// 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
/// Future<T> lastWhere (
///     bool test(T element), {
///     dynamic defaultValue(),
///     T orElse()
/// })
/// Finds the last element in this stream matching test.
///
/// As firstWhere, except that the last matching element is found. That means
/// that the result cannot be provided before this stream is done.
/// . . .
///   If no such element is found before this stream is done, and a orElse
///   function is provided, the result of calling orElse becomes the value
///   of the future.
///
/// @description Checks that if no such element is found before this stream is
/// done, and a orElse function is provided, the result of calling orElse becomes
/// the value of the future.
/// @author ngl@unipro.ru

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

check(test, rValue, expected) {
  asyncStart();
  var address = InternetAddress.loopbackIPv4;
  RawDatagramSocket.bind(address, 0).then((producer) {
    RawDatagramSocket.bind(address, 0).then((receiver) {
      int sent = 0;
      int counter = 0;
      producer.send([sent++], address, receiver.port);
      producer.send([sent++], address, receiver.port);
      producer.send([sent], address, receiver.port);
      producer.close();

      Stream<RawSocketEvent> bcs = receiver.asBroadcastStream();
      Future fValue = bcs.lastWhere(test, orElse: rValue);
      fValue.then((value) {
        Expect.equals(expected, value);
      }).whenComplete(() {
        asyncEnd();
      });

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

      bcs.listen((event) {
        counter++;
        receiver.receive();
      }).onDone(() {
        Expect.equals(4, counter);
      });
    });
  });
}

main() {
  check((e) => e == null, () => RawSocketEvent.readClosed,
      RawSocketEvent.readClosed);
  check((e) => e == 1, () => RawSocketEvent.read, RawSocketEvent.read);
  check((e) => !(e is RawSocketEvent), () => RawSocketEvent.closed,
      RawSocketEvent.closed);
  check((e) => false, () => RawSocketEvent.write, RawSocketEvent.write);
}