// Copyright (c) 2018, 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.

// @dart = 2.9

/// @assertion Stream<RawSocketEvent> takeWhile(bool test(T element))
/// Forwards data events while test is successful.
/// . . .
/// Stops listening to this stream after the accepted elements.
///
/// Internally the method cancels its subscription after these elements. This
/// means that single-subscription (non-broadcast) streams are closed and cannot
/// be reused after a call to this method.
///
/// @description Checks that method [takeWhile] stops listening to the stream
/// after the accepted elements and cancels its subscription, so that
/// single-subscription (non-broadcast) streams are closed and cannot be reused
/// after a call to this method.
/// @author ngl@unipro.ru

import "dart:io";
import "dart:async";
import "../../../Utils/expect.dart";

check(bool test(e), dataExpected) {
  asyncStart();
  var address = InternetAddress.loopbackIPv4;
  RawDatagramSocket.bind(address, 0).then((producer) {
    RawDatagramSocket.bind(address, 0).then((receiver) {
      int sent = 0;
      List list = [];
      producer.send([sent++], address, receiver.port);
      producer.send([sent++], address, receiver.port);
      producer.send([sent++], address, receiver.port);
      producer.close();

      Stream s = receiver.takeWhile(test);
      s.listen((event) {
        list.add(event);
        receiver.receive();
      }, onDone: () {
        Expect.listEquals(dataExpected, list);
        asyncEnd();
      });

      try {
        s.listen((event) {
          Expect.fail('Should not be here.');
        });
      } catch (e) {
        Expect.isTrue(e is StateError);
      }

      new Timer(const Duration(milliseconds: 200), () {
        Expect.isNull(receiver.receive());
        receiver.close();
      });
    });
  });
}

main() {
  List expected = [
    RawSocketEvent.write,
    RawSocketEvent.read,
    RawSocketEvent.read,
    RawSocketEvent.closed
  ];
  check((e) => e != RawSocketEvent.closed, expected.sublist(0, 3));
  check((e) => e != RawSocketEvent.read, expected.sublist(0, 1));
  check((e) => true, expected);
  check((e) => false, []);
}