/*
 * 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;
  }
}