/*
 * 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 org.apache.uima.ducc.agent.metrics.collectors;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.concurrent.Callable;

import org.apache.uima.ducc.common.node.metrics.NodeLoadAverage;
import org.apache.uima.ducc.common.node.metrics.UptimeNodeLoadAverage;

public class NodeLoadAverageCollector implements
		Callable<NodeLoadAverage> {

	public NodeLoadAverageCollector() {
	}

	public NodeLoadAverage call() throws Exception {
		return collect();
	}

	private NodeLoadAverage collect() throws Exception {
		InputStream stream = null;
		BufferedReader reader = null;
		UptimeNodeLoadAverage uptimeLoadAverage = new UptimeNodeLoadAverage();
		ProcessBuilder pb = new ProcessBuilder("uptime");
		;
		pb.redirectErrorStream(true);
		Process proc = pb.start();
		// spawn uptime command and scrape the output
		stream = proc.getInputStream();
		reader = new BufferedReader(new InputStreamReader(stream));
		String line;
		String regex = "\\s+";
		String filter = "load average:";
		// read the next line from ps output
		while ((line = reader.readLine()) != null) {
			int pos = 0;
			if ((pos = line.indexOf(filter)) > -1) {
				String la = line.substring(pos + filter.length()).replaceAll(
						regex, "");
				String[] averages = la.split(",");
				uptimeLoadAverage.setLoadAvg1(averages[0]);
				uptimeLoadAverage.setLoadAvg5(averages[1]);
				uptimeLoadAverage.setLoadAvg15(averages[2]);
			}
		}
		proc.waitFor();
		return uptimeLoadAverage;
	}
}