package at.knallgrau.textcat;

import java.util.Comparator;
import java.util.Map.Entry;

/**
 * @author Thomas Hammerl
 * 
 * Comparator for NGram entries in the FingerPrint collection. sorts a set of
 * Entry<String,Integer> entries in a FingerPrint collection in descending
 * order.
 * 
 */
class NGramEntryComparator implements Comparator<Entry<String, Integer>> {

    /**
         * @param entry1
         *                an NGram entry
         * @param entry2
         *                another NGram entry
         * @return a number indicating the relation of entry1 to entry2
         */
    public int compare(Entry<String, Integer> entry1,
	    Entry<String, Integer> entry2) {
	if (entry2.getValue() - entry1.getValue() == 0) {
	    if (entry1.getKey().length() - entry2.getKey().length() == 0) {
		return entry1.getKey().compareTo(entry2.getKey());
	    }
	    return entry1.getKey().length() - entry2.getKey().length();
	}
	return entry2.getValue() - entry1.getValue();
    }

}