/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 com.alibaba.nacos.spring.context.event.config;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.nacos.api.config.listener.AbstractListener;
import com.alibaba.nacos.api.config.listener.Listener;

/**
 * Timeout {@link Listener Nacos Config Listener}
 *
 * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
 * @since 0.1.0
 */
public abstract class TimeoutNacosConfigListener extends AbstractListener {

	private static AtomicInteger id = new AtomicInteger(0);

	private static ExecutorService executorService = Executors.newScheduledThreadPool(8,
			new ThreadFactory() {
				@Override
				public Thread newThread(Runnable r) {
					Thread t = new Thread(r);
					t.setDaemon(true);
					t.setName("com.alibaba.nacos.spring.configListener-"
							+ id.incrementAndGet());
					return t;
				}
			});

	private final Logger logger = LoggerFactory.getLogger(getClass());

	private final String dataId;

	private final String groupId;

	private final long timeout;

	public TimeoutNacosConfigListener(String dataId, String groupId, long timeout) {
		this.dataId = dataId;
		this.groupId = groupId;
		this.timeout = timeout;
	}

	@Override
	public void receiveConfigInfo(final String content) {
		Future future = executorService.submit(new Runnable() {
			@Override
			public void run() {
				onReceived(content);
			}
		});
		try {
			future.get(timeout, TimeUnit.MILLISECONDS);
		}
		catch (InterruptedException e) {
			Thread.currentThread().interrupt();
			throw new RuntimeException(e);
		}
		catch (ExecutionException e) {
			throw new RuntimeException(e);
		}
		catch (TimeoutException e) {
			future.cancel(true);
			logger.warn(
					"Listening on Nacos Config exceeds timeout {} ms "
							+ "[dataId : {}, groupId : {}, data : {}]",
					timeout, dataId, groupId, content);
		}
	}

	/**
	 * process Nacos Config when received.
	 *
	 * @param content Nacos Config
	 */
	protected abstract void onReceived(String content);

	/**
	 * Get timeout in milliseconds
	 *
	 * @return timeout in milliseconds
	 */
	public long getTimeout() {
		return timeout;
	}
}
