ANTOOZA-BACKEND/Web.Api/Extensions/FeatureGateExtensions.cs

using Microsoft.Extensions.Options;
using SharedKernel;

namespace Web.Api.Extensions;

/// <summary>
/// appsettings Features 섹션 기반 엔드포인트 게이트.
/// 플래그가 꺼져 있으면 매핑된 라우트가 404(NotFound)를 반환한다 — 라우트/핸들러 코드는 보존.
/// 사용: <c>.RequireFeature(c => c.Channel)</c>
/// </summary>
public static class FeatureGateExtensions
{
    public static TBuilder RequireFeature<TBuilder>(this TBuilder builder, Func<AppSettings.FeaturesSection, bool> feature) where TBuilder : IEndpointConventionBuilder
    {
        builder.AddEndpointFilter(async (context, next) => {
            var settings = context.HttpContext.RequestServices.GetRequiredService<IOptions<AppSettings>>().Value;
            if (!feature(settings.Features))
            {
                return Results.NotFound();
            }

            return await next(context);
        });

        return builder;
    }
}