/*
 * Copyright 2012-2023 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.batch.item.amqp;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.batch.item.Chunk;
import org.springframework.batch.item.ItemWriter;
import org.springframework.util.Assert;

/**
 * <p>
 * AMQP {@link ItemWriter} implementation using an {@link AmqpTemplate} to send messages.
 * Messages will be sent to the nameless exchange if not specified on the provided
 * {@link AmqpTemplate}.
 * </p>
 *
 * <p>
 * This writer is thread-safe as long as the delegate <code>AmqpTemplate</code>
 * implementation is thread-safe.
 * </p>
 *
 * @author Chris Schaefer
 * @author Mahmoud Ben Hassine
 */
public class AmqpItemWriter<T> implements ItemWriter<T> {

	private final AmqpTemplate amqpTemplate;

	private final Log log = LogFactory.getLog(getClass());

	public AmqpItemWriter(final AmqpTemplate amqpTemplate) {
		Assert.notNull(amqpTemplate, "AmqpTemplate must not be null");

		this.amqpTemplate = amqpTemplate;
	}

	@Override
	public void write(final Chunk<? extends T> items) throws Exception {
		if (log.isDebugEnabled()) {
			log.debug("Writing to AMQP with " + items.size() + " items.");
		}

		for (T item : items) {
			amqpTemplate.convertAndSend(item);
		}
	}

}
