// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.AspNetCore.Http;
 
namespace Microsoft.AspNetCore.Mvc.Filters;
 
/// <summary>
/// A filter which executes a user configured middleware pipeline.
/// </summary>
internal sealed class MiddlewareFilter : IAsyncResourceFilter
{
    private readonly RequestDelegate _middlewarePipeline;
 
    public MiddlewareFilter(RequestDelegate middlewarePipeline)
    {
        ArgumentNullException.ThrowIfNull(middlewarePipeline);
 
        _middlewarePipeline = middlewarePipeline;
    }
 
    public Task OnResourceExecutionAsync(ResourceExecutingContext context, ResourceExecutionDelegate next)
    {
        var httpContext = context.HttpContext;
 
        // Capture the current context into the feature. This will later be used in the end middleware to continue
        // the execution flow to later MVC layers.
        // Example:
        // this filter -> user-middleware1 -> user-middleware2 -> the-end-middleware -> resource filters or model binding
        var feature = new MiddlewareFilterFeature()
        {
            ResourceExecutionDelegate = next,
            ResourceExecutingContext = context
        };
        httpContext.Features.Set<IMiddlewareFilterFeature>(feature);
 
        return _middlewarePipeline(httpContext);
    }
}