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.completable;

import java.util.concurrent.atomic.*;

import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.internal.disposables.DisposableHelper;
import io.reactivex.plugins.RxJavaPlugins;

Terminates the sequence if either the main or the other Completable terminate.
History: 2.1.17 - experimental
Since:
2.2/**
 * Terminates the sequence if either the main or the other Completable terminate.
 * <p>History: 2.1.17 - experimental
 * @since 2.2
 */
public final class CompletableTakeUntilCompletable extends Completable {

    final Completable source;

    final CompletableSource other;

    public CompletableTakeUntilCompletable(Completable source,
            CompletableSource other) {
        this.source = source;
        this.other = other;
    }

    @Override
    protected void subscribeActual(CompletableObserver observer) {
        TakeUntilMainObserver parent = new TakeUntilMainObserver(observer);
        observer.onSubscribe(parent);

        other.subscribe(parent.other);
        source.subscribe(parent);
    }

    static final class TakeUntilMainObserver extends AtomicReference<Disposable>
    implements CompletableObserver, Disposable {

        private static final long serialVersionUID = 3533011714830024923L;

        final CompletableObserver downstream;

        final OtherObserver other;

        final AtomicBoolean once;

        TakeUntilMainObserver(CompletableObserver downstream) {
            this.downstream = downstream;
            this.other = new OtherObserver(this);
            this.once = new AtomicBoolean();
        }

        @Override
        public void dispose() {
            if (once.compareAndSet(false, true)) {
                DisposableHelper.dispose(this);
                DisposableHelper.dispose(other);
            }
        }

        @Override
        public boolean isDisposed() {
            return once.get();
        }

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

        @Override
        public void onComplete() {
            if (once.compareAndSet(false, true)) {
                DisposableHelper.dispose(other);
                downstream.onComplete();
            }
        }

        @Override
        public void onError(Throwable e) {
            if (once.compareAndSet(false, true)) {
                DisposableHelper.dispose(other);
                downstream.onError(e);
            } else {
                RxJavaPlugins.onError(e);
            }
        }

        void innerComplete() {
            if (once.compareAndSet(false, true)) {
                DisposableHelper.dispose(this);
                downstream.onComplete();
            }
        }

        void innerError(Throwable e) {
            if (once.compareAndSet(false, true)) {
                DisposableHelper.dispose(this);
                downstream.onError(e);
            } else {
                RxJavaPlugins.onError(e);
            }
        }

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

            private static final long serialVersionUID = 5176264485428790318L;
            final TakeUntilMainObserver parent;

            OtherObserver(TakeUntilMainObserver parent) {
                this.parent = parent;
            }

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

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

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