package wsdm16.motifs;

import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class MapUtil {
	public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(
			Map<K, V> map) {
		return sortByValue(map, false);
	}

	public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(
			Map<K, V> map, boolean reverse) {
		Comparator<Map.Entry<K, V>> cmp;
		if (reverse)
			cmp = new Comparator<Map.Entry<K, V>>() {
				public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) {
					return (o2.getValue()).compareTo(o1.getValue());
				}
			};
		else
			cmp = new Comparator<Map.Entry<K, V>>() {
				public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) {
					return (o2.getValue()).compareTo(o1.getValue());
				}
			};
		List<Map.Entry<K, V>> list = new LinkedList<Map.Entry<K, V>>(
				map.entrySet());
		Collections.sort(list, cmp);

		Map<K, V> result = new LinkedHashMap<K, V>();
		for (Map.Entry<K, V> entry : list) {
			result.put(entry.getKey(), entry.getValue());
		}
		return result;
	}
}
