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.AtomicInteger;

import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.functions.Action;
import io.reactivex.internal.disposables.DisposableHelper;
import io.reactivex.plugins.RxJavaPlugins;

Execute an action after an onError, onComplete or a dispose event.
History: 2.0.1 - experimental
Since:
2.1/**
 * Execute an action after an onError, onComplete or a dispose event.
 * <p>History: 2.0.1 - experimental
 * @since 2.1
 */
public final class CompletableDoFinally extends Completable {

    final CompletableSource source;

    final Action onFinally;

    public CompletableDoFinally(CompletableSource source, Action onFinally) {
        this.source = source;
        this.onFinally = onFinally;
    }

    @Override
    protected void subscribeActual(CompletableObserver observer) {
        source.subscribe(new DoFinallyObserver(observer, onFinally));
    }

    static final class DoFinallyObserver extends AtomicInteger implements CompletableObserver, Disposable {

        private static final long serialVersionUID = 4109457741734051389L;

        final CompletableObserver downstream;

        final Action onFinally;

        Disposable upstream;

        DoFinallyObserver(CompletableObserver actual, Action onFinally) {
            this.downstream = actual;
            this.onFinally = onFinally;
        }

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

                downstream.onSubscribe(this);
            }
        }

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

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

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

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

        void runFinally() {
            if (compareAndSet(0, 1)) {
                try {
                    onFinally.run();
                } catch (Throwable ex) {
                    Exceptions.throwIfFatal(ex);
                    RxJavaPlugins.onError(ex);
                }
            }
        }
    }
}