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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:
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   *    this list of conditions and the following disclaimer.
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  package java.time.chrono;
  
  import static java.time.temporal.ChronoField.EPOCH_DAY;
  import static java.time.temporal.ChronoField.NANO_OF_DAY;
  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.LocalDateTime;
  import java.time.LocalTime;
  import java.time.ZoneId;
  import java.time.ZoneOffset;
  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.zone.ZoneRules;
  import java.util.Comparator;
  import java.util.Objects;
  
  /**
   * A date-time without 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 LocalDateTime}, not this interface.</b>
   * <p>
   * A {@code ChronoLocalDateTime} is the abstract representation of a local 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 LocalDateTime} 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 ChronoLocalDateTime<D extends ChronoLocalDate>
          extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDateTime<?>> {
  
      /**
       * Gets a comparator that compares {@code ChronoLocalDateTime} in
       * time-line order ignoring the chronology.
       * <p>
       * This comparator differs from the comparison in {@link #compareTo} in that it
       * only compares the underlying date-time and not the chronology.
       * This allows dates in different calendar systems to be compared based
       * on the position of the date-time on the local time-line.
       * The underlying comparison is equivalent to comparing the epoch-day and nano-of-day.
       *
       * @return a comparator that compares in time-line order ignoring the chronology
       * @see #isAfter
       * @see #isBefore
       * @see #isEqual
       */
      static Comparator<ChronoLocalDateTime<?>> timeLineOrder() {
          return AbstractChronology.DATE_TIME_ORDER;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code ChronoLocalDateTime} from a temporal object.
       * <p>
       * This obtains a local 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 ChronoLocalDateTime}.
       * <p>
       * The conversion extracts and combines the chronology and the date-time
       * from the temporal object. The behavior is equivalent to using
       * {@link Chronology#localDateTime(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 ChronoLocalDateTime::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 ChronoLocalDateTime}
       * @see Chronology#localDateTime(TemporalAccessor)
       */
      static ChronoLocalDateTime<?> from(TemporalAccessor temporal) {
          if (temporal instanceof ChronoLocalDateTime) {
              return (ChronoLocalDateTime<?>) temporal;
          }
          Objects.requireNonNull(temporal, "temporal");
          Chronology chrono = temporal.query(TemporalQueries.chronology());
          if (chrono == null) {
              throw new DateTimeException("Unable to obtain ChronoLocalDateTime from TemporalAccessor: " + temporal.getClass());
          }
          return chrono.localDateTime(temporal);
      }
  
      //-----------------------------------------------------------------------
      /**
       * 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 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
       */
      D 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
       */
      LocalTime toLocalTime();
  
      /**
       * 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} date and time 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 ChronoLocalDateTime<D> with(TemporalAdjuster adjuster) {
          return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.with(adjuster));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      ChronoLocalDateTime<D> with(TemporalField field, long newValue);
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoLocalDateTime<D> plus(TemporalAmount amount) {
          return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.plus(amount));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      ChronoLocalDateTime<D> plus(long amountToAdd, TemporalUnit unit);
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoLocalDateTime<D> minus(TemporalAmount amount) {
          return ChronoLocalDateTimeImpl.ensureValid(getChronology(), Temporal.super.minus(amount));
      }
  
      /**
       * {@inheritDoc}
       * @throws DateTimeException {@inheritDoc}
       * @throws ArithmeticException {@inheritDoc}
       */
      @Override
      default ChronoLocalDateTime<D> minus(long amountToSubtract, TemporalUnit unit) {
          return ChronoLocalDateTimeImpl.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.zoneId() || query == TemporalQueries.zone() || query == TemporalQueries.offset()) {
              return null;
          } 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);
      }
  
      /**
       * Adjusts the specified temporal object to have the same date and time as this object.
       * <p>
       * This returns a temporal object of the same observable type as the input
       * with the date and time changed to be the same as this.
       * <p>
       * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
       * twice, passing {@link ChronoField#EPOCH_DAY} and
       * {@link ChronoField#NANO_OF_DAY} as the fields.
       * <p>
       * In most cases, it is clearer to reverse the calling pattern by using
       * {@link Temporal#with(TemporalAdjuster)}:
       * <pre>
       *   // these two lines are equivalent, but the second approach is recommended
       *   temporal = thisLocalDateTime.adjustInto(temporal);
       *   temporal = temporal.with(thisLocalDateTime);
       * </pre>
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param temporal  the target object to be adjusted, not null
       * @return the adjusted object, not null
       * @throws DateTimeException if unable to make the adjustment
       * @throws ArithmeticException if numeric overflow occurs
       */
      @Override
      default Temporal adjustInto(Temporal temporal) {
          return temporal
                  .with(EPOCH_DAY, toLocalDate().toEpochDay())
                  .with(NANO_OF_DAY, toLocalTime().toNanoOfDay());
      }
  
      /**
       * 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);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Combines this time with a time-zone to create a {@code ChronoZonedDateTime}.
       * <p>
       * This returns a {@code ChronoZonedDateTime} formed from this date-time at the
       * specified time-zone. The result will match this date-time as closely as possible.
       * Time-zone rules, such as daylight savings, mean that not every local date-time
       * is valid for the specified zone, thus the local date-time may be adjusted.
       * <p>
       * The local date-time is resolved to a single instant on the time-line.
       * This is achieved by finding a valid offset from UTC/Greenwich for the local
       * date-time as defined by the {@link ZoneRules rules} of the zone ID.
       *<p>
       * In most cases, there is only one valid offset for a local date-time.
       * In the case of an overlap, where clocks are set back, there are two valid offsets.
       * This method uses the earlier offset typically corresponding to "summer".
       * <p>
       * In the case of a gap, where clocks jump forward, there is no valid offset.
       * Instead, the local date-time is adjusted to be later by the length of the gap.
       * For a typical one hour daylight savings change, the local date-time will be
       * moved one hour later into the offset typically corresponding to "summer".
       * <p>
       * To obtain the later offset during an overlap, call
       * {@link ChronoZonedDateTime#withLaterOffsetAtOverlap()} on the result of this method.
       *
       * @param zone  the time-zone to use, not null
       * @return the zoned date-time formed from this date-time, not null
       */
      ChronoZonedDateTime<D> atZone(ZoneId zone);
  
      //-----------------------------------------------------------------------
      /**
       * Converts this date-time to an {@code Instant}.
       * <p>
       * This combines this local date-time and the specified offset to form
       * an {@code Instant}.
       * <p>
       * This default implementation calculates from the epoch-day of the date and the
       * second-of-day of the time.
       *
       * @param offset  the offset to use for the conversion, not null
       * @return an {@code Instant} representing the same instant, not null
       */
      default Instant toInstant(ZoneOffset offset) {
          return Instant.ofEpochSecond(toEpochSecond(offset), toLocalTime().getNano());
      }
  
      /**
       * Converts this date-time to the number of seconds from the epoch
       * of 1970-01-01T00:00:00Z.
       * <p>
       * This combines this local date-time and the specified 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.
       * <p>
       * This default implementation calculates from the epoch-day of the date and the
       * second-of-day of the time.
       *
       * @param offset  the offset to use for the conversion, not null
       * @return the number of seconds from the epoch of 1970-01-01T00:00:00Z
       */
      default long toEpochSecond(ZoneOffset offset) {
          Objects.requireNonNull(offset, "offset");
          long epochDay = toLocalDate().toEpochDay();
          long secs = epochDay * 86400 + toLocalTime().toSecondOfDay();
          secs -= offset.getTotalSeconds();
          return secs;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Compares this date-time to another date-time, including the chronology.
       * <p>
       * The comparison is based first on the underlying time-line date-time, then
       * on the chronology.
       * It is "consistent with equals", as defined by {@link Comparable}.
       * <p>
       * For example, the following is the comparator order:
       * <ol>
       * <li>{@code 2012-12-03T12:00 (ISO)}</li>
       * <li>{@code 2012-12-04T12:00 (ISO)}</li>
       * <li>{@code 2555-12-04T12:00 (ThaiBuddhist)}</li>
       * <li>{@code 2012-12-05T12:00 (ISO)}</li>
       * </ol>
       * Values #2 and #3 represent the same date-time on the time-line.
       * When two values represent the same date-time, the chronology ID is compared to distinguish them.
       * This step is needed to make the ordering "consistent with equals".
       * <p>
       * If all the date-time objects being compared are in the same chronology, then the
       * additional chronology stage is not required and only the local date-time is used.
       * <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(ChronoLocalDateTime<?> other) {
          int cmp = toLocalDate().compareTo(other.toLocalDate());
          if (cmp == 0) {
              cmp = toLocalTime().compareTo(other.toLocalTime());
              if (cmp == 0) {
                  cmp = getChronology().compareTo(other.getChronology());
              }
          }
          return cmp;
      }
  
      /**
       * Checks if this date-time is after the specified date-time ignoring the chronology.
       * <p>
       * This method differs from the comparison in {@link #compareTo} in that it
       * only compares the underlying date-time and not the chronology.
       * This allows dates in different calendar systems to be compared based
       * on the time-line position.
       * <p>
       * This default implementation performs the comparison based on the epoch-day
       * and nano-of-day.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if this is after the specified date-time
       */
      default boolean isAfter(ChronoLocalDateTime<?> other) {
          long thisEpDay = this.toLocalDate().toEpochDay();
          long otherEpDay = other.toLocalDate().toEpochDay();
          return thisEpDay > otherEpDay ||
              (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() > other.toLocalTime().toNanoOfDay());
      }
  
      /**
       * Checks if this date-time is before the specified date-time ignoring the chronology.
       * <p>
       * This method differs from the comparison in {@link #compareTo} in that it
       * only compares the underlying date-time and not the chronology.
       * This allows dates in different calendar systems to be compared based
       * on the time-line position.
       * <p>
       * This default implementation performs the comparison based on the epoch-day
       * and nano-of-day.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if this is before the specified date-time
       */
      default boolean isBefore(ChronoLocalDateTime<?> other) {
          long thisEpDay = this.toLocalDate().toEpochDay();
          long otherEpDay = other.toLocalDate().toEpochDay();
          return thisEpDay < otherEpDay ||
              (thisEpDay == otherEpDay && this.toLocalTime().toNanoOfDay() < other.toLocalTime().toNanoOfDay());
      }
  
      /**
       * Checks if this date-time is equal to the specified date-time ignoring the chronology.
       * <p>
       * This method differs from the comparison in {@link #compareTo} in that it
       * only compares the underlying date and time and not the chronology.
       * This allows date-times in different calendar systems to be compared based
       * on the time-line position.
       * <p>
       * This default implementation performs the comparison based on the epoch-day
       * and nano-of-day.
       *
       * @param other  the other date-time to compare to, not null
       * @return true if the underlying date-time is equal to the specified date-time on the timeline
       */
      default boolean isEqual(ChronoLocalDateTime<?> other) {
          // Do the time check first, it is cheaper than computing EPOCH day.
          return this.toLocalTime().toNanoOfDay() == other.toLocalTime().toNanoOfDay() &&
                 this.toLocalDate().toEpochDay() == other.toLocalDate().toEpochDay();
      }
  
      /**
       * Checks if this date-time is equal to another date-time, including the chronology.
       * <p>
       * Compares this date-time with another ensuring that the date-time and chronology are the same.
       *
       * @param obj  the object to check, null returns false
       * @return true if this is equal to the other date
       */
      @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 local date-time.
       *
       * @return a string representation of this date-time, not null
       */
      @Override
      String toString();
  
  }
  