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 io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.internal.disposables.*;
import io.reactivex.observers.SerializedObserver;

public final class ObservableSkipUntil<T, U> extends AbstractObservableWithUpstream<T, T> {
    final ObservableSource<U> other;
    public ObservableSkipUntil(ObservableSource<T> source, ObservableSource<U> other) {
        super(source);
        this.other = other;
    }

    @Override
    public void subscribeActual(Observer<? super T> child) {

        final SerializedObserver<T> serial = new SerializedObserver<T>(child);

        final ArrayCompositeDisposable frc = new ArrayCompositeDisposable(2);

        serial.onSubscribe(frc);

        final SkipUntilObserver<T> sus = new SkipUntilObserver<T>(serial, frc);

        other.subscribe(new SkipUntil(frc, sus, serial));

        source.subscribe(sus);
    }

    static final class SkipUntilObserver<T> implements Observer<T> {

        final Observer<? super T> downstream;
        final ArrayCompositeDisposable frc;

        Disposable upstream;

        volatile boolean notSkipping;
        boolean notSkippingLocal;

        SkipUntilObserver(Observer<? super T> actual, ArrayCompositeDisposable frc) {
            this.downstream = actual;
            this.frc = frc;
        }

        @Override
        public void onSubscribe(Disposable d) {
            if (DisposableHelper.validate(this.upstream, d)) {
                this.upstream = d;
                frc.setResource(0, d);
            }
        }

        @Override
        public void onNext(T t) {
            if (notSkippingLocal) {
                downstream.onNext(t);
            } else
            if (notSkipping) {
                notSkippingLocal = true;
                downstream.onNext(t);
            }
        }

        @Override
        public void onError(Throwable t) {
            frc.dispose();
            downstream.onError(t);
        }

        @Override
        public void onComplete() {
            frc.dispose();
            downstream.onComplete();
        }
    }

    final class SkipUntil implements Observer<U> {
        final ArrayCompositeDisposable frc;
        final SkipUntilObserver<T> sus;
        final SerializedObserver<T> serial;
        Disposable upstream;

        SkipUntil(ArrayCompositeDisposable frc, SkipUntilObserver<T> sus, SerializedObserver<T> serial) {
            this.frc = frc;
            this.sus = sus;
            this.serial = serial;
        }

        @Override
        public void onSubscribe(Disposable d) {
            if (DisposableHelper.validate(this.upstream, d)) {
                this.upstream = d;
                frc.setResource(1, d);
            }
        }

        @Override
        public void onNext(U t) {
            upstream.dispose();
            sus.notSkipping = true;
        }

        @Override
        public void onError(Throwable t) {
            frc.dispose();
            serial.onError(t);
        }

        @Override
        public void onComplete() {
            sus.notSkipping = true;
        }
    }
}