/*
 * Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
 *
 * 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
 *
 *       https://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 reactor.core.publisher;

import java.time.Duration;
import java.util.Objects;

import reactor.core.CoreSubscriber;
import reactor.core.Fuseable;

See Also:
Reactive-Streams-Commons/**
 * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
 */
final class MonoJust<T> 
extends Mono<T>
		implements Fuseable.ScalarCallable<T>, Fuseable, SourceProducer<T>  {

	final T value;

	MonoJust(T value) {
		this.value = Objects.requireNonNull(value, "value");
	}

	@Override
	public T call() throws Exception {
		return value;
	}

	@Override
	public T block(Duration m) {
		return value;
	}

	@Override
	public T block() {
		return value;
	}

	@Override
	public void subscribe(CoreSubscriber<? super T> actual) {
		actual.onSubscribe(Operators.scalarSubscription(actual, value));
	}

	@Override
	public Object scanUnsafe(Attr key) {
		if (key == Attr.BUFFERED) return 1;
		if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC;
		return null;
	}
}