/*
 * 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.InputStreamReader;
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.util.concurrent.Callable;

import org.apache.uima.ducc.common.node.metrics.NodeCpuInfo;

public class NodeCpuCollector implements Callable<NodeCpuInfo> {

  public NodeCpuInfo call() throws Exception {
    OperatingSystemMXBean osBean = ManagementFactory.getOperatingSystemMXBean();
    return new NodeCpuInfo(osBean.getAvailableProcessors(), String.valueOf(getCPULoad()));
  }

  private double getCPULoad() throws Exception {
    double cpu = 0.0;
    InputStreamReader in = null;
    String[] command = { "/bin/sh", "-c",
        "/bin/grep 'cpu' /proc/stat | /bin/awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage}'" };
    try {
      ProcessBuilder pb = new ProcessBuilder();
      pb.command(command);

      pb.redirectErrorStream(true);
      Process swapCollectorProcess = pb.start();
      in = new InputStreamReader(swapCollectorProcess.getInputStream());
      BufferedReader reader = new BufferedReader(in);
      String line = null;
      while ((line = reader.readLine()) != null) {
        System.out.println(line);
        try {
          cpu = Double.parseDouble(line.trim());
        } catch (NumberFormatException e) {
          cpu = 0;
          e.printStackTrace();
        }
      }
    } catch (Exception e) {
      throw e;
    } finally {
      if (in != null) {
        try {
          in.close();
        } catch (Exception e) {
        }

      }
    }

    return cpu;
  }
}