/*
 * Copyright (c) 2013, 2014, 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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 */

package sun.util.locale.provider;

import java.util.Calendar;
import java.util.Locale;
import java.util.Set;
import java.util.TimeZone;
import sun.util.spi.CalendarProvider;

/**
 * Concrete implementation of the  {@link sun.util.spi.CalendarProvider
 * CalendarProvider} class for the JRE LocaleProviderAdapter.
 *
 * @author Naoto Sato
 */
public class CalendarProviderImpl extends CalendarProvider implements AvailableLanguageTags {
    private final LocaleProviderAdapter.Type type;
    private Set<String> langtags;

    public CalendarProviderImpl(LocaleProviderAdapter.Type type) {
        this.type = type;
    }

    /**
     * Returns an array of all locales for which this locale service provider
     * can provide localized objects or names.
     *
     * @return An array of all locales for which this locale service provider
     * can provide localized objects or names.
     */
    @Override
    public Locale[] getAvailableLocales() {
        return LocaleProviderAdapter.toLocaleArray(getLangTags());
    }

    @Override
    public boolean isSupportedLocale(Locale locale) {
        // Support any locales.
        return true;
    }

    /**
     * Returns a new <code>Calendar</code> instance for the
     * specified locale.
     *
     * @param zone the time zone
     * @param locale the desired locale
     * @exception NullPointerException if <code>locale</code> is null
     * @exception IllegalArgumentException if <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @return a <code>Calendar</code> instance.
     * @see java.util.Calendar#getInstance(java.util.Locale)
     */
    @Override
    public Calendar getInstance(TimeZone zone, Locale locale) {
        return new Calendar.Builder()
                     .setLocale(locale)
                     .setTimeZone(zone)
                     .setInstant(System.currentTimeMillis())
                     .build();
    }

    @Override
    public Set<String> getAvailableLanguageTags() {
        return getLangTags();
    }

    private Set<String> getLangTags() {
        if (langtags == null) {
            langtags = ((JRELocaleProviderAdapter)LocaleProviderAdapter.forType(type)).getLanguageTagSet("CalendarData");
        }
        return langtags;
    }
}