namespace Admin.NET.Core;

/// <summary>
/// 当前用户 PC 菜单访问判定。
/// </summary>
public interface ICurrentUserMenuAccessService
{
    /// <summary>
    /// 判断当前 JWT 用户是否拥有指定 PC 菜单 path。
    /// </summary>
    Task<bool> HasMenuPathAsync(string menuPath);
}

/// <summary>
/// 要求当前用户拥有指定 PC 菜单 path。
/// </summary>
/// <remarks>
/// 认证缺失返回 401；权限服务缺失、判定异常或无权限均返回 403（fail-closed）。
/// 超级管理员和系统管理员的豁免口径由 <see cref="ICurrentUserMenuAccessService"/>
/// 按登录菜单树规则统一处理。
/// </remarks>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public sealed class RequirePcMenuPathAttribute : Attribute, IAsyncAuthorizationFilter
{
    /// <summary>
    /// 要求具备其中任意一个的 PC 菜单 path。
    /// </summary>
    public IReadOnlyList<string> MenuPaths { get; }
    /// <summary>兼容单 path 调用方；多 path 时返回首项。</summary>
    public string MenuPath => MenuPaths[0];

    public RequirePcMenuPathAttribute(params string[] menuPaths)
    {
        if (menuPaths == null || menuPaths.Length == 0 || menuPaths.Any(string.IsNullOrWhiteSpace))
            throw new ArgumentException("PC 菜单 path 不能为空", nameof(menuPaths));

        MenuPaths = menuPaths;
    }

    public async Task OnAuthorizationAsync(AuthorizationFilterContext context)
    {
        if (context.HttpContext.User?.Identity?.IsAuthenticated != true)
        {
            context.Result = new UnauthorizedResult();
            return;
        }

        var accessService = context.HttpContext.RequestServices.GetService<ICurrentUserMenuAccessService>();
        if (accessService == null)
        {
            context.Result = Forbid();
            return;
        }

        try
        {
            foreach (var menuPath in MenuPaths)
            {
                if (await accessService.HasMenuPathAsync(menuPath)) return;
            }
        }
        catch
        {
            // 权限基础设施异常时不得放行受保护端点。
        }

        context.Result = Forbid();
    }

    private static ObjectResult Forbid() => new(new { message = "没有权限访问该功能" })
    {
        StatusCode = StatusCodes.Status403Forbidden
    };
}