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.flowable;

import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;

import org.reactivestreams.*;

import io.reactivex.*;
import io.reactivex.exceptions.CompositeException;
import io.reactivex.internal.subscriptions.SubscriptionArbiter;

public final class FlowableConcatArray<T> extends Flowable<T> {

    final Publisher<? extends T>[] sources;

    final boolean delayError;

    public FlowableConcatArray(Publisher<? extends T>[] sources, boolean delayError) {
        this.sources = sources;
        this.delayError = delayError;
    }

    @Override
    protected void subscribeActual(Subscriber<? super T> s) {
        ConcatArraySubscriber<T> parent = new ConcatArraySubscriber<T>(sources, delayError, s);
        s.onSubscribe(parent);

        parent.onComplete();
    }

    static final class ConcatArraySubscriber<T> extends SubscriptionArbiter implements FlowableSubscriber<T> {

        private static final long serialVersionUID = -8158322871608889516L;

        final Subscriber<? super T> downstream;

        final Publisher<? extends T>[] sources;

        final boolean delayError;

        final AtomicInteger wip;

        int index;

        List<Throwable> errors;

        long produced;

        ConcatArraySubscriber(Publisher<? extends T>[] sources, boolean delayError, Subscriber<? super T> downstream) {
            super(false);
            this.downstream = downstream;
            this.sources = sources;
            this.delayError = delayError;
            this.wip = new AtomicInteger();
        }

        @Override
        public void onSubscribe(Subscription s) {
            setSubscription(s);
        }

        @Override
        public void onNext(T t) {
            produced++;
            downstream.onNext(t);
        }

        @Override
        public void onError(Throwable t) {
            if (delayError) {
                List<Throwable> list = errors;
                if (list == null) {
                    list = new ArrayList<Throwable>(sources.length - index + 1);
                    errors = list;
                }
                list.add(t);
                onComplete();
            } else {
                downstream.onError(t);
            }
        }

        @Override
        public void onComplete() {
            if (wip.getAndIncrement() == 0) {
                Publisher<? extends T>[] sources = this.sources;
                int n = sources.length;
                int i = index;
                for (;;) {

                    if (i == n) {
                        List<Throwable> list = errors;
                        if (list != null) {
                            if (list.size() == 1) {
                                downstream.onError(list.get(0));
                            } else {
                                downstream.onError(new CompositeException(list));
                            }
                        } else {
                            downstream.onComplete();
                        }
                        return;
                    }

                    Publisher<? extends T> p = sources[i];

                    if (p == null) {
                        Throwable ex = new NullPointerException("A Publisher entry is null");
                        if (delayError) {
                            List<Throwable> list = errors;
                            if (list == null) {
                                list = new ArrayList<Throwable>(n - i + 1);
                                errors = list;
                            }
                            list.add(ex);
                            i++;
                            continue;
                        } else {
                            downstream.onError(ex);
                            return;
                        }
                    } else {
                        long r = produced;
                        if (r != 0L) {
                            produced = 0L;
                            produced(r);
                        }
                        p.subscribe(this);
                    }

                    index = ++i;

                    if (wip.decrementAndGet() == 0) {
                        break;
                    }
                }
            }
        }
    }

}