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	/*
	* Copyright (c) 2012, 2020, 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
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	* questions.
	*/

	/*
	* 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) 2009-2012, 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
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	* 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.zone;

	import static java.time.temporal.TemporalAdjusters.nextOrSame;
	import static java.time.temporal.TemporalAdjusters.previousOrSame;

	import java.io.DataInput;
	import java.io.DataOutput;
	import java.io.IOException;
	import java.io.InvalidObjectException;
	import java.io.ObjectInputStream;
	import java.io.Serializable;
	import java.time.DayOfWeek;
	import java.time.LocalDate;
	import java.time.LocalDateTime;
	import java.time.LocalTime;
	import java.time.Month;
	import java.time.ZoneOffset;
	import java.time.chrono.IsoChronology;
	import java.util.Objects;

	/**
	* A rule expressing how to create a transition.
	* <p>
	* This class allows rules for identifying future transitions to be expressed.
	* A rule might be written in many forms:
	* <ul>
	* <li>the 16th March
	* <li>the Sunday on or after the 16th March
	* <li>the Sunday on or before the 16th March
	* <li>the last Sunday in February
	* </ul>
	* These different rule types can be expressed and queried.
	*
	* @implSpec
	* This class is immutable and thread-safe.
	*
	* @since 1.8
	*/
	public final class ZoneOffsetTransitionRule implements Serializable {

	/**
	* Serialization version.
	*/
	private static final long serialVersionUID = 6889046316657758795L;

	/**
	* The month of the month-day of the first day of the cutover week.
	* The actual date will be adjusted by the dowChange field.
	*/
	private final Month month;
	/**
	* The day-of-month of the month-day of the cutover week.
	* If positive, it is the start of the week where the cutover can occur.
	* If negative, it represents the end of the week where cutover can occur.
	* The value is the number of days from the end of the month, such that
	* {@code -1} is the last day of the month, {@code -2} is the second
	* to last day, and so on.
	*/
	private final byte dom;
	/**
	* The cutover day-of-week, null to retain the day-of-month.
	*/
	private final DayOfWeek dow;
	/**
	* The cutover time in the 'before' offset.
	*/
	private final LocalTime time;
	/**
	* Whether the cutover time is midnight at the end of day.
	*/
	private final boolean timeEndOfDay;
	/**
	* The definition of how the local time should be interpreted.
	*/
	private final TimeDefinition timeDefinition;
	/**
	* The standard offset at the cutover.
	*/
	private final ZoneOffset standardOffset;
	/**
	* The offset before the cutover.
	*/
	private final ZoneOffset offsetBefore;
	/**
	* The offset after the cutover.
	*/
	private final ZoneOffset offsetAfter;

	/**
	* Obtains an instance defining the yearly rule to create transitions between two offsets.
	* <p>
	* Applications should normally obtain an instance from {@link ZoneRules}.
	* This factory is only intended for use when creating {@link ZoneRules}.
	*
	* @param month the month of the month-day of the first day of the cutover week, not null
	* @param dayOfMonthIndicator the day of the month-day of the cutover week, positive if the week is that
	* day or later, negative if the week is that day or earlier, counting from the last day of the month,
	* from -28 to 31 excluding 0
	* @param dayOfWeek the required day-of-week, null if the month-day should not be changed
	* @param time the cutover time in the 'before' offset, not null
	* @param timeEndOfDay whether the time is midnight at the end of day
	* @param timeDefinition how to interpret the cutover
	* @param standardOffset the standard offset in force at the cutover, not null
	* @param offsetBefore the offset before the cutover, not null
	* @param offsetAfter the offset after the cutover, not null
	* @return the rule, not null
	* @throws IllegalArgumentException if the day of month indicator is invalid
	* @throws IllegalArgumentException if the end of day flag is true when the time is not midnight
	* @throws IllegalArgumentException if {@code time.getNano()} returns non-zero value
	*/
	public static ZoneOffsetTransitionRule of(
	Month month,
	int dayOfMonthIndicator,
	DayOfWeek dayOfWeek,
	LocalTime time,
	boolean timeEndOfDay,
	TimeDefinition timeDefinition,
	ZoneOffset standardOffset,
	ZoneOffset offsetBefore,
	ZoneOffset offsetAfter) {
	Objects.requireNonNull(month, "month");
	Objects.requireNonNull(time, "time");
	Objects.requireNonNull(timeDefinition, "timeDefinition");
	Objects.requireNonNull(standardOffset, "standardOffset");
	Objects.requireNonNull(offsetBefore, "offsetBefore");
	Objects.requireNonNull(offsetAfter, "offsetAfter");
	if (dayOfMonthIndicator < -28 \|\| dayOfMonthIndicator > 31 \|\| dayOfMonthIndicator == 0) {
	throw new IllegalArgumentException("Day of month indicator must be between -28 and 31 inclusive excluding zero");
	}
	if (timeEndOfDay && time.equals(LocalTime.MIDNIGHT) == false) {
	throw new IllegalArgumentException("Time must be midnight when end of day flag is true");
	}
	if (time.getNano() != 0) {
	throw new IllegalArgumentException("Time's nano-of-second must be zero");
	}
	return new ZoneOffsetTransitionRule(month, dayOfMonthIndicator, dayOfWeek, time, timeEndOfDay, timeDefinition, standardOffset, offsetBefore, offsetAfter);
	}

	/**
	* Creates an instance defining the yearly rule to create transitions between two offsets.
	*
	* @param month the month of the month-day of the first day of the cutover week, not null
	* @param dayOfMonthIndicator the day of the month-day of the cutover week, positive if the week is that
	* day or later, negative if the week is that day or earlier, counting from the last day of the month,
	* from -28 to 31 excluding 0
	* @param dayOfWeek the required day-of-week, null if the month-day should not be changed
	* @param time the cutover time in the 'before' offset, not null
	* @param timeEndOfDay whether the time is midnight at the end of day
	* @param timeDefinition how to interpret the cutover
	* @param standardOffset the standard offset in force at the cutover, not null
	* @param offsetBefore the offset before the cutover, not null
	* @param offsetAfter the offset after the cutover, not null
	* @throws IllegalArgumentException if the day of month indicator is invalid
	* @throws IllegalArgumentException if the end of day flag is true when the time is not midnight
	*/
	ZoneOffsetTransitionRule(
	Month month,
	int dayOfMonthIndicator,
	DayOfWeek dayOfWeek,
	LocalTime time,
	boolean timeEndOfDay,
	TimeDefinition timeDefinition,
	ZoneOffset standardOffset,
	ZoneOffset offsetBefore,
	ZoneOffset offsetAfter) {
	assert time.getNano() == 0;
	this.month = month;
	this.dom = (byte) dayOfMonthIndicator;
	this.dow = dayOfWeek;
	this.time = time;
	this.timeEndOfDay = timeEndOfDay;
	this.timeDefinition = timeDefinition;
	this.standardOffset = standardOffset;
	this.offsetBefore = offsetBefore;
	this.offsetAfter = offsetAfter;
	}

	//-----------------------------------------------------------------------
	/**
	* Defend against malicious streams.
	*
	* @param s the stream to read
	* @throws InvalidObjectException always
	*/
	private void readObject(ObjectInputStream s) throws InvalidObjectException {
	throw new InvalidObjectException("Deserialization via serialization delegate");
	}

	/**
	* Writes the object using a
	* <a href="{@docRoot}/serialized-form.html#java.time.zone.Ser">dedicated serialized form</a>.
	* @serialData
	* Refer to the serialized form of
	* <a href="{@docRoot}/serialized-form.html#java.time.zone.ZoneRules">ZoneRules.writeReplace</a>
	* for the encoding of epoch seconds and offsets.
	* <pre style="font-size:1.0em">{@code
	*
	* out.writeByte(3); // identifies a ZoneOffsetTransitionRule
	* final int timeSecs = (timeEndOfDay ? 86400 : time.toSecondOfDay());
	* final int stdOffset = standardOffset.getTotalSeconds();
	* final int beforeDiff = offsetBefore.getTotalSeconds() - stdOffset;
	* final int afterDiff = offsetAfter.getTotalSeconds() - stdOffset;
	* final int timeByte = (timeSecs % 3600 == 0 ? (timeEndOfDay ? 24 : time.getHour()) : 31);
	* final int stdOffsetByte = (stdOffset % 900 == 0 ? stdOffset / 900 + 128 : 255);
	* final int beforeByte = (beforeDiff == 0 \|\| beforeDiff == 1800 \|\| beforeDiff == 3600 ? beforeDiff / 1800 : 3);
	* final int afterByte = (afterDiff == 0 \|\| afterDiff == 1800 \|\| afterDiff == 3600 ? afterDiff / 1800 : 3);
	* final int dowByte = (dow == null ? 0 : dow.getValue());
	* int b = (month.getValue() << 28) + // 4 bits
	* ((dom + 32) << 22) + // 6 bits
	* (dowByte << 19) + // 3 bits
	* (timeByte << 14) + // 5 bits
	* (timeDefinition.ordinal() << 12) + // 2 bits
	* (stdOffsetByte << 4) + // 8 bits
	* (beforeByte << 2) + // 2 bits
	* afterByte; // 2 bits
	* out.writeInt(b);
	* if (timeByte == 31) {
	* out.writeInt(timeSecs);
	* }
	* if (stdOffsetByte == 255) {
	* out.writeInt(stdOffset);
	* }
	* if (beforeByte == 3) {
	* out.writeInt(offsetBefore.getTotalSeconds());
	* }
	* if (afterByte == 3) {
	* out.writeInt(offsetAfter.getTotalSeconds());
	* }
	* }
	* </pre>
	*
	* @return the replacing object, not null
	*/
	private Object writeReplace() {
	return new Ser(Ser.ZOTRULE, this);
	}

	/**
	* Writes the state to the stream.
	*
	* @param out the output stream, not null
	* @throws IOException if an error occurs
	*/
	void writeExternal(DataOutput out) throws IOException {
	final int timeSecs = (timeEndOfDay ? 86400 : time.toSecondOfDay());
	final int stdOffset = standardOffset.getTotalSeconds();
	final int beforeDiff = offsetBefore.getTotalSeconds() - stdOffset;
	final int afterDiff = offsetAfter.getTotalSeconds() - stdOffset;
	final int timeByte = (timeSecs % 3600 == 0 ? (timeEndOfDay ? 24 : time.getHour()) : 31);
	final int stdOffsetByte = (stdOffset % 900 == 0 ? stdOffset / 900 + 128 : 255);
	final int beforeByte = (beforeDiff == 0 \|\| beforeDiff == 1800 \|\| beforeDiff == 3600 ? beforeDiff / 1800 : 3);
	final int afterByte = (afterDiff == 0 \|\| afterDiff == 1800 \|\| afterDiff == 3600 ? afterDiff / 1800 : 3);
	final int dowByte = (dow == null ? 0 : dow.getValue());
	int b = (month.getValue() << 28) + // 4 bits
	((dom + 32) << 22) + // 6 bits
	(dowByte << 19) + // 3 bits
	(timeByte << 14) + // 5 bits
	(timeDefinition.ordinal() << 12) + // 2 bits
	(stdOffsetByte << 4) + // 8 bits
	(beforeByte << 2) + // 2 bits
	afterByte; // 2 bits
	out.writeInt(b);
	if (timeByte == 31) {
	out.writeInt(timeSecs);
	}
	if (stdOffsetByte == 255) {
	out.writeInt(stdOffset);
	}
	if (beforeByte == 3) {
	out.writeInt(offsetBefore.getTotalSeconds());
	}
	if (afterByte == 3) {
	out.writeInt(offsetAfter.getTotalSeconds());
	}
	}

	/**
	* Reads the state from the stream.
	*
	* @param in the input stream, not null
	* @return the created object, not null
	* @throws IOException if an error occurs
	*/
	static ZoneOffsetTransitionRule readExternal(DataInput in) throws IOException {
	int data = in.readInt();
	Month month = Month.of(data >>> 28);
	int dom = ((data & (63 << 22)) >>> 22) - 32;
	int dowByte = (data & (7 << 19)) >>> 19;
	DayOfWeek dow = dowByte == 0 ? null : DayOfWeek.of(dowByte);
	int timeByte = (data & (31 << 14)) >>> 14;
	TimeDefinition defn = TimeDefinition.values()[(data & (3 << 12)) >>> 12];
	int stdByte = (data & (255 << 4)) >>> 4;
	int beforeByte = (data & (3 << 2)) >>> 2;
	int afterByte = (data & 3);
	LocalTime time = (timeByte == 31 ? LocalTime.ofSecondOfDay(in.readInt()) : LocalTime.of(timeByte % 24, 0));
	ZoneOffset std = (stdByte == 255 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds((stdByte - 128) * 900));
	ZoneOffset before = (beforeByte == 3 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(std.getTotalSeconds() + beforeByte * 1800));
	ZoneOffset after = (afterByte == 3 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(std.getTotalSeconds() + afterByte * 1800));
	return ZoneOffsetTransitionRule.of(month, dom, dow, time, timeByte == 24, defn, std, before, after);
	}

	//-----------------------------------------------------------------------
	/**
	* Gets the month of the transition.
	* <p>
	* If the rule defines an exact date then the month is the month of that date.
	* <p>
	* If the rule defines a week where the transition might occur, then the month
	* if the month of either the earliest or latest possible date of the cutover.
	*
	* @return the month of the transition, not null
	*/
	public Month getMonth() {
	return month;
	}

	/**
	* Gets the indicator of the day-of-month of the transition.
	* <p>
	* If the rule defines an exact date then the day is the month of that date.
	* <p>
	* If the rule defines a week where the transition might occur, then the day
	* defines either the start of the end of the transition week.
	* <p>
	* If the value is positive, then it represents a normal day-of-month, and is the
	* earliest possible date that the transition can be.
	* The date may refer to 29th February which should be treated as 1st March in non-leap years.
	* <p>
	* If the value is negative, then it represents the number of days back from the
	* end of the month where {@code -1} is the last day of the month.
	* In this case, the day identified is the latest possible date that the transition can be.
	*
	* @return the day-of-month indicator, from -28 to 31 excluding 0
	*/
	public int getDayOfMonthIndicator() {
	return dom;
	}

	/**
	* Gets the day-of-week of the transition.
	* <p>
	* If the rule defines an exact date then this returns null.
	* <p>
	* If the rule defines a week where the cutover might occur, then this method
	* returns the day-of-week that the month-day will be adjusted to.
	* If the day is positive then the adjustment is later.
	* If the day is negative then the adjustment is earlier.
	*
	* @return the day-of-week that the transition occurs, null if the rule defines an exact date
	*/
	public DayOfWeek getDayOfWeek() {
	return dow;
	}

	/**
	* Gets the local time of day of the transition which must be checked with
	* {@link #isMidnightEndOfDay()}.
	* <p>
	* The time is converted into an instant using the time definition.
	*
	* @return the local time of day of the transition, not null
	*/
	public LocalTime getLocalTime() {
	return time;
	}

	/**
	* Is the transition local time midnight at the end of day.
	* <p>
	* The transition may be represented as occurring at 24:00.
	*
	* @return whether a local time of midnight is at the start or end of the day
	*/
	public boolean isMidnightEndOfDay() {
	return timeEndOfDay;
	}

	/**
	* Gets the time definition, specifying how to convert the time to an instant.
	* <p>
	* The local time can be converted to an instant using the standard offset,
	* the wall offset or UTC.
	*
	* @return the time definition, not null
	*/
	public TimeDefinition getTimeDefinition() {
	return timeDefinition;
	}

	/**
	* Gets the standard offset in force at the transition.
	*
	* @return the standard offset, not null
	*/
	public ZoneOffset getStandardOffset() {
	return standardOffset;
	}

	/**
	* Gets the offset before the transition.
	*
	* @return the offset before, not null
	*/
	public ZoneOffset getOffsetBefore() {
	return offsetBefore;
	}

	/**
	* Gets the offset after the transition.
	*
	* @return the offset after, not null
	*/
	public ZoneOffset getOffsetAfter() {
	return offsetAfter;
	}

	//-----------------------------------------------------------------------
	/**
	* Creates a transition instance for the specified year.
	* <p>
	* Calculations are performed using the ISO-8601 chronology.
	*
	* @param year the year to create a transition for, not null
	* @return the transition instance, not null
	*/
	public ZoneOffsetTransition createTransition(int year) {
	LocalDate date;
	if (dom < 0) {
	date = LocalDate.of(year, month, month.length(IsoChronology.INSTANCE.isLeapYear(year)) + 1 + dom);
	if (dow != null) {
	date = date.with(previousOrSame(dow));
	}
	} else {
	date = LocalDate.of(year, month, dom);
	if (dow != null) {
	date = date.with(nextOrSame(dow));
	}
	}
	if (timeEndOfDay) {
	date = date.plusDays(1);
	}
	LocalDateTime localDT = LocalDateTime.of(date, time);
	LocalDateTime transition = timeDefinition.createDateTime(localDT, standardOffset, offsetBefore);
	return new ZoneOffsetTransition(transition, offsetBefore, offsetAfter);
	}

	//-----------------------------------------------------------------------
	/**
	* Checks if this object equals another.
	* <p>
	* The entire state of the object is compared.
	*
	* @param otherRule the other object to compare to, null returns false
	* @return true if equal
	*/
	@Override
	public boolean equals(Object otherRule) {
	if (otherRule == this) {
	return true;
	}
	return (otherRule instanceof ZoneOffsetTransitionRule other)
	&& month == other.month
	&& dom == other.dom
	&& dow == other.dow
	&& timeDefinition == other.timeDefinition
	&& timeEndOfDay == other.timeEndOfDay
	&& time.equals(other.time)
	&& standardOffset.equals(other.standardOffset)
	&& offsetBefore.equals(other.offsetBefore)
	&& offsetAfter.equals(other.offsetAfter);
	}

	/**
	* Returns a suitable hash code.
	*
	* @return the hash code
	*/
	@Override
	public int hashCode() {
	int hash = ((time.toSecondOfDay() + (timeEndOfDay ? 1 : 0)) << 15) +
	(month.ordinal() << 11) + ((dom + 32) << 5) +
	((dow == null ? 7 : dow.ordinal()) << 2) + (timeDefinition.ordinal());
	return hash ^ standardOffset.hashCode() ^
	offsetBefore.hashCode() ^ offsetAfter.hashCode();
	}

	//-----------------------------------------------------------------------
	/**
	* Returns a string describing this object.
	*
	* @return a string for debugging, not null
	*/
	@Override
	public String toString() {
	StringBuilder buf = new StringBuilder();
	buf.append("TransitionRule[")
	.append(offsetBefore.compareTo(offsetAfter) > 0 ? "Gap " : "Overlap ")
	.append(offsetBefore).append(" to ").append(offsetAfter).append(", ");
	if (dow != null) {
	if (dom == -1) {
	buf.append(dow.name()).append(" on or before last day of ").append(month.name());
	} else if (dom < 0) {
	buf.append(dow.name()).append(" on or before last day minus ").append(-dom - 1).append(" of ").append(month.name());
	} else {
	buf.append(dow.name()).append(" on or after ").append(month.name()).append(' ').append(dom);
	}
	} else {
	buf.append(month.name()).append(' ').append(dom);
	}
	buf.append(" at ").append(timeEndOfDay ? "24:00" : time.toString())
	.append(" ").append(timeDefinition)
	.append(", standard offset ").append(standardOffset)
	.append(']');
	return buf.toString();
	}

	//-----------------------------------------------------------------------
	/**
	* A definition of the way a local time can be converted to the actual
	* transition date-time.
	* <p>
	* Time zone rules are expressed in one of three ways:
	* <ul>
	* <li>Relative to UTC</li>
	* <li>Relative to the standard offset in force</li>
	* <li>Relative to the wall offset (what you would see on a clock on the wall)</li>
	* </ul>
	*/
	public static enum TimeDefinition {
	/** The local date-time is expressed in terms of the UTC offset. */
	UTC,
	/** The local date-time is expressed in terms of the wall offset. */
	WALL,
	/** The local date-time is expressed in terms of the standard offset. */
	STANDARD;

	/**
	* Converts the specified local date-time to the local date-time actually
	* seen on a wall clock.
	* <p>
	* This method converts using the type of this enum.
	* The output is defined relative to the 'before' offset of the transition.
	* <p>
	* The UTC type uses the UTC offset.
	* The STANDARD type uses the standard offset.
	* The WALL type returns the input date-time.
	* The result is intended for use with the wall-offset.
	*
	* @param dateTime the local date-time, not null
	* @param standardOffset the standard offset, not null
	* @param wallOffset the wall offset, not null
	* @return the date-time relative to the wall/before offset, not null
	*/
	public LocalDateTime createDateTime(LocalDateTime dateTime, ZoneOffset standardOffset, ZoneOffset wallOffset) {
	switch (this) {
	case UTC: {
	int difference = wallOffset.getTotalSeconds() - ZoneOffset.UTC.getTotalSeconds();
	return dateTime.plusSeconds(difference);
	}
	case STANDARD: {
	int difference = wallOffset.getTotalSeconds() - standardOffset.getTotalSeconds();
	return dateTime.plusSeconds(difference);
	}
	default: // WALL
	return dateTime;
	}
	}
	}

	}

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