build-flow.api/src/shared/BuildFlow.Shared/Infrastructure/AuditInterceptor.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using BuildFlow.Shared.Domain.Common;

namespace BuildFlow.Shared.Infrastructure;

/// <summary>
/// 审计拦截器，在 SaveChanges 时自动填充实体的审计字段（创建人/时间、修改人/时间、IP、软删除）。
/// 通过标记接口（IAuditable/ISoftDelete/IHasOperatorIP）判断实体需要哪些审计行为。
/// 注意：未实现 ISoftDelete 的实体在 Deleted 分支不触发，走真实物理删除。
/// </summary>
public class AuditInterceptor : SaveChangesInterceptor
{
    private readonly ICurrentUserContext _currentUserContext;

    public AuditInterceptor(ICurrentUserContext currentUserContext)
    {
        _currentUserContext = currentUserContext;
    }

    public override InterceptionResult<int> SavingChanges(
        DbContextEventData eventData,
        InterceptionResult<int> result)
    {
        ApplyAuditFields(eventData.Context);
        return base.SavingChanges(eventData, result);
    }

    public override ValueTask<InterceptionResult<int>> SavingChangesAsync(
        DbContextEventData eventData,
        InterceptionResult<int> result,
        CancellationToken cancellationToken = default)
    {
        ApplyAuditFields(eventData.Context);
        return base.SavingChangesAsync(eventData, result, cancellationToken);
    }

    /// <summary>
    /// 遍历 ChangeTracker 中所有实体，根据状态和标记接口自动填充审计字段。
    /// </summary>
    private void ApplyAuditFields(DbContext? context)
    {
        if (context is null) return;

        var userId = _currentUserContext.UserId;
        var ipAddress = _currentUserContext.IPAddress;
        var utcNow = DateTime.UtcNow;

        foreach (var entry in context.ChangeTracker.Entries())
        {
            switch (entry.State)
            {
                case EntityState.Added:
                    if (entry.Entity is IAuditable auditableAdded)
                    {
                        auditableAdded.CreatedBy = userId;
                        auditableAdded.CreatedAt = utcNow;
                        // 新增时也填充 Updated 字段，便于"最后变更"查询
                        auditableAdded.UpdatedBy = userId;
                        auditableAdded.UpdatedAt = utcNow;
                    }
                    if (entry.Entity is IHasOperatorIP hasIpAdded)
                    {
                        hasIpAdded.OperatorIP = ipAddress;
                    }
                    break;

                case EntityState.Modified:
                    if (entry.Entity is IAuditable auditableModified)
                    {
                        auditableModified.UpdatedBy = userId;
                        auditableModified.UpdatedAt = utcNow;
                        // 防止业务层误改创建信息，强制标记为未修改
                        entry.Property(nameof(IAuditable.CreatedBy)).IsModified = false;
                        entry.Property(nameof(IAuditable.CreatedAt)).IsModified = false;
                    }
                    if (entry.Entity is IHasOperatorIP hasIpModified)
                    {
                        hasIpModified.OperatorIP = ipAddress;
                    }
                    break;

                case EntityState.Deleted:
                    // 软删除：将硬删除操作拦截，转为修改 IsDeleted = true
                    // 未实现 ISoftDelete 的实体（如 RefreshToken）仍走硬删除
                    if (entry.Entity is ISoftDelete softDeletable)
                    {
                        entry.State = EntityState.Modified;
                        softDeletable.IsDeleted = true;

                        if (entry.Entity is IAuditable auditableDeleted)
                        {
                            auditableDeleted.UpdatedBy = userId;
                            auditableDeleted.UpdatedAt = utcNow;
                            entry.Property(nameof(IAuditable.CreatedBy)).IsModified = false;
                            entry.Property(nameof(IAuditable.CreatedAt)).IsModified = false;
                        }
                        if (entry.Entity is IHasOperatorIP hasIpDeleted)
                        {
                            hasIpDeleted.OperatorIP = ipAddress;
                        }
                    }
                    break;
            }
        }
    }
}