/*

* 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.Utilities;

using SymbianParserLib.Elements;

using SymbianParserLib.RegExTranslators.Types;

namespace SymbianParserLib.RegExTranslators

{

    public static class TheTickCounter

    {

        public static long TickCount;

    }

    internal class RegExTranslatorManager

    {

        #region Constructors

        public RegExTranslatorManager()

        {

            iTranslators.AddRange( KDefaultList );

        }

        #endregion

        #region API

        public static ParserLine PreCachedCompiledEntry( string aKey )

        {

            ParserLine ret = TheTranslator.iCache.CreateClone( aKey );

            return ret;

        }

        public static void CompileToRegularExpression( ParserLine aLine )

        {

            TheTranslator.DoCompileToRegularExpression( aLine );

        }

        #endregion

        #region Properties

        public static RegExTranslatorManager TheTranslator

        {

            get { return iTheTranslator; }

        }

        #endregion

        #region Internal methods

        private static string FixupOriginalValue( string aLine )

        {

            StringBuilder ret = new StringBuilder( ParserUtils.RemoveLineEndings( aLine ) );

            // Escape double percents

            ret = ret.Replace( KEscapedPercent, KReplacementPercent );

            // Escape [ and ]

            ret = EscapeCharacter( ".", ret );

            ret = EscapeCharacter( "$", ret );

            ret = EscapeCharacter( "+", ret );

            ret = EscapeCharacter( "?", ret );

            ret = EscapeCharacter( "^", ret );

            ret = EscapeCharacter( "*", ret );

            ret = EscapeCharacter( "\\", ret );

            ret = EscapeCharacter( "[", ret );

            ret = EscapeCharacter( "]", ret );

            ret = EscapeCharacter( "(", ret );

            ret = EscapeCharacter( ")", ret );

            ret = EscapeCharacter( "{", ret );

            ret = EscapeCharacter( "}", ret );

            return ret.ToString();

        }

        private static StringBuilder EscapeCharacter( string aCharacter, StringBuilder aObject )

        {

            string replaceWith = "\\" + aCharacter;

            return aObject.Replace( aCharacter, replaceWith );

        }

        private void DoCompileToRegularExpression( ParserLine aLine )

        {

            System.DateTime starTime = DateTime.Now;

            string input = aLine.OriginalValue;

            // First phase is to replace all excaped percents with a single percent

            aLine.OriginalValue = FixupOriginalValue( aLine.OriginalValue );

            // Next phase is to identify all format specifiers

            MatchCollection matches = KRegExFormatSpecifier.Matches( aLine.OriginalValue );

            if ( matches.Count != 0 )

            {

                // Get combined list of all captures spanning all matches. There must be a better way to do this?

                List<Capture> captureList = new List<Capture>();

                foreach ( Match m in matches )

                {

                    if ( m.Success )

                    {

                        foreach ( Capture cap in m.Captures )

                        {

                            captureList.Add( cap );

                        }

                    }

                }

                // Convert captures into format specifiers

                FixupFormatSpecifiers( captureList, aLine );

                // Cache entry

                iCache.Add( input, aLine );

            }

            else

            {

            }

            System.DateTime endTime = DateTime.Now;

            long tickDuration = ( ( endTime.Ticks - starTime.Ticks ) / 100 );

            TheTickCounter.TickCount += tickDuration;

        }

        private void FixupFormatSpecifiers( List<Capture> aCaptures, ParserLine aLine )

        {

            int lastCapturePos = 0;

            // Pull out all the format specifiers and build regular expressions

            int count = aCaptures.Count;

            for ( int i = 0; i < count; i++ )

            {

                Capture capture = aCaptures[ i ];

                // Process the capture, starting at the last capture pos

                lastCapturePos = TryToProcessCapture( capture, lastCapturePos, aLine );

            }

            aLine.Finalise();

        }

        private int TryToProcessCapture( Capture aCapture, int aStartAt, ParserLine aLine )

        {

            // Return the end position of the current capture.

            int ret = -1;

            //

            foreach ( RegExTranslatorBase translator in iTranslators )

            {

                ParserField field = translator.Process( aCapture, aStartAt, aLine );

                if ( field != null )

                {

                    aLine.Add( field );

                    ret = field.FormatSpecifier.OriginalLocation + field.FormatSpecifier.OriginalLength;

                    break;

                }

            }

            //

            return ret;

        }

        #endregion

        #region Internal constants

        private static readonly RegExTranslatorBase[] KDefaultList = new RegExTranslatorBase[]

            {

                new RegExTranslatorDecimal(),

                new RegExTranslatorHex(),

                new RegExTranslatorString()

            };

        private static readonly Regex KRegExFormatSpecifier = new Regex(

              "%{1}",

              RegexOptions.IgnoreCase

            | RegexOptions.CultureInvariant

            | RegexOptions.IgnorePatternWhitespace

            | RegexOptions.Compiled

            );

        private const string KEscapedPercent = "%%";

        private const string KReplacementPercent = "%";

        #endregion

        #region From System.Object

        public override string ToString()

        {

            return base.ToString();

        }

        #endregion

        #region Data members

        private static RegExTranslatorManager iTheTranslator = new RegExTranslatorManager();

        private List<RegExTranslatorBase> iTranslators = new List<RegExTranslatorBase>();

        private Cache.RegExTranslatorCache iCache = new SymbianParserLib.RegExTranslators.Cache.RegExTranslatorCache();

        #endregion

    }

}