/*
  A wrapper for some common sorting/filtering methods etc, mostly using java.util.Collections
*/

public static class TransactionUtils
{
  //sort a List of transactions by the title
  public static void sortTransactionsByTitle(ArrayList transactions)
  {
    Collections.sort(transactions, new Comparator()
    {
      public int compare(Object o1, Object o2)
      {
        Transaction t1 = (Transaction) o1;
        Transaction t2 = (Transaction) o2;

        return t1.title.compareToIgnoreCase(t2.title);
      }
    }
    );
  }
  
  
  public static void sortWords(HashMap words)
  {
    Iterator it;
    Map.Entry me;
    Word w;
    sortedWords.clear();
    
    it = words.entrySet().iterator();  // Get an iterator
    //skim through the word set and add it to an array list
  
    while(it.hasNext()){
      me = (Map.Entry)it.next();
      w = (Word) me.getValue();
      if(w.totFreq > MINVALUE){
      sortedWords.add(w);  
      }
   }
    
    
    Collections.sort(sortedWords, new Comparator()
    {
      public int compare(Object o1, Object o2)
      {
        Word t1 = (Word) o1;
        Word t2 = (Word) o2;

        return t1.word.compareToIgnoreCase(t2.word);
      }
    }
    );
  }
  
  
   public static void sortValues(HashMap words)
  {
    Iterator it;
    Map.Entry me;
    Word w;
     sortedWords.clear();
    it = words.entrySet().iterator();  // Get an iterator
    //skim through the word set and add it to an array list
  
    while(it.hasNext()){
      me = (Map.Entry)it.next();
      w = (Word) me.getValue();
      if(w.totFreq > MINVALUE){
      sortedWords.add(w);  
      }
   }
    
    
    Collections.sort(sortedWords, new Comparator()
    {
      public int compare(Object o1, Object o2)
      {
        Word t1 = (Word) o1;
        Word t2 = (Word) o2;
        return t2.totFreq - t1.totFreq;
      }
    }
    );
  }
  

  //reverse order of List
  public static void reverse(ArrayList transactions)
  {
    Collections.reverse(transactions); 
  }
  
  public static void filterOutNonAlphabeticalTitles(ArrayList transactions)
  {
    for (int i = transactions.size() - 1; i >= 0; i--)  
    {
      Transaction t = (Transaction) transactions.get(i);
      if (t.title.length() < 1)
      {
        transactions.remove(t);
        continue;
      }
      char firstLetter = t.title.charAt(0); 
      if (! ((firstLetter >= 'a' && firstLetter <= 'z') || (firstLetter >= 'A' && firstLetter <= 'Z')) )
      {
       transactions.remove(t);
        continue;  
      }
         
    }
  }

}