/*

 * Copyright (c) 2017, 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.cldr;

import static sun.util.locale.provider.LocaleProviderAdapter.Type;

import java.util.Arrays;

import java.util.Map;

import java.util.Locale;

import java.util.Set;

import java.util.Optional;

import java.util.concurrent.ConcurrentHashMap;

import sun.util.locale.provider.LocaleProviderAdapter;

import sun.util.locale.provider.LocaleResources;

import sun.util.locale.provider.CalendarDataProviderImpl;

import sun.util.locale.provider.CalendarDataUtility;

/**

 * Concrete implementation of the

 * {@link java.util.spi.CalendarDataProvider CalendarDataProvider} class

 * for the CLDR LocaleProviderAdapter.

 *

 * @author Naoto Sato

 */

public class CLDRCalendarDataProviderImpl extends CalendarDataProviderImpl {

    private static Map<String, Integer> firstDay = new ConcurrentHashMap<>();

    private static Map<String, Integer> minDays = new ConcurrentHashMap<>();

    public CLDRCalendarDataProviderImpl(Type type, Set<String> langtags) {

        super(type, langtags);

    }

    @Override

    public int getFirstDayOfWeek(Locale locale) {

        return findValue(CalendarDataUtility.FIRST_DAY_OF_WEEK, locale);

    }

    @Override

    public int getMinimalDaysInFirstWeek(Locale locale) {

        return findValue(CalendarDataUtility.MINIMAL_DAYS_IN_FIRST_WEEK, locale);

    }

    /**

     * Finds the requested integer value for the locale.

     * Each resource consists of the following:

     *

     *    (n: cc1 cc2 ... ccx;)*

     *

     * where 'n' is the integer for the following region codes, terminated by

     * a ';'.

     *

     */

    private static int findValue(String key, Locale locale) {

        Map<String, Integer> map = CalendarDataUtility.FIRST_DAY_OF_WEEK.equals(key) ?

            firstDay : minDays;

        String region = locale.getCountry();

        if (region.isEmpty()) {

            return 0;

        }

        Integer val = map.get(region);

        if (val == null) {

            String valStr =

                LocaleProviderAdapter.forType(Type.CLDR).getLocaleResources(Locale.ROOT)

                   .getCalendarData(key);

            val = retrieveInteger(valStr, region)

                .orElse(retrieveInteger(valStr, "001").orElse(0));

            map.putIfAbsent(region, val);

        }

        return val;

    }

    private static Optional<Integer> retrieveInteger(String src, String region) {

        int regionIndex = src.indexOf(region);

        if (regionIndex >= 0) {

            int start = src.lastIndexOf(';', regionIndex) + 1;

            return Optional.of(Integer.parseInt(src, start, src.indexOf(':', start), 10));

        }

        return Optional.empty();

    }

}