/*
 * [Martian.java]
 *
 * Summary: Display a numbmer in Martian (an artificial language that uses base 16 numbers).
 *
 * 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 1999-01-21 make all language specific String literals into constants.
 */
package com.mindprod.inwords;

/**
 * Display a numbmer in Martian (an artificial language that uses base 16 numbers).
 * <p/>
 * e.g.
 * -12345 -&gt; minus cocu aocu iu.
 * This is just having fun, inventing a rational number naming system.
 * <p/>
 * Martian counting is very simple.
 * Every power of 16 has a name ending in o: ao, bo, co etc.
 * Every digit has a name ending in u: au, bu, cu etc.
 * A number is formed of a pairs, written as one word, a power of 16 and a
 * multiplier, the reverse of usual languages, in order to put the most significant
 * information first.
 * <p/>
 * Why is this code written in an unusual way?   see inwords.use
 * <p/>
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 1999-01-21 make all language specific String literals into constants.
 * @noinspection UnusedDeclaration
 * @since 1999-01-17
 */
public final class Martian implements ToWords
    {
    private static final int FIRST_COPYRIGHT_YEAR = 1999;

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

    private static final String MINUS = "minus";

    private static final String ZERO = "au";

    private static final String[] digitName = {
            /* names of digits 0..15 */
            "au",
            "bu",
            "cu",
            "du",
            "eu",
            "fu",
            "gu",
            "hu",
            "iu",
            "ju",
            "ku",
            "lu",
            "mu",
            "nu",
            "ou",
            "pu" };

    private static final String[] groupName = {
            // every power of 16 is named a0=16^0 = 1
            "",
            "bo",
            "co",
            "do",
            "eo",
            "fo",
            "go",
            "ho",
            "io",
            "jo",
            "ko",
            "lo",
            "mo",
            "no",
            "po",
            "qo" };

    /**
     * test harness
     *
     * @param args not used
     */
    public static void main( String[] args )
        {
        Test.test( new Martian() );
        } // end main

    /**
     * convert long integer into Martian words e.g. -12345 -> minus cocu aocu iu. Handles negative and positive integers
     * on range -Long.MAX_VALUE .. Long.MAX_VALUE; It cannot handle Long.MIN_VALUE;
     *
     * @param num number to convert to words
     *
     * @return words
     */
    @SuppressWarnings( { "WeakerAccess" } )
    public String toWords( long num )
        {
        if ( num == 0 )
            {
            return ZERO;
            }
        boolean negative = ( num < 0 );
        if ( negative )
            {
            num = -num;
            }
        String s = "";
        // Work least significant digit to most, right to left.
        // until high order part is all 0s.
        for ( int group = 0; num > 0; group++ )
            {
            int remdr = ( int ) ( num % 16 );
            num = num / 16;
            if ( remdr == 0 )
                {
                continue;
                }
            s = groupName[ group ] + digitName[ remdr ] + " " + s;
            } // end for
        s = s.trim();
        if ( negative )
            {
            s = MINUS + " " + s;
            }
        return s;
        } // end inWords
    } // end Martian