"""
Printing 模块信号处理函数

监听 stateflow 信号，在流程完成时执行业务逻辑。
"""

import logging
from django.db import transaction

logger = logging.getLogger(__name__)


def on_printing_job_process_completed(sender, **kwargs):
    """
    PrintingJob 流程完成时的处理
    
    当 PrintingJob 的工艺流程全部完成时，自动创建 SalesItem（销售品）。
    
    Args:
        sender: PrintingJob 类
        content_object: PrintingJob 实例
        last_completed_by: 最后步骤操作人
        其他参数见 stateflow.signals.process_completed
    """
    from shipment.models import SalesItem, UnitChoices
    
    content_object = kwargs.get('content_object')
    last_completed_by = kwargs.get('last_completed_by')
    
    if content_object is None:
        logger.warning('process_completed 信号缺少 content_object')
        return
    
    printing_job = content_object
    
    # 单位映射：PrintingJob.unit（字符串）→ SalesItem.unit（IntegerChoices）
    unit_mapping = {
        '米': UnitChoices.METER,
        'm': UnitChoices.METER,
        'M': UnitChoices.METER,
        '件': UnitChoices.PIECE,
        '码': UnitChoices.YARD,
        'yd': UnitChoices.YARD,
        'YD': UnitChoices.YARD,
        '个': UnitChoices.UNIT,
        'pcs': UnitChoices.UNIT,
        'PCS': UnitChoices.UNIT,
    }
    
    # 默认单位为"件"
    sales_unit = unit_mapping.get(printing_job.unit, UnitChoices.PIECE)
    
    # 获取产品名称
    product_name = printing_job.product.name if printing_job.product else '未知产品'
    
    # 获取客户ID（从主订单获取）
    customer_id = None
    if printing_job.printing_order and printing_job.printing_order.customer:
        customer_id = printing_job.printing_order.customer_id
    
    try:
        with transaction.atomic():
            sales_item = SalesItem.objects.create(
                shipment=None,  # 暂不关联出货单，待后续分配
                name=product_name,
                quantity=printing_job.quantity,
                unit=sales_unit,
                created_by=last_completed_by,
                printing_job_id=printing_job.id,
                customer_id=customer_id,
            )
            
            logger.info(
                f'PrintingJob #{printing_job.id} 流程完成，'
                f'已创建销售品 SalesItem #{sales_item.id}: '
                f'{product_name} x {printing_job.quantity}'
            )
            
    except Exception as e:
        logger.error(
            f'PrintingJob #{printing_job.id} 流程完成后创建销售品失败: {e}',
            exc_info=True
        )