from rest_framework.mixins import ListModelMixin, DestroyModelMixin, CreateModelMixin, RetrieveModelMixin
from rest_framework.viewsets import GenericViewSet
from rest_framework.response import Response
from apps.inm.models import FIFO, FIFOItem, FIFOItemProduct, IProduct, WareHouse
from apps.inm.services import InmService
from apps.mtm.models import Material, PackItem
from apps.sam.models import Sale, SalePack, SaleProduct
from apps.sam.serializers_sale import SRemarkItemCreateSerializer, SaleCreateSerializer, SaleListSerializer, SaleProductCreateSerializer, SaleProductListSerializer, SaleProductPackDetailSerializer, SaleProductPackSerializer
from rest_framework import exceptions
from django.db import transaction
from rest_framework.decorators import action
from django.utils import timezone

from apps.system.mixins import CreateUpdateModelAMixin
from rest_framework import serializers
from django.db.models import Count

from utils.tools import ranstr

class SaleViewSet(CreateUpdateModelAMixin, ListModelMixin, RetrieveModelMixin, CreateModelMixin, DestroyModelMixin, GenericViewSet):
    """
    销售记录
    """
    perms_map = {'get': '*', 'post':'sale_create', 'delete':'sale_delete'}
    queryset = Sale.objects.select_related('customer', 'order', 'product', 'order__contract').all()
    serializer_class = SaleListSerializer
    search_fields = ['customer__name', 'order__number']
    filterset_fields = ['product', 'order', 'customer']
    ordering_fields = ['create_time']
    ordering = ['-create_time']

    def get_serializer_class(self):
        if self.action == 'create':
            return SaleCreateSerializer
        elif self.action == 'retrieve':
            return SaleListSerializer
        return super().get_serializer_class()
    
    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        if obj.is_audited:
            raise exceptions.APIException('该销售记录已审核,不可删除')
        obj.delete()
        IProduct.objects.filter(sale_iproduct__sale=obj).update()

    def create(self, request, *args, **kwargs):
        data = request.data
        serializer = SaleCreateSerializer(data=data)
        serializer.is_valid(raise_exception=True)
        vdata = serializer.validated_data
        with transaction.atomic():
            iproducts = vdata.pop('iproducts')
            vdata['count'] = len(iproducts)
            if vdata['count'] + vdata['order'].delivered_count > vdata['order'].count:
                raise exceptions.APIException('超过订单所需数量')
            sale = Sale.objects.create(**vdata)
            i_l = []
            for i in iproducts:
                i.state = IProduct.SALE_LOCK
                i.save()
                i_d ={}
                i_d['sale'] = sale
                i_d['number'] = i.number
                i_d['iproduct'] = i
                i_l.append(SaleProduct(**i_d))
            SaleProduct.objects.bulk_create(i_l)
        return Response()

    @action(methods=['post'], detail=True, perms_map={'post':'sale_audit'}, serializer_class=serializers.Serializer)
    @transaction.atomic
    def audit(self, request, pk=None):
        """
        审核
        """
        obj = self.get_object()
        if obj.is_audited:
            raise exceptions.APIException('已审核通过')
        if obj.order:
            if obj.count + obj.order.delivered_count > obj.order.count:
                raise exceptions.APIException('超过订单所需数量')
        # 创建出库记录
        fifo = FIFO()
        fifo.sale = obj
        fifo.type = FIFO.FIFO_TYPE_SALE_OUT
        fifo.is_audited = False
        fifo.auditor = request.user
        fifo.inout_date = timezone.now()
        fifo.create_by = request.user
        fifo.number = 'CK' + ranstr(7)
        fifo.save()
        
        obj.is_audited = True
        obj.save()

        return Response()



class SaleProductViewSet(ListModelMixin, DestroyModelMixin, CreateModelMixin, GenericViewSet):
    """
    销售记录关联产品
    """
    perms_map = {'get': '*', 'post':'sale_update', 'delete':'sale_delete'}
    queryset = SaleProduct.objects.select_related('iproduct', 'iproduct__material', 'iproduct__warehouse').all()
    serializer_class = SaleProductListSerializer
    search_fields = []
    filterset_fields = ['sale', 'iproduct']
    ordering_fields = ['create_time']
    ordering = ['id']

    def get_serializer_class(self):
        if self.action == 'create':
            return SaleProductCreateSerializer
        return super().get_serializer_class()
    
    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        sale = obj.sale
        if sale.is_audited:
            raise exceptions.APIException('该销售记录已审核,不可删除产品')
        obj.delete()
        sale.count = SaleProduct.objects.filter(sale=obj.sale).count()
        sale.save()
        return Response()

    def create(self, request, *args, **kwargs):
        obj = self.get_object()
        sale = obj.sale
        if sale.is_audited:
            raise exceptions.APIException('该销售记录已审核,不可添加产品')
        return super().create(request, *args, **kwargs)

    @action(methods=['get', 'post'], detail=True, perms_map={'post':'sale_pack', 'get':'*'}, serializer_class=SaleProductPackSerializer)
    @transaction.atomic
    def pack(self, request, pk=None):
        """
        打包装箱
        """
        obj = self.get_object()
        if request.method == 'GET':
            for i in PackItem.objects.filter(product=obj.iproduct.material, is_deleted=False):
                SalePack.objects.get_or_create(sale_product=obj, packitem=i,
                defaults={
                    "sale_product":obj,
                    "packitem":i,
                    "count":i.count
                })
            return Response(SaleProductPackDetailSerializer(instance=obj).data)
        elif request.method == 'POST':
            serializer = SaleProductPackSerializer(data=request.data)
            serializer.is_valid(raise_exception=True)
            vdata = serializer.validated_data
            obj.packnum = vdata['packnum']
            obj.remark = vdata.get('remark', '')
            for i in vdata['detail']:
                pi = i['id']
                pi.count = i['count']
                pi.save()
            obj.save()
            return Response()

    @action(methods=['post'], detail=True, perms_map={'post':'sale_pack'}, serializer_class=SRemarkItemCreateSerializer)
    @transaction.atomic
    def remark(self, request, pk=None):
        """
        不装箱备注
        """
        obj = self.get_object()
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        vdata = serializer.validated_data
        obj.remark = vdata['remark']
        obj.save()
        return Response()