/*
 * JFugue, an Application Programming Interface (API) for Music Programming
 * http://www.jfugue.org
 *
 * Copyright (C) 2003-2014 David Koelle
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.staccato;

import org.jfugue.midi.MidiDictionary;

/**
 * Parses both Instrument and Layer tokens. Each has values that are parsed as bytes. 
 * 
 * @author dkoelle
 */
public class TempoSubparser implements Subparser 
{
	public static final char TEMPO = 'T';
	
	private static TempoSubparser instance;
	
	public static TempoSubparser getInstance() {
		if (instance == null) {
			instance = new TempoSubparser();
		}
		return instance;
	}
	
	@Override
	public boolean matches(String music) {
		return (music.charAt(0) == TEMPO);
	}

	@Override
	public int parse(String music, StaccatoParserContext context) {
		if (matches(music)) {
			int posNextSpace = StaccatoUtil.findNextOrEnd(music, ' ', 0);
			int tempo = -1;
			if (posNextSpace > 1) {
				String tempoId = music.substring(1, posNextSpace);
				if (tempoId.matches("\\d+")) {
					tempo = Integer.parseInt(tempoId);
				} else {
					if (tempoId.charAt(0) == '[') {
						tempoId = tempoId.substring(1, tempoId.length()-1);
					}
					tempo = (Integer)context.getDictionary().get(tempoId);
				}
			}
			context.getParser().fireTempoChanged(tempo);
			return posNextSpace + 1;
		}
		return 0;
	}
	
	public static void populateContext(StaccatoParserContext context) {
        // Instruments
        context.getDictionary().putAll(MidiDictionary.TEMPO_STRING_TO_INT);
	}		
}