"""
Shipment API ViewSet
"""
from rest_framework import status
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.permissions import IsAuthenticated

from .serializers import SalesItemSerializer, ShipmentSerializer, ShipmentCreateSerializer


class ShipmentCreateView(APIView):
    """
    创建出货单
    
    POST /api/v1/shipment/shipments/
    
    请求体:
    {
        "customer": 1,
        "shipment_date": "2026-01-14",
        "remark": "备注信息（可选）",
        "sales_items": [1, 2, 3]
    }
    
    返回:
    {
        "id": 1,
        "customer": 1,
        "customer_name": "客户A",
        "shipment_date": "2026-01-14",
        "remark": "备注信息",
        "items_count": 3,
        "created_by_id": 1,
        "created_by_name": "张三",
        "created_at": "2026-01-14T10:00:00Z",
        "updated_at": "2026-01-14T10:00:00Z"
    }
    """
    permission_classes = [IsAuthenticated]
    
    def post(self, request):
        # 验证请求数据
        serializer = ShipmentCreateSerializer(data=request.data)
        if not serializer.is_valid():
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
        
        data = serializer.validated_data
        
        # 调用业务逻辑
        from shipment.services import create_shipment
        try:
            shipment = create_shipment(
                customer_id=data['customer'],
                shipment_date=data['shipment_date'],
                sales_item_ids=data['sales_items'],
                created_by=request.user,
                remark=data.get('remark', ''),
            )
        except ValueError as e:
            return Response({'detail': str(e)}, status=status.HTTP_400_BAD_REQUEST)
        
        # 返回创建的出货单
        response_serializer = ShipmentSerializer(shipment)
        return Response(response_serializer.data, status=status.HTTP_201_CREATED)


class SalesItemByPrintingOrderView(APIView):
    """
    通过生产订单查询销售品
    
    GET /api/v1/shipment/sales-items/by-printing-order/<printing_order_id>/
    
    返回与该 PrintingOrder 下所有 PrintingJob 关联的 SalesItem 列表。
    
    查询参数:
    - include_already_has_shipment: 是否包含已关联出货单的销售品（true/false），默认 false
    
    返回:
    {
        "count": 5,
        "results": [
            {
                "id": 1,
                "name": "产品A",
                "quantity": "100.00",
                "unit": 1,
                "unit_display": "米",
                "position": "A1-01",
                "remark": "",
                "printing_job_id": 123,
                "customer_id": null,
                "shipment_id": null,
                "shipment_date": null,
                "created_at": "2026-01-14T10:00:00Z",
                "created_by_id": 1,
                "created_by_name": "张三"
            },
            ...
        ]
    }
    """
    permission_classes = [IsAuthenticated]
    
    def get(self, request, printing_order_id):
        # 验证生产订单是否存在
        from printing.models import PrintingOrder
        try:
            printing_order = PrintingOrder.objects.get(id=printing_order_id)
        except PrintingOrder.DoesNotExist:
            return Response(
                {'detail': f'生产订单 {printing_order_id} 不存在'},
                status=status.HTTP_404_NOT_FOUND
            )
        
        # 获取查询参数
        include_already_has_shipment = request.query_params.get(
            'include_already_has_shipment', 'false'
        ).lower() == 'true'
        
        # 调用 shipment 业务逻辑
        from shipment.services import get_sales_items_by_printing_order
        sales_items = get_sales_items_by_printing_order(
            printing_order_id=printing_order.id,
            include_already_has_shipment=include_already_has_shipment,
        )
        
        # 序列化返回
        serializer = SalesItemSerializer(sales_items, many=True)
        
        return Response({
            'count': len(serializer.data),
            'results': serializer.data
        })