/*

 * Copyright (c) 2012, 2021, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.util.locale.provider;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.text.spi.BreakIteratorProvider;

import java.text.spi.CollatorProvider;

import java.text.spi.DateFormatProvider;

import java.text.spi.DateFormatSymbolsProvider;

import java.text.spi.DecimalFormatSymbolsProvider;

import java.text.spi.NumberFormatProvider;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.Locale;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.spi.CalendarDataProvider;

import java.util.spi.CalendarNameProvider;

import java.util.spi.CurrencyNameProvider;

import java.util.spi.LocaleNameProvider;

import java.util.spi.LocaleServiceProvider;

import java.util.spi.TimeZoneNameProvider;

import sun.text.spi.JavaTimeDateTimePatternProvider;

import sun.util.spi.CalendarProvider;

/**

 * An abstract parent class for the

 * HostLocaleProviderAdapter/SPILocaleProviderAdapter.

 *

 * @author Naoto Sato

 * @author Masayoshi Okutsu

 */

public abstract class AuxLocaleProviderAdapter extends LocaleProviderAdapter {

    /**

     * SPI implementations map

     */

    private final ConcurrentMap<Class<? extends LocaleServiceProvider>, LocaleServiceProvider> providersMap =

            new ConcurrentHashMap<>();

    /**

     * Getter method for Locale Service Providers

     */

    @Override

    public <P extends LocaleServiceProvider> P getLocaleServiceProvider(Class<P> c) {

        @SuppressWarnings("unchecked")

        P lsp = (P) providersMap.get(c);

        if (lsp == null) {

            lsp = findInstalledProvider(c);

            providersMap.putIfAbsent(c, lsp == null ? NULL_PROVIDER : lsp);

        }

        return lsp;

    }

    /**

     * Real body to find an implementation for each SPI.

     *

     * @param <P>

     * @param c

     * @return

     */

    protected abstract <P extends LocaleServiceProvider> P findInstalledProvider(final Class<P> c);

    @Override

    public BreakIteratorProvider getBreakIteratorProvider() {

        return getLocaleServiceProvider(BreakIteratorProvider.class);

    }

    @Override

    public CollatorProvider getCollatorProvider() {

        return getLocaleServiceProvider(CollatorProvider.class);

    }

    @Override

    public DateFormatProvider getDateFormatProvider() {

        return getLocaleServiceProvider(DateFormatProvider.class);

    }

    @Override

    public DateFormatSymbolsProvider getDateFormatSymbolsProvider() {

        return getLocaleServiceProvider(DateFormatSymbolsProvider.class);

    }

    @Override

    public DecimalFormatSymbolsProvider getDecimalFormatSymbolsProvider() {

        return getLocaleServiceProvider(DecimalFormatSymbolsProvider.class);

    }

    @Override

    public NumberFormatProvider getNumberFormatProvider() {

        return getLocaleServiceProvider(NumberFormatProvider.class);

    }

    /**

     * Getter methods for java.util.spi.* providers

     */

    @Override

    public CurrencyNameProvider getCurrencyNameProvider() {

        return getLocaleServiceProvider(CurrencyNameProvider.class);

    }

    @Override

    public LocaleNameProvider getLocaleNameProvider() {

        return getLocaleServiceProvider(LocaleNameProvider.class);

    }

    @Override

    public TimeZoneNameProvider getTimeZoneNameProvider() {

        return getLocaleServiceProvider(TimeZoneNameProvider.class);

    }

    @Override

    public CalendarDataProvider getCalendarDataProvider() {

        return getLocaleServiceProvider(CalendarDataProvider.class);

    }

    @Override

    public CalendarNameProvider getCalendarNameProvider() {

        return getLocaleServiceProvider(CalendarNameProvider.class);

    }

    /**

     * Getter methods for sun.util.spi.* providers

     */

    @Override

    public CalendarProvider getCalendarProvider() {

        return getLocaleServiceProvider(CalendarProvider.class);

    }

    @Override

    public LocaleResources getLocaleResources(Locale locale) {

        return null;

    }

    @Override

    public JavaTimeDateTimePatternProvider getJavaTimeDateTimePatternProvider() {

        return getLocaleServiceProvider(JavaTimeDateTimePatternProvider.class);

    }

    private static Locale[] availableLocales = null;

    @Override

    public Locale[] getAvailableLocales() {

        if (availableLocales == null) {

            List<Locale> avail = new ArrayList<>();

            for (Class<? extends LocaleServiceProvider> c :

                    LocaleServiceProviderPool.spiClasses) {

                LocaleServiceProvider lsp = getLocaleServiceProvider(c);

                if (lsp != null) {

                    avail.addAll(Arrays.asList(lsp.getAvailableLocales()));

                }

            }

            availableLocales = avail.toArray(new Locale[0]);

        }

        // assuming caller won't mutate the array.

        return availableLocales;

    }

    /**

     * A dummy locale service provider that indicates there is no

     * provider available

     */

    @SuppressWarnings("removal")

    private static final NullProvider NULL_PROVIDER = AccessController.doPrivileged(

        (PrivilegedAction<NullProvider>) () -> new NullProvider());

    private static class NullProvider extends LocaleServiceProvider {

        @Override

        public Locale[] getAvailableLocales() {

            return new Locale[0];

        }

    }

}