/**
 * Copyright 2010-2013 Jingjing Li.
 *
 * This file is part of jplot2d.
 *
 * jplot2d is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 *
 * jplot2d is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with jplot2d. If not, see .
 */
package org.jplot2d.axtick;

import java.text.FieldPosition;
import java.text.Format;
import java.text.ParsePosition;
import java.util.Formatter;

/**
 * @author Jingjing Li
 * 
 */
public class ArcDmsFormat extends Format {

	private static final long serialVersionUID = 1L;

	private int fraDigits;

	public ArcDmsFormat(int fraDigits) {
		this.fraDigits = fraDigits;
	}

	@Override
	public StringBuffer format(Object number, StringBuffer toAppendTo, FieldPosition pos) {
		if (number instanceof Number) {
			return format(((Number) number).doubleValue(), toAppendTo, pos);
		} else {
			throw new IllegalArgumentException("Cannot format given Object as a Number");
		}
	}

	@SuppressWarnings("resource")
	private StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition) {

		boolean negative = false;
		if (number < 0) {
			number = -number;
			negative = true;
		}

		int degree = (int) number;
		number -= degree;
		number *= 60;
		int minute = (int) number;
		number -= minute;
		number *= 60;
		int second = (int) number;
		number -= second;

		StringBuilder sb = new StringBuilder();
		new Formatter(sb).format("%." + fraDigits + "f\u2033", number);
		if (sb.charAt(0) == '1') {
			second++;
			if (second == 60) {
				second = 0;
				minute++;
				if (minute == 60) {
					minute = 0;
					degree++;
				}
			}
		}

		if (negative) {
			result.append('-');
		}
		Formatter foramtter = new Formatter(result);
		foramtter.format("%02d\u00b0%02d\u2032%02d", degree, minute, second);
		if (fraDigits > 0) {
			// remove the digit before dot
			result.append(sb, 1, sb.length());
		} else {
			result.append('\u2033');
		}

		return result;
	}

	@Override
	public Object parseObject(String source, ParsePosition pos) {
		// not support
		return null;
	}

	public boolean equals(Object obj) {
		if (obj instanceof ArcDmsFormat) {
			return fraDigits == ((ArcDmsFormat) obj).fraDigits;
		}
		return false;
	}

}