/*

 * Copyright (c) 1996, 2019, 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,

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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/*

 * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved

 * (C) Copyright IBM Corp. 1996 - All Rights Reserved

 *

 *   The original version of this source code and documentation is copyrighted

 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These

 * materials are provided under terms of a License Agreement between Taligent

 * and Sun. This technology is protected by multiple US and International

 * patents. This notice and attribution to Taligent may not be removed.

 *   Taligent is a registered trademark of Taligent, Inc.

 *

 */

package java.util;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.IOException;

import java.io.InvalidObjectException;

import sun.util.calendar.CalendarSystem;

import sun.util.calendar.CalendarUtils;

import sun.util.calendar.BaseCalendar;

import sun.util.calendar.Gregorian;

/**

 * {@code SimpleTimeZone} is a concrete subclass of {@code TimeZone}

 * that represents a time zone for use with a Gregorian calendar.

 * The class holds an offset from GMT, called <em>raw offset</em>, and start

 * and end rules for a daylight saving time schedule.  Since it only holds

 * single values for each, it cannot handle historical changes in the offset

 * from GMT and the daylight saving schedule, except that the {@link

 * #setStartYear setStartYear} method can specify the year when the daylight

 * saving time schedule starts in effect.

 * <p>

 * To construct a {@code SimpleTimeZone} with a daylight saving time

 * schedule, the schedule can be described with a set of rules,

 * <em>start-rule</em> and <em>end-rule</em>. A day when daylight saving time

 * starts or ends is specified by a combination of <em>month</em>,

 * <em>day-of-month</em>, and <em>day-of-week</em> values. The <em>month</em>

 * value is represented by a Calendar {@link Calendar#MONTH MONTH} field

 * value, such as {@link Calendar#MARCH}. The <em>day-of-week</em> value is

 * represented by a Calendar {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} value,

 * such as {@link Calendar#SUNDAY SUNDAY}. The meanings of value combinations

 * are as follows.

 *

 * <ul>

 * <li><b>Exact day of month</b><br>

 * To specify an exact day of month, set the <em>month</em> and

 * <em>day-of-month</em> to an exact value, and <em>day-of-week</em> to zero. For

 * example, to specify March 1, set the <em>month</em> to {@link Calendar#MARCH

 * MARCH}, <em>day-of-month</em> to 1, and <em>day-of-week</em> to 0.</li>

 *

 * <li><b>Day of week on or after day of month</b><br>

 * To specify a day of week on or after an exact day of month, set the

 * <em>month</em> to an exact month value, <em>day-of-month</em> to the day on

 * or after which the rule is applied, and <em>day-of-week</em> to a negative {@link

 * Calendar#DAY_OF_WEEK DAY_OF_WEEK} field value. For example, to specify the

 * second Sunday of April, set <em>month</em> to {@link Calendar#APRIL APRIL},

 * <em>day-of-month</em> to 8, and <em>day-of-week</em> to {@code -}{@link

 * Calendar#SUNDAY SUNDAY}.</li>

 *

 * <li><b>Day of week on or before day of month</b><br>

 * To specify a day of the week on or before an exact day of the month, set

 * <em>day-of-month</em> and <em>day-of-week</em> to a negative value. For

 * example, to specify the last Wednesday on or before the 21st of March, set

 * <em>month</em> to {@link Calendar#MARCH MARCH}, <em>day-of-month</em> is -21

 * and <em>day-of-week</em> is {@code -}{@link Calendar#WEDNESDAY WEDNESDAY}. </li>

 *

 * <li><b>Last day-of-week of month</b><br>

 * To specify, the last day-of-week of the month, set <em>day-of-week</em> to a

 * {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} value and <em>day-of-month</em> to

 * -1. For example, to specify the last Sunday of October, set <em>month</em>

 * to {@link Calendar#OCTOBER OCTOBER}, <em>day-of-week</em> to {@link

 * Calendar#SUNDAY SUNDAY} and <em>day-of-month</em> to -1.  </li>

 *

 * </ul>

 * The time of the day at which daylight saving time starts or ends is

 * specified by a millisecond value within the day. There are three kinds of

 * <em>mode</em>s to specify the time: {@link #WALL_TIME}, {@link

 * #STANDARD_TIME} and {@link #UTC_TIME}. For example, if daylight

 * saving time ends

 * at 2:00 am in the wall clock time, it can be specified by 7200000

 * milliseconds in the {@link #WALL_TIME} mode. In this case, the wall clock time

 * for an <em>end-rule</em> means the same thing as the daylight time.

 * <p>

 * The following are examples of parameters for constructing time zone objects.

 * <pre><code>

 *      // Base GMT offset: -8:00

 *      // DST starts:      at 2:00am in standard time

 *      //                  on the first Sunday in April

 *      // DST ends:        at 2:00am in daylight time

 *      //                  on the last Sunday in October

 *      // Save:            1 hour

 *      SimpleTimeZone(-28800000,

 *                     "America/Los_Angeles",

 *                     Calendar.APRIL, 1, -Calendar.SUNDAY,

 *                     7200000,

 *                     Calendar.OCTOBER, -1, Calendar.SUNDAY,

 *                     7200000,

 *                     3600000)

 *

 *      // Base GMT offset: +1:00

 *      // DST starts:      at 1:00am in UTC time

 *      //                  on the last Sunday in March

 *      // DST ends:        at 1:00am in UTC time

 *      //                  on the last Sunday in October

 *      // Save:            1 hour

 *      SimpleTimeZone(3600000,

 *                     "Europe/Paris",

 *                     Calendar.MARCH, -1, Calendar.SUNDAY,

 *                     3600000, SimpleTimeZone.UTC_TIME,

 *                     Calendar.OCTOBER, -1, Calendar.SUNDAY,

 *                     3600000, SimpleTimeZone.UTC_TIME,

 *                     3600000)

 * </code></pre>

 * These parameter rules are also applicable to the set rule methods, such as

 * {@code setStartRule}.

 *

 * @since 1.1

 * @see      Calendar

 * @see      GregorianCalendar

 * @see      TimeZone

 * @author   David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu

 */

public class SimpleTimeZone extends TimeZone {

    /**

     * Constructs a SimpleTimeZone with the given base time zone offset from GMT

     * and time zone ID with no daylight saving time schedule.

     *

     * @param rawOffset  The base time zone offset in milliseconds to GMT.

     * @param ID         The time zone name that is given to this instance.

     */

    public SimpleTimeZone(int rawOffset, String ID)

    {

        this.rawOffset = rawOffset;

        setID (ID);

        dstSavings = millisPerHour; // In case user sets rules later

    }

    /**

     * Constructs a SimpleTimeZone with the given base time zone offset from

     * GMT, time zone ID, and rules for starting and ending the daylight

     * time.

     * Both {@code startTime} and {@code endTime} are specified to be

     * represented in the wall clock time. The amount of daylight saving is

     * assumed to be 3600000 milliseconds (i.e., one hour). This constructor is

     * equivalent to:

     * <pre><code>

     *     SimpleTimeZone(rawOffset,

     *                    ID,

     *                    startMonth,

     *                    startDay,

     *                    startDayOfWeek,

     *                    startTime,

     *                    SimpleTimeZone.{@link #WALL_TIME},

     *                    endMonth,

     *                    endDay,

     *                    endDayOfWeek,

     *                    endTime,

     *                    SimpleTimeZone.{@link #WALL_TIME},

     *                    3600000)

     * </code></pre>

     *

     * @param rawOffset       The given base time zone offset from GMT.

     * @param ID              The time zone ID which is given to this object.

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field value (0-based. e.g., 0

     *                        for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     *                        See the class description for the special cases of this parameter.

     * @param startDayOfWeek  The daylight saving time starting day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param startTime       The daylight saving time starting time in local wall clock

     *                        time (in milliseconds within the day), which is local

     *                        standard time in this case.

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     *                        See the class description for the special cases of this parameter.

     * @param endDayOfWeek    The daylight saving time ending day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param endTime         The daylight saving ending time in local wall clock time,

     *                        (in milliseconds within the day) which is local daylight

     *                        time in this case.

     * @throws    IllegalArgumentException if the month, day, dayOfWeek, or time

     * parameters are out of range for the start or end rule

     */

    public SimpleTimeZone(int rawOffset, String ID,

                          int startMonth, int startDay, int startDayOfWeek, int startTime,

                          int endMonth, int endDay, int endDayOfWeek, int endTime)

    {

        this(rawOffset, ID,

             startMonth, startDay, startDayOfWeek, startTime, WALL_TIME,

             endMonth, endDay, endDayOfWeek, endTime, WALL_TIME,

             millisPerHour);

    }

    /**

     * Constructs a SimpleTimeZone with the given base time zone offset from

     * GMT, time zone ID, and rules for starting and ending the daylight

     * time.

     * Both {@code startTime} and {@code endTime} are assumed to be

     * represented in the wall clock time. This constructor is equivalent to:

     * <pre><code>

     *     SimpleTimeZone(rawOffset,

     *                    ID,

     *                    startMonth,

     *                    startDay,

     *                    startDayOfWeek,

     *                    startTime,

     *                    SimpleTimeZone.{@link #WALL_TIME},

     *                    endMonth,

     *                    endDay,

     *                    endDayOfWeek,

     *                    endTime,

     *                    SimpleTimeZone.{@link #WALL_TIME},

     *                    dstSavings)

     * </code></pre>

     *

     * @param rawOffset       The given base time zone offset from GMT.

     * @param ID              The time zone ID which is given to this object.

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 0 for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     *                        See the class description for the special cases of this parameter.

     * @param startDayOfWeek  The daylight saving time starting day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param startTime       The daylight saving time starting time in local wall clock

     *                        time, which is local standard time in this case.

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     *                        See the class description for the special cases of this parameter.

     * @param endDayOfWeek    The daylight saving time ending day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param endTime         The daylight saving ending time in local wall clock time,

     *                        which is local daylight time in this case.

     * @param dstSavings      The amount of time in milliseconds saved during

     *                        daylight saving time.

     * @throws    IllegalArgumentException if the month, day, dayOfWeek, or time

     * parameters are out of range for the start or end rule

     * @since 1.2

     */

    public SimpleTimeZone(int rawOffset, String ID,

                          int startMonth, int startDay, int startDayOfWeek, int startTime,

                          int endMonth, int endDay, int endDayOfWeek, int endTime,

                          int dstSavings)

    {

        this(rawOffset, ID,

             startMonth, startDay, startDayOfWeek, startTime, WALL_TIME,

             endMonth, endDay, endDayOfWeek, endTime, WALL_TIME,

             dstSavings);

    }

    /**

     * Constructs a SimpleTimeZone with the given base time zone offset from

     * GMT, time zone ID, and rules for starting and ending the daylight

     * time.

     * This constructor takes the full set of the start and end rules

     * parameters, including modes of {@code startTime} and

     * {@code endTime}. The mode specifies either {@link #WALL_TIME wall

     * time} or {@link #STANDARD_TIME standard time} or {@link #UTC_TIME UTC

     * time}.

     *

     * @param rawOffset       The given base time zone offset from GMT.

     * @param ID              The time zone ID which is given to this object.

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 0 for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     *                        See the class description for the special cases of this parameter.

     * @param startDayOfWeek  The daylight saving time starting day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param startTime       The daylight saving time starting time in the time mode

     *                        specified by {@code startTimeMode}.

     * @param startTimeMode   The mode of the start time specified by startTime.

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     *                        See the class description for the special cases of this parameter.

     * @param endDayOfWeek    The daylight saving time ending day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param endTime         The daylight saving ending time in time mode

     *                        specified by {@code endTimeMode}.

     * @param endTimeMode     The mode of the end time specified by endTime

     * @param dstSavings      The amount of time in milliseconds saved during

     *                        daylight saving time.

     *

     * @throws    IllegalArgumentException if the month, day, dayOfWeek, time more, or

     * time parameters are out of range for the start or end rule, or if a time mode

     * value is invalid.

     *

     * @see #WALL_TIME

     * @see #STANDARD_TIME

     * @see #UTC_TIME

     *

     * @since 1.4

     */

    public SimpleTimeZone(int rawOffset, String ID,

                          int startMonth, int startDay, int startDayOfWeek,

                          int startTime, int startTimeMode,

                          int endMonth, int endDay, int endDayOfWeek,

                          int endTime, int endTimeMode,

                          int dstSavings) {

        setID(ID);

        this.rawOffset      = rawOffset;

        this.startMonth     = startMonth;

        this.startDay       = startDay;

        this.startDayOfWeek = startDayOfWeek;

        this.startTime      = startTime;

        this.startTimeMode  = startTimeMode;

        this.endMonth       = endMonth;

        this.endDay         = endDay;

        this.endDayOfWeek   = endDayOfWeek;

        this.endTime        = endTime;

        this.endTimeMode    = endTimeMode;

        this.dstSavings     = dstSavings;

        // this.useDaylight is set by decodeRules

        decodeRules();

        if (dstSavings <= 0) {

            throw new IllegalArgumentException("Illegal daylight saving value: " + dstSavings);

        }

    }

    /**

     * Sets the daylight saving time starting year.

     *

     * @param year  The daylight saving starting year.

     */

    public void setStartYear(int year)

    {

        startYear = year;

        invalidateCache();

    }

    /**

     * Sets the daylight saving time start rule. For example, if daylight saving

     * time starts on the first Sunday in April at 2 am in local wall clock

     * time, you can set the start rule by calling:

     * <pre>{@code setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);}</pre>

     *

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 0 for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     *                        See the class description for the special cases of this parameter.

     * @param startDayOfWeek  The daylight saving time starting day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param startTime       The daylight saving time starting time in local wall clock

     *                        time, which is local standard time in this case.

     * @throws    IllegalArgumentException if the {@code startMonth}, {@code startDay},

     * {@code startDayOfWeek}, or {@code startTime} parameters are out of range

     */

    public void setStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime)

    {

        this.startMonth = startMonth;

        this.startDay = startDay;

        this.startDayOfWeek = startDayOfWeek;

        this.startTime = startTime;

        startTimeMode = WALL_TIME;

        decodeStartRule();

        invalidateCache();

    }

    /**

     * Sets the daylight saving time start rule to a fixed date within a month.

     * This method is equivalent to:

     * <pre>{@code setStartRule(startMonth, startDay, 0, startTime)}</pre>

     *

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 0 for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     * @param startTime       The daylight saving time starting time in local wall clock

     *                        time, which is local standard time in this case.

     *                        See the class description for the special cases of this parameter.

     * @throws    IllegalArgumentException if the {@code startMonth},

     * {@code startDayOfMonth}, or {@code startTime} parameters are out of range

     * @since 1.2

     */

    public void setStartRule(int startMonth, int startDay, int startTime) {

        setStartRule(startMonth, startDay, 0, startTime);

    }

    /**

     * Sets the daylight saving time start rule to a weekday before or after the given date within

     * a month, e.g., the first Monday on or after the 8th.

     *

     * @param startMonth      The daylight saving time starting month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 0 for January).

     * @param startDay        The day of the month on which the daylight saving time starts.

     * @param startDayOfWeek  The daylight saving time starting day-of-week.

     * @param startTime       The daylight saving time starting time in local wall clock

     *                        time, which is local standard time in this case.

     * @param after           If true, this rule selects the first {@code dayOfWeek} on or

     *                        <em>after</em> {@code dayOfMonth}.  If false, this rule

     *                        selects the last {@code dayOfWeek} on or <em>before</em>

     *                        {@code dayOfMonth}.

     * @throws    IllegalArgumentException if the {@code startMonth}, {@code startDay},

     * {@code startDayOfWeek}, or {@code startTime} parameters are out of range

     * @since 1.2

     */

    public void setStartRule(int startMonth, int startDay, int startDayOfWeek,

                             int startTime, boolean after)

    {

        // TODO: this method doesn't check the initial values of dayOfMonth or dayOfWeek.

        if (after) {

            setStartRule(startMonth, startDay, -startDayOfWeek, startTime);

        } else {

            setStartRule(startMonth, -startDay, -startDayOfWeek, startTime);

        }

    }

    /**

     * Sets the daylight saving time end rule. For example, if daylight saving time

     * ends on the last Sunday in October at 2 am in wall clock time,

     * you can set the end rule by calling:

     * {@code setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);}

     *

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     *                        See the class description for the special cases of this parameter.

     * @param endDayOfWeek    The daylight saving time ending day-of-week.

     *                        See the class description for the special cases of this parameter.

     * @param endTime         The daylight saving ending time in local wall clock time,

     *                        (in milliseconds within the day) which is local daylight

     *                        time in this case.

     * @throws    IllegalArgumentException if the {@code endMonth}, {@code endDay},

     * {@code endDayOfWeek}, or {@code endTime} parameters are out of range

     */

    public void setEndRule(int endMonth, int endDay, int endDayOfWeek,

                           int endTime)

    {

        this.endMonth = endMonth;

        this.endDay = endDay;

        this.endDayOfWeek = endDayOfWeek;

        this.endTime = endTime;

        this.endTimeMode = WALL_TIME;

        decodeEndRule();

        invalidateCache();

    }

    /**

     * Sets the daylight saving time end rule to a fixed date within a month.

     * This method is equivalent to:

     * <pre>{@code setEndRule(endMonth, endDay, 0, endTime)}</pre>

     *

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     * @param endTime         The daylight saving ending time in local wall clock time,

     *                        (in milliseconds within the day) which is local daylight

     *                        time in this case.

     * @throws    IllegalArgumentException the {@code endMonth}, {@code endDay},

     * or {@code endTime} parameters are out of range

     * @since 1.2

     */

    public void setEndRule(int endMonth, int endDay, int endTime)

    {

        setEndRule(endMonth, endDay, 0, endTime);

    }

    /**

     * Sets the daylight saving time end rule to a weekday before or after the given date within

     * a month, e.g., the first Monday on or after the 8th.

     *

     * @param endMonth        The daylight saving time ending month. Month is

     *                        a {@link Calendar#MONTH MONTH} field

     *                        value (0-based. e.g., 9 for October).

     * @param endDay          The day of the month on which the daylight saving time ends.

     * @param endDayOfWeek    The daylight saving time ending day-of-week.

     * @param endTime         The daylight saving ending time in local wall clock time,

     *                        (in milliseconds within the day) which is local daylight

     *                        time in this case.

     * @param after           If true, this rule selects the first {@code endDayOfWeek} on

     *                        or <em>after</em> {@code endDay}.  If false, this rule

     *                        selects the last {@code endDayOfWeek} on or before

     *                        {@code endDay} of the month.

     * @throws    IllegalArgumentException the {@code endMonth}, {@code endDay},

     * {@code endDayOfWeek}, or {@code endTime} parameters are out of range

     * @since 1.2

     */

    public void setEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime, boolean after)

    {

        if (after) {