import logging
from typing import Any, Dict, List

from celery import shared_task
from django.contrib.auth import get_user_model

from business import models as business_models
from stock import models as stock_models
from stock.services import StockFlowService


logger = logging.getLogger(__name__)


@shared_task(bind=True)
def create_purchase_order_stock_entries(
    self,
    *,
    purchase_order_id: int,
    warehouse_id: int,
    items: List[Dict[str, Any]],
    created_by_id: int | None = None,
):
    """
    为采购单创建入库记录。仅支持入库（StockFlowService.stock_in）。
    """
    try:
        purchase_order = business_models.PurchaseOrder.objects.select_related('merchant').get(id=purchase_order_id)
    except business_models.PurchaseOrder.DoesNotExist:
        logger.error('PurchaseOrder %s 不存在，无法创建入库单', purchase_order_id)
        return {'error': 'purchase_order_not_found', 'purchase_order_id': purchase_order_id}

    merchant = purchase_order.merchant

    created_by = None
    if created_by_id:
        UserModel = get_user_model()
        created_by = UserModel.objects.filter(id=created_by_id).first()

    service = StockFlowService(merchant=merchant, created_by=created_by)
    record, details, created_count = service.stock_in(
        warehouse_id=warehouse_id,
        source_type=stock_models.StockChangeSourceEnum.PURCHASE,
        source_id=purchase_order.id,
        items=items,
    )

    payload = {
        'task_id': self.request.id,
        'purchase_order_id': purchase_order.id,
        'stock_change_record_id': getattr(record, 'id', None),
        'created_details_count': created_count,
    }
    logger.info('采购单 %s 入库任务完成: %s', purchase_order.id, payload)
    return payload