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.
/**
 * 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.observable;

import java.util.concurrent.atomic.*;

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

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

    final CompletableSource other;

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

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

    static final class MergeWithObserver<T> extends AtomicInteger
    implements Observer<T>, Disposable {

        private static final long serialVersionUID = -4592979584110982903L;

        final Observer<? super T> downstream;

        final AtomicReference<Disposable> mainDisposable;

        final OtherObserver otherObserver;

        final AtomicThrowable error;

        volatile boolean mainDone;

        volatile boolean otherDone;

        MergeWithObserver(Observer<? super T> downstream) {
            this.downstream = downstream;
            this.mainDisposable = new AtomicReference<Disposable>();
            this.otherObserver = new OtherObserver(this);
            this.error = new AtomicThrowable();
        }

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

        @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 boolean isDisposed() {
            return DisposableHelper.isDisposed(mainDisposable.get());
        }

        @Override
        public void dispose() {
            DisposableHelper.dispose(mainDisposable);
            DisposableHelper.dispose(otherObserver);
        }

        void otherError(Throwable ex) {
            DisposableHelper.dispose(mainDisposable);
            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 MergeWithObserver<?> parent;

            OtherObserver(MergeWithObserver<?> 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();
            }
        }
    }
}