/*
 * 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.rxjava4.internal.operators.maybe;

import static org.junit.Assert.*;

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

import org.junit.Test;

import io.reactivex.rxjava4.annotations.NonNull;
import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.disposables.Disposable;
import io.reactivex.rxjava4.exceptions.TestException;
import io.reactivex.rxjava4.functions.*;
import io.reactivex.rxjava4.internal.functions.Functions;
import io.reactivex.rxjava4.observers.TestObserver;
import io.reactivex.rxjava4.plugins.RxJavaPlugins;
import io.reactivex.rxjava4.processors.PublishProcessor;
import io.reactivex.rxjava4.subjects.MaybeSubject;
import io.reactivex.rxjava4.testsupport.TestHelper;

public class MaybeZipArrayTest extends RxJavaTest {

    final BiFunction<Object, Object, Object> addString = new BiFunction<Object, Object, Object>() {
        @Override
        public Object apply(Object a, Object b) throws Exception {
            return "" + a + b;
        }
    };

    final Function3<Object, Object, Object, Object> addString3 = new Function3<Object, Object, Object, Object>() {
        @Override
        public Object apply(Object a, Object b, Object c) throws Exception {
            return "" + a + b + c;
        }
    };

    @Test
    public void firstError() {
        Maybe.zip(Maybe.error(new TestException()), Maybe.just(1), addString)
        .test()
        .assertFailure(TestException.class);
    }

    @Test
    public void secondError() {
        Maybe.zip(Maybe.just(1), Maybe.<Integer>error(new TestException()), addString)
        .test()
        .assertFailure(TestException.class);
    }

    @Test
    public void dispose() {
        PublishProcessor<Integer> pp = PublishProcessor.create();

        TestObserver<Object> to = Maybe.zip(pp.singleElement(), pp.singleElement(), addString)
        .test();

        assertTrue(pp.hasSubscribers());

        to.dispose();

        assertFalse(pp.hasSubscribers());
    }

    @Test
    public void zipperThrows() {
        Maybe.zip(Maybe.just(1), Maybe.just(2), new BiFunction<Integer, Integer, Object>() {
            @Override
            public Object apply(Integer a, Integer b) throws Exception {
                throw new TestException();
            }
        })
        .test()
        .assertFailure(TestException.class);
    }

    @Test
    public void zipperReturnsNull() {
        Maybe.zip(Maybe.just(1), Maybe.just(2), new BiFunction<Integer, Integer, Object>() {
            @Override
            public Object apply(Integer a, Integer b) throws Exception {
                return null;
            }
        })
        .test()
        .assertFailure(NullPointerException.class);
    }

    @Test
    public void middleError() {
        PublishProcessor<Integer> pp0 = PublishProcessor.create();
        PublishProcessor<Integer> pp1 = PublishProcessor.create();

        TestObserver<Object> to = Maybe.zip(pp0.singleElement(), pp1.singleElement(), pp0.singleElement(), addString3)
        .test();

        pp1.onError(new TestException());

        assertFalse(pp0.hasSubscribers());

        to.assertFailure(TestException.class);
    }

    @Test
    public void innerErrorRace() {
        for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
            List<Throwable> errors = TestHelper.trackPluginErrors();
            try {
                final PublishProcessor<Integer> pp0 = PublishProcessor.create();
                final PublishProcessor<Integer> pp1 = PublishProcessor.create();

                final TestObserver<Object> to = Maybe.zip(pp0.singleElement(), pp1.singleElement(), addString)
                .test();

                final TestException ex = new TestException();

                Runnable r1 = new Runnable() {
                    @Override
                    public void run() {
                        pp0.onError(ex);
                    }
                };

                Runnable r2 = new Runnable() {
                    @Override
                    public void run() {
                        pp1.onError(ex);
                    }
                };

                TestHelper.race(r1, r2);

                to.assertFailure(TestException.class);

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

    @Test(expected = NullPointerException.class)
    public void zipArrayOneIsNull() {
        Maybe.zipArray(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, Maybe.just(1), null)
        .blockingGet();
    }

    @Test
    public void singleSourceZipperReturnsNull() {
        Maybe.zipArray(Functions.justFunction(null), Maybe.just(1))
        .to(TestHelper.<Object>testConsumer())
        .assertFailureAndMessage(NullPointerException.class, "The zipper returned a null value");
    }

    @Test
    public void dispose2() {
        TestHelper.checkDisposed(Maybe.zipArray(v -> v, MaybeSubject.create(), MaybeSubject.create()));
    }

    @Test
    public void bothComplete() {
        AtomicReference<MaybeObserver<? super Integer>> ref1 = new AtomicReference<>();
        AtomicReference<MaybeObserver<? super Integer>> ref2 = new AtomicReference<>();

        Maybe<Integer> m1 = new Maybe<Integer>() {
            @Override
            protected void subscribeActual(@NonNull MaybeObserver<? super Integer> observer) {
                ref1.set(observer);
            }
        };
        Maybe<Integer> m2 = new Maybe<Integer>() {
            @Override
            protected void subscribeActual(@NonNull MaybeObserver<? super Integer> observer) {
                ref2.set(observer);
            }
        };

        TestObserver<Object[]> to = Maybe.zipArray(v -> v, m1, m2)
        .test();

        ref1.get().onSubscribe(Disposable.empty());
        ref2.get().onSubscribe(Disposable.empty());

        ref1.get().onComplete();
        ref2.get().onComplete();

        to.assertResult();
    }

    @Test
    public void bothSucceed() {
        Maybe.zipArray(v -> Arrays.asList(v), Maybe.just(1), Maybe.just(2))
        .test()
        .assertResult(Arrays.asList(1, 2));
    }

    @Test
    public void oneSourceOnly() {
        Maybe.zipArray(v -> Arrays.asList(v), Maybe.just(1))
        .test()
        .assertResult(Arrays.asList(1));
    }

    @Test
    public void onSuccessAfterDispose() {
        AtomicReference<MaybeObserver<? super Integer>> emitter = new AtomicReference<>();

        TestObserver<List<Object>> to = Maybe.zipArray(Arrays::asList,
                (MaybeSource<Integer>)o -> emitter.set(o), Maybe.<Integer>never())
        .test();

        emitter.get().onSubscribe(Disposable.empty());

        to.dispose();

        emitter.get().onSuccess(1);

        to.assertEmpty();
    }
}
