from rest_framework import permissions, status, viewsets
from rest_framework.decorators import action
from rest_framework.response import Response

from apps.documents.models import Document

from .models import Collection
from .serializers import (
    CollectionDetailSerializer,
    CollectionDocumentActionSerializer,
    CollectionSerializer,
)


class CollectionViewSet(viewsets.ModelViewSet):
    """CRUD for user collections."""
    permission_classes = [permissions.IsAuthenticated]

    def get_serializer_class(self):
        if self.action in ("retrieve", "update", "partial_update"):
            return CollectionDetailSerializer
        return CollectionSerializer

    def get_queryset(self):
        return Collection.objects.filter(owner=self.request.user).prefetch_related("documents")

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

    @action(detail=True, methods=["post"])
    def add_documents(self, request, pk=None):
        """Add documents to a collection."""
        collection = self.get_object()
        serializer = CollectionDocumentActionSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        docs = Document.objects.filter(
            id__in=serializer.validated_data["document_ids"],
            owner=request.user,
        )
        collection.documents.add(*docs)
        return Response({"detail": f"Added {docs.count()} document(s)."}, status=status.HTTP_200_OK)

    @action(detail=True, methods=["post"])
    def remove_documents(self, request, pk=None):
        """Remove documents from a collection."""
        collection = self.get_object()
        serializer = CollectionDocumentActionSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        collection.documents.remove(*serializer.validated_data["document_ids"])
        return Response({"detail": "Documents removed."}, status=status.HTTP_200_OK)