/*
	This file is part of Utatane.

	Utatane is free software: you can redistribute it and/or modify it under
	the terms of the GNU Affero General Public License as published by the Free
	Software Foundation, either version 3 of the License, or (at your option)
	any later version.

	Utatane is distributed in the hope that it will be useful, but WITHOUT ANY
	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
	FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for
	more details.

	You should have received a copy of the GNU Affero General Public License
	along with Utatane. If not, see <http://www.gnu.org/licenses/>.
*/

using System.IO.Compression;
using System.Text;
using Utatane.Components;
using Microsoft.AspNetCore.ResponseCompression;
using Microsoft.AspNetCore.Rewrite;
using Utatane;

var builder = WebApplication.CreateBuilder(new WebApplicationOptions() {
	Args = args,
	WebRootPath = "public"
});

// Add services to the container.
// Add services to the container.
builder.Services.AddRazorComponents();
builder.Services.AddResponseCompression(options => {
	options.EnableForHttps = true;
	options.Providers.Add<BrotliCompressionProvider>();
	options.Providers.Add<GzipCompressionProvider>();
	options.MimeTypes = ResponseCompressionDefaults.MimeTypes;
} );
builder.Services.Configure<BrotliCompressionProviderOptions>(options => {
	options.Level = CompressionLevel.SmallestSize;
});

builder.Services.Configure<GzipCompressionProviderOptions>(options => {
	options.Level = CompressionLevel.SmallestSize;
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment()) {
	app.UseExceptionHandler("/Error", createScopeForErrors: true);
	// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
	app.UseHsts();
}

app.UseStatusCodePagesWithReExecute("/not-found", createScopeForStatusCodePages: true);
app.UseHttpsRedirection();

app.UseAntiforgery();
app.UseResponseCompression();

// HTML compression
app.Use(async (context, next) => {
	// context.Response.Body is a direct line to the client, so
	// swap it out for our own in-memory stream for now
	Stream responseStream = context.Response.Body;
	using var memoryStream = new MemoryStream();
	context.Response.Body = memoryStream;

	// let downstream render the response & write to our stream
	await next(context);

	if (
		context.Response.ContentType?.StartsWith("text/html") != true
		/* || TODO: don't compress when serving HTML files found by Utatane!! */ ) {
		// oops my bad gangalang
		// ok now put it back
		memoryStream.Position = 0;
		await memoryStream.CopyToAsync(responseStream);
		context.Response.Body = responseStream;

		return;
	}
	
	memoryStream.Position = 0;
	String html = await new StreamReader(memoryStream).ReadToEndAsync();
	String minified = Utils.OptimizeHtml(html);

	context.Response.ContentLength = Encoding.UTF8.GetByteCount(minified);
	await responseStream.WriteAsync(Encoding.UTF8.GetBytes(minified));
	context.Response.Body = responseStream;
});

// check paths exist
app.Use(async (context, next) => {
	if (
		context.Request.Path.StartsWithSegments("/api/files")
		|| context.Request.Path.StartsWithSegments("/.nhnd")
	) {
		await next(context);
		return;
	}
	
	var resolved = Utils.VerifyPath(context.Request.Path);
	
	if (resolved.IsFailed) {
		context.Response.StatusCode = StatusCodes.Status404NotFound;
		return;
	}
	
	// if we're a file AND we aren't a link to a directory
	if (resolved.Value.IsT2 && resolved.Value.AsT2().UnravelLink() is not DirectoryInfo) {
		FileInfo file = new FileInfo(resolved.Value.AsT2().UnravelLink().FullName);
		
		await Results.File(
			file.FullName,
			MimeMapping.MimeUtility.GetMimeMapping(file.Name),
			file.Name,
			lastModified: file.LastWriteTimeUtc,
			enableRangeProcessing: true
		).ExecuteAsync(context);
		
		return;
	}
	
	// Console.WriteLine($"dir={resolved.Value.IsT1} file={resolved.Value.IsT2}");
	
	// we are either a directory or a link to one
	
	await next(context);
});

app.UseRewriter(new RewriteOptions().AddRedirect(@"^favicon\.ico$", "/.nhnd/favicon.ico"));

app.UseStaticFiles(new StaticFileOptions {
	RequestPath = "/.nhnd"
});
app.MapRazorComponents<App>();

app.Run();