# inventory-backend/app/services/inbound/buy_service.py from flask_jwt_extended import get_jwt from app.extensions import db from app.models.inbound.buy import StockBuy from app.models.inbound.product import StockProduct from app.models.base import MaterialBase from app.models.purchase import PurchaseRequest from datetime import datetime, timedelta, timezone from sqlalchemy import or_, func, text, and_ from sqlalchemy.exc import IntegrityError import traceback import json import numpy as np from app.utils.ai_vision import extract_and_embed from app.services.image_embedding_service import ImageEmbeddingService class BuyInboundService: # ============================================================ # 0. 辅助：唯一性校验 # ============================================================ @staticmethod def _check_unique(base_id, serial_number, batch_number, exclude_id=None): if serial_number: query = StockBuy.query.filter(StockBuy.serial_number == serial_number) if exclude_id: query = query.filter(StockBuy.id != exclude_id) exists = query.first() if exists: occupied_name = exists.base.name if exists.base else "未知物料" raise ValueError(f"序列号【{serial_number}】已存在！被物料 [{occupied_name}] 占用，请核查。") if batch_number and base_id: query = StockBuy.query.filter( StockBuy.base_id == base_id, StockBuy.batch_number == batch_number ) if exclude_id: query = query.filter(StockBuy.id != exclude_id) if query.first(): raise ValueError(f"该物料已存在批号【{batch_number}】，请勿重复录入，可直接在该批次下追加库存。") # ============================================================ # 1. 基础物料搜索 # ============================================================ @staticmethod def search_base_material(keyword, page=1, limit=50): try: query = MaterialBase.query.filter(MaterialBase.is_enabled == True) if keyword: k = keyword.strip() k_str = f'%{k}%' query = query.filter(and_( or_( MaterialBase.name.ilike(k_str), MaterialBase.spec_model.ilike(k_str), MaterialBase.company_name.ilike(k_str) # 支持搜公司 ) )) # ★ 行级公司隔离：只能搜索/选择本公司的物料（超管/跨域不受限） from app.utils.decorators import get_current_company_filter company_limit = get_current_company_filter() if company_limit is not None: query = query.filter(MaterialBase.company_name == company_limit) query = query.order_by(MaterialBase.id.desc()) pagination = query.paginate(page=page, per_page=limit, error_out=False) items = [] for item in pagination.items: items.append({ 'id': item.id, 'company_name': item.company_name, # [新增] 'name': item.name, 'spec': item.spec_model, 'category': item.category, 'unit': item.unit, 'type': item.material_type, 'brand': getattr(item, 'brand', ''), 'manufacturer': getattr(item, 'manufacturer', ''), 'pinyin': getattr(item, 'pinyin', ''), 'status': '启用' }) return { "items": items, "total": pagination.total, "page": page, "has_next": pagination.has_next } except Exception as e: traceback.print_exc() return {"items": [], "total": 0, "page": 1, "has_next": False} # ============================================================ # 2. 新增入库逻辑 # ============================================================ @staticmethod def handle_inbound(data): try: base_id = data.get('base_id') if not base_id: raise ValueError("必须选择基础物料") material = MaterialBase.query.get(base_id) if not material: raise ValueError("所选物料不存在") if not material.is_enabled: raise ValueError(f"物料【{material.name}】已停用") # ============================================================ # 物料类别隔离校验：采购入库禁止【半成品】和【成品】（黑名单拦截制） # ============================================================ if material.category and ('/半成品' in material.category or '/成品' in material.category): raise ValueError(f"物料【{material.name}】属于【{material.category}】，【半成品】和【成品】不允许直接采购入库！") # ============================================================ # 强制质检校验：如果物料标记为强制质检，则必须提供到检状态和检测报告 # ============================================================ if material.is_inspection_required: inspection_status = data.get('inspection_status') if not inspection_status: raise ValueError(f"物料【{material.name}】为强管控物料，必须选择到检状态") # 检查检测报告：文件列表或外部链接至少有一个 # 前端会将外部链接添加到 inspection_report 数组中一起提交 inspection_report_list = data.get('inspection_report', []) # 过滤空字符串，只保留有效报告（字符串长度 > 0 且去除空格后非空） valid_reports = [r for r in inspection_report_list if r and str(r).strip()] has_report_file = valid_reports and len(valid_reports) > 0 if not has_report_file: raise ValueError(f"物料【{material.name}】为强管控物料，必须提供检测报告文件或外部链接") BuyInboundService._check_unique( base_id=base_id, serial_number=data.get('serial_number'), batch_number=data.get('batch_number') ) beijing_tz = timezone(timedelta(hours=8)) current_time = datetime.now(beijing_tz).replace(tzinfo=None) in_date_val = current_time if data.get('in_date'): try: date_str = str(data['in_date']) if len(date_str) > 10: in_date_val = datetime.strptime(date_str, '%Y-%m-%d %H:%M:%S') else: d_temp = datetime.strptime(date_str, '%Y-%m-%d') in_date_val = datetime(d_temp.year, d_temp.month, d_temp.day, current_time.hour, current_time.minute, current_time.second) except: in_date_val = current_time in_qty = float(data.get('in_quantity') or 0) u_price = float(data.get('unit_price') or 0) tax_rate = float(data.get('tax_rate') or 0) post_tax_price = float(data.get('post_tax_unit_price') or 0) # [新增] 按单入库：关联采购申请单 request_id = data.get('request_id') # ★ 补价：库管角色没有 inbound_purchase:unit_price / total_price 权限， # 采购单接口（api/v1/purchase.py）会把价格字段整个 pop 掉，前端导入时 # 因此带不出价（buy.vue 的 hasUnitPrice/hasTotalPrice 双双落空， # 两个分支都不进）→ 入库成本被记成 0。 # 这里在落库前从采购申请单补回：价格**不经过前端**，库管依旧看不到 # 采购价，权限边界不变，但成本可追溯。 # 注：采购申请单的 unit_price 存的是**含税**单价（见 purchase/index.vue # 的列名"含税单价"），需要反算不含税单价。 if request_id and u_price <= 0 and post_tax_price <= 0: _req = PurchaseRequest.query.get(request_id) if _req and float(_req.unit_price or 0) > 0: tax_rate = float(_req.tax_rate or 0) post_tax_price = float(_req.unit_price) u_price = post_tax_price / (1 + tax_rate / 100) # 计算税后单价（保底：只给了不含税价时反推） if post_tax_price == 0 and u_price > 0: tax_multiplier = 1 + (tax_rate / 100) post_tax_price = u_price * tax_multiplier try: seq_sql = text("SELECT nextval('global_print_seq')") result = db.session.execute(seq_sql) next_global_id = result.scalar() except: next_global_id = None generated_sku = str(next_global_id).zfill(10) if next_global_id else datetime.now().strftime('%Y%m%d%H%M%S') final_barcode = data.get('barcode') or generated_sku new_stock = StockBuy( base_id=material.id, global_print_id=next_global_id, sku=generated_sku, barcode=final_barcode, in_date=in_date_val, serial_number=data.get('serial_number'), batch_number=data.get('batch_number'), status=data.get('status', '在库'), in_quantity=in_qty, stock_quantity=in_qty, available_quantity=in_qty, inspection_status=data.get('inspection_status', '未检'), warehouse_location=data.get('warehouse_location'), # [新增] 按单入库关联 request_id=request_id, # 价格信息 pre_tax_unit_price=u_price, post_tax_unit_price=post_tax_price, tax_rate=tax_rate, total_price=in_qty * u_price, currency=data.get('currency', 'CNY'), exchange_rate=data.get('exchange_rate', 1.0), supplier_name=data.get('supplier_name'), buyer_name=data.get('purchaser'), buyer_email=data.get('purchaser_email'), original_link=data.get('source_link'), detail_link=data.get('detail_link'), arrival_photo=json.dumps(data.get('arrival_photo', [])), inspection_report=json.dumps(data.get('inspection_report', [])) ) db.session.add(new_stock) db.session.flush() # 获取 new_stock.id # [新增] 按单入库：反写采购申请单状态为"已完成" # 注：原先此处有一句局部 `from app.models.purchase import PurchaseRequest`， # 它会让 Python 把 PurchaseRequest 视为本函数的局部变量，导致上方补价 # 逻辑（在 import 之前使用）抛 UnboundLocalError。已改用文件顶部的全局导入。 if request_id: purchase_req = db.session.get(PurchaseRequest, request_id) if purchase_req: if purchase_req.status != 1: raise ValueError(f"采购单【{purchase_req.request_no}】当前状态不允许入库，请确认审批状态") purchase_req.status = 3 # 3 = 已完成/已入库 # 先提交主事务（入库单必须落盘），图片向量异步后台提取 db.session.commit() photo_list = data.get('arrival_photo', []) if isinstance(photo_list, list) and photo_list: from flask import current_app from app.utils.executor import run_embedding_task run_embedding_task( ImageEmbeddingService.save_embeddings_background, current_app._get_current_object(), ImageEmbeddingService.MODULE_STOCK_BUY, new_stock.id, photo_list ) return new_stock except Exception as e: db.session.rollback() raise e # ============================================================ # 3. 更新入库 # ============================================================ @staticmethod def update_inbound(stock_id, data): try: stock = StockBuy.query.get(stock_id) if not stock: raise ValueError("记录不存在") # 获取物料信息用于校验 base_id = data.get('base_id', stock.base_id) material = MaterialBase.query.get(base_id) # ============================================================ # 强制质检校验：如果物料标记为强制质检，则必须提供到检状态和检测报告 # ============================================================ if material and material.is_inspection_required: inspection_status = data.get('inspection_status', stock.inspection_status) if not inspection_status: raise ValueError(f"物料【{material.name}】为强管控物料，必须选择到检状态") # 检查检测报告：文件列表至少有一个 inspection_report_list = data.get('inspection_report') if inspection_report_list is None: # 如果没有传入，使用现有的 import json as json_module try: existing_reports = json_module.loads(stock.inspection_report) if stock.inspection_report else [] except: existing_reports = [] # 过滤空字符串，只保留有效报告 valid_reports = [r for r in existing_reports if r and str(r).strip()] has_report_file = valid_reports and len(valid_reports) > 0 else: # 过滤空字符串，只保留有效报告 valid_reports = [r for r in inspection_report_list if r and str(r).strip()] has_report_file = valid_reports and len(valid_reports) > 0 if not has_report_file: raise ValueError(f"物料【{material.name}】为强管控物料，必须提供检测报告文件或外部链接") BuyInboundService._check_unique(base_id=base_id, serial_number=data.get('serial_number', stock.serial_number), batch_number=data.get('batch_number', stock.batch_number), exclude_id=stock_id) field_mapping = {'sku': 'sku', 'barcode': 'barcode', 'base_id': 'base_id', 'warehouse_location': 'warehouse_location', 'serial_number': 'serial_number', 'batch_number': 'batch_number', 'status': 'status', 'inspection_status': 'inspection_status', 'supplier_name': 'supplier_name', 'detail_link': 'detail_link', 'currency': 'currency', 'exchange_rate': 'exchange_rate', 'purchaser': 'buyer_name', 'purchaser_email': 'buyer_email', 'source_link': 'original_link'} for k, v in field_mapping.items(): if k in data: setattr(stock, v, data[k]) # ★ 仅当 payload 明确携带 arrival_photo 时才更新（含 [] 表示清空）；改其它字段不动图片 if 'arrival_photo' in data: new_photo_list = data['arrival_photo'] stock.arrival_photo = json.dumps(new_photo_list) # 立即触发异步向量提取，不阻塞主事务提交 if isinstance(new_photo_list, list) and new_photo_list: from flask import current_app from app.utils.executor import run_embedding_task run_embedding_task( ImageEmbeddingService.save_embeddings_background, current_app._get_current_object(), ImageEmbeddingService.MODULE_STOCK_BUY, stock.id, new_photo_list ) else: # 图片被清空([])时，同步清理该记录的图片向量 ImageEmbeddingService.delete_embeddings( ImageEmbeddingService.MODULE_STOCK_BUY, stock.id ) if 'inspection_report' in data: stock.inspection_report = json.dumps(data['inspection_report']) # 更新税率 if 'tax_rate' in data: stock.tax_rate = float(data['tax_rate']) # 更新税前单价 if 'unit_price' in data: stock.pre_tax_unit_price = float(data['unit_price']) # 更新税后单价 if 'post_tax_unit_price' in data: stock.post_tax_unit_price = float(data['post_tax_unit_price']) else: # 如果税后单价没有提供，根据税前单价和税率计算 if 'unit_price' in data or 'tax_rate' in data: tax_multiplier = 1 + (float(data.get('tax_rate', stock.tax_rate or 0)) / 100) stock.post_tax_unit_price = float(stock.pre_tax_unit_price) * tax_multiplier if 'in_quantity' in data: diff = float(data['in_quantity']) - float(stock.in_quantity) if diff != 0: # ★ 下调数量前校验可用数下限。 # 该批次可能已有部分被预占/出库/借出，硬扣会让 # available_quantity 变成负数 —— 而它一旦为负， # 预占释放、行级防穿仓校验、盘点平账的全部算术都会失真。 # 注意：stock >= available 恒成立（正常数据下）， # 故守住 available 同时也就守住了 stock 不会为负。 if diff < 0: avail_now = float(stock.available_quantity or 0) if -diff > avail_now: raise ValueError( f"无法下调入库数量：该批次已有部分被预占/出库/借出，" f"当前可用数（{avail_now}）不足以支持向下调整 {-diff}。" f"请先处理相关单据或改为调整盘点差异。" ) stock.in_quantity = float(data['in_quantity']) stock.stock_quantity = float(stock.stock_quantity) + diff stock.available_quantity = float(stock.available_quantity) + diff # 重新计算总价 stock.total_price = float(stock.in_quantity) * float(stock.pre_tax_unit_price) db.session.commit() return stock except Exception as e: db.session.rollback() raise e # ============================================================ # 4. 删除 # ============================================================ @staticmethod def delete_inbound(stock_id): try: stock = StockBuy.query.get(stock_id) if not stock: raise ValueError("记录不存在") material_name = stock.base.name if stock.base else '未知物料' # 删除时同步清理向量记录 ImageEmbeddingService.delete_embeddings( ImageEmbeddingService.MODULE_STOCK_BUY, stock.id ) db.session.delete(stock) db.session.commit() return material_name except IntegrityError: db.session.rollback() raise ValueError("该入库单已被出库、盘点或借还等业务关联，为保证账目完整，禁止删除！") except Exception as e: db.session.rollback() raise e # ============================================================ # 5. 获取列表 (支持排序和高级筛选) # ============================================================ @staticmethod def get_list(page, limit, keyword=None, sku=None, search_field='all', statuses=None, category=None, material_type=None, company=None, order_by='', is_asc='', advanced_filters=None): try: from sqlalchemy import and_, or_ query = db.session.query(StockBuy).outerjoin(MaterialBase, StockBuy.base_id == MaterialBase.id) # 1. 通用关键词搜索（支持指定字段精准搜索） if keyword: k_str = f'%{keyword.strip()}%' if search_field == 'name': query = query.filter(MaterialBase.name.ilike(k_str)) elif search_field == 'spec': query = query.filter(MaterialBase.spec_model.ilike(k_str)) elif search_field == 'common_name': query = query.filter(MaterialBase.common_name.ilike(k_str)) elif search_field == 'barcode': query = query.filter(StockBuy.barcode.ilike(k_str)) elif search_field == 'batch_number': query = query.filter(StockBuy.batch_number.ilike(k_str)) elif search_field == 'supplier_name': query = query.filter(StockBuy.supplier_name.ilike(k_str)) elif search_field == 'buyer_name': query = query.filter(StockBuy.buyer_name.ilike(k_str)) else: # 'all' 默认全局模糊匹配 conditions = [ StockBuy.barcode.ilike(k_str), StockBuy.batch_number.ilike(k_str), StockBuy.serial_number.ilike(k_str), StockBuy.supplier_name.ilike(k_str), StockBuy.buyer_name.ilike(k_str), MaterialBase.name.ilike(k_str), MaterialBase.spec_model.ilike(k_str), MaterialBase.company_name.ilike(k_str), ] query = query.filter(or_(*conditions)) # 1.1 SKU 独立搜索 if sku and sku.strip(): sku_str = f'%{sku.strip()}%' query = query.filter(StockBuy.sku.ilike(sku_str)) # 2. 类别独立搜索 if category and category.strip(): # 级联选择器：中间节点用前缀匹配，与 base_service.get_list 行为一致 query = query.filter(MaterialBase.category.ilike(f"{category.strip()}%")) # 3. 类型独立搜索 if material_type and material_type.strip(): query = query.filter(MaterialBase.material_type == material_type.strip()) # ============================================================ # 【行级数据隔离】基于 JWT 多租户公司过滤 # ============================================================ from app.utils.decorators import get_current_company_filter company_limit = get_current_company_filter() if company_limit is not None: query = query.filter(MaterialBase.company_name == company_limit) # 4. 状态筛选 if not statuses: statuses = ['在库', '借库'] if '已出库' in statuses: query = query.filter(StockBuy.status.in_(statuses)) else: query = query.filter(and_(StockBuy.status.in_(statuses), StockBuy.stock_quantity > 0)) # 5. 高级动态筛选 if advanced_filters: allowed_fields = { 'company_name': MaterialBase.company_name, 'material_name': MaterialBase.name, 'material_type': MaterialBase.material_type, 'category': MaterialBase.category, 'spec_model': MaterialBase.spec_model, 'unit': MaterialBase.unit, 'sku': StockBuy.sku, 'barcode': StockBuy.barcode, 'batch_number': StockBuy.batch_number, 'serial_number': StockBuy.serial_number, 'warehouse_location': StockBuy.warehouse_location, 'status': StockBuy.status, 'inspection_status': StockBuy.inspection_status, 'qty_inbound': StockBuy.in_quantity, 'qty_stock': StockBuy.stock_quantity, 'qty_available': StockBuy.available_quantity, 'unit_price': StockBuy.pre_tax_unit_price, 'total_price': StockBuy.total_price, 'tax_rate': StockBuy.tax_rate, 'currency': StockBuy.currency, 'exchange_rate': StockBuy.exchange_rate, 'supplier_name': StockBuy.supplier_name, 'purchaser': StockBuy.buyer_name, 'purchaser_email': StockBuy.buyer_email, 'source_link': StockBuy.original_link, 'detail_link': StockBuy.detail_link, } filter_conditions = [] for condition in advanced_filters: field = condition.get('field') operator = condition.get('operator') value = condition.get('value') if not field or not operator or value is None: continue column = allowed_fields.get(field) if column is None: continue if operator == 'eq': filter_conditions.append(column == value) elif operator == 'ne': filter_conditions.append(column != value) elif operator == 'contains': filter_conditions.append(column.ilike(f'%{value}%')) elif operator == 'not_contains': filter_conditions.append(~column.ilike(f'%{value}%')) elif operator == 'ge': try: num_val = float(value) filter_conditions.append(column >= num_val) except ValueError: continue elif operator == 'le': try: num_val = float(value) filter_conditions.append(column <= num_val) except ValueError: continue if filter_conditions: query = query.filter(and_(*filter_conditions)) # 6. 排序处理 if order_by: sort_field_map = { 'company_name': MaterialBase.company_name, 'material_name': MaterialBase.name, 'material_type': MaterialBase.material_type, 'category': MaterialBase.category, 'spec_model': MaterialBase.spec_model, 'unit': MaterialBase.unit, 'sku': StockBuy.sku, 'barcode': StockBuy.barcode, 'inbound_date': StockBuy.in_date, 'serial_number': StockBuy.serial_number, 'batch_number': StockBuy.batch_number, 'status': StockBuy.status, 'inspection_status': StockBuy.inspection_status, 'qty_inbound': StockBuy.in_quantity, 'qty_stock': StockBuy.stock_quantity, 'qty_available': StockBuy.available_quantity, 'warehouse_loc': StockBuy.warehouse_location, 'unit_price': StockBuy.pre_tax_unit_price, 'total_price': StockBuy.total_price, 'tax_rate': StockBuy.tax_rate, 'currency': StockBuy.currency, 'exchange_rate': StockBuy.exchange_rate, 'supplier_name': StockBuy.supplier_name, 'purchaser': StockBuy.buyer_name, 'purchaser_email': StockBuy.buyer_email, 'source_link': StockBuy.original_link, 'detail_link': StockBuy.detail_link, } column = sort_field_map.get(order_by) if column: if is_asc == 'asc': query = query.order_by(column.asc()) elif is_asc == 'desc': query = query.order_by(column.desc()) else: # 默认排序 query = query.order_by(StockBuy.in_date.desc()) pagination = query.paginate(page=page, per_page=limit, error_out=False) items = [] for item in pagination.items: items.append(item.to_dict()) # 直接使用 model 的 to_dict return {"total": pagination.total, "items": items} except Exception: traceback.print_exc() return {"total": 0, "items": []} # ============================================================ # 6. 获取筛选选项（类别、类型、公司）并排序 # ============================================================ @staticmethod def get_filter_options(): try: # 类别 categories = db.session.query(MaterialBase.category) \ .filter(MaterialBase.category != None, MaterialBase.category != '') \ .distinct().all() sorted_categories = sorted([r[0] for r in categories]) # 类型 types = db.session.query(MaterialBase.material_type) \ .filter(MaterialBase.material_type != None, MaterialBase.material_type != '') \ .distinct().all() sorted_types = sorted([r[0] for r in types]) # [新增] 公司 companies = db.session.query(MaterialBase.company_name) \ .filter(MaterialBase.company_name != None, MaterialBase.company_name != '') \ .distinct().all() sorted_companies = sorted([r[0] for r in companies]) return { "categories": sorted_categories, "types": sorted_types, "companies": sorted_companies } except Exception: traceback.print_exc() return {"categories": [], "types": [], "companies": []} # 7-10 建议类接口保持不变 @staticmethod def get_history_suppliers(base_id): return [r[0] for r in db.session.query(StockBuy.supplier_name).filter(StockBuy.base_id == base_id, StockBuy.supplier_name != '').distinct().all()] @staticmethod def get_history_purchasers(keyword): return [{'value': r.buyer_name, 'email': r.buyer_email} for r in db.session.query(StockBuy.buyer_name, StockBuy.buyer_email).filter( StockBuy.buyer_name != '').distinct().all()] @staticmethod def get_history_links(base_id, type): return [r[0] for r in db.session.query(StockBuy.original_link if type == 'original' else StockBuy.detail_link).filter( StockBuy.base_id == base_id).distinct().all()] @staticmethod def get_history_locations(base_id): return [r[0] for r in db.session.query(StockBuy.warehouse_location).filter(StockBuy.base_id == base_id).distinct().all()] @staticmethod def get_latest_batch_record_by_base_id(base_id): """ 按物料精准取“最近一次采购入库记录”（SQL 直接 filter base_id + limit，O(1)、不分页）。 用于采购入库表单的批号自增：避免以前端拉 getBuyList 前 1000 条再过滤造成的 “历史被截断 → 误判无历史 → 批号退回 000001/重复入库被拦”问题。 返回: {'has_history': bool, 'mode': 'serial'|'batch', 'latest_batch': str} """ if not base_id: return {'has_history': False, 'mode': 'batch', 'latest_batch': ''} latest = StockBuy.query.filter( StockBuy.base_id == base_id ).order_by( StockBuy.in_date.desc().nullslast(), StockBuy.id.desc() ).first() if latest is None: return {'has_history': False, 'mode': 'batch', 'latest_batch': ''} if latest.serial_number: return {'has_history': True, 'mode': 'serial', 'latest_batch': latest.batch_number or ''} return {'has_history': True, 'mode': 'batch', 'latest_batch': latest.batch_number or ''} @staticmethod def get_last_location_by_base_id(base_id): """ 获取指定物料最近一次入库的库位（跨表查询） 查询顺序：采购入库 -> 成品入库 -> 半成品入库，返回最新入库的库位 """ from app.models.inbound.semi import StockSemi # 1. 查询采购入库最新记录 last_buy = StockBuy.query.filter( StockBuy.base_id == base_id ).order_by(StockBuy.in_date.desc()).first() # 2. 查询成品入库最新记录 last_product = StockProduct.query.filter( StockProduct.base_id == base_id ).order_by(StockProduct.production_date.desc()).first() # 3. 查询半成品入库最新记录 last_semi = StockSemi.query.filter( StockSemi.base_id == base_id ).order_by(StockSemi.production_date.desc()).first() # 比较三个表中的最新入库时间，返回最新的库位 candidates = [] if last_buy and last_buy.warehouse_location: candidates.append((last_buy.in_date, last_buy.warehouse_location)) if last_product and last_product.warehouse_location: candidates.append((last_product.production_date, last_product.warehouse_location)) if last_semi and last_semi.warehouse_location: candidates.append((last_semi.production_date, last_semi.warehouse_location)) if not candidates: return "" # 按时间倒序排序，返回最新的库位 candidates.sort(key=lambda x: x[0] if x[0] else datetime.min, reverse=True) return candidates[0][1] if candidates[0][1] else ""