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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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/*

 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 *  * Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *

 *  * Neither the name of JSR-310 nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

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 */

package java.time.chrono;

import static java.time.temporal.ChronoField.YEAR;

import java.io.Serializable;

import java.time.Clock;

import java.time.DateTimeException;

import java.time.Instant;

import java.time.LocalDate;

import java.time.ZoneId;

import java.time.temporal.ChronoField;

import java.time.temporal.TemporalAccessor;

import java.time.temporal.ValueRange;

import java.util.Arrays;

import java.util.List;

import java.util.Locale;

/**

 * The Minguo calendar system.

 * <p>

 * This chronology defines the rules of the Minguo calendar system.

 * This calendar system is primarily used in the Republic of China, often known as Taiwan.

 * Dates are aligned such that {@code 0001-01-01 (Minguo)} is {@code 1912-01-01 (ISO)}.

 * <p>

 * The fields are defined as follows:

 * <p><ul>

 * <li>era - There are two eras, the current 'Republic' (ERA_ROC) and the previous era (ERA_BEFORE_ROC).

 * <li>year-of-era - The year-of-era for the current era increases uniformly from the epoch at year one.

 *  For the previous era the year increases from one as time goes backwards.

 *  The value for the current era is equal to the ISO proleptic-year minus 1911.

 * <li>proleptic-year - The proleptic year is the same as the year-of-era for the

 *  current era. For the previous era, years have zero, then negative values.

 *  The value is equal to the ISO proleptic-year minus 1911.

 * <li>month-of-year - The Minguo month-of-year exactly matches ISO.

 * <li>day-of-month - The Minguo day-of-month exactly matches ISO.

 * <li>day-of-year - The Minguo day-of-year exactly matches ISO.

 * <li>leap-year - The Minguo leap-year pattern exactly matches ISO, such that the two calendars

 *  are never out of step.

 * </ul><p>

 *

 * <h3>Specification for implementors</h3>

 * This class is immutable and thread-safe.

 *

 * @since 1.8

 */

public final class MinguoChronology extends Chronology implements Serializable {

    /**

     * Singleton instance for the Minguo chronology.

     */

    public static final MinguoChronology INSTANCE = new MinguoChronology();

    /**

     * The singleton instance for the era ROC.

     */

    public static final Era ERA_ROC = MinguoEra.ROC;

    /**

     * The singleton instance for the era BEFORE_ROC.

     */

    public static final Era ERA_BEFORE_ROC = MinguoEra.BEFORE_ROC;

    /**

     * Serialization version.

     */

    private static final long serialVersionUID = 1039765215346859963L;

    /**

     * The difference in years between ISO and Minguo.

     */

    static final int YEARS_DIFFERENCE = 1911;

    /**

     * Restricted constructor.

     */

    private MinguoChronology() {

    }

    /**

     * Resolve singleton.

     *

     * @return the singleton instance, not null

     */

    private Object readResolve() {

        return INSTANCE;

    }

    //-----------------------------------------------------------------------

    /**

     * Gets the ID of the chronology - 'Minguo'.

     * <p>

     * The ID uniquely identifies the {@code Chronology}.

     * It can be used to lookup the {@code Chronology} using {@link #of(String)}.

     *

     * @return the chronology ID - 'Minguo'

     * @see #getCalendarType()

     */

    @Override

    public String getId() {

        return "Minguo";

    }

    /**

     * Gets the calendar type of the underlying calendar system - 'roc'.

     * <p>

     * The calendar type is an identifier defined by the

     * <em>Unicode Locale Data Markup Language (LDML)</em> specification.

     * It can be used to lookup the {@code Chronology} using {@link #of(String)}.

     * It can also be used as part of a locale, accessible via

     * {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'.

     *

     * @return the calendar system type - 'roc'

     * @see #getId()

     */

    @Override

    public String getCalendarType() {

        return "roc";

    }

    //-----------------------------------------------------------------------

    @Override

    public MinguoDate date(int prolepticYear, int month, int dayOfMonth) {

        return new MinguoDate(LocalDate.of(prolepticYear + YEARS_DIFFERENCE, month, dayOfMonth));

    }

    @Override

    public MinguoDate dateYearDay(int prolepticYear, int dayOfYear) {

        return new MinguoDate(LocalDate.ofYearDay(prolepticYear + YEARS_DIFFERENCE, dayOfYear));

    }

    @Override

    public MinguoDate date(TemporalAccessor temporal) {

        if (temporal instanceof MinguoDate) {

            return (MinguoDate) temporal;

        }

        return new MinguoDate(LocalDate.from(temporal));

    }

    @Override

    public MinguoDate date(Era era, int yearOfEra, int month, int dayOfMonth) {

        return date(prolepticYear(era, yearOfEra), month, dayOfMonth);

    }

    @Override

    public MinguoDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {

        return dateYearDay(prolepticYear(era, yearOfEra), dayOfYear);

    }

    @Override

    public MinguoDate dateNow() {

        return dateNow(Clock.systemDefaultZone());

    }

    @Override

    public MinguoDate dateNow(ZoneId zone) {

        return dateNow(Clock.system(zone));

    }

    @Override

    public MinguoDate dateNow(Clock clock) {

        return date(LocalDate.now(clock));

    }

    @Override

    public ChronoLocalDateTime<MinguoDate> localDateTime(TemporalAccessor temporal) {

        return (ChronoLocalDateTime<MinguoDate>)super.localDateTime(temporal);

    }

    @Override

    public ChronoZonedDateTime<MinguoDate> zonedDateTime(TemporalAccessor temporal) {

        return (ChronoZonedDateTime<MinguoDate>)super.zonedDateTime(temporal);

    }

    @Override

    public ChronoZonedDateTime<MinguoDate> zonedDateTime(Instant instant, ZoneId zone) {

        return (ChronoZonedDateTime<MinguoDate>)super.zonedDateTime(instant, zone);

    }

    //-----------------------------------------------------------------------

    /**

     * Checks if the specified year is a leap year.

     * <p>

     * Minguo leap years occur exactly in line with ISO leap years.

     * This method does not validate the year passed in, and only has a

     * well-defined result for years in the supported range.

     *

     * @param prolepticYear  the proleptic-year to check, not validated for range

     * @return true if the year is a leap year

     */

    @Override

    public boolean isLeapYear(long prolepticYear) {

        return IsoChronology.INSTANCE.isLeapYear(prolepticYear + YEARS_DIFFERENCE);

    }

    @Override

    public int prolepticYear(Era era, int yearOfEra) {

        if (era instanceof MinguoEra == false) {

            throw new DateTimeException("Era must be MinguoEra");

        }

        return (era == MinguoEra.ROC ? yearOfEra : 1 - yearOfEra);

    }

    @Override

    public Era eraOf(int eraValue) {

        return MinguoEra.of(eraValue);

    }

    @Override

    public List<Era> eras() {

        return Arrays.<Era>asList(MinguoEra.values());

    }

    //-----------------------------------------------------------------------

    @Override

    public ValueRange range(ChronoField field) {

        switch (field) {

            case YEAR_OF_ERA: {

                ValueRange range = YEAR.range();

                return ValueRange.of(1, range.getMaximum() - YEARS_DIFFERENCE, -range.getMinimum() + 1 + YEARS_DIFFERENCE);

            }

            case YEAR: {

                ValueRange range = YEAR.range();

                return ValueRange.of(range.getMinimum() - YEARS_DIFFERENCE, range.getMaximum() - YEARS_DIFFERENCE);

            }

        }

        return field.range();

    }

}