from django.conf import settings
from django.urls.exceptions import NoReverseMatch
from rest_framework import status
from rest_framework.decorators import api_view, permission_classes
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.reverse import reverse


class ResponseTypeViewHeaderMixin:
    ''' Adds a response type to the Header of a HTTP Response '''
    DATA = 'data'
    VIEW_SET = 'view'

    def dispatch(self, request, *args, **kwargs):
        response = super().dispatch(request, *args, **kwargs)
        if hasattr(self, 'RESPONSE_TYPE'):
            response['X-ResponseType'] = self.RESPONSE_TYPE
        else:
            response['X-ResponseType'] = self.VIEW_SET
        return response


class AppModelResponseHeaderMixin:
    ''' Adds the app to the Header of a HTTP Response '''

    def dispatch(self, request, *args, **kwargs):
        response = super().dispatch(request, *args, **kwargs)
        if hasattr(self, 'IDENTIFIER'):
            response['X-Identifier'] = self.IDENTIFIER
        return response


@api_view(["GET"])
@permission_classes([IsAuthenticated])
def api_endpoints_root(request, format=None):
    try:
        return Response({
            wb_endpoint: reverse(
                f"{wb_endpoint}:api-root", request=request, format=format
            )
            for wb_endpoint in settings.WB_ENDPOINTS
        })
    except AttributeError:
        return Response({'error': 'No Endpoints specified.'}, status=status.HTTP_400_BAD_REQUEST)
    except NoReverseMatch:
        return Response({'error': 'No API Root specified for one app.'}, status=status.HTTP_400_BAD_REQUEST)