/**
 * 
 */
package org.codehaus.classloader;

import java.io.File;
import java.util.Comparator;

class NewerFileFirst implements Comparator{
  private NewerFileFirst(){}
  private static final NewerFileFirst singleton = new NewerFileFirst();
  public static Comparator instance(){
    return singleton;
  }
  private int compareTime(File f1, File f2){
    long ts1 = f1.lastModified();
    long ts2 = f2.lastModified();
    if(ts1<ts2){
      //newer file first
      return 1;
    }
    else if(ts1>ts2){
      //newer file first
      return -1;
    }
    else{
      return f1.getName().compareTo(f2.getName());
    }
  }
  public int compare(Object arg1, Object arg2) {
    final File f1 = (File)arg1;
    final File f2 = (File)arg2;
    if(f1.isDirectory()){
      if(f2.isDirectory()){
        return compareTime(f1, f2);
      }
      else{
        //file first.
        return 1;
      }
    }
    else{
      if(f2.isDirectory()){
        //file first
        return -1;
      }
      else{
        return compareTime(f1, f2);
      }
    }
  }
  
}