// 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.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
 
[assembly: HostingStartup(typeof(Microsoft.AspNetCore.Watch.BrowserRefresh.HostingStartup))]
 
namespace Microsoft.AspNetCore.Watch.BrowserRefresh
{
    internal sealed class HostingStartup : IHostingStartup, IStartupFilter
    {
        public void Configure(IWebHostBuilder builder)
        {
            builder.ConfigureServices(services => services.TryAddEnumerable(ServiceDescriptor.Singleton<IStartupFilter>(this)));
        }
 
        public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)
        {
            return app =>
            {
                app.MapWhen(
                    static (context) =>
                    {
                        var path = context.Request.Path;
                        return path.StartsWithSegments(ApplicationPaths.FrameworkRoot) &&
                            (path.StartsWithSegments(ApplicationPaths.ClearSiteData) ||
                            path.StartsWithSegments(ApplicationPaths.BlazorHotReloadMiddleware) ||
                            path.StartsWithSegments(ApplicationPaths.BrowserRefreshJS) ||
                            path.StartsWithSegments(ApplicationPaths.BlazorHotReloadJS));
                    },
                    static app =>
                    {
                        app.Map(ApplicationPaths.ClearSiteData, static app => app.Run(context =>
                        {
                            // Scoped css files can contain links to other css files. We'll try clearing out the http caches to force the browser to re-download.
                            // See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Clear-Site-Data#directives
                            context.Response.Headers["Clear-Site-Data"] = "\"cache\"";
                            return Task.CompletedTask;
                        }));
 
                        app.Map(ApplicationPaths.BlazorHotReloadMiddleware, static app => app.UseMiddleware<BlazorWasmHotReloadMiddleware>());
 
                        app.Map(ApplicationPaths.BrowserRefreshJS,
                            static app => app.UseMiddleware<BrowserScriptMiddleware>(ApplicationPaths.BrowserRefreshJS, BrowserScriptMiddleware.GetBrowserRefreshJS()));
 
                        // backwards compat only:
                        app.Map(ApplicationPaths.BlazorHotReloadJS,
                            static app => app.UseMiddleware<BrowserScriptMiddleware>(ApplicationPaths.BlazorHotReloadJS, BrowserScriptMiddleware.GetBlazorHotReloadJS()));
                    });
 
                app.UseMiddleware<BrowserRefreshMiddleware>();
                next(app);
            };
        }
    }
}