namespace Admin.NET.Core;

/// <summary>
/// 镜像写入方在范围内更新带外源标记的主数据。页面保存不进入该范围，因此会被只读守卫拒绝。
/// </summary>
public static class MdmMirrorWriteScope
{
    private static readonly AsyncLocal<int> Depth = new();

    public static bool IsWriter => Depth.Value > 0;

    /// <summary>
    /// 页面更新或删除 S0 行时，外源行（source_system 非空且不是 AIDOP_NATIVE）拒绝。
    /// 只认 Entity.S0 命名空间，避免中立层实体上的同名列被误拦。
    /// </summary>
    public static void RejectPageWrite(object? entity)
    {
        if (entity == null || IsWriter)
            return;
        var type = entity.GetType();
        var ns = type.Namespace ?? string.Empty;
        if (ns.IndexOf(".Entity.S0", StringComparison.Ordinal) < 0)
            return;
        var value = type.GetProperty("SourceSystem")?.GetValue(entity) as string;
        if (string.IsNullOrWhiteSpace(value))
            return;
        if (string.Equals(value, "AIDOP_NATIVE", StringComparison.OrdinalIgnoreCase))
            return;
        throw new InvalidOperationException($"该记录来自 {value}，只读");
    }

    public static IDisposable Enter()
    {
        Depth.Value++;
        return new Popper();
    }

    private sealed class Popper : IDisposable
    {
        public void Dispose()
        {
            if (Depth.Value > 0)
                Depth.Value--;
        }
    }
}