from django.db.models import Q
from drf_spectacular.utils import OpenApiParameter, extend_schema, extend_schema_view
from rest_framework import mixins, viewsets
from rest_framework.decorators import action
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.response import Response

from apps.gooyal_oauth2.rest_framework import IsAuthenticatedOrTokenMatchesOASRequirements

from apps.core.permissions import IsStoreOwner
from apps.stores.models import Store

from .models import Product, ProductCategory
from .serializers import (
    ProductCategorySerializer,
    ProductDetailSerializer,
    ProductListSerializer,
    SellerProductSerializer,
    StockAdjustSerializer,
)


class ProductCategoryViewSet(mixins.ListModelMixin, viewsets.GenericViewSet):
    schema_tags = ['Catalog']
    permission_classes = [AllowAny]
    serializer_class = ProductCategorySerializer
    queryset = ProductCategory.objects.all()


@extend_schema_view(
    list=extend_schema(
        parameters=[
            OpenApiParameter('store', str, description='Filter by store UUID.'),
            OpenApiParameter('category', str, description='Filter by product category UUID.'),
            OpenApiParameter('search', str, description='Search by product name/description.'),
        ],
    ),
)
class ProductViewSet(mixins.ListModelMixin, mixins.RetrieveModelMixin, viewsets.GenericViewSet):
    """Customer-facing product browsing (store page, product detail, search)."""

    schema_tags = ['Catalog']
    permission_classes = [AllowAny]
    queryset = Product.objects.filter(
        is_active=True, store__status=Store.Status.APPROVED,
    ).select_related('store', 'category')

    def get_serializer_class(self):
        if self.action == 'retrieve':
            return ProductDetailSerializer
        return ProductListSerializer

    def get_queryset(self):
        queryset = super().get_queryset()

        store_uuid = self.request.query_params.get('store')
        if store_uuid:
            queryset = queryset.filter(store__uuid=store_uuid)

        category_uuid = self.request.query_params.get('category')
        if category_uuid:
            queryset = queryset.filter(category__uuid=category_uuid)

        search = self.request.query_params.get('search')
        if search:
            queryset = queryset.filter(Q(name__icontains=search) | Q(description__icontains=search))

        return queryset


class SellerProductViewSet(viewsets.ModelViewSet):
    """Seller's own product management (S06 list, S07 add, S08 inventory)."""

    schema_tags = ['Seller · Products']
    serializer_class = SellerProductSerializer
    # permission_classes = [IsAuthenticated, IsStoreOwner]
    # TODO: IsStoreOwner?
    permission_classes = [IsAuthenticatedOrTokenMatchesOASRequirements]
    required_alternate_scopes = {
        "POST": [[]],
    }

    def get_queryset(self):
        if getattr(self, 'swagger_fake_view', False):
            return Product.objects.none()
        return Product.objects.filter(store=self.request.user.store).select_related('category')

    @action(detail=True, methods=['patch'], url_path='stock')
    def adjust_stock(self, request, pk=None):
        product = self.get_object()
        serializer = StockAdjustSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        product.stock_quantity = serializer.validated_data['stock_quantity']
        product.save(update_fields=['stock_quantity', 'updated_at'])
        return Response(SellerProductSerializer(product).data)