/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.cassandra.utils;

import java.util.Collection;
import java.util.NavigableMap;
import java.util.TreeMap;

import com.google.common.collect.SortedSetMultimap;
import com.google.common.collect.TreeMultimap;

public class SortedBiMultiValMap<K, V> extends AbstractBiMultiValMap<K, V>
{
    protected final NavigableMap<K, V> forwardMap;
    protected final SortedSetMultimap<V, K> reverseMap;

    protected SortedBiMultiValMap(NavigableMap<K, V> forwardMap, SortedSetMultimap<V, K> reverseMap)
    {
        this.forwardMap = forwardMap;
        this.reverseMap = reverseMap;
    }

    public static <K extends Comparable<K>, V extends Comparable<V>> SortedBiMultiValMap<K, V> create()
    {
        return new SortedBiMultiValMap<K, V>(new TreeMap<K,V>(), TreeMultimap.<V, K>create());
    }

    public static <K extends Comparable<K>, V extends Comparable<V>, M extends AbstractBiMultiValMap<K, V>> SortedBiMultiValMap<K, V> create(M map)
    {
        SortedBiMultiValMap<K, V> newMap = SortedBiMultiValMap.<K,V>create();
        newMap.forwardMap.putAll(map.forwardDelegate());
        // Put each individual TreeSet instead of Multimap#putAll(Multimap) to get linear complexity
        // See CASSANDRA-14660
        for (Entry<V, Collection<K>> entry : map.inverse().asMap().entrySet())
            newMap.reverseMap.putAll(entry.getKey(), entry.getValue());
        return newMap;
    }

    @Override
    protected NavigableMap<K, V> forwardDelegate()
    {
        return forwardMap;
    }

    @Override
    protected SortedSetMultimap<V, K> reverseDelegate()
    {
        return reverseMap;
    }
}
