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   * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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 Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
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   */
  
  /*
   * Copyright (c) 2011-2012, 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
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package java.time.temporal;
  
  import android.icu.text.DateTimePatternGenerator;
  import android.icu.util.ULocale;
  
  import static java.time.DayOfWeek.THURSDAY;
  import static java.time.DayOfWeek.WEDNESDAY;
  import static java.time.temporal.ChronoField.DAY_OF_WEEK;
  import static java.time.temporal.ChronoField.DAY_OF_YEAR;
  import static java.time.temporal.ChronoField.EPOCH_DAY;
  import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
  import static java.time.temporal.ChronoField.YEAR;
  import static java.time.temporal.ChronoUnit.DAYS;
  import static java.time.temporal.ChronoUnit.FOREVER;
  import static java.time.temporal.ChronoUnit.MONTHS;
  import static java.time.temporal.ChronoUnit.WEEKS;
  import static java.time.temporal.ChronoUnit.YEARS;
  
  import java.time.DateTimeException;
  import java.time.Duration;
  import java.time.LocalDate;
  import java.time.chrono.ChronoLocalDate;
  import java.time.chrono.Chronology;
  import java.time.chrono.IsoChronology;
  import java.time.format.ResolverStyle;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  
  /**
   * Fields and units specific to the ISO-8601 calendar system,
   * including quarter-of-year and week-based-year.
   * <p>
   * This class defines fields and units that are specific to the ISO calendar system.
   *
   * <h3>Quarter of year</h3>
   * The ISO-8601 standard is based on the standard civic 12 month year.
   * This is commonly divided into four quarters, often abbreviated as Q1, Q2, Q3 and Q4.
   * <p>
   * January, February and March are in Q1.
   * April, May and June are in Q2.
   * July, August and September are in Q3.
   * October, November and December are in Q4.
   * <p>
   * The complete date is expressed using three fields:
   * <ul>
   * <li>{@link #DAY_OF_QUARTER DAY_OF_QUARTER} - the day within the quarter, from 1 to 90, 91 or 92
   * <li>{@link #QUARTER_OF_YEAR QUARTER_OF_YEAR} - the week within the week-based-year
   * <li>{@link ChronoField#YEAR YEAR} - the standard ISO year
   * </ul>
   *
   * <h3>Week based years</h3>
   * The ISO-8601 standard was originally intended as a data interchange format,
   * defining a string format for dates and times. However, it also defines an
   * alternate way of expressing the date, based on the concept of week-based-year.
   * <p>
   * The date is expressed using three fields:
   * <ul>
   * <li>{@link ChronoField#DAY_OF_WEEK DAY_OF_WEEK} - the standard field defining the
   *  day-of-week from Monday (1) to Sunday (7)
   * <li>{@link #WEEK_OF_WEEK_BASED_YEAR} - the week within the week-based-year
   * <li>{@link #WEEK_BASED_YEAR WEEK_BASED_YEAR} - the week-based-year
   * </ul>
   * The week-based-year itself is defined relative to the standard ISO proleptic year.
   * It differs from the standard year in that it always starts on a Monday.
   * <p>
   * The first week of a week-based-year is the first Monday-based week of the standard
   * ISO year that has at least 4 days in the new year.
   * <ul>
   * <li>If January 1st is Monday then week 1 starts on January 1st
   * <li>If January 1st is Tuesday then week 1 starts on December 31st of the previous standard year
   * <li>If January 1st is Wednesday then week 1 starts on December 30th of the previous standard year
   * <li>If January 1st is Thursday then week 1 starts on December 29th of the previous standard year
   * <li>If January 1st is Friday then week 1 starts on January 4th
   * <li>If January 1st is Saturday then week 1 starts on January 3rd
   * <li>If January 1st is Sunday then week 1 starts on January 2nd
   * </ul>
   * There are 52 weeks in most week-based years, however on occasion there are 53 weeks.
   * <p>
   * For example:
   *
   * <table cellpadding="0" cellspacing="3" border="0" style="text-align: left; width: 50%;">
   * <caption>Examples of Week based Years</caption>
   * <tr><th>Date</th><th>Day-of-week</th><th>Field values</th></tr>
   * <tr><th>2008-12-28</th><td>Sunday</td><td>Week 52 of week-based-year 2008</td></tr>
   * <tr><th>2008-12-29</th><td>Monday</td><td>Week 1 of week-based-year 2009</td></tr>
   * <tr><th>2008-12-31</th><td>Wednesday</td><td>Week 1 of week-based-year 2009</td></tr>
   * <tr><th>2009-01-01</th><td>Thursday</td><td>Week 1 of week-based-year 2009</td></tr>
   * <tr><th>2009-01-04</th><td>Sunday</td><td>Week 1 of week-based-year 2009</td></tr>
   * <tr><th>2009-01-05</th><td>Monday</td><td>Week 2 of week-based-year 2009</td></tr>
   * </table>
   *
   * @implSpec
   * <p>
   * This class is immutable and thread-safe.
   *
   * @since 1.8
   */
  public final class IsoFields {
  
      /**
       * The field that represents the day-of-quarter.
       * <p>
       * This field allows the day-of-quarter value to be queried and set.
       * The day-of-quarter has values from 1 to 90 in Q1 of a standard year, from 1 to 91
       * in Q1 of a leap year, from 1 to 91 in Q2 and from 1 to 92 in Q3 and Q4.
       * <p>
       * The day-of-quarter can only be calculated if the day-of-year, month-of-year and year
       * are available.
       * <p>
       * When setting this field, the value is allowed to be partially lenient, taking any
       * value from 1 to 92. If the quarter has less than 92 days, then day 92, and
       * potentially day 91, is in the following quarter.
       * <p>
       * In the resolving phase of parsing, a date can be created from a year,
       * quarter-of-year and day-of-quarter.
       * <p>
       * In {@linkplain ResolverStyle#STRICT strict mode}, all three fields are
       * validated against their range of valid values. The day-of-quarter field
       * is validated from 1 to 90, 91 or 92 depending on the year and quarter.
       * <p>
       * In {@linkplain ResolverStyle#SMART smart mode}, all three fields are
       * validated against their range of valid values. The day-of-quarter field is
       * validated between 1 and 92, ignoring the actual range based on the year and quarter.
       * If the day-of-quarter exceeds the actual range by one day, then the resulting date
       * is one day later. If the day-of-quarter exceeds the actual range by two days,
       * then the resulting date is two days later.
       * <p>
       * In {@linkplain ResolverStyle#LENIENT lenient mode}, only the year is validated
       * against the range of valid values. The resulting date is calculated equivalent to
       * the following three stage approach. First, create a date on the first of January
       * in the requested year. Then take the quarter-of-year, subtract one, and add the
       * amount in quarters to the date. Finally, take the day-of-quarter, subtract one,
       * and add the amount in days to the date.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalField DAY_OF_QUARTER = Field.DAY_OF_QUARTER;
      /**
       * The field that represents the quarter-of-year.
       * <p>
       * This field allows the quarter-of-year value to be queried and set.
       * The quarter-of-year has values from 1 to 4.
       * <p>
       * The quarter-of-year can only be calculated if the month-of-year is available.
       * <p>
       * In the resolving phase of parsing, a date can be created from a year,
       * quarter-of-year and day-of-quarter.
       * See {@link #DAY_OF_QUARTER} for details.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalField QUARTER_OF_YEAR = Field.QUARTER_OF_YEAR;
      /**
       * The field that represents the week-of-week-based-year.
       * <p>
       * This field allows the week of the week-based-year value to be queried and set.
       * The week-of-week-based-year has values from 1 to 52, or 53 if the
       * week-based-year has 53 weeks.
       * <p>
       * In the resolving phase of parsing, a date can be created from a
       * week-based-year, week-of-week-based-year and day-of-week.
       * <p>
       * In {@linkplain ResolverStyle#STRICT strict mode}, all three fields are
       * validated against their range of valid values. The week-of-week-based-year
       * field is validated from 1 to 52 or 53 depending on the week-based-year.
       * <p>
       * In {@linkplain ResolverStyle#SMART smart mode}, all three fields are
       * validated against their range of valid values. The week-of-week-based-year
       * field is validated between 1 and 53, ignoring the week-based-year.
       * If the week-of-week-based-year is 53, but the week-based-year only has
       * 52 weeks, then the resulting date is in week 1 of the following week-based-year.
       * <p>
       * In {@linkplain ResolverStyle#LENIENT lenient mode}, only the week-based-year
       * is validated against the range of valid values. If the day-of-week is outside
       * the range 1 to 7, then the resulting date is adjusted by a suitable number of
       * weeks to reduce the day-of-week to the range 1 to 7. If the week-of-week-based-year
       * value is outside the range 1 to 52, then any excess weeks are added or subtracted
       * from the resulting date.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalField WEEK_OF_WEEK_BASED_YEAR = Field.WEEK_OF_WEEK_BASED_YEAR;
      /**
       * The field that represents the week-based-year.
       * <p>
       * This field allows the week-based-year value to be queried and set.
       * <p>
       * The field has a range that matches {@link LocalDate#MAX} and {@link LocalDate#MIN}.
       * <p>
       * In the resolving phase of parsing, a date can be created from a
       * week-based-year, week-of-week-based-year and day-of-week.
       * See {@link #WEEK_OF_WEEK_BASED_YEAR} for details.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalField WEEK_BASED_YEAR = Field.WEEK_BASED_YEAR;
      /**
       * The unit that represents week-based-years for the purpose of addition and subtraction.
       * <p>
       * This allows a number of week-based-years to be added to, or subtracted from, a date.
       * The unit is equal to either 52 or 53 weeks.
       * The estimated duration of a week-based-year is the same as that of a standard ISO
       * year at {@code 365.2425 Days}.
       * <p>
       * The rules for addition add the number of week-based-years to the existing value
       * for the week-based-year field. If the resulting week-based-year only has 52 weeks,
       * then the date will be in week 1 of the following week-based-year.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalUnit WEEK_BASED_YEARS = Unit.WEEK_BASED_YEARS;
      /**
       * Unit that represents the concept of a quarter-year.
       * For the ISO calendar system, it is equal to 3 months.
       * The estimated duration of a quarter-year is one quarter of {@code 365.2425 Days}.
       * <p>
       * This unit is an immutable and thread-safe singleton.
       */
      public static final TemporalUnit QUARTER_YEARS = Unit.QUARTER_YEARS;
  
      /**
       * Restricted constructor.
       */
      private IsoFields() {
          throw new AssertionError("Not instantiable");
      }
  
      //-----------------------------------------------------------------------
      /**
       * Implementation of the field.
       */
      private static enum Field implements TemporalField {
          DAY_OF_QUARTER {
              @Override
              public TemporalUnit getBaseUnit() {
                  return DAYS;
              }
              @Override
              public TemporalUnit getRangeUnit() {
                  return QUARTER_YEARS;
              }
              @Override
              public ValueRange range() {
                  return ValueRange.of(1, 90, 92);
              }
              @Override
              public boolean isSupportedBy(TemporalAccessor temporal) {
                  return temporal.isSupported(DAY_OF_YEAR) && temporal.isSupported(MONTH_OF_YEAR) &&
                          temporal.isSupported(YEAR) && isIso(temporal);
              }
              @Override
              public ValueRange rangeRefinedBy(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: DayOfQuarter");
                  }
                  long qoy = temporal.getLong(QUARTER_OF_YEAR);
                  if (qoy == 1) {
                      long year = temporal.getLong(YEAR);
                      return (IsoChronology.INSTANCE.isLeapYear(year) ? ValueRange.of(1, 91) : ValueRange.of(1, 90));
                  } else if (qoy == 2) {
                      return ValueRange.of(1, 91);
                  } else if (qoy == 3 || qoy == 4) {
                      return ValueRange.of(1, 92);
                  } // else value not from 1 to 4, so drop through
                  return range();
              }
              @Override
              public long getFrom(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: DayOfQuarter");
                  }
                  int doy = temporal.get(DAY_OF_YEAR);
                  int moy = temporal.get(MONTH_OF_YEAR);
                  long year = temporal.getLong(YEAR);
                  return doy - QUARTER_DAYS[((moy - 1) / 3) + (IsoChronology.INSTANCE.isLeapYear(year) ? 4 : 0)];
              }
              @SuppressWarnings("unchecked")
              @Override
              public <R extends Temporal> R adjustInto(R temporal, long newValue) {
                  // calls getFrom() to check if supported
                  long curValue = getFrom(temporal);
                  range().checkValidValue(newValue, this);  // leniently check from 1 to 92 TODO: check
                  return (R) temporal.with(DAY_OF_YEAR, temporal.getLong(DAY_OF_YEAR) + (newValue - curValue));
              }
              @Override
              public ChronoLocalDate resolve(
                      Map<TemporalField, Long> fieldValues, TemporalAccessor partialTemporal, ResolverStyle resolverStyle) {
                  Long yearLong = fieldValues.get(YEAR);
                  Long qoyLong = fieldValues.get(QUARTER_OF_YEAR);
                  if (yearLong == null || qoyLong == null) {
                      return null;
                  }
                  int y = YEAR.checkValidIntValue(yearLong);  // always validate
                  long doq = fieldValues.get(DAY_OF_QUARTER);
                  ensureIso(partialTemporal);
                  LocalDate date;
                  if (resolverStyle == ResolverStyle.LENIENT) {
                      date = LocalDate.of(y, 1, 1).plusMonths(Math.multiplyExact(Math.subtractExact(qoyLong, 1), 3));
                      doq = Math.subtractExact(doq, 1);
                  } else {
                      int qoy = QUARTER_OF_YEAR.range().checkValidIntValue(qoyLong, QUARTER_OF_YEAR);  // validated
                      date = LocalDate.of(y, ((qoy - 1) * 3) + 1, 1);
                      if (doq < 1 || doq > 90) {
                          if (resolverStyle == ResolverStyle.STRICT) {
                              rangeRefinedBy(date).checkValidValue(doq, this);  // only allow exact range
                          } else {  // SMART
                              range().checkValidValue(doq, this);  // allow 1-92 rolling into next quarter
                          }
                      }
                      doq--;
                  }
                  fieldValues.remove(this);
                  fieldValues.remove(YEAR);
                  fieldValues.remove(QUARTER_OF_YEAR);
                  return date.plusDays(doq);
              }
              @Override
              public String toString() {
                  return "DayOfQuarter";
              }
          },
          QUARTER_OF_YEAR {
              @Override
              public TemporalUnit getBaseUnit() {
                  return QUARTER_YEARS;
              }
              @Override
              public TemporalUnit getRangeUnit() {
                  return YEARS;
              }
              @Override
              public ValueRange range() {
                  return ValueRange.of(1, 4);
              }
              @Override
              public boolean isSupportedBy(TemporalAccessor temporal) {
                  return temporal.isSupported(MONTH_OF_YEAR) && isIso(temporal);
              }
              @Override
              public long getFrom(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: QuarterOfYear");
                  }
                  long moy = temporal.getLong(MONTH_OF_YEAR);
                  return ((moy + 2) / 3);
              }
              @SuppressWarnings("unchecked")
              @Override
              public <R extends Temporal> R adjustInto(R temporal, long newValue) {
                  // calls getFrom() to check if supported
                  long curValue = getFrom(temporal);
                  range().checkValidValue(newValue, this);  // strictly check from 1 to 4
                  return (R) temporal.with(MONTH_OF_YEAR, temporal.getLong(MONTH_OF_YEAR) + (newValue - curValue) * 3);
              }
              @Override
              public String toString() {
                  return "QuarterOfYear";
              }
          },
          WEEK_OF_WEEK_BASED_YEAR {
              @Override
              public String getDisplayName(Locale locale) {
                  Objects.requireNonNull(locale, "locale");
                  // Android-changed: Use ICU name values.
                  DateTimePatternGenerator dateTimePatternGenerator = DateTimePatternGenerator
                          .getFrozenInstance(ULocale.forLocale(locale));
                  String icuName = dateTimePatternGenerator
                          .getAppendItemName(DateTimePatternGenerator.WEEK_OF_YEAR);
                  return icuName != null && !icuName.isEmpty() ? icuName : toString();
              }
  
              @Override
              public TemporalUnit getBaseUnit() {
                  return WEEKS;
              }
              @Override
              public TemporalUnit getRangeUnit() {
                  return WEEK_BASED_YEARS;
              }
              @Override
              public ValueRange range() {
                  return ValueRange.of(1, 52, 53);
              }
              @Override
              public boolean isSupportedBy(TemporalAccessor temporal) {
                  return temporal.isSupported(EPOCH_DAY) && isIso(temporal);
              }
              @Override
              public ValueRange rangeRefinedBy(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: WeekOfWeekBasedYear");
                  }
                  return getWeekRange(LocalDate.from(temporal));
              }
              @Override
              public long getFrom(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: WeekOfWeekBasedYear");
                  }
                  return getWeek(LocalDate.from(temporal));
              }
              @SuppressWarnings("unchecked")
              @Override
              public <R extends Temporal> R adjustInto(R temporal, long newValue) {
                  // calls getFrom() to check if supported
                  range().checkValidValue(newValue, this);  // lenient range
                  return (R) temporal.plus(Math.subtractExact(newValue, getFrom(temporal)), WEEKS);
              }
              @Override
              public ChronoLocalDate resolve(
                      Map<TemporalField, Long> fieldValues, TemporalAccessor partialTemporal, ResolverStyle resolverStyle) {
                  Long wbyLong = fieldValues.get(WEEK_BASED_YEAR);
                  Long dowLong = fieldValues.get(DAY_OF_WEEK);
                  if (wbyLong == null || dowLong == null) {
                      return null;
                  }
                  int wby = WEEK_BASED_YEAR.range().checkValidIntValue(wbyLong, WEEK_BASED_YEAR);  // always validate
                  long wowby = fieldValues.get(WEEK_OF_WEEK_BASED_YEAR);
                  ensureIso(partialTemporal);
                  LocalDate date = LocalDate.of(wby, 1, 4);
                  if (resolverStyle == ResolverStyle.LENIENT) {
                      long dow = dowLong;  // unvalidated
                      if (dow > 7) {
                          date = date.plusWeeks((dow - 1) / 7);
                          dow = ((dow - 1) % 7) + 1;
                      } else if (dow < 1) {
                          date = date.plusWeeks(Math.subtractExact(dow,  7) / 7);
                          dow = ((dow + 6) % 7) + 1;
                      }
                      date = date.plusWeeks(Math.subtractExact(wowby, 1)).with(DAY_OF_WEEK, dow);
                  } else {
                      int dow = DAY_OF_WEEK.checkValidIntValue(dowLong);  // validated
                      if (wowby < 1 || wowby > 52) {
                          if (resolverStyle == ResolverStyle.STRICT) {
                              getWeekRange(date).checkValidValue(wowby, this);  // only allow exact range
                          } else {  // SMART
                              range().checkValidValue(wowby, this);  // allow 1-53 rolling into next year
                          }
                      }
                      date = date.plusWeeks(wowby - 1).with(DAY_OF_WEEK, dow);
                  }
                  fieldValues.remove(this);
                  fieldValues.remove(WEEK_BASED_YEAR);
                  fieldValues.remove(DAY_OF_WEEK);
                  return date;
              }
              @Override
              public String toString() {
                  return "WeekOfWeekBasedYear";
              }
          },
          WEEK_BASED_YEAR {
              @Override
              public TemporalUnit getBaseUnit() {
                  return WEEK_BASED_YEARS;
              }
              @Override
              public TemporalUnit getRangeUnit() {
                  return FOREVER;
              }
              @Override
              public ValueRange range() {
                  return YEAR.range();
              }
              @Override
              public boolean isSupportedBy(TemporalAccessor temporal) {
                  return temporal.isSupported(EPOCH_DAY) && isIso(temporal);
              }
              @Override
              public long getFrom(TemporalAccessor temporal) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: WeekBasedYear");
                  }
                  return getWeekBasedYear(LocalDate.from(temporal));
              }
              @SuppressWarnings("unchecked")
              @Override
              public <R extends Temporal> R adjustInto(R temporal, long newValue) {
                  if (isSupportedBy(temporal) == false) {
                      throw new UnsupportedTemporalTypeException("Unsupported field: WeekBasedYear");
                  }
                  int newWby = range().checkValidIntValue(newValue, WEEK_BASED_YEAR);  // strict check
                  LocalDate date = LocalDate.from(temporal);
                  int dow = date.get(DAY_OF_WEEK);
                  int week = getWeek(date);
                  if (week == 53 && getWeekRange(newWby) == 52) {
                      week = 52;
                  }
                  LocalDate resolved = LocalDate.of(newWby, 1, 4);  // 4th is guaranteed to be in week one
                  int days = (dow - resolved.get(DAY_OF_WEEK)) + ((week - 1) * 7);
                  resolved = resolved.plusDays(days);
                  return (R) temporal.with(resolved);
              }
              @Override
              public String toString() {
                  return "WeekBasedYear";
              }
          };
  
          @Override
          public boolean isDateBased() {
              return true;
          }
  
          @Override
          public boolean isTimeBased() {
              return false;
          }
  
          @Override
          public ValueRange rangeRefinedBy(TemporalAccessor temporal) {
              return range();
          }
  
          //-------------------------------------------------------------------------
          private static final int[] QUARTER_DAYS = {0, 90, 181, 273, 0, 91, 182, 274};
  
          private static boolean isIso(TemporalAccessor temporal) {
              return Chronology.from(temporal).equals(IsoChronology.INSTANCE);
          }
  
          private static void ensureIso(TemporalAccessor temporal) {
              if (isIso(temporal) == false) {
                  throw new DateTimeException("Resolve requires IsoChronology");
              }
          }
  
          private static ValueRange getWeekRange(LocalDate date) {
              int wby = getWeekBasedYear(date);
              return ValueRange.of(1, getWeekRange(wby));
          }
  
          private static int getWeekRange(int wby) {
              LocalDate date = LocalDate.of(wby, 1, 1);
              // 53 weeks if standard year starts on Thursday, or Wed in a leap year
              if (date.getDayOfWeek() == THURSDAY || (date.getDayOfWeek() == WEDNESDAY && date.isLeapYear())) {
                  return 53;
              }
              return 52;
          }
  
          private static int getWeek(LocalDate date) {
              int dow0 = date.getDayOfWeek().ordinal();
              int doy0 = date.getDayOfYear() - 1;
              int doyThu0 = doy0 + (3 - dow0);  // adjust to mid-week Thursday (which is 3 indexed from zero)
              int alignedWeek = doyThu0 / 7;
              int firstThuDoy0 = doyThu0 - (alignedWeek * 7);
              int firstMonDoy0 = firstThuDoy0 - 3;
              if (firstMonDoy0 < -3) {
                  firstMonDoy0 += 7;
              }
              if (doy0 < firstMonDoy0) {
                  return (int) getWeekRange(date.withDayOfYear(180).minusYears(1)).getMaximum();
              }
              int week = ((doy0 - firstMonDoy0) / 7) + 1;
              if (week == 53) {
                  if ((firstMonDoy0 == -3 || (firstMonDoy0 == -2 && date.isLeapYear())) == false) {
                      week = 1;
                  }
              }
              return week;
          }
  
          private static int getWeekBasedYear(LocalDate date) {
              int year = date.getYear();
              int doy = date.getDayOfYear();
              if (doy <= 3) {
                  int dow = date.getDayOfWeek().ordinal();
                  if (doy - dow < -2) {
                      year--;
                  }
              } else if (doy >= 363) {
                  int dow = date.getDayOfWeek().ordinal();
                  doy = doy - 363 - (date.isLeapYear() ? 1 : 0);
                  if (doy - dow >= 0) {
                      year++;
                  }
              }
              return year;
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Implementation of the unit.
       */
      private static enum Unit implements TemporalUnit {
  
          /**
           * Unit that represents the concept of a week-based-year.
           */
          WEEK_BASED_YEARS("WeekBasedYears", Duration.ofSeconds(31556952L)),
          /**
           * Unit that represents the concept of a quarter-year.
           */
          QUARTER_YEARS("QuarterYears", Duration.ofSeconds(31556952L / 4));
  
          private final String name;
          private final Duration duration;
  
          private Unit(String name, Duration estimatedDuration) {
              this.name = name;
              this.duration = estimatedDuration;
          }
  
          @Override
          public Duration getDuration() {
              return duration;
          }
  
          @Override
          public boolean isDurationEstimated() {
              return true;
          }
  
          @Override
          public boolean isDateBased() {
              return true;
          }
  
          @Override
          public boolean isTimeBased() {
              return false;
          }
  
          @Override
          public boolean isSupportedBy(Temporal temporal) {
              return temporal.isSupported(EPOCH_DAY);
          }
  
          @SuppressWarnings("unchecked")
          @Override
          public <R extends Temporal> R addTo(R temporal, long amount) {
              switch (this) {
                  case WEEK_BASED_YEARS:
                      return (R) temporal.with(WEEK_BASED_YEAR,
                              Math.addExact(temporal.get(WEEK_BASED_YEAR), amount));
                  case QUARTER_YEARS:
                      // no overflow (256 is multiple of 4)
                      return (R) temporal.plus(amount / 256, YEARS)
                              .plus((amount % 256) * 3, MONTHS);
                  default:
                      throw new IllegalStateException("Unreachable");
              }
          }
  
          @Override
          public long between(Temporal temporal1Inclusive, Temporal temporal2Exclusive) {
              if (temporal1Inclusive.getClass() != temporal2Exclusive.getClass()) {
                  return temporal1Inclusive.until(temporal2Exclusive, this);
              }
              switch(this) {
                  case WEEK_BASED_YEARS:
                      return Math.subtractExact(temporal2Exclusive.getLong(WEEK_BASED_YEAR),
                              temporal1Inclusive.getLong(WEEK_BASED_YEAR));
                  case QUARTER_YEARS:
                      return temporal1Inclusive.until(temporal2Exclusive, MONTHS) / 3;
                  default:
                      throw new IllegalStateException("Unreachable");
              }
          }
  
          @Override
          public String toString() {
              return name;
          }
      }
  }
  