// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';
import 'dart:convert' show utf8;

import 'package:http2/transport.dart';
import 'package:test/test.dart';

import 'helper.dart';

void main() {
  group('streams', () {
    group('server-push', () {
      const numOfOneKB = 1000;

      var expectedHeaders = [Header.ascii('key', 'value')];
      var allBytes = List.generate(numOfOneKB * 1024, (i) => i % 256);
      allBytes.addAll(List.generate(42, (i) => 42));

      void testHeaders(List<Header> headers) {
        expect(headers, hasLength(expectedHeaders.length));
        for (var i = 0; i < headers.length; i++) {
          expect(headers[i].name, expectedHeaders[i].name);
          expect(headers[i].value, expectedHeaders[i].value);
        }
      }

      void Function(StreamMessage) headersTestFun() {
        return expectAsync1((StreamMessage msg) {
          expect(msg, isA<HeadersStreamMessage>());
          testHeaders((msg as HeadersStreamMessage).headers);
        });
      }

      var serverReceivedAllBytes = Completer<void>();

      Future<String> readData(StreamIterator<StreamMessage> iterator) async {
        var all = <int>[];

        while (await iterator.moveNext()) {
          var msg = iterator.current;
          expect(msg, isA<DataStreamMessage>());
          all.addAll((msg as DataStreamMessage).bytes);
        }

        return utf8.decode(all);
      }

      Future sendData(TransportStream stream, String data) {
        stream.outgoingMessages
          ..add(DataStreamMessage(utf8.encode(data)))
          ..close();
        return stream.outgoingMessages.done;
      }

      streamTest('server-push', (ClientTransportConnection client,
          ServerTransportConnection server) async {
        server.incomingStreams
            .listen(expectAsync1((ServerTransportStream sStream) async {
          var pushStream = sStream.push(expectedHeaders);
          pushStream.sendHeaders(expectedHeaders);
          await sendData(pushStream, 'pushing "hello world" :)');

          unawaited(sStream.incomingMessages.drain());
          sStream.sendHeaders(expectedHeaders, endStream: true);

          await serverReceivedAllBytes.future;
        }));

        var cStream = client.makeRequest(expectedHeaders, endStream: true);
        cStream.incomingMessages
            .listen(headersTestFun(), onDone: expectAsync0(() {}));
        cStream.peerPushes
            .listen(expectAsync1((TransportStreamPush push) async {
          testHeaders(push.requestHeaders);

          var iterator = StreamIterator(push.stream.incomingMessages);
          var hasNext = await iterator.moveNext();
          expect(hasNext, isTrue);
          testHeaders((iterator.current as HeadersStreamMessage).headers);

          var msg = await readData(iterator);
          expect(msg, 'pushing "hello world" :)');
        }));
      }, settings: const ClientSettings(allowServerPushes: true));
    });
  });
}