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   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   * 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
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  /*
   * This file is available under and governed by the GNU General Public
   * License version 2 only, as published by the Free Software Foundation.
   * However, the following notice accompanied the original version of this
   * file:
   *
   * Copyright (c) 2007-2012, 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.
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   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
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   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
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   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package java.time.chrono;
  
  import static java.time.temporal.ChronoField.INSTANT_SECONDS;
  import static java.time.temporal.ChronoField.OFFSET_SECONDS;
  import static java.time.temporal.ChronoUnit.FOREVER;
  import static java.time.temporal.ChronoUnit.NANOS;
  
  import java.time.DateTimeException;
  import java.time.Instant;
  import java.time.LocalTime;
  import java.time.ZoneId;
  import java.time.ZoneOffset;
  import java.time.ZonedDateTime;
  import java.time.format.DateTimeFormatter;
  import java.time.temporal.ChronoField;
  import java.time.temporal.ChronoUnit;
  import java.time.temporal.Temporal;
  import java.time.temporal.TemporalAccessor;
  import java.time.temporal.TemporalAdjuster;
  import java.time.temporal.TemporalAmount;
  import java.time.temporal.TemporalField;
  import java.time.temporal.TemporalQueries;
  import java.time.temporal.TemporalQuery;
  import java.time.temporal.TemporalUnit;
  import java.time.temporal.UnsupportedTemporalTypeException;
  import java.time.temporal.ValueRange;
  import java.util.Comparator;
  import java.util.Objects;
  
  /**
   * A date-time with a time-zone in an arbitrary chronology,
   * intended for advanced globalization use cases.
   * <p>
   * <b>Most applications should declare method signatures, fields and variables
   * as {@link ZonedDateTime}, not this interface.</b>
   * <p>
   * A {@code ChronoZonedDateTime} is the abstract representation of an offset date-time
   * where the {@code Chronology chronology}, or calendar system, is pluggable.
   * The date-time is defined in terms of fields expressed by {@link TemporalField},
   * where most common implementations are defined in {@link ChronoField}.
   * The chronology defines how the calendar system operates and the meaning of
   * the standard fields.
   *
   * <h3>When to use this interface</h3>
   * The design of the API encourages the use of {@code ZonedDateTime} rather than this
   * interface, even in the case where the application needs to deal with multiple
   * calendar systems. The rationale for this is explored in detail in {@link ChronoLocalDate}.
   * <p>
   * Ensure that the discussion in {@code ChronoLocalDate} has been read and understood
   * before using this interface.
   *
   * @implSpec
   * This interface must be implemented with care to ensure other classes operate correctly.
   * All implementations that can be instantiated must be final, immutable and thread-safe.
   * Subclasses should be Serializable wherever possible.
   *
   * @param <D> the concrete type for the date of this date-time
   * @since 1.8
   */
  public interface ChronoZonedDateTime<D extends ChronoLocalDate>
          extends Temporal, Comparable<ChronoZonedDateTime<?>> {
  
      /**
       * Gets a comparator that compares {@code ChronoZonedDateTime} in
       * time-line order ignoring the chronology.
       * <p>
       * This comparator differs from the comparison in {@link #compareTo} in that it
       * only compares the underlying instant and not the chronology.
       * This allows dates in different calendar systems to be compared based
       * on the position of the date-time on the instant time-line.
       * The underlying comparison is equivalent to comparing the epoch-second and nano-of-second.
       *
       * @return a comparator that compares in time-line order ignoring the chronology
       * @see #isAfter
       * @see #isBefore
       * @see #isEqual
       */
      static Comparator<ChronoZonedDateTime<?>> timeLineOrder() {
          return AbstractChronology.INSTANT_ORDER;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code ChronoZonedDateTime} from a temporal object.
       * <p>
       * This creates a zoned date-time based on the specified temporal.
       * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
       * which this factory converts to an instance of {@code ChronoZonedDateTime}.
       * <p>
       * The conversion extracts and combines the chronology, date, time and zone
       * from the temporal object. The behavior is equivalent to using
       * {@link Chronology#zonedDateTime(TemporalAccessor)} with the extracted chronology.
       * Implementations are permitted to perform optimizations such as accessing
       * those fields that are equivalent to the relevant objects.
       * <p>
       * This method matches the signature of the functional interface {@link TemporalQuery}
       * allowing it to be used as a query via method reference, {@code ChronoZonedDateTime::from}.
       *
       * @param temporal  the temporal object to convert, not null
       * @return the date-time, not null
       * @throws DateTimeException if unable to convert to a {@code ChronoZonedDateTime}
       * @see Chronology#zonedDateTime(TemporalAccessor)
       */
      static ChronoZonedDateTime<?> from(TemporalAccessor temporal) {
          if (temporal instanceof ChronoZonedDateTime) {
              return (ChronoZonedDateTime<?>) temporal;
          }
          Objects.requireNonNull(temporal, "temporal");
          Chronology chrono = temporal.query(TemporalQueries.chronology());
          if (chrono == null) {
              throw new DateTimeException("Unable to obtain ChronoZonedDateTime from TemporalAccessor: " + temporal.getClass());
          }
          return chrono.zonedDateTime(temporal);
      }
  
      //-----------------------------------------------------------------------
      @Override
      default ValueRange range(TemporalField field) {
          if (field instanceof ChronoField) {
              if (field == INSTANT_SECONDS || field == OFFSET_SECONDS) {
                  return field.range();
              }
              return toLocalDateTime().range(field);
          }
          return field.rangeRefinedBy(this);
      }
  
      @Override
      default int get(TemporalField field) {
          if (field instanceof ChronoField) {
              switch ((ChronoField) field) {
                  case INSTANT_SECONDS:
                      throw new UnsupportedTemporalTypeException("Invalid field 'InstantSeconds' for get() method, use getLong() instead");
                  case OFFSET_SECONDS:
                      return getOffset().getTotalSeconds();
              }
              return toLocalDateTime().get(field);
          }
          return Temporal.super.get(field);
      }
  
      @Override
      default long getLong(TemporalField field) {
          if (field instanceof ChronoField) {
              switch ((ChronoField) field) {
                  case INSTANT_SECONDS: return toEpochSecond();
                  case OFFSET_SECONDS: return getOffset().getTotalSeconds();
              }
              return toLocalDateTime().getLong(field);
          }
          return field.getFrom(this);
      }
  
      /**
       * Gets the local date part of this date-time.
       * <p>
       * This returns a local date with the same year, month and day
       * as this date-time.
       *
       * @return the date part of this date-time, not null
       */
      default D toLocalDate() {
          return toLocalDateTime().toLocalDate();
      }
  
      /**
       * Gets the local time part of this date-time.
       * <p>
       * This returns a local time with the same hour, minute, second and
       * nanosecond as this date-time.
       *
       * @return the time part of this date-time, not null
       */
      default LocalTime toLocalTime() {
          return toLocalDateTime().toLocalTime();
      }
  
      /**
       * Gets the local date-time part of this date-time.
       * <p>
       * This returns a local date with the same year, month and day
       * as this date-time.
       *
       * @return the local date-time part of this date-time, not null
       */
      ChronoLocalDateTime<D> toLocalDateTime();
  
      /**
       * Gets the chronology of this date-time.
       * <p>
       * The {@code Chronology} represents the calendar system in use.
       * The era and other fields in {@link ChronoField} are defined by the chronology.
       *
       * @return the chronology, not null
       */
      default Chronology getChronology() {
          return toLocalDate().getChronology();
      }
  
      /**
       * Gets the zone offset, such as '+01:00'.
       * <p>
       * This is the offset of the local date-time from UTC/Greenwich.
       *
       * @return the zone offset, not null
       */
      ZoneOffset getOffset();
  
      /**
       * Gets the zone ID, such as 'Europe/Paris'.
       * <p>
       * This returns the stored time-zone id used to determine the time-zone rules.
       *
       * @return the zone ID, not null
       */
      ZoneId getZone();
  
      //-----------------------------------------------------------------------
      /**
       * Returns a copy of this date-time changing the zone offset to the
       * earlier of the two valid offsets at a local time-line overlap.
       * <p>
       * This method only has any effect when the local time-line overlaps, such as
       * at an autumn daylight savings cutover. In this scenario, there are two
       * valid offsets for the local date-time. Calling this method will return
       * a zoned date-time with the earlier of the two selected.
       * <p>
       * If this method is called when it is not an overlap, {@code this}
       * is returned.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @return a {@code ChronoZonedDateTime} based on this date-time with the earlier offset, not null
       * @throws DateTimeException if no rules can be found for the zone
       * @throws DateTimeException if no rules are valid for this date-time
       */
      ChronoZonedDateTime<D> withEarlierOffsetAtOverlap();
  
      /**
       * Returns a copy of this date-time changing the zone offset to the
       * later of the two valid offsets at a local time-line overlap.
       * <p>
       * This method only has any effect when the local time-line overlaps, such as
       * at an autumn daylight savings cutover. In this scenario, there are two
       * valid offsets for the local date-time. Calling this method will return
       * a zoned date-time with the later of the two selected.
       * <p>
       * If this method is called when it is not an overlap, {@code this}
       * is returned.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @return a {@code ChronoZonedDateTime} based on this date-time with the later offset, not null
       * @throws DateTimeException if no rules can be found for the zone
       * @throws DateTimeException if no rules are valid for this date-time
       */
      ChronoZonedDateTime<D> withLaterOffsetAtOverlap();
  
      /**
       * Returns a copy of this date-time with a different time-zone,
       * retaining the local date-time if possible.
       * <p>
       * This method changes the time-zone and retains the local date-time.
       * The local date-time is only changed if it is invalid for the new zone.
       * <p>
       * To change the zone and adjust the local date-time,
       * use {@link #withZoneSameInstant(ZoneId)}.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param zone  the time-zone to change to, not null
       * @return a {@code ChronoZonedDateTime} based on this date-time with the requested zone, not null
       */
      ChronoZonedDateTime<D> withZoneSameLocal(ZoneId zone);
  
      /**
       * Returns a copy of this date-time with a different time-zone,
       * retaining the instant.
       * <p>
       * This method changes the time-zone and retains the instant.
       * This normally results in a change to the local date-time.
       * <p>
       * This method is based on retaining the same instant, thus gaps and overlaps
       * in the local time-line have no effect on the result.
       * <p>
       * To change the offset while keeping the local time,
       * use {@link #withZoneSameLocal(ZoneId)}.
       *
       * @param zone  the time-zone to change to, not null
       * @return a {@code ChronoZonedDateTime} based on this date-time with the requested zone, not null
       * @throws DateTimeException if the result exceeds the supported date range
       */
      ChronoZonedDateTime<D> withZoneSameInstant(ZoneId zone);
  
      /**
       * Checks if the specified field is supported.
       * <p>
       * This checks if the specified field can be queried on this date-time.
       * If false, then calling the {@link #range(TemporalField) range},
       * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
       * methods will throw an exception.
       * <p>
       * The set of supported fields is defined by the chronology and normally includes
       * all {@code ChronoField} fields.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
       * passing {@code this} as the argument.
       * Whether the field is supported is determined by the field.
       *
       * @param field  the field to check, null returns false
       * @return true if the field can be queried, false if not
       */
      @Override
      boolean isSupported(TemporalField field);
  
      /**
       * Checks if the specified unit is supported.
       * <p>
       * This checks if the specified unit can be added to or subtracted from this date-time.
       * If false, then calling the {@link #plus(long, TemporalUnit)} and
       * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
       * <p>
       * The set of supported units is defined by the chronology and normally includes
       * all {@code ChronoUnit} units except {@code FOREVER}.
       * <p>
       * If the unit is not a {@code ChronoUnit}, then the result of this method
       * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
       * passing {@code this} as the argument.
       * Whether the unit is supported is determined by the unit.
       *
       * @param unit  the unit to check, null returns false
       * @return true if the unit can be added/subtracted, false if not
       */
      @Override
      default boolean isSupported(TemporalUnit unit) {
          if (unit instanceof ChronoUnit) {
              return unit != FOREVER;
          }
          return unit != null && unit.isSupportedBy(this);
      }
  
      //-----------------------------------------------------------------------
      // override for covariant return type
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoZonedDateTime<D> with(TemporalAdjuster adjuster) {
          return ChronoZonedDateTimeImpl.ensureValid(getChronology(), Temporal.super.with(adjuster));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      ChronoZonedDateTime<D> with(TemporalField field, long newValue);
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoZonedDateTime<D> plus(TemporalAmount amount) {
          return ChronoZonedDateTimeImpl.ensureValid(getChronology(), Temporal.super.plus(amount));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      ChronoZonedDateTime<D> plus(long amountToAdd, TemporalUnit unit);
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoZonedDateTime<D> minus(TemporalAmount amount) {
          return ChronoZonedDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amount));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoZonedDateTime<D> minus(long amountToSubtract, TemporalUnit unit) {
          return ChronoZonedDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amountToSubtract, unit));
      }
  
      //-----------------------------------------------------------------------
      /**
       * Queries this date-time using the specified query.
       * <p>
       * This queries this date-time using the specified query strategy object.
       * The {@code TemporalQuery} object defines the logic to be used to
       * obtain the result. Read the documentation of the query to understand
       * what the result of this method will be.
       * <p>
       * The result of this method is obtained by invoking the
       * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
       * specified query passing {@code this} as the argument.
       *
       * @param <R> the type of the result
       * @param query  the query to invoke, not null
       * @return the query result, null may be returned (defined by the query)
       * @throws DateTimeException if unable to query (defined by the query)
       * @throws ArithmeticException if numeric overflow occurs (defined by the query)
       */
      @SuppressWarnings("unchecked")
      @Override
      default <R> R query(TemporalQuery<R> query) {
          if (query == TemporalQueries.zone() || query == TemporalQueries.zoneId()) {
              return (R) getZone();
          } else if (query == TemporalQueries.offset()) {
              return (R) getOffset();
          } else if (query == TemporalQueries.localTime()) {
              return (R) toLocalTime();
          } else if (query == TemporalQueries.chronology()) {
              return (R) getChronology();
          } else if (query == TemporalQueries.precision()) {
              return (R) NANOS;
          }
          // inline TemporalAccessor.super.query(query) as an optimization
          // non-JDK classes are not permitted to make this optimization
          return query.queryFrom(this);
      }
  
      /**
       * Formats this date-time using the specified formatter.
       * <p>
       * This date-time will be passed to the formatter to produce a string.
       * <p>
       * The default implementation must behave as follows:
       * <pre>
       *  return formatter.format(this);
       * </pre>
       *
       * @param formatter  the formatter to use, not null
       * @return the formatted date-time string, not null
       * @throws DateTimeException if an error occurs during printing
       */
      default String format(DateTimeFormatter formatter) {
          Objects.requireNonNull(formatter, "formatter");
          return formatter.format(this);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Converts this date-time to an {@code Instant}.
       * <p>
       * This returns an {@code Instant} representing the same point on the
       * time-line as this date-time. The calculation combines the
       * {@linkplain #toLocalDateTime() local date-time} and
       * {@linkplain #getOffset() offset}.
       *
       * @return an {@code Instant} representing the same instant, not null
       */
      default Instant toInstant() {
          return Instant.ofEpochSecond(toEpochSecond(), toLocalTime().getNano());
      }
  
      /**
       * Converts this date-time to the number of seconds from the epoch
       * of 1970-01-01T00:00:00Z.
       * <p>
       * This uses the {@linkplain #toLocalDateTime() local date-time} and
       * {@linkplain #getOffset() offset} to calculate the epoch-second value,
       * which is the number of elapsed seconds from 1970-01-01T00:00:00Z.
       * Instants on the time-line after the epoch are positive, earlier are negative.
       *
       * @return the number of seconds from the epoch of 1970-01-01T00:00:00Z
       */
      default long toEpochSecond() {
          long epochDay = toLocalDate().toEpochDay();
          long secs = epochDay * 86400 + toLocalTime().toSecondOfDay();
          secs -= getOffset().getTotalSeconds();
          return secs;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Compares this date-time to another date-time, including the chronology.
       * <p>
       * The comparison is based first on the instant, then on the local date-time,
       * then on the zone ID, then on the chronology.
       * It is "consistent with equals", as defined by {@link Comparable}.
       * <p>
       * If all the date-time objects being compared are in the same chronology, then the
       * additional chronology stage is not required.
       * <p>
       * This default implementation performs the comparison defined above.
       *
       * @param other  the other date-time to compare to, not null
       * @return the comparator value, negative if less, positive if greater
       */
      @Override
      default int compareTo(ChronoZonedDateTime<?> other) {
          int cmp = Long.compare(toEpochSecond(), other.toEpochSecond());
          if (cmp == 0) {
              cmp = toLocalTime().getNano() - other.toLocalTime().getNano();
              if (cmp == 0) {
                  cmp = toLocalDateTime().compareTo(other.toLocalDateTime());
                  if (cmp == 0) {
                      cmp = getZone().getId().compareTo(other.getZone().getId());
                      if (cmp == 0) {
                          cmp = getChronology().compareTo(other.getChronology());
                      }
                  }
              }
          }
          return cmp;
      }
  
      /**
       * Checks if the instant of this date-time is before that of the specified date-time.
       * <p>
       * This method differs from the comparison in {@link #compareTo} in that it
       * only compares the instant of the date-time. This is equivalent to using
       * {@code dateTime1.toInstant().isBefore(dateTime2.toInstant());}.
       * <p>
       * This default implementation performs the comparison based on the epoch-second
       * and nano-of-second.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if this point is before the specified date-time
       */
      default boolean isBefore(ChronoZonedDateTime<?> other) {
          long thisEpochSec = toEpochSecond();
          long otherEpochSec = other.toEpochSecond();
          return thisEpochSec < otherEpochSec ||
              (thisEpochSec == otherEpochSec && toLocalTime().getNano() < other.toLocalTime().getNano());
      }
  
      /**
       * Checks if the instant of this date-time is after that of the specified date-time.
       * <p>
       * This method differs from the comparison in {@link #compareTo} in that it
       * only compares the instant of the date-time. This is equivalent to using
       * {@code dateTime1.toInstant().isAfter(dateTime2.toInstant());}.
       * <p>
       * This default implementation performs the comparison based on the epoch-second
       * and nano-of-second.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if this is after the specified date-time
       */
      default boolean isAfter(ChronoZonedDateTime<?> other) {
          long thisEpochSec = toEpochSecond();
          long otherEpochSec = other.toEpochSecond();
          return thisEpochSec > otherEpochSec ||
              (thisEpochSec == otherEpochSec && toLocalTime().getNano() > other.toLocalTime().getNano());
      }
  
      /**
       * Checks if the instant of this date-time is equal to that of the specified date-time.
       * <p>
       * This method differs from the comparison in {@link #compareTo} and {@link #equals}
       * in that it only compares the instant of the date-time. This is equivalent to using
       * {@code dateTime1.toInstant().equals(dateTime2.toInstant());}.
       * <p>
       * This default implementation performs the comparison based on the epoch-second
       * and nano-of-second.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if the instant equals the instant of the specified date-time
       */
      default boolean isEqual(ChronoZonedDateTime<?> other) {
          return toEpochSecond() == other.toEpochSecond() &&
                  toLocalTime().getNano() == other.toLocalTime().getNano();
      }
  
      //-----------------------------------------------------------------------
      /**
       * Checks if this date-time is equal to another date-time.
       * <p>
       * The comparison is based on the offset date-time and the zone.
       * To compare for the same instant on the time-line, use {@link #compareTo}.
       * Only objects of type {@code ChronoZonedDateTime} are compared, other types return false.
       *
       * @param obj  the object to check, null returns false
       * @return true if this is equal to the other date-time
       */
      @Override
      boolean equals(Object obj);
  
      /**
       * A hash code for this date-time.
       *
       * @return a suitable hash code
       */
      @Override
      int hashCode();
  
      //-----------------------------------------------------------------------
      /**
       * Outputs this date-time as a {@code String}.
       * <p>
       * The output will include the full zoned date-time.
       *
       * @return a string representation of this date-time, not null
       */
      @Override
      String toString();
  
  }
  