin(ScopedViewMixin):
    user_scope_name = 'user'

    def get_scopes(self, r, *args, **kwargs):
        return {self.user_scope_name: r.user}