feat: 完善库存锁定幂等与批次扣减策略

src/Application/TakeoutSaaS.Application/App/Inventory/Handlers/ReleaseInventoryCommandHandler.cs

@@ -0,0 +1,76 @@
+using MediatR;
+using Microsoft.Extensions.Logging;
+using TakeoutSaaS.Application.App.Inventory.Commands;
+using TakeoutSaaS.Application.App.Inventory.Dto;
+using TakeoutSaaS.Domain.Inventory.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Inventory.Handlers;
+
+/// <summary>
+/// 库存释放处理器。
+/// </summary>
+public sealed class ReleaseInventoryCommandHandler(
+    IInventoryRepository inventoryRepository,
+    ITenantProvider tenantProvider,
+    ILogger<ReleaseInventoryCommandHandler> logger)
+    : IRequestHandler<ReleaseInventoryCommand, InventoryItemDto>
+{
+    /// <inheritdoc />
+    public async Task<InventoryItemDto> Handle(ReleaseInventoryCommand request, CancellationToken cancellationToken)
+    {
+        // 1. 读取库存
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var item = await inventoryRepository.GetForUpdateAsync(tenantId, request.StoreId, request.ProductSkuId, cancellationToken);
+        if (item is null)
+        {
+            throw new BusinessException(ErrorCodes.NotFound, "库存不存在");
+        }
+
+        // 1.1 幂等处理：若提供键且锁记录不存在，直接视为已释放
+        if (!string.IsNullOrWhiteSpace(request.IdempotencyKey))
+        {
+            var lockRecord = await inventoryRepository.FindLockByKeyAsync(tenantId, request.IdempotencyKey, cancellationToken);
+            if (lockRecord is not null)
+            {
+                if (lockRecord.Status != Domain.Inventory.Enums.InventoryLockStatus.Locked)
+                {
+                    return InventoryMapping.ToDto(item);
+                }
+
+                // 将数量同步为锁记录数，避免重复释放不一致
+                request = request with { Quantity = lockRecord.Quantity };
+                await inventoryRepository.MarkLockStatusAsync(lockRecord, Domain.Inventory.Enums.InventoryLockStatus.Released, cancellationToken);
+            }
+        }
+
+        // 2. 计算释放
+        var isPresale = request.IsPresaleOrder || item.IsPresale;
+        if (isPresale)
+        {
+            if (item.PresaleLocked < request.Quantity)
+            {
+                throw new BusinessException(ErrorCodes.Conflict, "预售锁定不足");
+            }
+
+            item.PresaleLocked -= request.Quantity;
+        }
+        else
+        {
+            if (item.QuantityReserved < request.Quantity)
+            {
+                throw new BusinessException(ErrorCodes.Conflict, "锁定库存不足");
+            }
+
+            item.QuantityReserved -= request.Quantity;
+        }
+
+        item.IsSoldOut = item.QuantityOnHand - item.QuantityReserved - item.PresaleLocked <= (item.SafetyStock ?? 0);
+        await inventoryRepository.UpdateItemAsync(item, cancellationToken);
+        await inventoryRepository.SaveChangesAsync(cancellationToken);
+        logger.LogInformation("释放库存 门店 {StoreId} SKU {ProductSkuId} 数量 {Quantity}", request.StoreId, request.ProductSkuId, request.Quantity);
+        return InventoryMapping.ToDto(item);
+    }
+}