/*
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
 * the License for the specific language governing permissions and limitations under the License.
 */

package io.reactivex.rxjava3.internal.operators.single;

import static org.junit.Assert.*;

import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicBoolean;

import org.junit.Test;

import io.reactivex.rxjava3.core.*;
import io.reactivex.rxjava3.exceptions.TestException;
import io.reactivex.rxjava3.functions.BiConsumer;
import io.reactivex.rxjava3.observers.TestObserver;
import io.reactivex.rxjava3.plugins.RxJavaPlugins;
import io.reactivex.rxjava3.processors.PublishProcessor;
import io.reactivex.rxjava3.schedulers.Schedulers;
import io.reactivex.rxjava3.subjects.*;
import io.reactivex.rxjava3.testsupport.TestHelper;

public class SingleAmbTest extends RxJavaTest {
    @Test
    public void ambWithFirstFires() {
        PublishProcessor<Integer> pp1 = PublishProcessor.create();
        PublishProcessor<Integer> pp2 = PublishProcessor.create();

        TestObserver<Integer> to = pp1.single(-99).ambWith(pp2.single(-99)).test();

        assertTrue(pp1.hasSubscribers());
        assertTrue(pp2.hasSubscribers());

        pp1.onNext(1);
        pp1.onComplete();

        assertFalse(pp1.hasSubscribers());
        assertFalse(pp2.hasSubscribers());

        to.assertResult(1);

    }

    @Test
    public void ambWithSecondFires() {
        PublishProcessor<Integer> pp1 = PublishProcessor.create();
        PublishProcessor<Integer> pp2 = PublishProcessor.create();

        TestObserver<Integer> to = pp1.single(-99).ambWith(pp2.single(-99)).test();

        assertTrue(pp1.hasSubscribers());
        assertTrue(pp2.hasSubscribers());

        pp2.onNext(2);
        pp2.onComplete();

        assertFalse(pp1.hasSubscribers());
        assertFalse(pp2.hasSubscribers());

        to.assertResult(2);
    }

    @Test
    public void ambIterableWithFirstFires() {
        PublishProcessor<Integer> pp1 = PublishProcessor.create();
        PublishProcessor<Integer> pp2 = PublishProcessor.create();

        List<Single<Integer>> singles = Arrays.asList(pp1.single(-99), pp2.single(-99));
        TestObserver<Integer> to = Single.amb(singles).test();

        assertTrue(pp1.hasSubscribers());
        assertTrue(pp2.hasSubscribers());

        pp1.onNext(1);
        pp1.onComplete();

        assertFalse(pp1.hasSubscribers());
        assertFalse(pp2.hasSubscribers());

        to.assertResult(1);

    }

    @Test
    public void ambIterableWithSecondFires() {
        PublishProcessor<Integer> pp1 = PublishProcessor.create();
        PublishProcessor<Integer> pp2 = PublishProcessor.create();

        List<Single<Integer>> singles = Arrays.asList(pp1.single(-99), pp2.single(-99));
        TestObserver<Integer> to = Single.amb(singles).test();

        assertTrue(pp1.hasSubscribers());
        assertTrue(pp2.hasSubscribers());

        pp2.onNext(2);
        pp2.onComplete();

        assertFalse(pp1.hasSubscribers());
        assertFalse(pp2.hasSubscribers());

        to.assertResult(2);
    }

    @Test
    public void ambArrayEmpty() {
        Single.ambArray()
        .test()
        .assertFailure(NoSuchElementException.class);
    }

    @Test
    public void ambSingleSource() {
        assertSame(Single.never(), Single.ambArray(Single.never()));
    }

    @Test
    public void error() {
        Single.ambArray(Single.error(new TestException()), Single.just(1))
        .test()
        .assertFailure(TestException.class);
    }

    @Test
    public void nullSourceSuccessRace() {
        for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
            List<Throwable> errors = TestHelper.trackPluginErrors();

            try {

                final Subject<Integer> ps = ReplaySubject.create();
                ps.onNext(1);

                final Single<Integer> source = Single.ambArray(ps.singleOrError(), Single.<Integer>never(), Single.<Integer>never(), null);

                Runnable r1 = new Runnable() {
                    @Override
                    public void run() {
                        source.test();
                    }
                };

                Runnable r2 = new Runnable() {
                    @Override
                    public void run() {
                        ps.onComplete();
                    }
                };

                TestHelper.race(r1, r2);

                if (!errors.isEmpty()) {
                    TestHelper.assertError(errors, 0, NullPointerException.class);
                }
            } finally {
                RxJavaPlugins.reset();
            }
        }
    }

    @Test
    public void multipleErrorRace() {
        for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
            List<Throwable> errors = TestHelper.trackPluginErrors();

            try {

                final Subject<Integer> ps1 = PublishSubject.create();
                final Subject<Integer> ps2 = PublishSubject.create();

                Single.ambArray(ps1.singleOrError(), ps2.singleOrError()).test();

                final TestException ex = new TestException();

                Runnable r1 = new Runnable() {
                    @Override
                    public void run() {
                        ps1.onError(ex);
                    }
                };

                Runnable r2 = new Runnable() {
                    @Override
                    public void run() {
                        ps2.onError(ex);
                    }
                };

                TestHelper.race(r1, r2);

                if (!errors.isEmpty()) {
                    TestHelper.assertUndeliverable(errors, 0, TestException.class);
                }
            } finally {
                RxJavaPlugins.reset();
            }
        }
    }

    @Test
    public void successErrorRace() {
        for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
            List<Throwable> errors = TestHelper.trackPluginErrors();

            try {

                final Subject<Integer> ps1 = PublishSubject.create();
                final Subject<Integer> ps2 = PublishSubject.create();

                Single.ambArray(ps1.singleOrError(), ps2.singleOrError()).test();

                final TestException ex = new TestException();

                Runnable r1 = new Runnable() {
                    @Override
                    public void run() {
                        ps1.onNext(1);
                        ps1.onComplete();
                    }
                };

                Runnable r2 = new Runnable() {
                    @Override
                    public void run() {
                        ps2.onError(ex);
                    }
                };

                TestHelper.race(r1, r2);

                if (!errors.isEmpty()) {
                    TestHelper.assertUndeliverable(errors, 0, TestException.class);
                }
            } finally {
                RxJavaPlugins.reset();
            }
        }
    }

    @Test
    public void manySources() {
        Single<?>[] sources = new Single[32];
        Arrays.fill(sources, Single.never());
        sources[31] = Single.just(31);

        Single.amb(Arrays.asList(sources))
        .test()
        .assertResult(31);
    }

    @Test
    public void ambWithOrder() {
        Single<Integer> error = Single.error(new RuntimeException());
        Single.just(1).ambWith(error).test().assertValue(1);
    }

    @Test
    public void ambIterableOrder() {
        Single<Integer> error = Single.error(new RuntimeException());
        Single.amb(Arrays.asList(Single.just(1), error)).test().assertValue(1);
    }

    @Test
    public void ambArrayOrder() {
        Single<Integer> error = Single.error(new RuntimeException());
        Single.ambArray(Single.just(1), error).test().assertValue(1);
    }

    @Test
    public void noWinnerSuccessDispose() throws Exception {
        for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
            final AtomicBoolean interrupted = new AtomicBoolean();
            final CountDownLatch cdl = new CountDownLatch(1);

            Single.ambArray(
                Single.just(1)
                    .subscribeOn(Schedulers.single())
                    .observeOn(Schedulers.computation()),
                Single.never()
            )
            .subscribe(new BiConsumer<Object, Throwable>() {
                @Override
                public void accept(Object v, Throwable e) throws Exception {
                    assertNotNull(v);
                    assertNull(e);
                    interrupted.set(Thread.currentThread().isInterrupted());
                    cdl.countDown();
                }
            });

            assertTrue(cdl.await(500, TimeUnit.SECONDS));
            assertFalse("Interrupted!", interrupted.get());
        }
    }

    @Test
    public void noWinnerErrorDispose() throws Exception {
        final TestException ex = new TestException();
        for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
            final AtomicBoolean interrupted = new AtomicBoolean();
            final CountDownLatch cdl = new CountDownLatch(1);

            Single.ambArray(
                Single.error(ex)
                    .subscribeOn(Schedulers.single())
                    .observeOn(Schedulers.computation()),
                Single.never()
            )
            .subscribe(new BiConsumer<Object, Throwable>() {
                @Override
                public void accept(Object v, Throwable e) throws Exception {
                    assertNull(v);
                    assertNotNull(e);
                    interrupted.set(Thread.currentThread().isInterrupted());
                    cdl.countDown();
                }
            });

            assertTrue(cdl.await(500, TimeUnit.SECONDS));
            assertFalse("Interrupted!", interrupted.get());
        }
    }

    @Test
    public void singleSourcesInIterable() {
        SingleSource<Integer> source = new SingleSource<Integer>() {
            @Override
            public void subscribe(SingleObserver<? super Integer> observer) {
                Single.just(1).subscribe(observer);
            }
        };

        Single.amb(Arrays.asList(source, source))
        .test()
        .assertResult(1);
    }
}
