// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.core.formatters;

public class WholePartFormatHelper implements NumericFormatPartHelper
{
    String mFormat;

    public WholePartFormatHelper( String pFormat )
    {
        mFormat = pFormat;
    }

    public void process( StringBuilder pSB, NFparsedparts pParts )
    {
        String zParsedWholePart = pParts.getWholeDigits();

        switch ( mFormat.length() )
        {
            case 1: // 0 or #
                if ( mFormat.equals( "0" ) )
                {
                    if ( zParsedWholePart.length() > 1 )
                    {
                        throw new IllegalArgumentException( "Whole part " + zParsedWholePart + " is too large to be formatted" );
                    }
                    else if ( zParsedWholePart.length() == 0 )
                    {
                        pSB.append( pParts.getBeforeAnyDigits() );
                        pSB.append( "0" );
                    }
                    else
                    {
                        pSB.append( pParts.getBeforeAnyDigits() );
                        pSB.append( pParts.getWholeDigits() );
                    }
                }
                else if ( mFormat.equals( "#" ) )
                {
                    pSB.append( pParts.getBeforeAnyDigits() );
                    pSB.append( zParsedWholePart );
                }
                else
                {
                    throw new IllegalArgumentException( "Illegal Whole Part Format String" );
                }
                break;
            case 2: // #0
                if ( mFormat.equals( "#0" ) )
                {
                    if ( zParsedWholePart.length() >= 1 )
                    {
                        pSB.append( pParts.getBeforeAnyDigits() );
                        pSB.append( zParsedWholePart );
                    }
                    else
                    {
                        pSB.append( pParts.getBeforeAnyDigits() );
                        pSB.append( "0" );
                    }
                }
                else
                {
                    throw new IllegalArgumentException( "Illegal Whole Part Format String" );
                }
                break;
            case 5: // #,##0
                if ( mFormat.equals( "#,##0" ) )
                {
                    pSB.append( insertCommas( zParsedWholePart ) );
                }
                else
                {
                    throw new IllegalArgumentException( "Illegal Whole Part Format String" );
                }
                break;
            default:
                break;
        }
    }

    private String insertCommas( String pValue )
    {
        StringBuilder sb = new StringBuilder();
        char[] zChars = pValue.toCharArray();

        String zReversed = reverseOrder( zChars );
        char[] zRevChars = zReversed.toCharArray();

        for ( int i = 0; i < zRevChars.length; i++ )
        {
            if ( (i == 0) || ((i % 3) != 0) )
            {
                sb.append( zRevChars[i] );
            }
            else
            {
                sb.append( ',' );
                sb.append( zRevChars[i] );
            }
        }

        return reverseOrder( sb.toString() );
    }

    private String reverseOrder( char[] pToReverse )
    {
        StringBuilder sb = new StringBuilder();

        for ( int i = pToReverse.length - 1; i >= 0; i-- )
        {
            sb.append( pToReverse[i] );
        }

        return sb.toString();
    }

    private String reverseOrder( String pToReverse )
    {
        return reverseOrder( pToReverse.toCharArray() );
    }
}