feat: 完善库存锁定幂等与批次扣减策略

src/Domain/TakeoutSaaS.Domain/Inventory/Entities/InventoryBatch.cs

@@ -1,3 +1,5 @@
+using System;
+using System.ComponentModel.DataAnnotations;
 using TakeoutSaaS.Shared.Abstractions.Entities;
 
 namespace TakeoutSaaS.Domain.Inventory.Entities;
@@ -41,4 +43,10 @@ public sealed class InventoryBatch : MultiTenantEntityBase
     /// 剩余数量。
     /// </summary>
     public int RemainingQuantity { get; set; }
+
+    /// <summary>
+    /// 并发控制字段。
+    /// </summary>
+    [Timestamp]
+    public byte[] RowVersion { get; set; } = Array.Empty<byte>();
 }

src/Domain/TakeoutSaaS.Domain/Inventory/Entities/InventoryItem.cs

@@ -1,4 +1,7 @@
+using System;
+using System.ComponentModel.DataAnnotations;
 using TakeoutSaaS.Shared.Abstractions.Entities;
+using TakeoutSaaS.Domain.Inventory.Enums;
 
 namespace TakeoutSaaS.Domain.Inventory.Entities;
 
@@ -46,4 +49,50 @@ public sealed class InventoryItem : MultiTenantEntityBase
     /// 过期日期。
     /// </summary>
     public DateTime? ExpireDate { get; set; }
+
+    /// <summary>
+    /// 是否预售商品。
+    /// </summary>
+    public bool IsPresale { get; set; }
+
+    /// <summary>
+    /// 预售开始时间（UTC）。
+    /// </summary>
+    public DateTime? PresaleStartTime { get; set; }
+
+    /// <summary>
+    /// 预售结束时间（UTC）。
+    /// </summary>
+    public DateTime? PresaleEndTime { get; set; }
+
+    /// <summary>
+    /// 预售名额（上限）。
+    /// </summary>
+    public int? PresaleCapacity { get; set; }
+
+    /// <summary>
+    /// 当前预售已锁定数量。
+    /// </summary>
+    public int PresaleLocked { get; set; }
+
+    /// <summary>
+    /// 单品限购（覆盖商品级 MaxQuantityPerOrder）。
+    /// </summary>
+    public int? MaxQuantityPerOrder { get; set; }
+
+    /// <summary>
+    /// 是否标记售罄。
+    /// </summary>
+    public bool IsSoldOut { get; set; }
+
+    /// <summary>
+    /// 批次扣减策略。
+    /// </summary>
+    public InventoryBatchConsumeStrategy BatchConsumeStrategy { get; set; } = InventoryBatchConsumeStrategy.Fifo;
+
+    /// <summary>
+    /// 并发控制字段。
+    /// </summary>
+    [Timestamp]
+    public byte[] RowVersion { get; set; } = Array.Empty<byte>();
 }

src/Domain/TakeoutSaaS.Domain/Inventory/Entities/InventoryLockRecord.cs

@@ -0,0 +1,52 @@
+using System.ComponentModel.DataAnnotations;
+using TakeoutSaaS.Domain.Inventory.Enums;
+using TakeoutSaaS.Shared.Abstractions.Entities;
+
+namespace TakeoutSaaS.Domain.Inventory.Entities;
+
+/// <summary>
+/// 库存锁定记录。
+/// </summary>
+public sealed class InventoryLockRecord : MultiTenantEntityBase
+{
+    /// <summary>
+    /// 门店 ID。
+    /// </summary>
+    public long StoreId { get; set; }
+
+    /// <summary>
+    /// SKU ID。
+    /// </summary>
+    public long ProductSkuId { get; set; }
+
+    /// <summary>
+    /// 锁定数量。
+    /// </summary>
+    public int Quantity { get; set; }
+
+    /// <summary>
+    /// 是否预售锁定。
+    /// </summary>
+    public bool IsPresale { get; set; }
+
+    /// <summary>
+    /// 幂等键。
+    /// </summary>
+    public string IdempotencyKey { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 过期时间（UTC）。
+    /// </summary>
+    public DateTime? ExpiresAt { get; set; }
+
+    /// <summary>
+    /// 锁定状态。
+    /// </summary>
+    public InventoryLockStatus Status { get; set; } = InventoryLockStatus.Locked;
+
+    /// <summary>
+    /// 并发控制字段。
+    /// </summary>
+    [Timestamp]
+    public byte[] RowVersion { get; set; } = Array.Empty<byte>();
+}

src/Domain/TakeoutSaaS.Domain/Inventory/Enums/InventoryBatchConsumeStrategy.cs

@@ -0,0 +1,17 @@
+namespace TakeoutSaaS.Domain.Inventory.Enums;
+
+/// <summary>
+/// 批次扣减策略。
+/// </summary>
+public enum InventoryBatchConsumeStrategy
+{
+    /// <summary>
+    /// 先进先出。
+    /// </summary>
+    Fifo = 0,
+
+    /// <summary>
+    /// 先到期先出。
+    /// </summary>
+    Fefo = 1
+}

src/Domain/TakeoutSaaS.Domain/Inventory/Enums/InventoryLockStatus.cs

@@ -0,0 +1,22 @@
+namespace TakeoutSaaS.Domain.Inventory.Enums;
+
+/// <summary>
+/// 库存锁定状态。
+/// </summary>
+public enum InventoryLockStatus
+{
+    /// <summary>
+    /// 已锁定。
+    /// </summary>
+    Locked = 0,
+
+    /// <summary>
+    /// 已释放。
+    /// </summary>
+    Released = 1,
+
+    /// <summary>
+    /// 已扣减。
+    /// </summary>
+    Deducted = 2
+}

src/Domain/TakeoutSaaS.Domain/Inventory/Repositories/IInventoryRepository.cs

@@ -0,0 +1,95 @@
+using System;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using TakeoutSaaS.Domain.Inventory.Entities;
+using TakeoutSaaS.Domain.Inventory.Enums;
+
+namespace TakeoutSaaS.Domain.Inventory.Repositories;
+
+/// <summary>
+/// 库存仓储契约。
+/// </summary>
+public interface IInventoryRepository
+{
+    /// <summary>
+    /// 依据标识查询库存。
+    /// </summary>
+    Task<InventoryItem?> FindByIdAsync(long inventoryItemId, long tenantId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 按门店与 SKU 查询库存（只读）。
+    /// </summary>
+    Task<InventoryItem?> FindBySkuAsync(long tenantId, long storeId, long productSkuId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 按门店与 SKU 查询库存（跟踪用于更新）。
+    /// </summary>
+    Task<InventoryItem?> GetForUpdateAsync(long tenantId, long storeId, long productSkuId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 新增库存记录。
+    /// </summary>
+    Task AddItemAsync(InventoryItem item, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 更新库存记录。
+    /// </summary>
+    Task UpdateItemAsync(InventoryItem item, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 新增库存调整记录。
+    /// </summary>
+    Task AddAdjustmentAsync(InventoryAdjustment adjustment, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 新增锁定记录。
+    /// </summary>
+    Task AddLockAsync(InventoryLockRecord lockRecord, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 按幂等键查询锁记录。
+    /// </summary>
+    Task<InventoryLockRecord?> FindLockByKeyAsync(long tenantId, string idempotencyKey, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 更新锁状态。
+    /// </summary>
+    Task MarkLockStatusAsync(InventoryLockRecord lockRecord, InventoryLockStatus status, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 查询过期锁定。
+    /// </summary>
+    Task<IReadOnlyList<InventoryLockRecord>> FindExpiredLocksAsync(long tenantId, DateTime utcNow, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 查询批次列表。
+    /// </summary>
+    Task<IReadOnlyList<InventoryBatch>> GetBatchesAsync(long tenantId, long storeId, long productSkuId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 批次扣减读取（带排序策略）。
+    /// </summary>
+    Task<IReadOnlyList<InventoryBatch>> GetBatchesForConsumeAsync(long tenantId, long storeId, long productSkuId, InventoryBatchConsumeStrategy strategy, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 查询批次（跟踪用于更新）。
+    /// </summary>
+    Task<InventoryBatch?> GetBatchForUpdateAsync(long tenantId, long storeId, long productSkuId, string batchNumber, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 新增批次。
+    /// </summary>
+    Task AddBatchAsync(InventoryBatch batch, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 更新批次。
+    /// </summary>
+    Task UpdateBatchAsync(InventoryBatch batch, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 持久化变更。
+    /// </summary>
+    Task SaveChangesAsync(CancellationToken cancellationToken = default);
+}