from django.shortcuts import get_object_or_404

from rest_framework import generics, views
from rest_framework.response import Response

from django_filters.rest_framework.backends import DjangoFilterBackend

from core.apps.shared.paginations.custom import PageNumberPagination
from core.apps.accounts.permissions.permissions import HasRolePermission
from core.apps.orders.serializers import offer as serializers
from core.apps.orders.models import Offer, Order
from core.apps.orders.filters.order import OrderFilter


class OffersCreateApiView(generics.GenericAPIView):
    permission_classes = [HasRolePermission]
    queryset = Offer.objects.all()
    serializer_class = serializers.MultipleOfferCreateSerializer

    def post(self, request):
        serializer = self.serializer_class(data=request.data)
        if serializer.is_valid(raise_exception=True):
            serializer.save()
            return Response(
                {
                    "success": True,
                    "message": "Offers created!"
                },
                status=201
            )


class OfferListApiView(generics.GenericAPIView):
    permission_classes = [HasRolePermission]
    queryset = Order.objects.select_related('product', 'unity').prefetch_related('offers').filter(
        offers__isnull=False
    ).distinct()
    serializer_class = serializers.OrderListForOfferSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_class = OrderFilter

    def get(self, request):
        offer_status = request.query_params.get('status', None)
        orders = self.filter_queryset(self.get_queryset())
        page = self.paginate_queryset(orders)
        if page is not None:
            if offer_status:
                serializer = self.serializer_class(page, many=True, context={'status': offer_status})
            else:
                serializer = self.serializer_class(page, many=True)
            return self.get_paginated_response(serializer.data)
        serializer = self.serializer_class(offers, many=True)
        return Response(serializer.data, status=200)
    

class OfferUpdateApiView(generics.GenericAPIView):
    serializer_class = serializers.OfferUpdateSerializer
    queryset = Offer.objects.all()
    lookup_field = 'id'
    permission_classes = [HasRolePermission]

    def put(self, request, id):
        offer = get_object_or_404(Offer, id=id)
        serializer = self.serializer_class(data=request.data, instance=offer)
        if serializer.is_valid(raise_exception=True):
            serializer.save()
            return Response(
                {
                    'success': True,
                    "message": "Offer successfully updated!"
                },
                status=200
            )
    
    def patch(self, request, id):
        offer = get_object_or_404(Offer, id=id)
        serializer = self.serializer_class(data=request.data, instance=offer, partial=True)
        if serializer.is_valid(raise_exception=True):
            serializer.save()
            return Response(
                {
                    'success': True,
                    "message": "Offer successfully updated!"
                },
                status=200
            )
        
    
class OfferDeleteApiView(views.APIView):
    permission_classes = [HasRolePermission]

    def delete(self, request, id):
        offer = get_object_or_404(Offer, id=id)
        offer.delete()
        return Response({'success': True}, status=204)


class DeleteMultipleOfferApiView(views.APIView):
    permission_classes = [HasRolePermission]

    def delete(self, request):
        ids = request.data.get("offer_ids", [])
        if not ids:
            return Response({"detail": "offer_ids kerak"}, status=400)

        deleted_count, _ = Offer.objects.filter(id__in=ids).delete()
        return Response({"deleted": deleted_count}, status=200)


class ChangeOfferStatusApiView(views.APIView):
    permission_classes = [HasRolePermission]

    def post(self, request, id):
        offer = get_object_or_404(Offer, id=id)
        status = request.data.get('status')
        if not status:
            return Response({'success': False, 'message': 'status field is required'}, status=400)
        offer.status = status
        offer.save()
        return Response(
            {'success': True, 'message': 'status updated'},
            status=200
        )