import 'dart:io';

import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as io;
import 'package:shelf_static/shelf_static.dart';
import 'package:stream_channel/stream_channel.dart';

const _corsHeaders = {'Access-Control-Allow-Origin': '*'};

Middleware cors() {
  Response? handleOptionsRequest(Request request) {
    if (request.method == 'OPTIONS') {
      return Response.ok(null, headers: _corsHeaders);
    } else {
      // Returning null will run the regular request handler
      return null;
    }
  }

  Response addCorsHeaders(Response response) {
    return response.change(headers: _corsHeaders);
  }

  return createMiddleware(
    requestHandler: handleOptionsRequest,
    responseHandler: addCorsHeaders,
  );
}

Future<void> hybridMain(StreamChannel<Object?> channel) async {
  final server = await HttpServer.bind('localhost', 0);

  final handler = const Pipeline()
      .addMiddleware(cors())
      .addHandler(createStaticHandler('.'));
  io.serveRequests(server, handler);

  channel.sink.add(server.port);
  await channel.stream
      .listen(null)
      .asFuture<void>()
      .then<void>((_) => server.close());
}