import importlib
from asgiref.sync import iscoroutinefunction, markcoroutinefunction

from django.conf import settings
from django.http import HttpResponse


def load_backing_class(path: str):
    mod_name, _, cls_name = path.rpartition(".")
    module = importlib.import_module(mod_name)
    return getattr(module, cls_name)


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

        if iscoroutinefunction(self.get_response):
            markcoroutinefunction(self)

        self.backing_class = getattr(getattr(settings, "AI_BLOCKER_CONF"), "backing_class", "ai_blocker.ualist_backers.ConfigBackedUAList")
        Backer = load_backing_class(self.backing_class)
        self.backer = Backer()

    async def __call__(self, request):
        ua = request.headers.get("User-Agent", "")


        if ua in self.backer:
            return HttpResponse(status=403)

        response = self.get_response(request)
        # Add code here to process the response after the view has been run.
        return response