/*
 * [InsensitiveOrder.java]
 *
 * Summary: Comparator to sort Funduc Search/Replace *.srs scripts.
 *
 * Copyright: (c) 2011-2017 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 2011-11-13 initial version
 */
package com.mindprod.sortsrs;

import com.mindprod.common18.ST;

import java.util.Comparator;

/**
 * Comparator to sort Funduc Search/Replace *.srs scripts.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2011-11-13 initial version
 * @since 2011-11-13
 */
class InsensitiveOrder implements Comparator<Item>
    {
    /**
     * Sort SRS Script items, user's preferred order.
     * Defines an alternate sort order for String with JDK 1.5+ generics.
     * Compare two String Objects.
     * Compares whole object case insensitively.
     * Informally, returns (a-b), or +ve if a comes after b.
     * The Java source code for this Comparator was generated by the
     * Canadian Mind Products ComparatorCutter Applet at http://mindprod.com/applet/comparatorcutter.html
     *
     * @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( Item a, Item b )
        {
        assert a != null && b != null : "null compare parms";
        int diff = a.section - b.section;
        if ( diff != 0 )
            {
            return diff;
            }
        // we now known a and b have the same section hence same typue
        if ( a instanceof SRItem )
            {
            // b can't be null
            SRItem as = ( SRItem ) a;
            SRItem bs = ( SRItem ) b;
            diff = ST.nullSafeStringCompareIgnoreCase( as.searchUntrimmed, bs.searchUntrimmed );
            if ( diff != 0 )
                {
                return diff;
                }
            diff = ST.nullSafeStringCompareIgnoreCase( as.replaceUntrimmed, bs.replaceUntrimmed );
            if ( diff != 0 )
                {
                return diff;
                }
            // tie breaker, sort including command switches
            return ST.nullSafeStringCompareIgnoreCase( as.options, bs.options );
            // comments are irrelevant.
            }
        if ( a instanceof PathItem )
            {
            // two pathItems
            PathItem ap = ( PathItem ) a;
            PathItem bp = ( PathItem ) b;
            return ST.nullSafeStringCompareIgnoreCase( ap.path, bp.path );
            }
        if ( a instanceof EndItem )
            {
            return 0; //  all as identical and hydrogen atoms.
            }
        throw new IllegalArgumentException( "Program bug [10]: Unexpected Object type compared" );
        }
    }