from extensions.permissions import *
from extensions.exceptions import *
from extensions.viewsets import *
from apps.purchase.serializers import *
from apps.purchase.permissions import *
from apps.purchase.filters import *
from apps.purchase.schemas import *
from apps.purchase.models import *
from apps.goods.models import *
from apps.flow.models import *


class PurchaseOrderViewSet(BaseViewSet, ListModelMixin, RetrieveModelMixin, CreateModelMixin):
    """采购单据"""

    serializer_class = PurchaseOrderSerializer
    permission_classes = [IsAuthenticated, PurchaseOrderPermission]
    filterset_class = PurchaseOrderFilter
    search_fields = ['number', 'supplier__number', 'supplier__name', 'remark']
    ordering_fields = ['id', 'number', 'total_quantity', 'total_amount', 'create_time']
    select_related_fields = ['warehouse', 'supplier', 'handler', 'creator']
    prefetch_related_fields = ['purchase_goods_set', 'purchase_goods_set__goods__unit',
                               'payment_order__payment_accounts']
    queryset = PurchaseOrder.objects.all()

    @transaction.atomic
    def perform_create(self, serializer):
        purchase_order = super().perform_create(serializer)

        # 同步入库
        if purchase_order.enable_auto_stock_in:

            # 同步库存, 流水
            inventory_flows = []
            for purchase_goods in purchase_order.purchase_goods_set.all():
                inventory = Inventory.objects.get(warehouse=purchase_order.warehouse,
                                                  goods=purchase_goods.goods, team=self.team)
                quantity_before = inventory.total_quantity
                quantity_change = purchase_goods.purchase_quantity
                quantity_after = NP.plus(inventory.total_quantity, purchase_goods.purchase_quantity)

                inventory_flows.append(InventoryFlow(
                    warehouse=purchase_order.warehouse, goods=purchase_goods.goods,
                    type=InventoryFlow.Type.PURCHASE, quantity_before=quantity_before,
                    quantity_change=quantity_change, quantity_after=quantity_after,
                    purchase_order=purchase_order, creator=self.user, team=self.team
                ))

                inventory.total_quantity = quantity_after
                inventory.save(update_fields=['total_quantity'])
            else:
                InventoryFlow.objects.bulk_create(inventory_flows)
        else:
            # 创建入库单据
            pass

        # 同步欠款
        supplier = purchase_order.supplier
        supplier.arrears_amount = NP.plus(supplier.arrears_amount, purchase_order.arrears_amount)
        supplier.save(update_fields=['arrears_amount'])

        # 同步账户, 流水
        if payment_order := purchase_order.payment_order:
            finance_flows = []
            for payemnt_account in payment_order.payemnt_accounts.all():
                account = payemnt_account.account
                amount_before = account.balance_amount
                amount_change = payemnt_account.payment_amount
                amount_after = NP.minus(amount_before, amount_change)

                finance_flows.append(FinanceFlow(
                    account=payemnt_account.account, type=FinanceFlow.Type.PAYMENT,
                    amount_before=amount_before, amount_change=amount_change, amount_after=amount_after,
                    payment_order=payment_order, creator=self.user, team=self.team
                ))

                account.balance_amount = amount_after
                account.save(update_fields=['balance_amount'])
            else:
                FinanceFlow.objects.bulk_create(finance_flows)

    @extend_schema(responses={200: NumberResponse})
    @action(detail=False, methods=['get'])
    def number(self, request, *args, **kwargs):
        """获取编号"""

        number = PurchaseOrder.get_number(self.team)
        return Response(data={'number': number}, status=status.HTTP_200_OK)

    @transaction.atomic
    @extend_schema(request=None, responses={200: PurchaseOrderSerializer})
    @action(detail=True, methods=['post'])
    def void(self, request, *args, **kwargs):
        """作废"""


__all__ = [
    'PurchaseOrderViewSet',
]