/*
 * [SortBooks.java]
 *
 * Summary: Sort publish dates in descending order in embedded Insert macros.
 *
 * Copyright: (c) 2016-2017 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 2016-06-26 initial version
 */
package com.mindprod.sortcode;

import java.util.Comparator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Sort publish dates in descending order in embedded Insert macros.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2016-06-26 initial version
 * @since 2016-06-26
 */
public class SortBooks implements Comparator<String>
    {
    // TidyBookMacros: reflow Book macros.  Update BookHead with recent title and published. Add missing published to BookHead.
    // RefreshInserts: refresh data on Insert macros from book page. Add missing published to book Insert.
    // InsertBookMarkers: put <!-- +++ --> between books to make it easier to sort.  One shot.
    // SortBooks: sort book Inserts on page so most recently published are first.
    // ProofreadInserts: check that sort worked.

    /**
     * will find publish date on Insert macro published=yyyy-mm-dd
     */
    private static final Pattern PUBLISHED_GRABBER = Pattern.compile( "published=(\\d{4})(-\\d{2})?(-\\d{2})?" );

    /**
     * @param s the entire block of text, somewhere containing published=yyyy-mm-dd
     *
     * @return yyyy-mm-dd
     */
    private static String computeKey( String s )
        {
        final Matcher m = PUBLISHED_GRABBER.matcher( s );
        if ( m.find() )
            {
            // found
            final String year = m.group( 1 );
            if ( m.groupCount() >= 2 )
                {
                final String month = m.group( 2 );
                if ( m.groupCount() >= 3 )
                    {
                    final String day = m.group( 3 );
                    return year + month + day; // including dashes.
                    }
                else
                    {
                    return year + month; // including dash
                    }
                }
            else
                {
                return year;
                }
            }
        else
            {
            return "0001-01-01";
            }
        } // /method

    /**
     * Compare two String Objects each containing publish dates
     *
     * @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 )
        {
        // reverse order to get descending sort
        return computeKey( b ).compareTo( computeKey( a ) );
        } // /methods
    } // end class