package com.charego.freecellfx.util;

import java.util.HashMap;
import java.util.Map;

/**
 * Maps a pair of coordinates to an object.
 *
 * @param <K1> the first coordinate
 * @param <K2> the second coordinate
 * @param <V>  the treasure
 */
public class DoubleKeyedMap<K1, K2, V> {

    private Map<K1, Map<K2, V>> map = new HashMap<>();

    public boolean contains(K1 firstKey, K2 secondKey) {
        return map.containsKey(firstKey) && map.get(firstKey).containsKey(secondKey);
    }

    public V get(K1 firstKey, K2 secondKey) {
        return map.get(firstKey).get(secondKey);
    }

    /**
     * Returns the old value if it exists, or null.
     */
    public V put(K1 firstKey, K2 secondKey, V newValue) {
        if (!map.containsKey(firstKey)) {
            map.put(firstKey, new HashMap<>());
        }
        return map.get(firstKey).put(secondKey, newValue);
    }
}