fix(order): 前置余额扣减并统一金额精度处理，补充余额校验与单测

- 抽取 validateSufficientBalance，统一使用 normalizeMoney 校验与比较，提升健壮性\n- AbstractOrderPlacementStrategy：在创建订单前根据 shouldDeduct 进行余额校验与扣减，使用上下文 orderId 记录流水，避免不一致\n- deductCustomerBalance：使用 amountToDeduct 变量并先归一化后运算，修正可能的精度问题\n- 调整/补充测试用例：扣减失败不插入订单、不保存用户信息；更新 selectById 调用次数校验

play-admin/src/main/java/com/starry/admin/modules/order/service/impl/AbstractOrderPlacementStrategy.java

@@ -7,6 +7,7 @@ import com.starry.admin.modules.order.module.dto.OrderPlacementCommand;
 import com.starry.admin.modules.order.module.dto.OrderPlacementResult;
 import com.starry.admin.modules.order.module.dto.PaymentInfo;
 import com.starry.admin.modules.order.module.entity.PlayOrderInfoEntity;
+import java.math.BigDecimal;
 
 abstract class AbstractOrderPlacementStrategy implements OrderPlacementStrategy {
 
@@ -26,16 +27,19 @@ abstract class AbstractOrderPlacementStrategy implements OrderPlacementStrategy
             throw new CustomException("支付信息不能为空");
         }
 
-        PlayOrderInfoEntity order = service.createOrderRecord(context);
+        BigDecimal netAmount = service.normalizeMoney(paymentInfo.getFinalAmount());
-
+        boolean shouldDeduct = command.isDeductBalance() && service.shouldDeductBalance(context);
-        if (command.isDeductBalance() && service.shouldDeductBalance(context)) {
+        if (shouldDeduct) {
+            service.validateSufficientBalance(context.getPurchaserBy(), netAmount);
             service.deductCustomerBalance(
                     context.getPurchaserBy(),
-                    service.normalizeMoney(paymentInfo.getFinalAmount()),
+                    netAmount,
                     command.getBalanceOperationAction(),
-                    order.getId());
+                    context.getOrderId());
         }
 
+        PlayOrderInfoEntity order = service.createOrderRecord(context);
+
         OrderAmountBreakdown amountBreakdown =
                 breakdown != null ? breakdown : service.fallbackBreakdown(paymentInfo);
         return OrderPlacementResult.of(order, amountBreakdown);

play-admin/src/main/java/com/starry/admin/modules/order/service/impl/OrderLifecycleServiceImpl.java

@@ -162,6 +162,7 @@ public class OrderLifecycleServiceImpl implements IOrderLifecycleService {
 
         validateCouponUsage(context);
 
+
         OrderConstant.RewardType rewardType = context.getRewardType() != null
                 ? context.getRewardType()
                 : OrderConstant.RewardType.NOT_APPLICABLE;
@@ -278,6 +279,18 @@ public class OrderLifecycleServiceImpl implements IOrderLifecycleService {
         return OrderAmountBreakdown.of(grossAmount, discountAmount, netAmount);
     }
 
+    void validateSufficientBalance(String customerId, BigDecimal requiredAmount) {
+        PlayCustomUserInfoEntity customer = customUserInfoService.selectById(customerId);
+        if (customer == null) {
+            throw new CustomException("顾客不存在");
+        }
+        BigDecimal before = normalizeMoney(customer.getAccountBalance());
+        BigDecimal required = normalizeMoney(requiredAmount);
+        if (required.compareTo(before) > 0) {
+            throw new ServiceException("余额不足", 998);
+        }
+    }
+
     void deductCustomerBalance(
             String customerId,
             BigDecimal netAmount,
@@ -288,10 +301,11 @@ public class OrderLifecycleServiceImpl implements IOrderLifecycleService {
             throw new CustomException("顾客不存在");
         }
         BigDecimal before = normalizeMoney(customer.getAccountBalance());
-        if (netAmount.compareTo(before) > 0) {
+        BigDecimal amountToDeduct = normalizeMoney(netAmount);
+        if (amountToDeduct.compareTo(before) > 0) {
             throw new ServiceException("余额不足", 998);
         }
-        BigDecimal after = normalizeMoney(before.subtract(netAmount));
+        BigDecimal after = normalizeMoney(before.subtract(amountToDeduct));
         String action = StrUtil.isNotBlank(operationAction) ? operationAction : "下单";
         customUserInfoService.updateAccountBalanceById(
                 customerId,
@@ -299,7 +313,7 @@ public class OrderLifecycleServiceImpl implements IOrderLifecycleService {
                 after,
                 BalanceOperationType.CONSUME.getCode(),
                 action,
-                netAmount,
+                amountToDeduct,
                 BigDecimal.ZERO,
                 orderId);
     }

play-admin/src/test/java/com/starry/admin/modules/order/service/impl/OrderLifecycleServiceImplTest.java

@@ -733,6 +733,8 @@ private PlayOrderLogInfoMapper orderLogInfoMapper;
 
         assertThrows(ServiceException.class, () -> lifecycleService.placeOrder(command));
         verify(customUserInfoService, never()).updateAccountBalanceById(anyString(), any(), any(), anyString(), anyString(), any(), any(), anyString());
+        verify(orderInfoMapper, never()).insert(any());
+        verify(customUserInfoService, never()).saveOrderInfo(any());
     }
 
     @Test
@@ -863,6 +865,8 @@ private PlayOrderLogInfoMapper orderLogInfoMapper;
                 null);
 
         assertThrows(ServiceException.class, () -> lifecycleService.placeOrder(command));
+        verify(orderInfoMapper, never()).insert(any());
+        verify(customUserInfoService, never()).saveOrderInfo(any());
     }
 
     @Test
@@ -962,7 +966,7 @@ private PlayOrderLogInfoMapper orderLogInfoMapper;
                 null,
                 null));
 
-        verify(customUserInfoService).selectById(context.getPurchaserBy());
+        verify(customUserInfoService, times(2)).selectById(context.getPurchaserBy());
         verify(customUserInfoService).updateAccountBalanceById(
                 eq(customer.getId()),
                 eq(customer.getAccountBalance()),