package auditory.described;

import java.util.*;



/**
 * A factory that can be used to create Note objects
 *
 * @author  Prof. David Bernstein, James Madison University
 * @version 1.0
 */ 
public class NoteFactory
{

    /**
     * Parse a String representation of a note and
     * construct a Note from the constituent parts.
     * In the event of a format error, this method returns null.
     *
     * For example:
     * 
     *  "C ,0,1"  is a middle C whole note
     *  "A#,1,4." is an A-sharp (one octave above middle C) dotted quarter note
     *  "D ,-1,8" is a D (one octave below middle c) eigth note
     *
     * @param   s   The String to parse
     */
    public static Note parseNote(String s)
    {
	boolean           dotted, sharp;
	char              pitch, sharpChar;
	int               duration, octave, octaveEnd;
	Note              theNote;
	String            durationString, octaveString, token;
        StringTokenizer   st;
        
        st = new StringTokenizer(s, ", ");

        try
        {
           token = st.nextToken();
        
           // Determine the pitch
           pitch = token.charAt(0);
           
           // Determine if this is a sharp or a natural
           sharp = false;        
           if (token.length() == 2)
           {
              sharpChar = token.charAt(1);
              if (sharpChar == '#') sharp = true;
           }
           
           // Detemine the octave (relative to middle C)
           // 
           octaveString = st.nextToken();
           octave       = Integer.parseInt(octaveString);
           
           // Determine the duration (which has an arbitrary length)
           dotted         = false;
           durationString = st.nextToken();
           if (durationString.endsWith(".")) dotted = true;
           duration = (int)Double.parseDouble(durationString);
           
           // Construct a new Note
           theNote = new Note(pitch, sharp, octave, duration, dotted);
        }
        catch (NoSuchElementException nsee)
        {
           theNote = null;           
        }
        
	return theNote;
    }
}