HolidayHelper.java

package br.com.willianantunes.utils;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.joda.time.DateTimeConstants;
import org.joda.time.LocalDate;

/**
 * This is designed only for Brazil and is based on Joda-Time library.
 * @author Willian Antunes
 */
public class HolidayHelper {
	private final static Map<LocalDate, Map<Scope, String>> holidaysConsolidated;

	static {
		holidaysConsolidated = new HashMap<LocalDate, Map<Scope, String>>();

		// Federal holidays for the next 3 years
		int[] years = new int[3];
		years[0] = LocalDate.now().getYear();
		years[1] = years[0] + 1;
		years[2] = years[1] + 1;

		constructFederalHolidays(years);
	}

	/**
	 * It constructs holidays which are changeable and include fixed ones as well.
	 * 
	 * @param years
	 *            The year which the holidays will be constructed.
	 * @see <a href=
	 *      "https://pt.wikipedia.org/wiki/C%C3%A1lculo_da_P%C3%A1scoa">Cálculo
	 *      da Páscoa</a>
	 */
	private static void constructFederalHolidays(int... years) {
		if (years == null || years.length == 0)
			throw new IllegalArgumentException("At least one year must be provided");

		for (int year : years) {
			int a = year % 19;
			int b = year / 100;
			int c = year % 100;
			int d = b / 4;
			int e = b % 4;
			int f = (b + 8) / 25;
			int g = (b - f + 1) / 3;
			int h = (19 * a + b - d - g + 15) % 30;
			int i = c / 4;
			int k = c % 4;
			int l = (32 + 2 * e + 2 * i - h - k) % 7;
			int m = (a + 11 * h + 22 * l) / 451;
			int month = (h + l - 7 * m + 114) / 31;
			int day = ((h + l - 7 * m + 114) % 31) + 1;

			// Páscoa
			LocalDate pascoaDate = new LocalDate(year, month, day);
			// Carnaval is 47 days prior Páscoa
			// LocalDate carnavalDate = pascoaDate.minusDays(47);
			// Corpus Christi is 60 days after Páscoa
			LocalDate corpusChristiDate = pascoaDate.plusDays(60);
			// Sexta-feira Santa is two days before Páscoa
			LocalDate sextaFeiraSantaDate = pascoaDate.minusDays(2);

			Map<Scope, String> holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Páscoa");
			holidaysConsolidated.put(pascoaDate, holidaysRegion);

			// holidaysRegion = new HashMap<Scope, String>();
			// holidaysRegion.put(Scope.FEDERAL, "Carnaval");
			// holidaysConsolidated.put(carnavalDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Corpus Christi");
			holidaysConsolidated.put(corpusChristiDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Sexta-feira Santa");
			holidaysConsolidated.put(sextaFeiraSantaDate, holidaysRegion);

			// Confraternização universal
			LocalDate confraternizacaoUniversalDate = new LocalDate(year, 1, 1);
			// Tiradentes
			LocalDate tiradentesDate = new LocalDate(year, 4, 21);
			// Dia do trabalhador
			LocalDate trabalhadorDate = new LocalDate(year, 5, 1);
			// Independência do Brasil
			LocalDate independenciaBrasilDate = new LocalDate(year, 9, 7);
			// Nossa Sra. Aparecida
			LocalDate nossaSraAparecidaDate = new LocalDate(year, 10, 12);
			// Finados
			LocalDate finadosDate = new LocalDate(year, 11, 2);
			// Proclamação da República
			LocalDate proclaRepubDate = new LocalDate(year, 11, 15);
			// Natal
			LocalDate natalDate = new LocalDate(year, 12, 25);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Confraternização Universal");
			holidaysConsolidated.put(confraternizacaoUniversalDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Tiradentes");
			holidaysConsolidated.put(tiradentesDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Dia do trabalhador");
			holidaysConsolidated.put(trabalhadorDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Independência do Brasil");
			holidaysConsolidated.put(independenciaBrasilDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Nossa Sra. Aparecida");
			holidaysConsolidated.put(nossaSraAparecidaDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Finados");
			holidaysConsolidated.put(finadosDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Proclamação da República");
			holidaysConsolidated.put(proclaRepubDate, holidaysRegion);

			holidaysRegion = new HashMap<Scope, String>();
			holidaysRegion.put(Scope.FEDERAL, "Natal");
			holidaysConsolidated.put(natalDate, holidaysRegion);
		}
	}

	/**
	 * It'll insert the remaining holidays in order to make the map complete for
	 * other scopes such as Rio de Janeiro, Minas Gerais and so on.
	 * 
	 * @param holidays
	 */
	public synchronized static void includeRemainingHolidays(Collection<Holiday> holidays) {
		Map<Scope, String> temp;
		for (Holiday holiday : holidays) {
			if (holidaysConsolidated.containsKey(holiday.getDate())) {
				// If the date is registered, then I can see if there is holiday
				// for the particular region
				temp = holidaysConsolidated.get(holiday.getDate());
				if (!temp.containsKey(holiday.getScope())) {
					// If it isn't then I can add it and refresh the content
					// with the new map
					temp.put(holiday.getScope(), holiday.getDescription());
					holidaysConsolidated.remove(holiday.getDate());
					holidaysConsolidated.put(holiday.getDate(), temp);
				}
			} else {
				// As far as the date is not available, then it's necessary to
				// add it
				temp = new HashMap<Scope, String>();
				temp.put(holiday.getScope(), holiday.getDescription());
				holidaysConsolidated.put(holiday.getDate(), temp);
			}
		}
	}

	/**
	 * Verify if the particular region and its date have a holiday.
	 * 
	 * @param date
	 *            Any valid LocalDate.
	 * @param scope
	 *            FEDERAL scope is always counted.
	 * @return A booleans statement if the date/region whether have holiday.
	 */
	public static boolean isHoliday(LocalDate date, Scope scope) {
		if (!holidaysConsolidated.containsKey(date))
			return false;
		else {
			Map<Scope, String> temp = holidaysConsolidated.get(date);
			if (temp.containsKey(Scope.FEDERAL))
				return true;
			if (temp.containsKey(scope))
				return true;
		}
		return false;
	}

	/**
	 * Verify if the particular region and its date have a holiday or whether
	 * the date is Saturday or Sunday.
	 * 
	 * @param date
	 *            Any valid LocalDate.
	 * @param scope
	 *            FEDERAL scope is always counted even if you insert null.
	 * @return A booleans statement if the date/region whether have holiday.
	 */
	public static boolean isHolidayOrWeekend(LocalDate date, Scope scope) {
		if (holidaysConsolidated.containsKey(date)) {
			Map<Scope, String> temp = holidaysConsolidated.get(date);
			if (temp.containsKey(Scope.FEDERAL))
				return true;
			if (temp.containsKey(scope))
				return true;
		}
		if (isOnWeekend(date))
			return true;
		return false;
	}

	/**
	 * 
	 * @param date
	 * @return
	 */
	public static boolean isOnWeekend(LocalDate date) {
		if (date.getDayOfWeek() == DateTimeConstants.SATURDAY || date.getDayOfWeek() == DateTimeConstants.SUNDAY)
			return true;
		return false;
	}

	/**
	 * Starting from now, it'll jump a certain quantity of working days
	 * retrieving a new date. It can only consider weekends instead of holidays
	 * with weekends if you want so.
	 * 
	 * @param numberOfWorkingDays
	 * @param onlyWeekends
	 * @return A new jumped date.
	 */
	public static LocalDate jumpWorkingDay(int numberOfWorkingDays, boolean onlyWeekends) {
		LocalDate tmp = LocalDate.now();
		int countWorkingDays = 0;

		while (countWorkingDays < numberOfWorkingDays) {
			if (onlyWeekends) {
				if (isOnWeekend(tmp)) {
					tmp = tmp.plusDays(1);
					continue;	
				}
			} else {
				if (isHolidayOrWeekend(tmp, null)) {
					tmp = tmp.plusDays(1);
					continue;
				}
			}
			tmp = tmp.plusDays(1);
			countWorkingDays++;
		}

		return tmp;
	}

	public enum Scope {
		FEDERAL, SAO_PAULO, RIO_DE_JANEIRO, MINAS_GERAIS, BAHIA
	}

	public interface Holiday {
		String getDescription();

		Scope getScope();

		LocalDate getDate();
	}
}