import java.rmi.UnexpectedException;

import javax.swing.JOptionPane;


/**
 * <P>Using arrays in conjunction with Strings (which appear as arrays of chars) to some
 * interesting (and maybe useful) things.</P>
 * @author Tom R.
 *
 */
public class StringArrayOps {
	/** <P>Used by the various internal routines to distinguish types of "letters".</P> */
	private static final char[] VOWELS = {'a','e','i','o','u'};
	/** <P>Preconditions: None.
	 * <br>
	 * PostConditions: returns the number of vowels in a <code>String</code>.
	 * </P>
	 * @param str (<code>String</code>)
	 * @return <code>int</code> >= 0.
	 */
	public static int countVowels( String str ) {
		int numberOfVowels = 0;
		
		
		return numberOfVowels;
		
	}
	
	/**
	 * <P>Preconditions: None.
	 * <br>
	 * Postconditions: Returns the number of times that the given <code>char ch</code> appears in the
	 * <code>String str</code>.
	 * </P>
	 * @param 
	 * @return <code> int </code> >= 0
	 */
	public static int countChar( char the_char, String str ) {
		int number_of_times_found = 0;
	
		
		return number_of_times_found;
	}
	
	/**
	 * <P>Preconditions: None.
	 * <br>
	 * Postconditions: Returns the number of consonants in a <code>String</code>.
	 * <P>
	 * @param str (<code>String</code>)
	 * @return <code>int >= 0</code>
	 */
	public static int countConsonants( String str ) {
		int number_of_consonants = 0;
		
		return number_of_consonants;
	}
	
	// entry point
	public static void main( String[] args ) {
		String str = JOptionPane.showInputDialog( null, "Enter an arbitary String: " );
		int number_of_vowels = countVowels(str);
		JOptionPane.showMessageDialog( null, "Your String contained " + number_of_vowels + " vowels, and " 
				+ countConsonants(str) + " consonants." );
		/* Notice what's going to happen here ... I'm using the try-catch
		 * statements below to verify that the user entered only one character.
		 * I don't really need to do this ... I could just ignore any extra 
		 * characters and accept the first, but doing so doesn't tell the user
		 * what's happened in the event they were expecting something different.
		 */
		char[] the_character_array=null; // ask yourself: why are these variables
		String the_char=null;			 // declared here and not within the try { }?
		try {
			the_char = JOptionPane.showInputDialog( 
					null, 
					"Enter a character\n and find out " +
					"how many times\nthe character appeared within the original String." );
			/* convert user input into an array of chars ... which we hope contains 
			 * only one!
			 */
			the_character_array = the_char.toCharArray();
			// If the character array does contain more than one char, complain .... 
			if( the_char.length() > 1 ) {
				throw new UnexpectedException("Too many chars" );
			}
			if( the_character_array.length  < 1 ) 
				throw new NullPointerException();
		} catch( UnexpectedException ue ) {
			/* Upon a complaint, inform ther user. */
			JOptionPane.showMessageDialog( null, "You entered more than 1 char; extras ignored!", 
					"Too many chars entered", JOptionPane.ERROR_MESSAGE );
		} catch( NullPointerException npe) {
			JOptionPane.showMessageDialog(null,  "You must enter a character ...", "Missing Input", JOptionPane.ERROR_MESSAGE );
		} finally {
			/* note the order of operations here: this will be done at the end of 
			 * dialogue ...
			 */
			if( the_character_array.length < 1 ) {
				JOptionPane.showMessageDialog( null, "Nothing entered ...", "Missing Input", JOptionPane.INFORMATION_MESSAGE );
				return;
			}
			JOptionPane.showMessageDialog(null,  
					"Your character appeared " + countChar(the_character_array[0], str ) + " times.");
			return;
		}
	}
}