/*
 * 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.rxjava4.internal.operators.single;

import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.disposables.Disposable;
import io.reactivex.rxjava4.exceptions.*;
import io.reactivex.rxjava4.functions.Consumer;

public final class SingleDoOnError<T> extends Single<T> {

    final SingleSource<T> source;

    final Consumer<? super Throwable> onError;

    public SingleDoOnError(SingleSource<T> source, Consumer<? super Throwable> onError) {
        this.source = source;
        this.onError = onError;
    }

    @Override
    protected void subscribeActual(final SingleObserver<? super T> observer) {

        source.subscribe(new DoOnError(observer));
    }

    final class DoOnError implements SingleObserver<T> {
        private final SingleObserver<? super T> downstream;

        DoOnError(SingleObserver<? super T> observer) {
            this.downstream = observer;
        }

        @Override
        public void onSubscribe(Disposable d) {
            downstream.onSubscribe(d);
        }

        @Override
        public void onSuccess(T value) {
            downstream.onSuccess(value);
        }

        @Override
        public void onError(Throwable e) {
            try {
                onError.accept(e);
            } catch (Throwable ex) {
                Exceptions.throwIfFatal(ex);
                e = new CompositeException(e, ex);
            }
            downstream.onError(e);
        }

    }
}
