from rest_framework.decorators import action
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.response import Response
from rest_framework.viewsets import ModelViewSet

from core.mixins import ActionBasedMixin
from core.permissions import IsAuthorOrReadOnly, IsAdminUserOrReadOnly
from market.models import Brand, Product, Post
from market.serializers import (
    BrandSerializer,
    ProductSerializer,
    PostSerializer,
    PostCreateSerializer,
    PostListSerializer,
    PostStatusUpdateSerializer,
)
from graph.models import Transaction
from graph.methods import create_transaction


class BrandViewset(ActionBasedMixin, ModelViewSet):
    queryset = Brand.objects.all()
    serializer_class = BrandSerializer
    permission_classes = [IsAdminUserOrReadOnly]
    pagination_class = None


class ProductViewset(ActionBasedMixin, ModelViewSet):
    queryset = Product.objects.all().select_related("brand")
    serializer_class = ProductSerializer
    serializer_class_map = {
        "posts": PostListSerializer,
    }
    permission_classes = [IsAdminUserOrReadOnly]

    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=["GET"])
    def posts(self, request, pk):
        product = self.get_object()
        queryset = product.posts.all()

        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)

        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)


class PostViewset(ActionBasedMixin, ModelViewSet):
    queryset = (
        Post.objects.all()
        .select_related("product", "author", "product__brand")
        .prefetch_related("images")
    )
    serializer_class = PostSerializer
    serializer_class_map = {
        "list": PostListSerializer,
        "create": PostCreateSerializer,
        "update": PostStatusUpdateSerializer,
    }
    permission_classes = [IsAuthenticated, IsAuthorOrReadOnly]
    permission_classes_map = {
        "list": [AllowAny],
        "retrieve": [AllowAny],
        "create": [AllowAny],
    }

    def perform_create(self, serializer):
        serializer.save(author=self.request.user)

    def perform_update(self, serializer):
        object = self.get_object()
        object_unsold = object.status == "s" or object.status == "r"
        instance = serializer.instance
        if object_unsold and serializer.validated_data.get("status") == "d":
            create_transaction(instance)
        elif (
            not object_unsold
            and serializer.validated_data.get("status") == "s"
        ):
            Transaction.objects.filter(
                price=instance.price, product=instance.product
            ).delete()
        return super().perform_update(serializer)