/*
 * [DecimalBase.java]
 *
 * Summary: common Base class for classes that convert numbers to formatted decimal.
 *
 * Copyright: (c) 1999-2017 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 1999-01-17
 *  1.1 2005-08-26 correct bug in 9-digit negative numbers
 *                 split off common logic from DecimalCommas and DecimalDots
 */
package com.mindprod.inwords;

/**
 * common Base class for classes that convert numbers to formatted decimal.
 * <p/>
 * com.mindprod.inwords.DecimalBase.java - convert long integer
 * into formatted Decimal  e.g.
 * -12345 -&gt; -12.345, uses variable separater e.g. space dot
 * comma.
 * <p/>
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 2005-08-26 correct bug in 9-digit negative numbers
 * split off common logic from DecimalCommas and DecimalDots
 * @ split off common logic from DecimalCommas and  DecimalDots
 * @noinspection WeakerAccess
 * @since 1999-01-17
 */
public class DecimalBase
    {
    private static final int FIRST_COPYRIGHT_YEAR = 1999;

    /**
     * undisplayed copyright notice
     *
     * @noinspection UnusedDeclaration
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 1999-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    /**
     * convert long integer into tidied Decimal e.g. -12345 -> -12.345 Handles negative and positive integers on range
     * -Long.MIN_VALUE .. Long.MAX_VALUE;
     *
     * @param num number to convert to words
     * @param sep separarator comma, period, space.
     *
     * @return words
     */
    public String toWords( long num, char sep )
        {
        boolean negative;
        if ( num < 0 )
            {
            negative = true;
            num = -num;
            }
        else
            {
            negative = false;
            }
        String s = Long.toString( num );
        // insert decorative dots every three
        int length = s.length();
        // count of separators we will insert
        int sepsCount = ( length - 1 ) / 3;
        if ( sepsCount > 0 )
            {
            StringBuilder b = new StringBuilder( length + sepsCount );
            // work left to right.
            // where we will insert first dot.
            int sepSpot = ( ( length - 1 ) % 3 ) + 1;
            b.append( s.substring( 0, sepSpot ) );
            for ( int group = 0; group < sepsCount; group++, sepSpot += 3 )
                {
                b.append( sep );
                b.append( s.substring( sepSpot, sepSpot + 3 ) );
                } // end for
            s = b.toString();
            } // end if
        return negative ? '-' + s : s;
        } // end toWords
    } // end DecimalBase