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.*;

public final class ObservableTakeUntil<T, U> extends AbstractObservableWithUpstream<T, T> {

    final ObservableSource<? extends U> other;

    public ObservableTakeUntil(ObservableSource<T> source, ObservableSource<? extends U> other) {
        super(source);
        this.other = other;
    }

    @Override
    public void subscribeActual(Observer<? super T> child) {
        TakeUntilMainObserver<T, U> parent = new TakeUntilMainObserver<T, U>(child);
        child.onSubscribe(parent);

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

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

        private static final long serialVersionUID = 1418547743690811973L;

        final Observer<? super T> downstream;

        final AtomicReference<Disposable> upstream;

        final OtherObserver otherObserver;

        final AtomicThrowable error;

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

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

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

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

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

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

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

        void otherError(Throwable e) {
            DisposableHelper.dispose(upstream);
            HalfSerializer.onError(downstream, e, this, error);
        }

        void otherComplete() {
            DisposableHelper.dispose(upstream);
            HalfSerializer.onComplete(downstream, this, error);
        }

        final class OtherObserver extends AtomicReference<Disposable>
        implements Observer<U> {

            private static final long serialVersionUID = -8693423678067375039L;

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

            @Override
            public void onNext(U t) {
                DisposableHelper.dispose(this);
                otherComplete();
            }

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

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

        }
    }

}