import uuid
from typing import cast

from django_core.mixins import BaseViewSetMixin  # type: ignore
from django.utils.translation import gettext as _
from drf_spectacular.utils import extend_schema
from rest_framework.exceptions import PermissionDenied  # type: ignore
from rest_framework.permissions import AllowAny, IsAdminUser  # type: ignore
from rest_framework.viewsets import ModelViewSet  # type: ignore
from rest_framework.request import HttpRequest  # type: ignore
from rest_framework.response import Response  # type: ignore
from rest_framework import status  # type: ignore
from rest_framework.generics import GenericAPIView  # type: ignore
from rest_framework.parsers import MultiPartParser, FormParser  # type: ignore
from rest_framework.generics import get_object_or_404  # type: ignore

from core.utils.views import BaseApiViewMixin
from core.apps.contracts.models import (
    ContractOwnerModel,
    ContractAttachedFileModel,
)
from core.apps.contracts.serializers import (
    CreateContractOwnerSerializer,
    ListContractOwnerSerializer,
    RetrieveContractOwnerSerializer,
    UpdateContractOwnerSerializer,
    DestroyContractOwnerSerializer,

    CreateContractFileContentFromOwnerSerializer,
)


###################################################################################
# @view-set  |  ALL - /contract-owners
###################################################################################
@extend_schema(tags=["Contract Owners"])
class ContractOwnerViewSet(BaseViewSetMixin, ModelViewSet):
    queryset = ContractOwnerModel.objects.all()
    serializer_class = ListContractOwnerSerializer
    permission_classes = [AllowAny]

    action_permission_classes = {
        "list": [IsAdminUser],
        "retrieve": [IsAdminUser],
        "create": [IsAdminUser],
        "update": [IsAdminUser],
        "destroy": [IsAdminUser],
    }
    action_serializer_class = {  # type: ignore
        "list": ListContractOwnerSerializer,
        "retrieve": RetrieveContractOwnerSerializer,
        "create": CreateContractOwnerSerializer,
        "update": UpdateContractOwnerSerializer,
        "destroy": DestroyContractOwnerSerializer,
    }


###################################################################################
# @api-view  |  DELETE - /contract-owners/{owner_id}/files/{file_id}
###################################################################################
@extend_schema(tags=["Contract Files"])
class ContractOwnerAttachedFileApiView(BaseApiViewMixin, GenericAPIView):  # type: ignore
    permission_classes = [AllowAny]
    serializer_class = ListContractOwnerSerializer
    queryset = ContractOwnerModel.objects.all()

    method_permission_classes = {"delete": [AllowAny]}
    method_serializer_class = {}

    @extend_schema(
        summary="Delete a file from contract",
        description="Deletes a contract-attached file if contract allows file deletion.",
    )
    def delete(
        self,
        request: HttpRequest,
        owner_id: uuid.UUID,
        file_id: uuid.UUID,
        *args: object,
        **kwargs: object
    ) -> Response:
        owner = get_object_or_404(
            ContractOwnerModel.objects.all().select_related("contract"), pk=owner_id
        )
        if not owner.contract.allow_delete_files:
            raise PermissionDenied(_("Deleting attached files was restricted for this contract"))
        
        file = get_object_or_404(
            ContractAttachedFileModel.objects.all().select_related("contract"), pk=file_id
        )
        if owner.contract.pk != file.contract.pk:
            raise PermissionDenied(_("Contract have no such file attached"))
        file.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)
        
    
###################################################################################
# @api-view  |  POST - /contract-owners/{owner_id}/files/{file_id}/upload
###################################################################################
@extend_schema(tags=["Contract File contents"])
class UploadFileContentApiView(BaseApiViewMixin, GenericAPIView):  # type: ignore
    permission_classes = [AllowAny]
    parser_classes = [MultiPartParser, FormParser]  # type: ignore

    method_permission_classes = {"post": [AllowAny]}
    method_serializer_class = {"post": CreateContractFileContentFromOwnerSerializer}

    @extend_schema(
        summary="Uploads a file for contract attached files",
        description="Creates a file for contract attached files.",
    )
    def post(
        self,
        request: HttpRequest,
        owner_id: uuid.UUID,
        file_id: uuid.UUID,
        *args: object,
        **kwargs: object
    ) -> Response:
        serializer_context = dict(file_id=file_id, contract_owner_id=owner_id)
        serializer = cast(
            CreateContractFileContentFromOwnerSerializer, 
            self.get_serializer(data=request.data, context=serializer_context)  # type: ignore
        )
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)