//********************************************************************
//  PigLatinTranslator.java       Author: Lewis and Loftus
//
//  Represents a translation system from English to Pig Latin.
//  Demonstrates method decomposition and the use of StringTokenizer.
//********************************************************************

import java.util.StringTokenizer;

public class PigLatinTranslator
{
   //-----------------------------------------------------------------
   //  Translates a sentence of words into Pig Latin.
   //-----------------------------------------------------------------
   public String translate (String sentence)
   {
      String result = "";

      sentence = sentence.toLowerCase();
      StringTokenizer tokenizer = new StringTokenizer (sentence);

      while (tokenizer.hasMoreTokens())
      {
         result += translateWord (tokenizer.nextToken());
         result += " ";
      }

      return result;
   }

   //-----------------------------------------------------------------
   //  Translates one word into Pig Latin. If the word begins with a
   //  vowel, the suffix "yay" is appended to the word.  Otherwise,
   //  the first letter or two are moved to the end of the word,
   //  and "ay" is appended.
   //-----------------------------------------------------------------
   private String translateWord (String word)
   {
      String result = "";

      if (beginsWithVowel(word))
         result = word + "yay";
      else
         if (beginsWithPrefix(word))
            result = word.substring(2) + word.substring(0,2) + "ay";
         else
            result = word.substring(1) + word.charAt(0) + "ay";

      return result;
   }

   //-----------------------------------------------------------------
   //  Determines if the specified word begins with a vowel.
   //-----------------------------------------------------------------
   private boolean beginsWithVowel (String word)
   {
      String vowels = "aeiouAEIOU";

      char letter = word.charAt(0);

      return (vowels.indexOf(letter) != -1);
   }

   //-----------------------------------------------------------------
   //  Determines if the specified word begins with a particular
   //  two-character prefix.
   //-----------------------------------------------------------------
   private boolean beginsWithPrefix (String str)
   {
      return ( str.startsWith ("bl") || str.startsWith ("pl") ||
               str.startsWith ("br") || str.startsWith ("pr") ||
               str.startsWith ("ch") || str.startsWith ("sh") ||
               str.startsWith ("cl") || str.startsWith ("sl") ||
               str.startsWith ("cr") || str.startsWith ("sp") ||
               str.startsWith ("dr") || str.startsWith ("sr") ||
               str.startsWith ("fl") || str.startsWith ("st") ||
               str.startsWith ("fr") || str.startsWith ("th") ||
               str.startsWith ("gl") || str.startsWith ("tr") ||
               str.startsWith ("gr") || str.startsWith ("wh") ||
               str.startsWith ("kl") || str.startsWith ("wr") ||
               str.startsWith ("ph") );
   }
}