package Lect42Review;

import javax.swing.*;

// Idea: This program will select a random word from an array and it will
// scramble the letters of the word.  The program will show the scrambled
// word to the user and keep asking the user for the original word.
//
// Reviews: do while, array of characters, Math.random, 
// instance variables, converting arrays of characters int
public class Scramble {	
	private String[] allWords = {"house", "cat", "table", "television",
			"newspaper", "dedication"};
	private String wordToScramble;
	private String scrambledWord;
		
	private void scrambleWord() {	
		// Note: uses nested loop as there is a chance the scrambled 
		// word generated is the same as the selected word.
		// Probability of this is high for short words (e.g. cat)
		
		do {
			int wordSize = wordToScramble.length();
			char[] scrambledArray = new char[wordSize];
			boolean[] picked = new boolean[wordSize];
			int index, currentPosition = 0;
		
			// We will repeatedly select a random character from the
			// word.  If the character has not been previously selected, 
			// we will use it for the next position in the scrambled 
			// array.  The alreadyPicked array will tell us whether 
			// a selected character was already considered.  
		
			do {
				index = (int)(Math.random() * wordSize);
			
				if (!picked[index]) {
					picked[index] = true;
					scrambledArray[currentPosition++] = wordToScramble.charAt(index);
				}
			} while (currentPosition < wordSize);
		
			// rely on String constructor that takes a character array
			scrambledWord = new String(scrambledArray);
			
		} while(wordToScramble.equals(scrambledWord));
	}
	
	private void doUserInput() {
		String message = "Guess the word represented by " + scrambledWord;
		String guess;
		do {
			guess = JOptionPane.showInputDialog(message);
		} while (!guess.equals(wordToScramble));
		
		message = "You unscrambled the word";
		JOptionPane.showMessageDialog(null, message);
	}
	
	public Scramble() {
		int selectedWordIndex = (int)(Math.random() * allWords.length);
		wordToScramble = allWords[selectedWordIndex];
		scrambleWord();
		doUserInput();
		System.exit(0);
	}
	
	public static void main(String[] args) {
		new Scramble();
	}
}