/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

* 

* Description:

*

*/

using System;

using System.Collections.Generic;

using System.Text;

using System.Text.RegularExpressions;

using System.Reflection;

using SymbianParserLib.Elements;

using SymbianParserLib.Enums;

namespace SymbianParserLib.RegExTranslators.Types

{

    internal class RegExTranslatorDecimal : RegExTranslatorBase

    {

        #region Constructors

        public RegExTranslatorDecimal()

        {

        }

        #endregion

        #region API

        public override ParserField Process( Capture aCapture, int aStartAt, ParserLine aLine )

        {

            ParserField ret = null;

            //

            RegExTranslatorExtractionInfo m = new RegExTranslatorExtractionInfo( aLine.OriginalValue, aStartAt );

            //

            if ( m.Success && ( m.ValueTypeChar == 'D' || m.ValueTypeChar == 'I' || m.ValueTypeChar == 'U' ) )

            {

                bool requiresNumberedCaptureGroup = true;

                // Build the regular expression

                StringBuilder regex = new StringBuilder( "[0-9]" );

                if ( m.Width != RegExTranslatorExtractionInfo.KNoWidthSpecified )

                {

                    // (?(\b[ 0-9+-]{4}\b:)(?:[ ]{0,3}([+-]?[0-9]{1,4}):))

                    int width = m.Width;

                    string padChar = m.PadChar;

                    // This becomes very complex now. We must match the pad character

                    regex = new StringBuilder();

                    // Start a conditional group

                    regex.Append( "(?" );

                    // Start the if-statement match. The idea here is to perform a first pass

                    // that matches any numbers, signs (-/+) and pad characters without any

                    // care about the ordering. The length, however, is critical.

                    regex.AppendFormat( "([{0}0-9+-]{{1}})", padChar, width );

                    // If the match above is true, then we'll execute this 'yes' case. The

                    // idea now is to pull out the specific value, ignoring the padding.

                    // We start a non-capturing group. This is the beginning of the value we

                    // need, but we don't want to capture the padding (although we validate it

                    // exists).

                    regex.AppendFormat( "(?:" );

                    if ( padChar != string.Empty )

                    {

                        // We must allow for width-1 pad characters.

                        regex.AppendFormat( "[{0}]", padChar );

                        regex.Append( "{0," );

                        regex.Append( width );

                        regex.Append( "}" );

                    }

                    // We must now allow for a plus/minus sign. We do this within

                    // a numbered group, since this is the bit we're eventually interested in.

                    regex.Append( "(" );

                    regex.Append( "[+-]?[0-9]" );

                    regex.Append( "{1," + width + "}" );

                    regex.Append( ")" );

                    // End non-capturing group

                    regex.Append( ")" );

                    // End conditional group

                    regex.Append( ")" );

                    // We explicitly managed this ourselves

                    requiresNumberedCaptureGroup = false;

                }

                else

                {

                    // Add "one or more" suffix

                    regex.Append( "+" );

                }

                ret = CreateField( regex.ToString(), m.Name, m.ValueType, m.CapturePos, m.CaptureLength, requiresNumberedCaptureGroup );

            }

            //

            return ret;

        }

        #endregion

        #region Properties

        #endregion

        #region Internal methods

        #endregion

        #region Internal constants

        #endregion

        #region From System.Object

        public override string ToString()

        {

            return base.ToString();

        }

        #endregion

        #region Data members

        #endregion

    }

}