from rest_framework import status
from rest_framework.decorators import api_view, permission_classes
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from django.db import transaction
from typing import List, Dict, Any
import logging

from stock import models as stock_models
from basic_info import models as basic_info_models
from drf_spectacular.utils import extend_schema
from . import serializers

logger = logging.getLogger(__name__)


@extend_schema(tags=['创建出入库'])
@api_view(['POST'])
def create_full_stock_change(request):
    """
    创建完整的库存变动记录（包含记录创建参数）
    
    POST /api/v1/stock-change/
    
    请求参数:
    {
        "type": 1,  // 1=入库, 2=出库
        "warehouse": 1,  // 仓库ID
        "source_type": 1,  // 来源类型
        "source_id": 1,  // 可选，来源单据ID
        "products": [
            {
                "product": 1,
                "quantity": [85, 75, 90]
            }
        ]
    }
    """
    
    # 提取库存变动记录参数
    record_data = {
        'type': request.data.get('type'),
        'warehouse': request.data.get('warehouse'),
        'source_type': request.data.get('source_type'),
        'source_id': request.data.get('source_id'),
    }
    
    # 验证必要参数
    if not all([record_data['type'], record_data['warehouse'], record_data['source_type']]):
        return Response({
            'error': '缺少必要参数',
            'message': '请提供 type, warehouse, source_type'
        }, status=status.HTTP_400_BAD_REQUEST)
    
    products_data = request.data.get('products', [])
    if not products_data:
        return Response({
            'error': '产品列表不能为空'
        }, status=status.HTTP_400_BAD_REQUEST)
    
    # 验证产品数据
    product_serializer = serializers.CreateStockChangeSerializer(data={
        'products': products_data
    })
    if not product_serializer.is_valid():
        return Response({
            'error': '产品数据验证失败',
            'details': product_serializer.errors
        }, status=status.HTTP_400_BAD_REQUEST)
    
    try:
        with transaction.atomic():
            # 1. 创建库存变动记录
            try:
                warehouse = basic_info_models.WareHouse.objects.get(id=record_data['warehouse'])
            except basic_info_models.WareHouse.DoesNotExist:
                return Response({
                    'error': f'仓库ID {record_data["warehouse"]} 不存在'
                }, status=status.HTTP_400_BAD_REQUEST)
            
            stock_change_record = stock_models.StockChangeRecord.objects.create(
                type=record_data['type'],
                warehouse=warehouse,
                source_type=record_data['source_type'],
                source_id=record_data['source_id'],
                # created_by=request.user
            )
            
            logger.info(f"创建新库存变动记录 ID: {stock_change_record.id}")
            
            # 2. 创建库存变动明细
            created_details = []
            created_count = 0
            
            for product_data in products_data:
                product_id = product_data['product']
                quantities = product_data['quantity']
                
                # 获取产品信息
                try:
                    product = basic_info_models.Product.objects.get(id=product_id)
                except basic_info_models.Product.DoesNotExist:
                    raise ValueError(f'产品ID {product_id} 不存在')
                
                # 为每个数量创建明细记录
                for quantity in quantities:
                    detail = stock_models.StockChangeDetail.objects.create(
                        stock_change_record=stock_change_record,
                        product=product,
                        quantity=quantity,
                        unit=product.unit
                    )
                    created_details.append(detail)
                    created_count += 1
            
            # 3. 构建响应
            response_serializer = serializers.CreateStockChangeResponseSerializer({
                'stock_change_record': stock_change_record,
                'details': created_details,
                'message': f'成功创建库存变动记录及 {created_count} 条明细',
                'created_details_count': created_count
            })
            
            return Response(response_serializer.data, status=status.HTTP_201_CREATED)
            
    except ValueError as e:
        return Response({
            'error': str(e)
        }, status=status.HTTP_400_BAD_REQUEST)
    
    except Exception as e:
        logger.error(f"创建完整库存变动记录失败: {str(e)}", exc_info=True)
        return Response({
            'error': '创建库存变动记录失败',
            'message': str(e)
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)