// 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.Builder;
using Microsoft.AspNetCore.Connections;
using Microsoft.AspNetCore.Hosting.Server;
using Microsoft.AspNetCore.Server.IIS;
using Microsoft.AspNetCore.Server.IIS.Core;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
 
namespace Microsoft.AspNetCore.Hosting;
 
/// <summary>
/// Extension methods for the IIS In-Process.
/// </summary>
public static class WebHostBuilderIISExtensions
{
    /// <summary>
    /// Configures the port and base path the server should listen on when running behind AspNetCoreModule.
    /// The app will also be configured to capture startup errors.
    /// </summary>
    /// <param name="hostBuilder">The <see cref="IWebHostBuilder"/> to configure.</param>
    /// <returns>The <see cref="IWebHostBuilder"/>.</returns>
    public static IWebHostBuilder UseIIS(this IWebHostBuilder hostBuilder)
    {
        ArgumentNullException.ThrowIfNull(hostBuilder);
 
        // Check if in process
        if (OperatingSystem.IsWindows() && NativeMethods.IsAspNetCoreModuleLoaded())
        {
            var iisConfigData = NativeMethods.HttpGetApplicationProperties();
            // Trim trailing slash to be consistent with other servers
            var contentRoot = iisConfigData.pwzFullApplicationPath.TrimEnd(Path.DirectorySeparatorChar);
            hostBuilder.UseContentRoot(contentRoot);
            return hostBuilder.ConfigureServices(
                services =>
                {
                    services.AddSingleton(new IISNativeApplication(new NativeSafeHandle(iisConfigData.pNativeApplication)));
                    services.AddSingleton<IServer, IISHttpServer>();
                    services.AddTransient<IISServerAuthenticationHandlerInternal>();
                    services.AddSingleton<IStartupFilter, IISServerSetupFilter>();
                    services.AddAuthenticationCore();
                    services.AddSingleton<IServerIntegratedAuth>(_ => new ServerIntegratedAuth()
                    {
                        IsEnabled = iisConfigData.fWindowsAuthEnabled || iisConfigData.fBasicAuthEnabled,
                        AuthenticationScheme = IISServerDefaults.AuthenticationScheme
                    });
                    services.Configure<IISServerOptions>(
                        options =>
                        {
                            options.ServerAddresses = iisConfigData.pwzBindings.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
                            options.ForwardWindowsAuthentication = iisConfigData.fWindowsAuthEnabled || iisConfigData.fBasicAuthEnabled;
                            options.MaxRequestBodySize = iisConfigData.maxRequestBodySize;
                            options.IisMaxRequestSizeLimit = iisConfigData.maxRequestBodySize;
                        }
                    );
 
                    services.TryAddSingleton<IMemoryPoolFactory<byte>, DefaultMemoryPoolFactory>();
                    services.TryAddSingleton<MemoryPoolMetrics>();
                });
        }
 
        return hostBuilder;
    }
}