/*

 * Copyright 2003-2005 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.util.calendar;

import java.util.Locale;

import java.util.TimeZone;

/**

 * The class <code>Era</code> represents a calendar era that defines a

 * period of time in which the same year numbering is used. For

 * example, Gregorian year 2004 is <I>Heisei</I> 16 in the Japanese

 * calendar system. An era starts at any point of time (Gregorian) that is

 * represented by <code>CalendarDate</code>.

 *

 * <p><code>Era</code>s that are applicable to a particular calendar

 * system can be obtained by calling {@link CalendarSystem#getEras}

 * one of which can be used to specify a date in

 * <code>CalendarDate</code>.

 *

 * <p>The following era names are defined in this release.

 * <!-- TODO: use HTML table -->

 * <pre><tt>

 *   Calendar system         Era name         Since (in Gregorian)

 *   -----------------------------------------------------------------------

 *   Japanese calendar       Meiji            1868-01-01 midnight local time

 *                           Taisho           1912-07-30 midnight local time

 *                           Showa            1926-12-26 midnight local time

 *                           Heisei           1989-01-08 midnight local time

 *   Julian calendar         BeforeCommonEra  -292275055-05-16T16:47:04.192Z

 *                           CommonEra        0000-12-30 midnight local time

 *   Taiwanese calendar      MinGuo           1911-01-01 midnight local time

 *   Thai Buddhist calendar  BuddhistEra      -543-01-01 midnight local time

 *   -----------------------------------------------------------------------

 * </tt></pre>

 *

 * @author Masayoshi Okutsu

 * @since 1.5

 */

public final class Era {

    private final String name;

    private final String abbr;

    private final long since;

    private final CalendarDate sinceDate;

    private final boolean localTime;

    /**

     * Constructs an <code>Era</code> instance.

     *

     * @param name the era name (e.g., "BeforeCommonEra" for the Julian calendar system)

     * @param abbr the abbreviation of the era name (e.g., "B.C.E." for "BeforeCommonEra")

     * @param since the time (millisecond offset from January 1, 1970

     * (Gregorian) UTC or local time) when the era starts, inclusive.

     * @param localTime <code>true</code> if <code>since</code>

     * specifies a local time; <code>false</code> if

     * <code>since</code> specifies UTC

     */

    public Era(String name, String abbr, long since, boolean localTime) {

        this.name = name;

        this.abbr = abbr;

        this.since = since;

        this.localTime = localTime;

        Gregorian gcal = CalendarSystem.getGregorianCalendar();

        BaseCalendar.Date d = (BaseCalendar.Date) gcal.newCalendarDate(null);

        gcal.getCalendarDate(since, d);

        sinceDate = new ImmutableGregorianDate(d);

    }

    public String getName() {

        return name;

    }

    public String getDisplayName(Locale locale) {

        return name;

    }

    public String getAbbreviation() {

        return abbr;

    }

    public String getDiaplayAbbreviation(Locale locale) {

        return abbr;

    }

    public long getSince(TimeZone zone) {

        if (zone == null || !localTime) {

            return since;

        }

        int offset = zone.getOffset(since);

        return since - offset;

    }

    public CalendarDate getSinceDate() {

        return sinceDate;

    }

    public boolean isLocalTime() {

        return localTime;

    }

    public boolean equals(Object o) {

        if (!(o instanceof Era)) {

            return false;

        }

        Era that = (Era) o;

        return name.equals(that.name)

            && abbr.equals(that.abbr)

            && since == that.since

            && localTime == that.localTime;

    }

    private int hash = 0;

    public int hashCode() {

        if (hash == 0) {

            hash = name.hashCode() ^ abbr.hashCode() ^ (int)since ^ (int)(since >> 32)

                ^ (localTime ? 1 : 0);

        }

        return hash;

    }

    public String toString() {

        StringBuilder sb = new StringBuilder();

        sb.append('[');

        sb.append(getName()).append(" (");

        sb.append(getAbbreviation()).append(')');

        sb.append(" since ").append(getSinceDate());

        if (localTime) {

            sb.setLength(sb.length() - 1); // remove 'Z'

            sb.append(" local time");

        }

        sb.append(']');

        return sb.toString();

    }

}