/*******************************************************************************
    * Copyright (c) 2007, 2014 Massimiliano Ziccardi
    *
    * 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
    *
    *     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 it.jnrpe.plugin;
  
  import it.jnrpe.ICommandLine;
  import it.jnrpe.plugins.Metric;
  import it.jnrpe.plugins.MetricGatheringException;
  import it.jnrpe.plugins.PluginBase;
  import it.jnrpe.utils.BadThresholdException;
  import it.jnrpe.utils.thresholds.ThresholdsEvaluatorBuilder;
  
  import java.io.File;
  import java.math.BigDecimal;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * Checks the disk space.
   *
   * @author Massimiliano Ziccardi
   *
   */
  public class CheckDisk extends PluginBase {
  
      /**
       * Number of bytes in a Kilobyte.
       */
      private static final long KB = 1024;
  
      /**
       * Number of kilobytes in a Megabyte.
       */
      private static final long MB = KB << 10;
  
      /**
       * Compute the percent values.
       *
       * @param val
       *            The value to be represented in percent
       * @param total
       *            The total value
       * @return The percent of val/total
       */
      private int percent(final long val, final long total) {
          if (total == 0) {
              return 100;
          }
  
          if (val == 0) {
              return 0;
          }
  
          double dVal = (double) val;
          double dTotal = (double) total;
  
          return (int) (dVal / dTotal * 100);
      }
  
      @Override
      public final void configureThresholdEvaluatorBuilder(
              final ThresholdsEvaluatorBuilder thrb,
              final ICommandLine cl)
              throws BadThresholdException {
          if (cl.hasOption("th")) {
              super.configureThresholdEvaluatorBuilder(thrb, cl);
          } else {
              thrb.withLegacyThreshold("freepct", null,
                      cl.getOptionValue("warning"),
                      cl.getOptionValue("critical"));
          }
      }
  
      @Override
      public final Collection<Metric> gatherMetrics(final ICommandLine cl)
              throws MetricGatheringException {
          String sPath = cl.getOptionValue("path");
  
          File f = new File(sPath);
  
          long lBytes = f.getFreeSpace();
          long lTotalSpace = f.getTotalSpace();
  
          String sFreeSpace = format(lBytes);
          String sUsedSpace = format(lTotalSpace - lBytes);
  
         int iFreePercent = percent(lBytes, lTotalSpace);
 
         String sFreePercent = "" + iFreePercent + "%";
         String sUsedPercent =
                 "" + percent(lTotalSpace - lBytes, lTotalSpace) + "%";
 
         List<Metric> res = new ArrayList<Metric>();
 
         String msg = "Used: " + sUsedSpace + "("
                 + sUsedPercent + ") Free: " + sFreeSpace + "("
                 + sFreePercent + ")";
 
         res.add(new Metric("freepct", msg, new BigDecimal(iFreePercent),
                 new BigDecimal(0), new BigDecimal(100)));
         res.add(new Metric("freespace", msg, new BigDecimal(iFreePercent),
                 new BigDecimal(0), new BigDecimal(lTotalSpace)));
 
         return res;
     }
 
     /**
      * Format the size returning it as MB or KB.
      *
      * @param bytes
      *            The size to be formatted
      * @return The formatted size
      */
     private String format(final long bytes) {
         if (bytes > MB) {
             return "" + (bytes / MB) + " MB";
         }
         return "" + (bytes / KB) + " KB";
     }
 
     @Override
     protected String getPluginName() {
         return "CHECK_DISK";
     }
 
 }