/*
 * [HTMLComparator.java]
 *
 * Summary: Compare keys containing HTML tags and entities.
 *
 * Copyright: (c) 2005-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2005-07-02 converted to Java 1.5
 */
package com.mindprod.comparators;

import com.mindprod.entities.DeEntifyStrings;

import java.util.Comparator;

/**
 * Compare keys containing HTML tags and entities.
 * <p/>
 * Defines an alternate sort order for String.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2005-07-02 converted to Java 1.5
 * @since 2005-07-02
 */
public class HTMLComparator implements Comparator<String>
    {
    /**
     * strip out anything inside &lt; .... &gt; Then strip lead/trail spaces, but not embedded spaces. Does not
     * covert to
     * lower case. Does not convert entities to Unicode.
     *
     * @param key string conttaining html tags.
     *
     * @return key with tags stripped out.
     */
    public static String flatten( String key )
        {
        // trim later so that lead/trail &nbsp will be trimmed.
        return DeEntifyStrings.flattenHTML( key, ' ' ).trim();
        } // end flatten

    /**
     * Compare keys containing HTML tags and entities.
     * Defines an alternate sort order for String.
     * Compare two String Objects.
     * Informally, returns (a-b), or +ve if a is more positive than b.
     *
     * @param a first String to compare
     * @param b second String to compare
     *
     * @return +ve if a&gt;b, 0 if a==b, -ve if a&lt;b
     */
    public final int compare( String a, String b )
        {
        return flatten( a ).compareToIgnoreCase( flatten( b ) );
        }
    }