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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() {

    }

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

    /**

     * 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;