/*
 * Copyright 2016-2017 the original author or authors.
 *
 * 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 org.springframework.cloud.stream.reactive;

import org.springframework.cloud.stream.binding.StreamListenerParameterAdapter;
import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;

/**
 * Adapts an {@link org.springframework.cloud.stream.annotation.Output} annotated
 * {@link FluxSender} to an outbound {@link MessageChannel}.
 *
 * @author Marius Bogoevici
 * @author Soby Chacko
 */
public class MessageChannelToFluxSenderParameterAdapter
		implements StreamListenerParameterAdapter<FluxSender, MessageChannel> {

	@Override
	public boolean supports(Class<?> bindingTargetType, MethodParameter methodParameter) {
		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
		return MessageChannel.class.isAssignableFrom(bindingTargetType)
				&& FluxSender.class.isAssignableFrom(type.getRawClass());
	}

	@Override
	public FluxSender adapt(MessageChannel bindingTarget, MethodParameter parameter) {
		return new DefaultFluxSender(result -> bindingTarget
				.send(result instanceof Message<?> ? (Message<?>) result
						: MessageBuilder.withPayload(result).build()));
	}

}
