/**
 * 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 org.reactivestreams.*;

import io.reactivex.*;
import io.reactivex.internal.subscriptions.SubscriptionArbiter;
import io.reactivex.plugins.RxJavaPlugins;

/**
 * Delays the subscription to the main source until the other
 * observable fires an event or completes.
 * @param <T> the main type
 * @param <U> the other value type, ignored
 */
public final class FlowableDelaySubscriptionOther<T, U> extends Flowable<T> {
    final Publisher<? extends T> main;
    final Publisher<U> other;

    public FlowableDelaySubscriptionOther(Publisher<? extends T> main, Publisher<U> other) {
        this.main = main;
        this.other = other;
    }

    @Override
    public void subscribeActual(final Subscriber<? super T> child) {
        final SubscriptionArbiter serial = new SubscriptionArbiter();
        child.onSubscribe(serial);

        FlowableSubscriber<U> otherSubscriber = new FlowableSubscriber<U>() {
            boolean done;

            @Override
            public void onSubscribe(final Subscription s) {
                serial.setSubscription(new Subscription() {
                    @Override
                    public void request(long n) {
                        // ignored
                    }

                    @Override
                    public void cancel() {
                        s.cancel();
                    }
                });
                s.request(Long.MAX_VALUE);
            }

            @Override
            public void onNext(U t) {
                onComplete();
            }

            @Override
            public void onError(Throwable e) {
                if (done) {
                    RxJavaPlugins.onError(e);
                    return;
                }
                done = true;
                child.onError(e);
            }

            @Override
            public void onComplete() {
                if (done) {
                    return;
                }
                done = true;

                main.subscribe(new FlowableSubscriber<T>() {
                    @Override
                    public void onSubscribe(Subscription s) {
                        serial.setSubscription(s);
                    }

                    @Override
                    public void onNext(T t) {
                        child.onNext(t);
                    }

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

                    @Override
                    public void onComplete() {
                        child.onComplete();
                    }
                });
            }
        };

        other.subscribe(otherSubscriber);
    }
}
