package net.cbaines.suca;

import java.security.InvalidParameterException;
import java.util.Calendar;
import java.util.GregorianCalendar;

/**
 * All info from here
 * https://www.soton.ac.uk/studentadmin/academic_year/index.html
 * 
 * @author Christopher Baines <cbaines8@gmail.com>
 * 
 */
public final class UniTermDates {

	/**
	 * Periods
	 */
	public static final int AUTUMN_TERM = 0;
	public static final int SPRING_TERM = 1;
	public static final int SUMMER_TERM = 2;

	public static final int SEMESTER_1 = 3;
	public static final int SEMESTER_2 = 4;

	public static final int YEAR_BEGINING_2011 = 2011;
	public static final int YEAR_BEGINING_2012 = 2012;
	public static final int YEAR_BEGINING_2013 = 2013;
	public static final int YEAR_BEGINING_2014 = 2014;
	public static final int YEAR_BEGINING_2015 = 2015;
	public static final int YEAR_BEGINING_2016 = 2016;
	public static final int YEAR_BEGINING_2017 = 2017;
	public static final int YEAR_BEGINING_2018 = 2018;
	public static final int YEAR_BEGINING_2019 = 2019;

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] startOfAutumnTermAndSemester1 = {
			new GregorianCalendar(2011, Calendar.SEPTEMBER, 29),
			new GregorianCalendar(2012, Calendar.SEPTEMBER, 27),
			new GregorianCalendar(2013, Calendar.SEPTEMBER, 26),
			new GregorianCalendar(2014, Calendar.SEPTEMBER, 25),
			new GregorianCalendar(2015, Calendar.SEPTEMBER, 24),
			new GregorianCalendar(2016, Calendar.SEPTEMBER, 29),
			new GregorianCalendar(2017, Calendar.SEPTEMBER, 28),
			new GregorianCalendar(2018, Calendar.SEPTEMBER, 27),
			new GregorianCalendar(2019, Calendar.SEPTEMBER, 26) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] endOfAutumnTerm = {
			new GregorianCalendar(2011, Calendar.DECEMBER, 17),
			new GregorianCalendar(2012, Calendar.DECEMBER, 15),
			new GregorianCalendar(2013, Calendar.DECEMBER, 14),
			new GregorianCalendar(2014, Calendar.DECEMBER, 13),
			new GregorianCalendar(2015, Calendar.DECEMBER, 12),
			new GregorianCalendar(2016, Calendar.DECEMBER, 17),
			new GregorianCalendar(2017, Calendar.DECEMBER, 16),
			new GregorianCalendar(2018, Calendar.DECEMBER, 15),
			new GregorianCalendar(2019, Calendar.DECEMBER, 14) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] startOfSpringTerm = {
			new GregorianCalendar(2012, Calendar.JANUARY, 9),
			new GregorianCalendar(2013, Calendar.JANUARY, 7),
			new GregorianCalendar(2014, Calendar.JANUARY, 6),
			new GregorianCalendar(2015, Calendar.JANUARY, 5),
			new GregorianCalendar(2016, Calendar.JANUARY, 4),
			new GregorianCalendar(2017, Calendar.JANUARY, 9),
			new GregorianCalendar(2018, Calendar.JANUARY, 8),
			new GregorianCalendar(2019, Calendar.JANUARY, 7),
			new GregorianCalendar(2020, Calendar.JANUARY, 6) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] endOfSemester1 = {
			new GregorianCalendar(2012, Calendar.JANUARY, 28),
			new GregorianCalendar(2013, Calendar.JANUARY, 26),
			new GregorianCalendar(2014, Calendar.JANUARY, 25),
			new GregorianCalendar(2015, Calendar.JANUARY, 24),
			new GregorianCalendar(2016, Calendar.JANUARY, 23),
			new GregorianCalendar(2017, Calendar.JANUARY, 28),
			new GregorianCalendar(2018, Calendar.JANUARY, 27),
			new GregorianCalendar(2019, Calendar.JANUARY, 26),
			new GregorianCalendar(2020, Calendar.JANUARY, 25) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] startOfSemester2 = {
			new GregorianCalendar(2012, Calendar.JANUARY, 30),
			new GregorianCalendar(2013, Calendar.JANUARY, 28),
			new GregorianCalendar(2014, Calendar.JANUARY, 27),
			new GregorianCalendar(2015, Calendar.JANUARY, 26),
			new GregorianCalendar(2016, Calendar.JANUARY, 25),
			new GregorianCalendar(2017, Calendar.JANUARY, 30),
			new GregorianCalendar(2018, Calendar.JANUARY, 29),
			new GregorianCalendar(2019, Calendar.JANUARY, 28),
			new GregorianCalendar(2020, Calendar.JANUARY, 27) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] endOfSpringTerm = {
			new GregorianCalendar(2012, Calendar.MARCH, 17),
			new GregorianCalendar(2013, Calendar.MARCH, 16),
			new GregorianCalendar(2014, Calendar.MARCH, 29),
			new GregorianCalendar(2015, Calendar.MARCH, 21),
			new GregorianCalendar(2016, Calendar.MARCH, 19),
			new GregorianCalendar(2017, Calendar.MARCH, 25),
			new GregorianCalendar(2018, Calendar.MARCH, 17),
			new GregorianCalendar(2019, Calendar.MARCH, 30),
			new GregorianCalendar(2020, Calendar.MARCH, 21) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] startOfSummerTerm = {
			new GregorianCalendar(2012, Calendar.APRIL, 16),
			new GregorianCalendar(2013, Calendar.APRIL, 15),
			new GregorianCalendar(2014, Calendar.APRIL, 28),
			new GregorianCalendar(2015, Calendar.APRIL, 20),
			new GregorianCalendar(2016, Calendar.APRIL, 18),
			new GregorianCalendar(2017, Calendar.APRIL, 24),
			new GregorianCalendar(2018, Calendar.APRIL, 16),
			new GregorianCalendar(2019, Calendar.APRIL, 29),
			new GregorianCalendar(2020, Calendar.APRIL, 20) };

	/**
	 * Start dates for the Autumn term's for each Academic Year starting from
	 * 2011 to 2019.
	 */
	private static final GregorianCalendar[] endOfSummerTermAndSemester2 = {
			new GregorianCalendar(2012, Calendar.JUNE, 16),
			new GregorianCalendar(2013, Calendar.JUNE, 15),
			new GregorianCalendar(2014, Calendar.JUNE, 14),
			new GregorianCalendar(2015, Calendar.JUNE, 13),
			new GregorianCalendar(2016, Calendar.JUNE, 11),
			new GregorianCalendar(2017, Calendar.JUNE, 17),
			new GregorianCalendar(2018, Calendar.JUNE, 16),
			new GregorianCalendar(2019, Calendar.JUNE, 15),
			new GregorianCalendar(2020, Calendar.JUNE, 13) };

	public static GregorianCalendar getStartOf(int period, int academicYear) {
		if (academicYear < YEAR_BEGINING_2011
				|| academicYear > YEAR_BEGINING_2019) {
			throw new InvalidParameterException();
		}
		if (period == AUTUMN_TERM) {
			return (GregorianCalendar) startOfAutumnTermAndSemester1[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SPRING_TERM) {
			return (GregorianCalendar) startOfSpringTerm[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SUMMER_TERM) {
			return (GregorianCalendar) startOfSummerTerm[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SEMESTER_1) {
			return (GregorianCalendar) startOfAutumnTermAndSemester1[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SEMESTER_2) {
			return (GregorianCalendar) startOfSemester2[academicYear
					- YEAR_BEGINING_2011].clone();
		} else {
			throw new InvalidParameterException();
		}
	}

	public static GregorianCalendar getEndOf(int period, int academicYear) {
		if (academicYear < YEAR_BEGINING_2011
				|| academicYear > YEAR_BEGINING_2019) {
			throw new InvalidParameterException();
		}
		if (period == AUTUMN_TERM) {
			return (GregorianCalendar) endOfAutumnTerm[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SPRING_TERM) {
			return (GregorianCalendar) endOfSpringTerm[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SUMMER_TERM) {
			return (GregorianCalendar) endOfSummerTermAndSemester2[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SEMESTER_1) {
			return (GregorianCalendar) endOfSemester1[academicYear
					- YEAR_BEGINING_2011].clone();
		} else if (period == SEMESTER_2) {
			return (GregorianCalendar) endOfSummerTermAndSemester2[academicYear
					- YEAR_BEGINING_2011].clone();
		} else {
			throw new InvalidParameterException();
		}
	}

}