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
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/**
 * 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.internal.operators.flowable;

import java.util.concurrent.atomic.*;

import org.reactivestreams.*;

import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.internal.disposables.DisposableHelper;
import io.reactivex.internal.subscriptions.SubscriptionHelper;
import io.reactivex.internal.util.*;

Merges a Flowable and a Completable by emitting the items of the Flowable and waiting until
both the Flowable and Completable complete normally.
History: 2.1.10 - experimental
Type parameters:
<T> – the element type of the Flowable
Since:
2.2/**
 * Merges a Flowable and a Completable by emitting the items of the Flowable and waiting until
 * both the Flowable and Completable complete normally.
 * <p>History: 2.1.10 - experimental
 * @param <T> the element type of the Flowable
 * @since 2.2
 */
public final class FlowableMergeWithCompletable<T> extends AbstractFlowableWithUpstream<T, T> {

    final CompletableSource other;

    public FlowableMergeWithCompletable(Flowable<T> source, CompletableSource other) {
        super(source);
        this.other = other;
    }

    @Override
    protected void subscribeActual(Subscriber<? super T> subscriber) {
        MergeWithSubscriber<T> parent = new MergeWithSubscriber<T>(subscriber);
        subscriber.onSubscribe(parent);
        source.subscribe(parent);
        other.subscribe(parent.otherObserver);
    }

    static final class MergeWithSubscriber<T> extends AtomicInteger
    implements FlowableSubscriber<T>, Subscription {

        private static final long serialVersionUID = -4592979584110982903L;

        final Subscriber<? super T> downstream;

        final AtomicReference<Subscription> mainSubscription;

        final OtherObserver otherObserver;

        final AtomicThrowable error;

        final AtomicLong requested;

        volatile boolean mainDone;

        volatile boolean otherDone;

        MergeWithSubscriber(Subscriber<? super T> downstream) {
            this.downstream = downstream;
            this.mainSubscription = new AtomicReference<Subscription>();
            this.otherObserver = new OtherObserver(this);
            this.error = new AtomicThrowable();
            this.requested = new AtomicLong();
        }

        @Override
        public void onSubscribe(Subscription s) {
            SubscriptionHelper.deferredSetOnce(mainSubscription, requested, s);
        }

        @Override
        public void onNext(T t) {
            HalfSerializer.onNext(downstream, t, this, error);
        }

        @Override
        public void onError(Throwable ex) {
            DisposableHelper.dispose(otherObserver);
            HalfSerializer.onError(downstream, ex, this, error);
        }

        @Override
        public void onComplete() {
            mainDone = true;
            if (otherDone) {
                HalfSerializer.onComplete(downstream, this, error);
            }
        }

        @Override
        public void request(long n) {
            SubscriptionHelper.deferredRequest(mainSubscription, requested, n);
        }

        @Override
        public void cancel() {
            SubscriptionHelper.cancel(mainSubscription);
            DisposableHelper.dispose(otherObserver);
        }

        void otherError(Throwable ex) {
            SubscriptionHelper.cancel(mainSubscription);
            HalfSerializer.onError(downstream, ex, this, error);
        }

        void otherComplete() {
            otherDone = true;
            if (mainDone) {
                HalfSerializer.onComplete(downstream, this, error);
            }
        }

        static final class OtherObserver extends AtomicReference<Disposable>
        implements CompletableObserver {

            private static final long serialVersionUID = -2935427570954647017L;

            final MergeWithSubscriber<?> parent;

            OtherObserver(MergeWithSubscriber<?> parent) {
                this.parent = parent;
            }

            @Override
            public void onSubscribe(Disposable d) {
                DisposableHelper.setOnce(this, d);
            }

            @Override
            public void onError(Throwable e) {
                parent.otherError(e);
            }

            @Override
            public void onComplete() {
                parent.otherComplete();
            }
        }
    }
}