import uuid  # .material -> .base refactor checked
from datetime import datetime, timezone, timedelta
from sqlalchemy import or_, func, desc, and_
from sqlalchemy.orm import joinedload
from app.extensions import db, beijing_time
from app.models.outbound import TransOutbound, OutboundApproval

# 引入所有库存模型以进行查询
from app.models.inbound.buy import StockBuy
from app.models.inbound.semi import StockSemi
from app.models.inbound.product import StockProduct
# 引入基础信息表
from app.models.base import MaterialBase
# 引入维修单表
from app.models.transaction import TransRepair
# 引入系统用户表
from app.models.system import SysUser
# Track 联动通知（出库 → Track 标记"已出库"）
from app.services.track_webhook_service import notify_track, get_current_operator


class OutboundService:

    @staticmethod
    def generate_outbound_no():
        """
        生成出库单号: OUT-yyyyMMdd-HHmm-当日流水(4位)
        例如: OUT-20260205-1558-0001
        """
        beijing_tz = timezone(timedelta(hours=8))
        now = datetime.now(beijing_tz)

        date_str = now.strftime('%Y%m%d')
        time_str = now.strftime('%H%M')

        prefix = f"OUT-{date_str}-"

        existing_count = db.session.query(func.count(func.distinct(TransOutbound.outbound_no))) \
            .filter(TransOutbound.outbound_no.like(f"{prefix}%")).scalar()

        sequence = existing_count + 1
        return f"OUT-{date_str}-{time_str}-{sequence:04d}"

    @staticmethod
    def get_stock_by_barcode(barcode, reserved_map=None):
        """
        根据扫码内容查找对应的库存物品，并附带价格信息

        reserved_map: {(source_table, stock_id): 本单预占量}，可选。
                      传入后 available_quantity 返回「有效可用量」
                      （= 实时值 + 本单预占），见 _format_scan_result。
        """
        if not barcode:
            return None

        clean_code = barcode.strip()

        def get_price(item, table_type):
            if table_type == 'stock_product':
                return float(item.sale_price) if item.sale_price else 0
            elif table_type == 'stock_buy':
                return float(item.pre_tax_unit_price) if item.pre_tax_unit_price else 0
            return 0

        # ★ 行级公司隔离：扫码出库/借库只能命中本公司的库存（超管/跨域不受限）
        from app.utils.decorators import get_current_company_filter
        from app.models.base import MaterialBase
        company_limit = get_current_company_filter()

        prod_q = StockProduct.query.filter(
            or_(StockProduct.barcode == clean_code, StockProduct.sku == clean_code)
        )
        if company_limit is not None:
            prod_q = prod_q.join(MaterialBase, StockProduct.base_id == MaterialBase.id) \
                           .filter(MaterialBase.company_name == company_limit)
        prod = prod_q.first()
        if prod:
            OutboundService._assert_scan_allocatable(prod)
            res = OutboundService._format_scan_result(prod, 'stock_product', reserved_map)
            res['price'] = get_price(prod, 'stock_product')
            return res

        semi_q = StockSemi.query.filter(
            or_(StockSemi.barcode == clean_code, StockSemi.sku == clean_code)
        )
        if company_limit is not None:
            semi_q = semi_q.join(MaterialBase, StockSemi.base_id == MaterialBase.id) \
                           .filter(MaterialBase.company_name == company_limit)
        semi = semi_q.first()
        if semi:
            OutboundService._assert_scan_allocatable(semi)
            res = OutboundService._format_scan_result(semi, 'stock_semi', reserved_map)
            res['price'] = 0
            return res

        buy_q = StockBuy.query.filter(
            or_(StockBuy.barcode == clean_code, StockBuy.sku == clean_code)
        )
        if company_limit is not None:
            buy_q = buy_q.join(MaterialBase, StockBuy.base_id == MaterialBase.id) \
                         .filter(MaterialBase.company_name == company_limit)
        buy = buy_q.first()
        if buy:
            OutboundService._assert_scan_allocatable(buy)
            res = OutboundService._format_scan_result(buy, 'stock_buy', reserved_map)
            res['price'] = get_price(buy, 'stock_buy')
            return res

        # 查询维修单表 (按SKU或序列号查询)
        # ★ 维修单不走库存 status 体系，用自身的 repair_status 做同等准入判断：
        #   已出库（货已交回客户）、报废转出（实物已销毁）都不该再被扫出库。
        #   原实现只排除 '已出库'，报废转出的维修件仍可被扫走。
        repair = TransRepair.query.filter(
            or_(TransRepair.sku == clean_code, TransRepair.serial_number == clean_code)
        ).filter(
            TransRepair.repair_status.notin_(['已出库', '报废转出'])
        ).first()
        if repair:
            res = {
                'id': repair.id,
                'sku': repair.sku,
                'name': repair.material_name or "维修件",
                'spec_model': "",
                'category': "",
                'material_type': "",
                'source_table': 'trans_repair',
                'stock_quantity': 1,
                # 维修单不参与预占，有效可用量恒等于实时值；
                # 字段形状与 _format_scan_result 对齐，避免前端拿到 undefined
                'available_quantity': 1,
                'raw_available_quantity': 1,
                'reserved_quantity': 0,
                'batch_number': repair.serial_number or '',
                'serial_number': repair.serial_number or '',
                'warehouse_location': repair.customer_location or '',
                'barcode': repair.sku,
                'price': float(repair.sale_price) if repair.sale_price else 0
            }
            return res

        return None

    @staticmethod
    def _assert_scan_allocatable(item):
        """
        扫码准入校验：状态异常的实物一律拦在扫码环节。

        ★ 为什么扫码就拦，而不只在提交时拦（verify_scanned 已有一道）：
          提交时的校验是整单粒度的，报错只说「物料 X 状态异常」，工人得自己
          在一整单里找是哪一件。扫码即拦能立刻定位到手上这一件。
          两道校验用同一个 is_allocatable() 判定，语义不会分叉。

        ★ 与分配器的关系：分配器只决定"申请时能不能把这行算进候选"，
          而冻结可能发生在「申请已通过、工人正在扫」的窗口内 ——
          扫码这道是覆盖该窗口的必要补充。
        """
        from app.services.inventory_reservation import is_allocatable

        if not is_allocatable(item):
            # status 为空时给出可读文案，避免报出 "当前为 " 这种半截话
            status = (getattr(item, 'status', None) or '').strip() or '未设置'
            raise ValueError(f"物料状态异常（当前为 {status}），禁止出库")

    @staticmethod
    def _format_scan_result(item, table_name, reserved_map=None):
        """
        reserved_map: {(source_table, stock_id): 本单预占量}，由调用方按
                      request_id 查得（见 api/v1/outbound.py 的 _own_reserved_index）。

        ★ available_quantity 返回的是「有效可用量」= 实时可用量 + 本单预占量。
          本单自己锁掉的货当然应该能扫 —— 若直接返回实时值，被本单占满的行
          会显示 0，工人扫不进去。该值与后端执行阶段
          restore_then_deduct() 释放预占后用于校验的数字精确相等。
          实时原值另以 raw_available_quantity 返回备查。
        """
        base_name = ""
        base_spec = ""
        base_cat = ""
        base_type = ""

        if hasattr(item, 'base') and item.base:
            base_name = item.base.name
            base_spec = item.base.spec_model
            base_cat = item.base.category
            base_type = item.base.material_type

        if not base_name and hasattr(item, 'base_id') and item.base_id:
            try:
                base_info = MaterialBase.query.get(item.base_id)
                if base_info:
                    base_name = base_info.name
                    base_spec = base_info.spec_model
                    base_cat = base_info.category
                    base_type = base_info.material_type
            except Exception:
                pass

        if not base_name and hasattr(item, 'base') and item.base:
            base_name = item.base.name

        stock_qty = float(item.stock_quantity) if item.stock_quantity else 0
        raw_avail = float(item.available_quantity) if item.available_quantity else 0

        # ★ 本单预占回加（别人单子的预占不回加，防超卖能力不丢）
        reserved = float((reserved_map or {}).get((table_name, item.id), 0) or 0)

        return {
            'id': item.id,
            'sku': item.sku,
            'name': base_name or "未知物品",
            'spec_model': base_spec or "",
            'category': base_cat or "",
            'material_type': base_type or "",
            'source_table': table_name,
            'stock_quantity': stock_qty,
            # 有效可用量：本单可扫的上限
            'available_quantity': raw_avail + reserved,
            # 实时原值与本单预占量，备查/展示用
            'raw_available_quantity': raw_avail,
            'reserved_quantity': reserved,
            'batch_number': getattr(item, 'batch_number', ''),
            'warehouse_location': getattr(item, 'warehouse_location', ''),
            'barcode': getattr(item, 'barcode', '')
        }

    @staticmethod
    def create_outbound_batch(data, operator_name='System'):
        items = data.get('items', [])
        if not items:
            raise ValueError("出库商品列表不能为空")

        outbound_no = OutboundService.generate_outbound_no()

        common_data = {
            'outbound_no': outbound_no,
            'consumer_name': data.get('consumer_name'),
            'outbound_type': data.get('outbound_type', 'SALES'),
            'signature_path': data.get('signature_path'),
            'operator_name': operator_name,
            'remark': data.get('remark'),
            # ⚠ applicant_id 不在这里赋值 —— 此刻 approval 尚未查询（见下方
            #   第 2 步「强制按单出库」），在这里引用它会直接 UnboundLocalError。
            #   待 approval 取出并校验后再补进本字典。
        }

        beijing_tz = timezone(timedelta(hours=8))
        current_time = datetime.now(beijing_tz).replace(tzinfo=None)

        # ==================================================================
        # ★ 强制按单出库（Fail-Closed）：所有出库必须关联有效的出库申请单
        #
        #   背景：改造前 request_id 为空时会跳过预占再平衡，落到所谓「散单」
        #   分支，而该分支的库存扣减逻辑从未落地 —— 旧注释点名的
        #   _apply_reservation_override() 在全仓并不存在。实测后果：散单出库
        #   只写 TransOutbound 台账，stock_quantity / available_quantity
        #   分毫不动，同一批货可被反复出库而不减库存。
        #
        #   前端已彻底移除散单入口（views/outbound/create.vue 在未选单时把
        #   扫码框整块 disabled），但 HTTP 接口仍可被直接调用绕过 —— 故在此
        #   后端硬阻断，防 API 级绕过。
        #
        #   ★ 强制按单同时保证库存扣减路径唯一：
        #       申请预占 → 扫码校验 → restore_then_deduct()
        #     status 硬隔离（仅有「在库」可被分配）也依赖这条路径才全程有效。
        # ==================================================================
        request_id = data.get('request_id')
        if not request_id:
            raise ValueError("非法操作：所有出库必须关联有效的出库申请单")

        approval = OutboundApproval.query.get(request_id)
        if not approval:
            raise ValueError(f"关联的审批单不存在 (ID: {request_id})")
        if approval.status != 1:
            status_map = {0: '待审批', 1: '已通过', 2: '已驳回', 3: '已完成'}
            current_status = status_map.get(approval.status, str(approval.status))
            raise ValueError(
                f"关联的审批单状态不允许出库 (当前状态: {current_status})，"
                f"仅已通过的审批单方可执行出库"
            )

        # ★ 申请人从**关联审批单**带出。落这一列是为了让后续「退回 → 补发」能把
        #   补发单挂回真正该拿东西的人名下 —— consumer_name 是扫码时自由填写的
        #   领用人/客户名，不能作为依据。
        #   ⚠ 必须放在 approval 取出并校验**之后**：common_data 在上面就已构造，
        #     在那里引用 approval 会直接 UnboundLocalError（上线时踩过）。
        common_data['applicant_id'] = approval.applicant_id

        model_map = {
            'stock_buy': StockBuy,
            'stock_semi': StockSemi,
            'stock_product': StockProduct
        }

        # ★ Track 联动收集：(serial_number, source_table, quantity)
        track_notifications = []

        # ==================================================================
        # ★ Phase 3：预占再平衡 —— 库存扣减的唯一路径
        #
        # 申请阶段已把货预占在「申请时选定的批次」上。工人实际扫的可能是
        # 同物料的**另一个批次**（物理覆盖），因此这里：
        #   1. 校验实扫的身份/数量未超出批准范围（base_id 主键，允许换批次）
        #   2. 释放全部预占
        #   3. 对实扫批次扣减 available_quantity 与 stock_quantity
        # 之后主循环只写 TransOutbound 流水，不再重复扣库存。
        #
        # ★ 本段已改为**无条件执行**：上方强制 request_id 必填，approval 恒非
        #   None。原「无关联审批单（散单）时跳过，走原有逐行扣减逻辑」的分支
        #   已删除 —— 它正是「散单出库不扣库存」的成因（被跳过的这里就是全仓
        #   唯一的扣减入口，而所谓的"原有逐行扣减逻辑"并不存在）。
        # ==================================================================
        # ★ 自带 rollback：restore_then_deduct() 先释放预占、后校验可用量，
        #   中途抛错时 session 已带脏改动。它自身不 commit，若此处不兜底，
        #   脏状态会一路带到请求结束。校验失败一律整单回滚，单据保持
        #   status=1 可重试（或走撤回/驳回），不会产生半扣留状态。
        try:
            from app.services.inventory_reservation import (
                verify_scanned, restore_then_deduct,
            )
            _approved = approval.get_items()

            # ★ Fail-Closed：只认库存类来源。只要一条库存物料都没扫到就整单失败。
            #
            #   旧代码写作 `_scanned = [... if source_table != 'trans_repair']`
            #   再 `if _scanned:` —— 一旦为假，校验与释放被整体跳过，而下方仍
            #   无条件执行 approval.status = 3。此时申请阶段 reserve_for_items()
            #   扣掉的 available_quantity 无人归还，且 status=3 没有任何释放入口
            #   （/close 要求 status==1、/withdraw 要求 status∈(0,1)），预占即
            #   永久锁死 —— 幽灵库存。
            #   现在直接要求 _scanned 非空：维修单等非库存来源一并被挡在门外。
            _scanned = [i for i in items if i.get('source_table') in model_map]
            if not _scanned:
                raise ValueError("未扫描到有效的库存物料，出库失败，请检查扫码内容")

            verify_scanned(_scanned, _approved)
            restore_then_deduct(_scanned, _approved)
        except Exception:
            db.session.rollback()
            raise

        try:
            for item in items:
                source_table = item.get('source_table')
                stock_id = item.get('stock_id')
                quantity = float(item.get('quantity', 0))
                unit_price = float(item.get('price', 0))

                if quantity <= 0:
                    raise ValueError(f"SKU {item.get('sku')} 的出库数量必须大于0")

                # 处理维修单出库
                if source_table == 'trans_repair':
                    repair = TransRepair.query.with_for_update().get(stock_id)
                    if not repair:
                        raise ValueError(f"维修单不存在 (ID: {stock_id})")

                    # 更新维修单状态为已出库
                    repair.repair_status = '已出库'
                    repair.shipping_date = current_time

                    # 收集 Track 联动信息（维修单带 serial_number）
                    track_notifications.append((getattr(repair, 'serial_number', None), source_table, quantity))

                    # 创建出库记录
                    new_record = TransOutbound(
                        sku=item.get('sku'),
                        source_table=source_table,
                        stock_id=stock_id,
                        barcode=item.get('barcode'),
                        quantity=quantity,
                        unit_price=unit_price,
                        outbound_time=current_time,
                        **common_data
                    )
                    db.session.add(new_record)
                    continue

                ModelClass = model_map.get(source_table)
                if not ModelClass:
                    continue

                # ==========================================================
                # ★ Phase 3：库存扣减已由「预占 + 再平衡」统一处理
                #
                # 流程（在下方 _apply_reservation_override 中完成）：
                #   1. 校验实扫身份/数量落在批准范围内（base_id 主键匹配，允许换批次）
                #   2. 释放申请时锁定的全部批次（available_quantity 还回池子）
                #   3. 对实扫批次扣减 available_quantity 与 stock_quantity
                #
                # 因此此处**不再**直接扣减库存，避免与再平衡逻辑重复扣两次。
                # ==========================================================
                stock_record = ModelClass.query.get(stock_id)
                if not stock_record:
                    raise ValueError(f"库存记录不存在 (ID: {stock_id})")

                # 收集 Track 联动信息（库存表 serial_number = Track 身份证）
                track_notifications.append((getattr(stock_record, 'serial_number', None), source_table, quantity))

                new_record = TransOutbound(
                    sku=item.get('sku'),
                    source_table=source_table,
                    stock_id=stock_id,
                    barcode=item.get('barcode'),
                    quantity=quantity,
                    unit_price=unit_price,
                    outbound_time=current_time,
                    # [新增] 记录出库时的库位快照
                    warehouse_location=getattr(stock_record, 'warehouse_location', None),
                    **common_data
                )
                db.session.add(new_record)

            # ★ 出库成功后更新审批单状态为"已完成"
            #   approval 恒非 None（上方已强制 request_id 必填），无需再判空
            approval.status = 3  # 3-已完成
            # updated_at 会在 commit 时由 SQLAlchemy 自动更新

            # ★ 先提交事务，释放所有行锁，避免 SMTP 调用延长锁持有时间
            db.session.commit()

            # ★ 出库后通知 Track（发货出库 → Track 标记"已出库"）
            #    仅在配置 TRACK_OUTBOUND_WEBHOOK_URL 时生效；notify_track 自身容错不阻断业务
            try:
                from flask import current_app
                outbound_url = current_app.config.get('TRACK_OUTBOUND_WEBHOOK_URL')
                for sn, src_tbl, qty in track_notifications:
                    if not sn:
                        continue
                    notify_track({
                        'event': 'outbound.created',
                        'source_table': src_tbl,
                        'serial_number': str(sn),
                        'quantity': float(qty or 0),
                        'outbound_type': common_data['outbound_type'],
                        'operator': get_current_operator(),
                    }, url=outbound_url)
            except Exception as e:
                import logging
                logging.getLogger(__name__).warning(f"⚠️ Track 出库通知失败: {e}")

            # ★ 出库后检查低库存预警（移到 commit 之后，避免事务内网络调用）
            try:
                from app.services.inventory_task import InventoryWarningService
                InventoryWarningService.check_and_send_warning_emails()
            except Exception as e:
                import logging
                logging.getLogger(__name__).warning(f"⚠️ 低库存预警检查失败: {e}")

            return outbound_no

        except Exception as e:
            db.session.rollback()
            raise e

    @staticmethod
    def get_grouped_list(page=1, per_page=10, keyword=None, search_type='all', start_date=None, end_date=None, company=None, consumer_name=None, advanced_filters=None):
        """
        查询出库记录（按出库单号分组），包含详细物品信息
        支持跨表搜索：单号、领用人、SKU、物料名称、规格型号
        search_type: all, no, name, sku, material_name, spec_model
        company: 可选的公司过滤参数
        advanced_filters: 高级筛选条件列表 [{'field','operator','value'}, ...]
        """
        # 日期补全：解决零点截断问题
        if end_date and len(str(end_date).strip()) == 10:
            end_date = f"{str(end_date).strip()} 23:59:59"
        if start_date and len(str(start_date).strip()) == 10:
            start_date = f"{str(start_date).strip()} 00:00:00"

        # 1. 构建基础查询
        # 如果有关键词，需要联表搜索物料名称和规格型号
        if keyword:
            # 根据 search_type 构建不同的搜索条件
            if search_type == 'all':
                # 原有逻辑：or_ 联表全局模糊搜索
                # 查询 stock_buy 路径匹配的名称/规格
                buy_match = db.session.query(TransOutbound.outbound_no).join(
                    StockBuy, and_(
                        TransOutbound.stock_id == StockBuy.id,
                        TransOutbound.source_table == 'stock_buy'
                    )
                ).join(
                    MaterialBase, StockBuy.base_id == MaterialBase.id
                ).filter(
                    or_(
                        MaterialBase.name.ilike(f'%{keyword}%'),
                        MaterialBase.spec_model.ilike(f'%{keyword}%')
                    )
                ).subquery()

                # 查询 stock_semi 路径匹配的名称/规格
                semi_match = db.session.query(TransOutbound.outbound_no).join(
                    StockSemi, and_(
                        TransOutbound.stock_id == StockSemi.id,
                        TransOutbound.source_table == 'stock_semi'
                    )
                ).join(
                    MaterialBase, StockSemi.base_id == MaterialBase.id
                ).filter(
                    or_(
                        MaterialBase.name.ilike(f'%{keyword}%'),
                        MaterialBase.spec_model.ilike(f'%{keyword}%')
                    )
                ).subquery()

                # 查询 stock_product 路径匹配的名称/规格
                product_match = db.session.query(TransOutbound.outbound_no).join(
                    StockProduct, and_(
                        TransOutbound.stock_id == StockProduct.id,
                        TransOutbound.source_table == 'stock_product'
                    )
                ).join(
                    MaterialBase, StockProduct.base_id == MaterialBase.id
                ).filter(
                    or_(
                        MaterialBase.name.ilike(f'%{keyword}%'),
                        MaterialBase.spec_model.ilike(f'%{keyword}%')
                    )
                ).subquery()

                # 合并三种来源的匹配单号
                all_matches = db.session.query(buy_match.c.outbound_no).union(
                    db.session.query(semi_match.c.outbound_no),
                    db.session.query(product_match.c.outbound_no)
                ).subquery()

                keyword_conditions = or_(
                    TransOutbound.outbound_no.ilike(f'%{keyword}%'),
                    TransOutbound.consumer_name.ilike(f'%{keyword}%'),
                    TransOutbound.sku.ilike(f'%{keyword}%'),
                    TransOutbound.outbound_no.in_(all_matches)
                )

            elif search_type == 'no':
                keyword_conditions = TransOutbound.outbound_no.ilike(f'%{keyword}%')

            elif search_type == 'name':
                keyword_conditions = TransOutbound.consumer_name.ilike(f'%{keyword}%')

            elif search_type == 'sku':
                keyword_conditions = TransOutbound.sku.ilike(f'%{keyword}%')

            elif search_type == 'material_name':
                # 联表查询物料名称
                buy_match = db.session.query(TransOutbound.outbound_no).join(
                    StockBuy, and_(
                        TransOutbound.stock_id == StockBuy.id,
                        TransOutbound.source_table == 'stock_buy'
                    )
                ).join(
                    MaterialBase, StockBuy.base_id == MaterialBase.id
                ).filter(MaterialBase.name.ilike(f'%{keyword}%')).subquery()

                semi_match = db.session.query(TransOutbound.outbound_no).join(
                    StockSemi, and_(
                        TransOutbound.stock_id == StockSemi.id,
                        TransOutbound.source_table == 'stock_semi'
                    )
                ).join(
                    MaterialBase, StockSemi.base_id == MaterialBase.id
                ).filter(MaterialBase.name.ilike(f'%{keyword}%')).subquery()

                product_match = db.session.query(TransOutbound.outbound_no).join(
                    StockProduct, and_(
                        TransOutbound.stock_id == StockProduct.id,
                        TransOutbound.source_table == 'stock_product'
                    )
                ).join(
                    MaterialBase, StockProduct.base_id == MaterialBase.id
                ).filter(MaterialBase.name.ilike(f'%{keyword}%')).subquery()

                all_matches = db.session.query(buy_match.c.outbound_no).union(
                    db.session.query(semi_match.c.outbound_no),
                    db.session.query(product_match.c.outbound_no)
                ).subquery()

                keyword_conditions = TransOutbound.outbound_no.in_(all_matches)

            elif search_type == 'spec_model':
                # 联表查询规格型号
                buy_match = db.session.query(TransOutbound.outbound_no).join(
                    StockBuy, and_(
                        TransOutbound.stock_id == StockBuy.id,
                        TransOutbound.source_table == 'stock_buy'
                    )
                ).join(
                    MaterialBase, StockBuy.base_id == MaterialBase.id
                ).filter(MaterialBase.spec_model.ilike(f'%{keyword}%')).subquery()

                semi_match = db.session.query(TransOutbound.outbound_no).join(
                    StockSemi, and_(
                        TransOutbound.stock_id == StockSemi.id,
                        TransOutbound.source_table == 'stock_semi'
                    )
                ).join(
                    MaterialBase, StockSemi.base_id == MaterialBase.id
                ).filter(MaterialBase.spec_model.ilike(f'%{keyword}%')).subquery()

                product_match = db.session.query(TransOutbound.outbound_no).join(
                    StockProduct, and_(
                        TransOutbound.stock_id == StockProduct.id,
                        TransOutbound.source_table == 'stock_product'
                    )
                ).join(
                    MaterialBase, StockProduct.base_id == MaterialBase.id
                ).filter(MaterialBase.spec_model.ilike(f'%{keyword}%')).subquery()

                all_matches = db.session.query(buy_match.c.outbound_no).union(
                    db.session.query(semi_match.c.outbound_no),
                    db.session.query(product_match.c.outbound_no)
                ).subquery()

                keyword_conditions = TransOutbound.outbound_no.in_(all_matches)

            else:
                keyword_conditions = None
        else:
            keyword_conditions = None

        # 【行级数据隔离】基于 JWT 多租户公司过滤
        # 通过三个库存表路径，找到匹配公司的出库单号（排除 trans_repair，因其无 MaterialBase 关联）
        from app.utils.decorators import get_current_company_filter

        company_limit = get_current_company_filter()
        if company_limit is not None:
            buy_comp = db.session.query(TransOutbound.outbound_no).join(
                StockBuy, and_(
                    TransOutbound.stock_id == StockBuy.id,
                    TransOutbound.source_table == 'stock_buy'
                )
            ).join(MaterialBase, StockBuy.base_id == MaterialBase.id).filter(
                MaterialBase.company_name == company_limit
            ).subquery()

            semi_comp = db.session.query(TransOutbound.outbound_no).join(
                StockSemi, and_(
                    TransOutbound.stock_id == StockSemi.id,
                    TransOutbound.source_table == 'stock_semi'
                )
            ).join(MaterialBase, StockSemi.base_id == MaterialBase.id).filter(
                MaterialBase.company_name == company_limit
            ).subquery()

            prod_comp = db.session.query(TransOutbound.outbound_no).join(
                StockProduct, and_(
                    TransOutbound.stock_id == StockProduct.id,
                    TransOutbound.source_table == 'stock_product'
                )
            ).join(MaterialBase, StockProduct.base_id == MaterialBase.id).filter(
                MaterialBase.company_name == company_limit
            ).subquery()

            comp_all = db.session.query(buy_comp.c.outbound_no).union(
                db.session.query(semi_comp.c.outbound_no),
                db.session.query(prod_comp.c.outbound_no)
            ).subquery()

        stmt = db.session.query(
            TransOutbound.outbound_no,
            func.max(TransOutbound.outbound_time).label('max_time')
        ).group_by(TransOutbound.outbound_no)

        if keyword_conditions is not None:
            stmt = stmt.filter(keyword_conditions)

        # ====================================================================
        # ★ 高级筛选：父级字段直接过滤，子级字段（SKU/物料名称）走
        #   「命中单号子查询 → 按单号 IN」的 EXISTS 语义。
        #
        #   绝不能写成 stmt.filter(TransOutbound.sku.ilike(...))：
        #   那样会在 GROUP BY 前收窄明细范围，展开行里的兄弟明细会丢失。
        # ====================================================================
        if advanced_filters:
            from app.utils.advanced_filter import (
                build_predicate, apply_child_condition,
            )

            # 父级字段：单号/操作人本身就在流水表上，直接 filter（否定操作符
            # 走标准 SQL != / NOT LIKE 即可，语义无歧义）
            parent_field_map = {
                'no': TransOutbound.outbound_no,
                'operator': TransOutbound.operator_name,
                'consumer_name': TransOutbound.consumer_name,
                'outbound_type': TransOutbound.outbound_type,
            }
            # 子级字段：SKU 直接列 + 物料名称（需三表联查）
            child_field_map = {'sku': TransOutbound.sku}
            material_stock_models = [
                (StockBuy, 'stock_buy'),
                (StockSemi, 'stock_semi'),
                (StockProduct, 'stock_product'),
            ]

            for cond in advanced_filters:
                field = cond.get('field')

                if field in parent_field_map:
                    p = build_predicate(cond, parent_field_map)
                    if p is not None:
                        stmt = stmt.filter(p)
                    continue

                if field in child_field_map or field == 'material_name':
                    # ★ 正/负操作符语义分派：否定 → 整单排除（NOT IN）
                    stmt = apply_child_condition(
                        stmt, TransOutbound.outbound_no, TransOutbound, cond,
                        child_field_map, material_stock_models,
                    )
                    continue

        # ★ 日期边界分别判断：用 BETWEEN 时若只传一侧会整段静默失效
        if start_date:
            stmt = stmt.filter(TransOutbound.outbound_time >= start_date)
        if end_date:
            stmt = stmt.filter(TransOutbound.outbound_time <= end_date)

        # 【行级数据隔离】应用公司过滤到主查询
        if company_limit is not None:
            stmt = stmt.filter(TransOutbound.outbound_no.in_(comp_all))

        # ★ 数据权限：普通用户只看“领用人=本人姓名(不含账号前缀)”的出库记录；
        #   同时兼容库里存成“姓名/xiaolongxia”全名的记录（姓名 + '/' 前缀也命中）
        if consumer_name:
            # 注意：or_ 已在模块顶部导入，此处绝不可再写 `from sqlalchemy import or_`
            # —— 函数内出现对 or_ 的赋值（import 即赋值）会让 Python 把 or_ 视为
            #    整个函数的局部变量，导致本函数中**位于该行之前**的所有 or_ 调用
            #    （keyword 搜索分支）抛 UnboundLocalError: referenced before assignment。
            _own_out_nos = (
                db.session.query(TransOutbound.outbound_no)
                .filter(or_(
                    TransOutbound.consumer_name == consumer_name,
                    TransOutbound.consumer_name.like(f"{consumer_name}/%")
                ))
                .distinct()
                .subquery()
            )
            stmt = stmt.filter(TransOutbound.outbound_no.in_(_own_out_nos))

        stmt = stmt.order_by(desc('max_time'))

        # 使用 distinct 确保跨表查询不重复
        stmt = stmt.distinct()

        pagination = stmt.paginate(page=page, per_page=per_page, error_out=False)
        outbound_nos = [row.outbound_no for row in pagination.items]

        if not outbound_nos:
            return {
                'items': [],
                'total': 0,
                'pages': 0,
                'current_page': page
            }

        # 2. 查询详细记录
        details = TransOutbound.query.filter(TransOutbound.outbound_no.in_(outbound_nos)).all()

        # 3. 组装数据并查询物品详情
        grouped_map = {}

        # 映射表模型以便查询
        model_map = {
            'stock_buy': StockBuy,
            'stock_semi': StockSemi,
            'stock_product': StockProduct
        }

        # ==========================================
        # ★ 优化步骤 1：第一遍循环，单纯收集所有的 stock_id
        # ==========================================
        stock_ids_by_table = {'stock_buy': set(), 'stock_semi': set(), 'stock_product': set()}

        for d in details:
            if d.source_table in stock_ids_by_table and d.stock_id:
                stock_ids_by_table[d.source_table].add(d.stock_id)

        # ==========================================
        # ★ 优化步骤 2：发起批量查询，并强制 JOIN 基础物料表
        # ==========================================
        # 格式: { ('stock_buy', 101): stock_obj, ... }
        preloaded_stocks = {}

        for table_name, ids in stock_ids_by_table.items():
            if not ids:
                continue

            ModelClass = model_map[table_name]
            # 魔法在这里：in_() 一次性查出所有库存，joinedload 顺便把 base 表的数据一起拉回来
            items = ModelClass.query.options(
                joinedload(ModelClass.base)
            ).filter(ModelClass.id.in_(ids)).all()

            for item in items:
                preloaded_stocks[(table_name, item.id)] = item

        # ==========================================
        # ★ 优化步骤 3：第二遍循环，纯内存拼装（极速）
        # ==========================================
        for d in details:
            ono = d.outbound_no
            if ono not in grouped_map:
                grouped_map[ono] = {
                    'outbound_no': ono,
                    'outbound_time': d.outbound_time.strftime('%Y-%m-%d %H:%M:%S'),
                    'outbound_type': d.outbound_type,
                    'consumer_name': d.consumer_name,
                    'operator_name': d.operator_name,
                    'signature_path': d.signature_path,
                    'remark': d.remark,
                    'total_amount': 0.0,
                    'items': []
                }

            # --- 直接从内存字典中获取，O(1) 复杂度，绝对不触发 SQL ---
            item_name, item_spec, item_cat, item_type, batch_sn = "未知物品", "", "", "", "-"

            stock_item = preloaded_stocks.get((d.source_table, d.stock_id))

            if stock_item:
                batch_sn = getattr(stock_item, 'batch_number', None) or getattr(stock_item, 'serial_number', None) or '-'

                # 因为前面用了 joinedload，这里调用 .base 瞬间返回，不会去查数据库
                if stock_item.base:
                    item_name = stock_item.base.name
                    item_spec = stock_item.base.spec_model
                    item_cat = stock_item.base.category
                    item_type = stock_item.base.material_type

            # 计算金额
            price = float(d.unit_price) if d.unit_price else 0
            qty = float(d.quantity)
            subtotal = price * qty

            grouped_map[ono]['total_amount'] += subtotal

            returned = float(d.returned_quantity or 0)
            grouped_map[ono]['items'].append({
                # ★ 退回功能所需：前端「退回」按钮要把本字段回传给
                #   POST /api/v1/inbound/stock/return-from-outbound 的 outbound_id。
                #   注意它是**出库明细行**的主键，不是出库单号。
                'id': d.id,
                'sku': d.sku,
                'name': item_name,
                'spec_model': item_spec,
                'category': item_cat,
                'material_type': item_type,
                'quantity': qty,
                # ★ 退回额度三件套：前端据此显示「已退 / 可退」并置灰已退满的行
                'returned_quantity': returned,
                'returnable_quantity': qty - returned,
                # ★ 原申请人ID：退回弹窗勾选「需要补发」时据此**精确预填**「补发给谁」。
                #   为 NULL 表示该出库产生于本列上线之前（历史无从回填），
                #   前端不预填，由库管在选择器里明确指定。
                'applicant_id': d.applicant_id,
                'unit_price': price,
                'subtotal': subtotal,
                'batch_sn': batch_sn,
                # [新增] 出库时的库位快照（展示用）
                'warehouse_location': getattr(d, 'warehouse_location', None) or ''
            })

        # 4. 排序输出
        result_list = []
        for ono in outbound_nos:
            if ono in grouped_map:
                obj = grouped_map[ono]
                obj['items'].sort(key=lambda x: x['unit_price'], reverse=True)
                obj['total_amount'] = round(obj['total_amount'], 2)
                result_list.append(obj)

        return {
            'items': result_list,
            'total': pagination.total,
            'pages': pagination.pages,
            'current_page': page
        }


class OutboundApprovalService:
    """出库审批服务"""

    @staticmethod
    def generate_request_no():
        """
        生成审批单号: APR-OUT-yyyyMMdd-HHmm-当日流水(4位)
        """
        beijing_tz = timezone(timedelta(hours=8))
        now = datetime.now(beijing_tz)

        date_str = now.strftime('%Y%m%d')
        time_str = now.strftime('%H%M')

        prefix = f"APR-OUT-{date_str}-"

        from app.models.outbound import OutboundApproval
        latest = db.session.query(OutboundApproval.request_no).filter(
            OutboundApproval.request_no.like(f"{prefix}%")
        ).order_by(OutboundApproval.id.desc()).first()

        if latest:
            last_seq = int(latest[0].split('-')[-1])
            sequence = last_seq + 1
        else:
            sequence = 1

        return f"APR-OUT-{date_str}-{time_str}-{sequence:04d}"

    @staticmethod
    def _items_require_approval(items):
        """
        明细中任一物料命中“出库/借库需审批”→ 需要审批。
        申请明细只存 name/spec_model，故按 (name, spec_model) 反查启用物料判定。
        """
        from app.models.base import MaterialBase
        seen = set()
        for item in items:
            name = str(item.get('name') or '').strip()
            spec = str(item.get('spec_model') or '').strip()
            if not name:
                continue
            key = (name, spec)
            if key in seen:
                continue
            seen.add(key)
            hit = MaterialBase.query.filter(
                MaterialBase.name == name,
                MaterialBase.spec_model == spec,
                MaterialBase.is_enabled == True,
                MaterialBase.is_approval_required == True
            ).first()
            if hit:
                return True
        return False

    @staticmethod
    def create_request(applicant_id, items, allowed_approvers, remark=None, approver_id=None, outbound_type=None, force_approval=False):
        """
        创建出库审批单（申请阶段，直接存储前端传来的物料信息快照，不关联具体库存记录）

        Args:
            applicant_id: 申请人ID
            items: 出库物品明细列表，每个物品应包含:
                - name: 物料名称 (必填)
                - spec_model: 规格型号 (必填)
                - quantity: 计划出库数量 (必填)
                - warehouse_location: 库位 (可选)
                - remark: 物品备注 (可选)
            allowed_approvers: 允许审批的人员/角色列表
            approver_id: 指定审批人ID（可选，传则覆盖 allowed_approvers）
            remark: 申请说明

        Returns:
            OutboundApproval 实例

        Raises:
            ValueError: 当 items 为空或缺少必填字段时抛出
        """
        from app.models.outbound import OutboundApproval

        # 校验 items 非空
        if not items:
            raise ValueError("出库物品列表不能为空")

        # 校验每个物品的宏观字段 (name, spec_model, quantity)
        required_fields = ['name', 'spec_model', 'quantity']
        for idx, item in enumerate(items):
            missing_fields = [f for f in required_fields if f not in item or str(item.get(f) or '').strip() == '']
            if missing_fields:
                raise ValueError(
                    f"第 {idx + 1} 条物品缺少必填字段: {', '.join(missing_fields)}。"
                    f"必须包含: name, spec_model, quantity"
                )
            try:
                qty = float(item.get('quantity', 0))
                if qty <= 0:
                    raise ValueError(f"第 {idx + 1} 条物品的出库数量必须大于0")
            except (TypeError, ValueError) as e:
                raise ValueError(f"第 {idx + 1} 条物品的 quantity 格式无效: {str(e)}")

        # ★ 需审批判定：库管代建(force_approval)或明细含需审批物料 → 走审批；否则默认自动通过
        from app.services.approval_control import resolve_approval_control
        need_approval, flagged_materials = resolve_approval_control(items)
        if force_approval:
            need_approval = True
        if need_approval and not approver_id:
            if force_approval:
                raise ValueError("库管代建出库申请必须选择审批人后再提交")
            _names = "；".join(f"{m['name']}（{m['spec_model'] or '-'}）" for m in flagged_materials)
            raise ValueError(f"以下物料需审批出库/借库：{_names}。请选择审批人后再提交")

        # ★ 指定审批人模式：approver_id 覆盖 allowed_approvers
        if approver_id:
            allowed_approvers = [{"type": "user", "value": int(approver_id)}]
        elif not need_approval:
            allowed_approvers = []  # 免审批单不绑定审批人

        request_no = OutboundApprovalService.generate_request_no()

        if need_approval:
            approval = OutboundApproval(
                request_no=request_no,
                applicant_id=applicant_id,
                remark=remark,
                outbound_type=outbound_type,  # 申请时确定的出库类型，扫码出库时带出
                status=0,  # 待审批
            )
        else:
            # 默认不审批：创建即已通过(status=1)，直接进入“待库管执行”
            # ★ approved_at 必须与 created_at(beijing_time) 同为 naive 本地时间：
            #   approved_at 列是 timestamp without time zone，传 aware 时间会被驱动转成 UTC 存库，导致早 8 小时
            approval = OutboundApproval(
                request_no=request_no,
                applicant_id=applicant_id,
                remark=remark,
                outbound_type=outbound_type,
                status=1,
                actual_approver_id=applicant_id,
                approved_at=beijing_time(),
            )

        # ==================================================================
        # ★ Phase 1：库存预占
        #
        # 改造前此处只存「要什么、要多少」的快照，不绑库存行，真正的
        # available_quantity 扣减留到执行阶段 —— 于是多张申请可以同时
        # claim 同一批货，等到扫码时才发现已被领走（超卖）。
        #
        # 现在提交即预占：分配器把需求落到具体库存行、立即扣减
        # available_quantity，并把 (stock_id, source_table, allocated_qty)
        # 连同 reserved 标记写进 items_json，驳回/撤回时据此原样归还。
        # ==================================================================
        from app.services.inventory_reservation import reserve_for_items
        from app.utils.decorators import get_current_company_filter

        reserved_items, _shortages = reserve_for_items(
            items, company_limit=get_current_company_filter(), strict=True,
        )

        approval.set_items(reserved_items)
        if allowed_approvers:
            approval.set_allowed_approvers(allowed_approvers)
        else:
            approval.allowed_approvers = '[]'

        db.session.add(approval)
        db.session.commit()

        # 仅需审批单通知审批人；免审批单静默进入“待库管执行”
        if need_approval:
            OutboundApprovalService._notify_new_request(approval, applicant_id, approver_id=approver_id)

        return approval

    @staticmethod
    def _get_emails_by_identifiers(applicant_id=None, role_codes=None):
        """
        根据用户ID或角色列表查询邮箱地址

        Args:
            applicant_id: 用户ID (按 SysUser.id 查找)
            role_codes:    角色代码列表，如 ['ADMIN', 'WAREHOUSE_ADMIN']

        Returns:
            去重后的邮箱地址列表
        """
        emails = []

        if applicant_id:
            user = SysUser.query.get(int(applicant_id))
            if user and user.email:
                emails.append(user.email)

        if role_codes:
            for code in role_codes:
                users = SysUser.query.filter_by(role=code).all()
                for u in users:
                    if u.email:
                        emails.append(u.email)

        return list(set(emails))

    @staticmethod
    def _notify_new_request(approval, applicant_id, approver_id=None):
        """发送新申请通知邮件给审批人和申请人（静默处理，不阻断主流程）"""
        try:
            from flask import current_app
            from app.utils.email_service import send_outbound_new_request_notify
            from app.models.system import SysUser

            applicant_name = ''
            applicant_emails = []

            # 1. 收集申请人信息
            if applicant_id:
                user = SysUser.query.get(int(applicant_id))
                if user and user.email:
                    applicant_emails.append(user.email)
                    applicant_name = str(user.username).split('/')[0] if '/' in (user.username or '') else (user.username or str(applicant_id))

            # 2. 收集审批人信息
            approver_emails = []
            if approver_id:
                user = SysUser.query.get(int(approver_id))
                if user and user.email:
                    approver_emails.append(user.email)
            else:
                # 兜底：按角色查询
                approvers = approval.get_allowed_approvers()
                role_codes = []
                for a in approvers:
                    if a.get('type') == 'role':
                        role_codes.append(a.get('value', ''))
                approver_emails = OutboundApprovalService._get_emails_by_identifiers(role_codes=role_codes)

            # 去重
            all_emails = list(set(applicant_emails + approver_emails))
            if not all_emails:
                current_app.logger.info(f"[Email] 审批单 {approval.request_no} 无收件人邮箱，跳过通知")
                return

            # 3. 获取物料明细
            items = approval.get_items()

            # 4. 分别发送邮件
            if applicant_emails:
                try:
                    send_outbound_new_request_notify(
                        to_emails=applicant_emails,
                        request_no=approval.request_no,
                        applicant_name=applicant_name,
                        remark=f"您的出库申请已提交，等待审批。{approval.remark or ''}",
                        items=items,
                        is_applicant_notify=True
                    )
                except Exception as e:
                    current_app.logger.error(f"[Email] 通知申请人失败: {e}")

            if approver_emails:
                try:
                    send_outbound_new_request_notify(
                        to_emails=approver_emails,
                        request_no=approval.request_no,
                        applicant_name=applicant_name,
                        remark=approval.remark or '',
                        items=items,
                        is_applicant_notify=False
                    )
                except Exception as e:
                    current_app.logger.error(f"[Email] 通知审批人失败: {e}")

        except Exception as e:
            try:
                from flask import current_app
                current_app.logger.error(f"[Email] 发送新申请通知邮件失败: {e}")
            except RuntimeError:
                import logging
                logging.getLogger(__name__).error(f"[Email] 发送新申请通知邮件失败: {e}")

    @staticmethod
    def can_approve(approval, user_id, user_role):
        """
        检查用户是否有权限审批

        Args:
            approval: OutboundApproval 实例
            user_id: 用户ID
            user_role: 用户角色

        Returns:
            bool, 是否有权限
        """
        approvers = approval.get_allowed_approvers()

        # 超级管理员可以直接审批
        if user_role and user_role.upper() == 'SUPER_ADMIN':
            return True

        # 拥有 outbound_approval:operation 权限的用户可以审批任意出库单
        # (前端按钮以此权限控制显示，后端也必须对齐)
        from app.models.system import SysRolePermission
        has_op = SysRolePermission.query.filter(
            SysRolePermission.role_code == user_role,
            SysRolePermission.target_code.in_(['outbound_approval:operation', 'outbound_approval:*'])
        ).first() is not None
        if has_op:
            return True

        for approver in approvers:
            approver_type = approver.get('type', '')
            approver_value = approver.get('value', '')

            if approver_type == 'user' and str(approver_value) == str(user_id):
                return True

            if approver_type == 'role' and approver_value == user_role:
                return True

        return False

    @staticmethod
    def approve(request_id, user_id, user_role, action='approve', reject_reason=None):
        """
        执行审批操作

        Args:
            request_id: 审批单ID
            user_id: 审批人ID
            user_role: 审批人角色
            action: 'approve' 通过, 'reject' 驳回
            reject_reason: 驳回原因

        Returns:
            (success: bool, message: str, approval: OutboundApproval or None)
        """
        from app.models.outbound import OutboundApproval

        # ★ 统一取 naive 北京时间，与 created_at(beijing_time) 同口径
        current_time = beijing_time()

        approval = OutboundApproval.query.get(request_id)
        if not approval:
            return False, "审批单不存在", None

        if approval.status != 0:
            return False, f"审批单状态已更新，无法重复审批 (当前状态: {approval.status})", None

        if not OutboundApprovalService.can_approve(approval, user_id, user_role):
            return False, "您没有审批此单的权限", None

        try:
            if action == 'approve':
                approval.status = 1  # 已通过
                approval.actual_approver_id = user_id
                approval.approved_at = current_time
                # 通过后预占继续保留：货已被本单锁定，直到扫码执行时才释放并扣减
            elif action == 'reject':
                # ★ Phase 2：驳回即释放预占，把 available_quantity 还回池子，
                #   否则这批货会被一张永远不会执行的单永久占住。
                from app.services.inventory_reservation import release_reserved
                release_reserved(approval.get_items())
                approval.status = 2  # 已驳回
                approval.reject_reason = reject_reason
            else:
                return False, "无效的审批操作", None

            db.session.commit()

            # ★ 审批成功后，发送邮件通知仓库管理员
            OutboundApprovalService._notify_approval_result(approval, user_id, action)

            return True, "审批成功", approval

        except Exception as e:
            db.session.rollback()
            return False, f"审批失败: {str(e)}", None

    @staticmethod
    def _notify_approval_result(approval, approver_id, action):
        """发送审批结果通知邮件（静默处理，不阻断主流程）"""
        import logging
        logger = logging.getLogger(__name__)

        try:
            from app.utils.email_service import send_outbound_approval_result_notify, send_outbound_dispatch_notify
            from app.models.system import SysUser as SU

            # 1. 提取申请人信息（供两个分支使用）
            applicant_name = ''
            applicant_emails = []
            if approval.applicant_id:
                user = SU.query.get(approval.applicant_id)
                if user:
                    applicant_name = str(user.username).split('/')[0] if '/' in (user.username or '') else (user.username or '')
                    if user.email:
                        applicant_emails.append(user.email)

            # 2. 提取物料明细（供通过分支使用）
            items = approval.get_items() if approval else []

            # 3. 分支逻辑
            if action == 'approve':
                # 3.1 通知库管（带明细）
                warehouse_role_codes = ['WAREHOUSE_MGR', 'OUTBOUND']
                warehouse_emails = OutboundApprovalService._get_emails_by_identifiers(role_codes=warehouse_role_codes)
                
                if warehouse_emails:
                    try:
                        send_outbound_dispatch_notify(
                            to_emails=warehouse_emails,
                            request_no=approval.request_no,
                            applicant_name=applicant_name,
                            items=items
                        )
                    except Exception as e:
                        logger.error(f"[Email] 通知库管失败: {e}")

                # 3.2 通知申请人（审批通过，带完整物料清单）
                if applicant_emails:
                    try:
                        send_outbound_dispatch_notify(
                            to_emails=applicant_emails,
                            request_no=approval.request_no,
                            applicant_name=applicant_name,
                            items=items
                        )
                    except Exception as e:
                        logger.error(f"[Email] 通知申请人（通过）失败: {e}")

            elif action == 'reject':
                # 3.3 通知申请人（已驳回）
                if applicant_emails:
                    try:
                        send_outbound_approval_result_notify(
                            to_emails=applicant_emails,
                            request_no=approval.request_no,
                            is_passed=False,
                            reject_reason=approval.reject_reason or '未说明原因',
                            applicant_name=applicant_name
                        )
                    except Exception as e:
                        logger.error(f"[Email] 通知申请人驳回失败: {e}")
                else:
                    logger.warning("[Email] 申请人无邮箱，无法发送驳回通知")

        except Exception as e:
            import traceback
            traceback.print_exc()
            logger.error(f"[Email] 外层发送异常: {e}")

    @staticmethod
    def close_request(request_id, user_id, user_role):
        """
        撤回 / 作废审批单（状态 1-已通过 → 4-已完结）

        适用场景：已通过但尚未（或未完整）执行的单据，申请人或管理者撤回，
        使其从"已审批通过"列表中消失，并**释放预占的库存**。

        ★ 修复说明（两处严重缺陷）：
          1. 原先只改状态、不释放预占 —— 申请阶段 reserve_for_items() 扣掉的
             available_quantity 就此永久泄漏，货被一张作废单锁死，谁也领不走。
             现调用 release_reserved() 按 items_json 原样归还。
          2. 原先无执行守卫 —— status=1 的单无论是否已出过货都能被"完结"，
             会把一张已部分执行的单标成"已完结"。
             现明确只允许「已通过且未执行」的单据撤回。

        Args:
            request_id: 审批单ID
            user_id: 操作人ID
            user_role: 操作人角色

        Returns:
            (success: bool, message: str, approval: OutboundApproval or None)
        """
        from app.models.outbound import OutboundApproval

        approval = OutboundApproval.query.get(request_id)
        if not approval:
            return False, "审批单不存在", None

        # ★ 执行守卫：执行成功后 create_outbound_batch 会把 status 置为 3，
        #   故此处的「仅 status==1 可撤回」本身就是执行守卫 ——
        #   已执行（3）或已撤回（4）的单都无法再次撤回。
        #   不额外查流水表：request_no(APR-OUT-…) 与 outbound_no(OUT-…) 格式不同、
        #   无关联字段，按单号比对是无效的。
        if approval.status != 1:
            status_map = {0: '待审批', 1: '已通过', 2: '已驳回', 3: '已完成', 4: '已完结'}
            return False, (
                f"仅「已通过(待执行)」的申请单可撤回 "
                f"(当前状态: {status_map.get(approval.status, approval.status)})"
            ), None

        # 权限检查：超级管理员、审批人 或 拥有出库操作权限（库管/主管）
        if not OutboundApprovalService.can_approve(approval, user_id, user_role):
            # 放宽：拥有 outbound_create:operation 的用户（库管）也可撤回
            from app.models.system import SysRolePermission
            has_outbound_op = SysRolePermission.query.filter(
                SysRolePermission.role_code == user_role,
                SysRolePermission.target_code.in_(['outbound_create:operation', 'outbound_create:*'])
            ).first() is not None
            if not has_outbound_op:
                return False, "您没有撤回此单的权限", None

        return OutboundApprovalService._release_and_close(approval, user_id)

    # ------------------------------------------------------------------
    # ★ 申请人撤回自己的申请单（严格职责分离）
    #
    # 与 close_request 的区别：
    #   · close_request  —— 管理路径，需 outbound_approval 等权限，仅 status==1
    #   · withdraw_request —— 申请人路径，仅校验「本人」，status 0 或 1 均可
    #
    # 为什么单独开一条路径而不是在 close_request 里加 if 分支：
    #   权限模型不同（管理角色 vs 单据归属），混在一个函数里容易在后续修改中
    #   互相影响 —— 这正是需要避免的访问控制风险。两条路径共用底层释放逻辑
    #   _release_and_close，实现上不重复。
    #
    # 状态说明：
    #   · status==0（待审批）：提交时已预占库存，撤回同样需要释放；
    #   · status==1（已通过待执行）：释放预占；
    #   · status>=2（已驳回/已完成/已撤回）：无可撤回内容，拒绝。
    # ------------------------------------------------------------------
    WITHDRAWABLE_STATUS = (0, 1)

    @staticmethod
    def withdraw_request(request_id, user_id, user_role=None):
        """
        申请人撤回自己的申请单。

        权限：仅单据本人；库管/主管/超管（is_privileged_viewer）可代撤。
        返回 (success, message, approval)
        """
        from app.models.outbound import OutboundApproval
        from app.utils.decorators import is_privileged_viewer

        approval = OutboundApproval.query.get(request_id)
        if not approval:
            return False, "申请单不存在", None

        # ★ 归属校验：非本人且非特权 → 拒绝（不漏出任何单据信息）
        if not is_privileged_viewer() and int(approval.applicant_id) != int(user_id):
            return False, "无权撤回他人的申请单", None

        if approval.status not in OutboundApprovalService.WITHDRAWABLE_STATUS:
            status_map = {0: '待审批', 1: '已通过(待执行)', 2: '已驳回', 3: '已完成', 4: '已撤回'}
            return False, (
                f"当前状态不可撤回：{status_map.get(approval.status, approval.status)}"
            ), None

        return OutboundApprovalService._release_and_close(approval, user_id)

    @staticmethod
    def _release_and_close(approval, user_id):
        """
        撤回的共用底层：释放预占 + 置为已撤回。

        两条入口（管理路径 close_request / 申请人路径 withdraw_request）
        各自完成权限与状态校验后调用本函数，确保释放逻辑只有一份实现，
        不会因修改其中一处而漏掉另一处。
        """
        try:
            from app.services.inventory_reservation import release_reserved
            restored = release_reserved(approval.get_items())

            # ★ 清理该单据的扫码草稿。
            #   草稿按 (user_id, request_id) 隔离，撤回后单据状态变为 4，
            #   不会再出现在扫码页的单据下拉里（那里只拉 status=1），
            #   草稿从此成为永远读不到的死数据。此处一并清掉。
            #
            #   注意：要清**所有用户**在这张单上的草稿，而非仅撤回者自己的 ——
            #   可能有多人扫过同一张单，只清自己的会留下他人的孤儿数据。
            from app.models.scan_draft import ScanDraft
            ScanDraft.query.filter_by(
                biz_type='outbound', request_id=approval.id
            ).delete(synchronize_session=False)

            approval.status = 4  # 4-已撤回/已完结
            approval.actual_approver_id = user_id
            approval.approved_at = None
            db.session.commit()

            return True, f"申请单已撤回，释放 {restored} 项预占库存", approval

        except Exception as e:
            db.session.rollback()
            return False, f"撤回归还失败: {str(e)}", None

    def get_request_list(page=1, per_page=10, applicant_id=None, status=None):
        """
        获取审批单列表

        Args:
            page: 页码
            per_page: 每页数量
            applicant_id: 按申请人筛选 (可选)
            status: 按状态筛选 (可选)

        Returns:
            分页结果
        """
        from app.models.outbound import OutboundApproval
        from app.models.system import SysUser
        from app.utils.decorators import get_current_company_filter
        from sqlalchemy import desc

        query = OutboundApproval.query

        if applicant_id:
            query = query.filter(OutboundApproval.applicant_id == applicant_id)

        if status is not None:
            query = query.filter(OutboundApproval.status == status)

        # 【行级数据隔离】通过申请人关联用户表过滤公司
        company_limit = get_current_company_filter()
        if company_limit is not None:
            query = query.join(SysUser, OutboundApproval.applicant_id == SysUser.id) \
                         .filter(SysUser.department == company_limit)

        query = query.order_by(desc(OutboundApproval.created_at))

        pagination = query.paginate(page=page, per_page=per_page, error_out=False)

        return {
            'items': [item.to_dict() for item in pagination.items],
            'total': pagination.total,
            'pages': pagination.pages,
            'current_page': page
        }

    @staticmethod
    def get_request_by_id(request_id):
        """根据ID获取审批单"""
        from app.models.outbound import OutboundApproval
        return OutboundApproval.query.get(request_id)