/*
 *  Copyright 2020 Alexey Andreev.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.threeten.bp.zone;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;
import org.teavm.classlib.impl.tz.DateTimeZone;
import org.teavm.classlib.impl.tz.DateTimeZoneProvider;

class JodaRulesProvider extends ZoneRulesProvider {
    private Set<String> zoneIds;
    private Map<String, ZoneRules> cache = new HashMap<>();

    @Override
    protected Set<String> provideZoneIds() {
        if (zoneIds == null) {
            zoneIds = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(DateTimeZoneProvider.getIds())));
        }
        return zoneIds;
    }

    @Override
    protected ZoneRules provideRules(String regionId, boolean forCaching) {
        ZoneRules result = cache.get(regionId);
        if (result == null) {
            DateTimeZone zone = DateTimeZoneProvider.getTimeZone(regionId);
            if (zone == null) {
                throw new ZoneRulesException(regionId);
            }
            result = (ZoneRules) (Object) zone.asZoneRules();
            cache.put(regionId, result);
        }
        return result;
    }

    @Override
    protected NavigableMap<String, ZoneRules> provideVersions(String zoneId) {
        ZoneRules result = provideRules(zoneId, false);
        TreeMap<String, ZoneRules> map = new TreeMap<>();
        map.put("", result);
        return map;
    }
}
