using System;
using System.Collections.Generic;

namespace TEngine.Localization
{

    public class RTLFixer
    {
        /// <summary>
        /// Fix the specified string.
        /// </summary>
        /// <param name='str'>
        /// String to be fixed.
        /// </param>
        public static string Fix(string str)
        {
            return Fix(str, false, true);
        }

        public static string Fix(string str, bool rtl)
        {
            if (rtl)

            {
                return Fix(str);
            }

            string[] words = str.Split(' ');
            string result = "";
            string arabicToIgnore = "";
            foreach (string word in words)
            {
                if (char.IsLower(word.ToLower()[word.Length / 2]))
                {
                    result += Fix(arabicToIgnore) + word + " ";
                    arabicToIgnore = "";
                }
                else
                {
                    arabicToIgnore += word + " ";

                }
            }
            if (arabicToIgnore != "")
                result += Fix(arabicToIgnore);

            return result;
        }

         /// <summary>
        /// Fix the specified string with customization options.
        /// </summary>
        /// <param name='str'>
        /// String to be fixed.
        /// </param>
        /// <param name='showTashkeel'>
        /// Show tashkeel.
        /// </param>
        /// <param name='useHinduNumbers'>
        /// Use hindu numbers.
        /// </param>
        public static string Fix(string str, bool showTashkeel, bool useHinduNumbers)
        {
            var newStr = HindiFixer.Fix(str);
            if (newStr != str)
                return newStr;
            RTLFixerTool.showTashkeel = showTashkeel;
            RTLFixerTool.useHinduNumbers = useHinduNumbers;

            if (str.Contains("\n"))
                str = str.Replace("\n", Environment.NewLine);

            if (str.Contains(Environment.NewLine))
            {
                string[] stringSeparators = { Environment.NewLine };
                string[] strSplit = str.Split(stringSeparators, StringSplitOptions.None);

                if (strSplit.Length == 0)
                    return RTLFixerTool.FixLine(str);
                if (strSplit.Length == 1)
                    return RTLFixerTool.FixLine(str);
                string outputString = RTLFixerTool.FixLine(strSplit[0]);
                int iteration = 1;
                if (strSplit.Length > 1)
                {
                    while (iteration < strSplit.Length)
                    {
                        outputString += Environment.NewLine + RTLFixerTool.FixLine(strSplit[iteration]);
                        iteration++;
                    }
                }
                return outputString;
            }

            return RTLFixerTool.FixLine(str);

        }

    }


    /// <summary>
    /// Arabic Contextual forms General - Unicode
    /// </summary>
    internal enum IsolatedArabicLetters
    {
        Hamza = 0xFE80,
        Alef = 0xFE8D,
        AlefHamza = 0xFE83,
        WawHamza = 0xFE85,
        AlefMaksoor = 0xFE87,
        AlefMaksora = 0xFBFC,
        HamzaNabera = 0xFE89,
        Ba = 0xFE8F,
        Ta = 0xFE95,
        Tha2 = 0xFE99,
        Jeem = 0xFE9D,
        H7aa = 0xFEA1,
        Khaa2 = 0xFEA5,
        Dal = 0xFEA9,
        Thal = 0xFEAB,
        Ra2 = 0xFEAD,
        Zeen = 0xFEAF,
        Seen = 0xFEB1,
        Sheen = 0xFEB5,
        S9a = 0xFEB9,
        Dha = 0xFEBD,
        T6a = 0xFEC1,
        T6ha = 0xFEC5,
        Ain = 0xFEC9,
        Gain = 0xFECD,
        Fa = 0xFED1,
        Gaf = 0xFED5,
        Kaf = 0xFED9,
        Lam = 0xFEDD,
        Meem = 0xFEE1,
        Noon = 0xFEE5,
        Ha = 0xFEE9,
        Waw = 0xFEED,
        Ya = 0xFEF1,
        AlefMad = 0xFE81,
        TaMarboota = 0xFE93,
        PersianPe = 0xFB56,     // Persian Letters;
        PersianChe = 0xFB7A,
        PersianZe = 0xFB8A,
        PersianGaf = 0xFB92,
        PersianGaf2 = 0xFB8E

    }

    /// <summary>
    /// Arabic Contextual forms - Isolated
    /// </summary>
    internal enum GeneralArabicLetters
    {
        Hamza = 0x0621,
        Alef = 0x0627,
        AlefHamza = 0x0623,
        WawHamza = 0x0624,
        AlefMaksoor = 0x0625,
        AlefMagsora = 0x0649,
        HamzaNabera = 0x0626,
        Ba = 0x0628,
        Ta = 0x062A,
        Tha2 = 0x062B,
        Jeem = 0x062C,
        H7aa = 0x062D,
        Khaa2 = 0x062E,
        Dal = 0x062F,
        Thal = 0x0630,
        Ra2 = 0x0631,
        Zeen = 0x0632,
        Seen = 0x0633,
        Sheen = 0x0634,
        S9a = 0x0635,
        Dha = 0x0636,
        T6a = 0x0637,
        T6ha = 0x0638,
        Ain = 0x0639,
        Gain = 0x063A,
        Fa = 0x0641,
        Gaf = 0x0642,
        Kaf = 0x0643,
        Lam = 0x0644,
        Meem = 0x0645,
        Noon = 0x0646,
        Ha = 0x0647,
        Waw = 0x0648,
        Ya = 0x064A,
        AlefMad = 0x0622,
        TaMarboota = 0x0629,
        PersianPe = 0x067E,     // Persian Letters;
        PersianChe = 0x0686,
        PersianZe = 0x0698,
        PersianGaf = 0x06AF,
        PersianGaf2 = 0x06A9

    }

    /// <summary>
    /// Data Structure for conversion
    /// </summary>
    internal class ArabicMapping
    {
        public int from;
        public int to;
        public ArabicMapping(int from, int to)
        {
            this.from = from;
            this.to = to;
        }
    }

    /// <summary>
    /// Sets up and creates the conversion table 
    /// </summary>
    internal class ArabicTable
    {

        private static List<ArabicMapping> mapList;
        private static ArabicTable arabicMapper;

        /// <summary>
        /// Setting up the conversion table
        /// </summary>
        private ArabicTable()
        {
            mapList = new List<ArabicMapping>();



            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Hamza, (int)IsolatedArabicLetters.Hamza));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Alef, (int)IsolatedArabicLetters.Alef));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.AlefHamza, (int)IsolatedArabicLetters.AlefHamza));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.WawHamza, (int)IsolatedArabicLetters.WawHamza));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.AlefMaksoor, (int)IsolatedArabicLetters.AlefMaksoor));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.AlefMagsora, (int)IsolatedArabicLetters.AlefMaksora));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.HamzaNabera, (int)IsolatedArabicLetters.HamzaNabera));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ba, (int)IsolatedArabicLetters.Ba));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ta, (int)IsolatedArabicLetters.Ta));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Tha2, (int)IsolatedArabicLetters.Tha2));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Jeem, (int)IsolatedArabicLetters.Jeem));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.H7aa, (int)IsolatedArabicLetters.H7aa));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Khaa2, (int)IsolatedArabicLetters.Khaa2));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Dal, (int)IsolatedArabicLetters.Dal));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Thal, (int)IsolatedArabicLetters.Thal));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ra2, (int)IsolatedArabicLetters.Ra2));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Zeen, (int)IsolatedArabicLetters.Zeen));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Seen, (int)IsolatedArabicLetters.Seen));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Sheen, (int)IsolatedArabicLetters.Sheen));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.S9a, (int)IsolatedArabicLetters.S9a));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Dha, (int)IsolatedArabicLetters.Dha));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.T6a, (int)IsolatedArabicLetters.T6a));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.T6ha, (int)IsolatedArabicLetters.T6ha));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ain, (int)IsolatedArabicLetters.Ain));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Gain, (int)IsolatedArabicLetters.Gain));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Fa, (int)IsolatedArabicLetters.Fa));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Gaf, (int)IsolatedArabicLetters.Gaf));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Kaf, (int)IsolatedArabicLetters.Kaf));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Lam, (int)IsolatedArabicLetters.Lam));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Meem, (int)IsolatedArabicLetters.Meem));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Noon, (int)IsolatedArabicLetters.Noon));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ha, (int)IsolatedArabicLetters.Ha));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Waw, (int)IsolatedArabicLetters.Waw));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.Ya, (int)IsolatedArabicLetters.Ya));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.AlefMad, (int)IsolatedArabicLetters.AlefMad));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.TaMarboota, (int)IsolatedArabicLetters.TaMarboota));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.PersianPe, (int)IsolatedArabicLetters.PersianPe));      // Persian Letters;
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.PersianChe, (int)IsolatedArabicLetters.PersianChe));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.PersianZe, (int)IsolatedArabicLetters.PersianZe));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.PersianGaf, (int)IsolatedArabicLetters.PersianGaf));
            mapList.Add(new ArabicMapping((int)GeneralArabicLetters.PersianGaf2, (int)IsolatedArabicLetters.PersianGaf2));




            //for (int i = 0; i < generalArabic.Length; i++)
            //    mapList.Add(new ArabicMapping((int)generalArabic.GetValue(i), (int)isolatedArabic.GetValue(i)));    // I


        }

        /// <summary>
        /// Singleton design pattern, Get the mapper. If it was not created before, create it.
        /// </summary>
        internal static ArabicTable ArabicMapper
        {
            get
            {
                if (arabicMapper == null)
                    arabicMapper = new ArabicTable();
                return arabicMapper;
            }
        }

        internal int Convert(int toBeConverted)
        {

            foreach (ArabicMapping arabicMap in mapList)
                if (arabicMap.from == toBeConverted)
                {
                    return arabicMap.to;
                }
            return toBeConverted;
        }


    }


    internal class TashkeelLocation
    {
        public char tashkeel;
        public int position;
        public TashkeelLocation(char tashkeel, int position)
        {
            this.tashkeel = tashkeel;
            this.position = position;
        }
    }


    internal class RTLFixerTool
    {
        internal static bool showTashkeel = true;
        internal static bool useHinduNumbers;


        internal static string RemoveTashkeel(string str, out List<TashkeelLocation> tashkeelLocation)
        {
            tashkeelLocation = new List<TashkeelLocation>();
            char[] letters = str.ToCharArray();

            int index = 0;
            for (int i = 0; i < letters.Length; i++)
            {
                if (letters[i] == (char)0x064B)
                { // Tanween Fatha
                    tashkeelLocation.Add(new TashkeelLocation((char)0x064B, i));
                    index++;
                }
                else if (letters[i] == (char)0x064C)
                { // DAMMATAN
                    tashkeelLocation.Add(new TashkeelLocation((char)0x064C, i));
                    index++;
                }
                else if (letters[i] == (char)0x064D)
                { // KASRATAN
                    tashkeelLocation.Add(new TashkeelLocation((char)0x064D, i));
                    index++;
                }
                else if (letters[i] == (char)0x064E)
                { // FATHA
                    if (index > 0)
                    {
                        if (tashkeelLocation[index - 1].tashkeel == (char)0x0651) // SHADDA
                        {
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC60; // Shadda With Fatha
                            continue;
                        }
                    }

                    tashkeelLocation.Add(new TashkeelLocation((char)0x064E, i));
                    index++;
                }
                else if (letters[i] == (char)0x064F)
                { // DAMMA
                    if (index > 0)
                    {
                        if (tashkeelLocation[index - 1].tashkeel == (char)0x0651)
                        { // SHADDA
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC61; // Shadda With DAMMA
                            continue;
                        }
                    }
                    tashkeelLocation.Add(new TashkeelLocation((char)0x064F, i));
                    index++;
                }
                else if (letters[i] == (char)0x0650)
                { // KASRA
                    if (index > 0)
                    {
                        if (tashkeelLocation[index - 1].tashkeel == (char)0x0651)
                        { // SHADDA
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC62; // Shadda With KASRA
                            continue;
                        }
                    }
                    tashkeelLocation.Add(new TashkeelLocation((char)0x0650, i));
                    index++;
                }
                else if (letters[i] == (char)0x0651)
                { // SHADDA
                    if (index > 0)
                    {
                        if (tashkeelLocation[index - 1].tashkeel == (char)0x064E) // FATHA
                        {
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC60; // Shadda With Fatha
                            continue;
                        }

                        if (tashkeelLocation[index - 1].tashkeel == (char)0x064F) // DAMMA
                        {
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC61; // Shadda With DAMMA
                            continue;
                        }

                        if (tashkeelLocation[index - 1].tashkeel == (char)0x0650) // KASRA
                        {
                            tashkeelLocation[index - 1].tashkeel = (char)0xFC62; // Shadda With KASRA
                            continue;
                        }
                    }

                    tashkeelLocation.Add(new TashkeelLocation((char)0x0651, i));
                    index++;
                }
                else if (letters[i] == (char)0x0652)
                { // SUKUN
                    tashkeelLocation.Add(new TashkeelLocation((char)0x0652, i));
                    index++;
                }
                else if (letters[i] == (char)0x0653)
                { // MADDAH ABOVE
                    tashkeelLocation.Add(new TashkeelLocation((char)0x0653, i));
                    index++;
                }
            }

            string[] split = str.Split((char)0x064B, (char)0x064C, (char)0x064D, (char)0x064E, (char)0x064F, (char)0x0650, (char)0x0651, (char)0x0652, (char)0x0653, (char)0xFC60, (char)0xFC61, (char)0xFC62);
            str = "";

            foreach (string s in split)
            {
                str += s;
            }

            return str;
        }

        internal static char[] ReturnTashkeel(char[] letters, List<TashkeelLocation> tashkeelLocation)
        {
            char[] lettersWithTashkeel = new char[letters.Length + tashkeelLocation.Count];

            int letterWithTashkeelTracker = 0;
            for (int i = 0; i < letters.Length; i++)
            {
                lettersWithTashkeel[letterWithTashkeelTracker] = letters[i];
                letterWithTashkeelTracker++;
                foreach (TashkeelLocation hLocation in tashkeelLocation)
                {
                    if (hLocation.position == letterWithTashkeelTracker)
                    {
                        lettersWithTashkeel[letterWithTashkeelTracker] = hLocation.tashkeel;
                        letterWithTashkeelTracker++;
                    }
                }
            }

            return lettersWithTashkeel;
        }

        /// <summary>
        /// Converts a string to a form in which the sting will be displayed correctly for arabic text.
        /// </summary>
        /// <param name="str">String to be converted. Example: "Aaa"</param>
        /// <returns>Converted string. Example: "aa aaa A" without the spaces.</returns>
        internal static string FixLine(string str)
        {
            string test = "";

            List<TashkeelLocation> tashkeelLocation;

            string originString = RemoveTashkeel(str, out tashkeelLocation);

            char[] lettersOrigin = originString.ToCharArray();
            char[] lettersFinal = originString.ToCharArray();



            for (int i = 0; i < lettersOrigin.Length; i++)
            {
                lettersOrigin[i] = (char)ArabicTable.ArabicMapper.Convert(lettersOrigin[i]);
            }

            for (int i = 0; i < lettersOrigin.Length; i++)
            {
                bool skip = false;


                //lettersOrigin[i] = (char)ArabicTable.ArabicMapper.Convert(lettersOrigin[i]);


                // For special Lam Letter connections.
                if (lettersOrigin[i] == (char)IsolatedArabicLetters.Lam)
                {

                    if (i < lettersOrigin.Length - 1)
                    {
                        //lettersOrigin[i + 1] = (char)ArabicTable.ArabicMapper.Convert(lettersOrigin[i + 1]);
                        if (lettersOrigin[i + 1] == (char)IsolatedArabicLetters.AlefMaksoor)
                        {
                            lettersOrigin[i] = (char)0xFEF7;
                            lettersFinal[i + 1] = (char)0xFFFF;
                            skip = true;
                        }
                        else if (lettersOrigin[i + 1] == (char)IsolatedArabicLetters.Alef)
                        {
                            lettersOrigin[i] = (char)0xFEF9;
                            lettersFinal[i + 1] = (char)0xFFFF;
                            skip = true;
                        }
                        else if (lettersOrigin[i + 1] == (char)IsolatedArabicLetters.AlefHamza)
                        {
                            lettersOrigin[i] = (char)0xFEF5;
                            lettersFinal[i + 1] = (char)0xFFFF;
                            skip = true;
                        }
                        else if (lettersOrigin[i + 1] == (char)IsolatedArabicLetters.AlefMad)
                        {
                            lettersOrigin[i] = (char)0xFEF3;
                            lettersFinal[i + 1] = (char)0xFFFF;
                            skip = true;
                        }
                    }

                }


                if (!IsIgnoredCharacter(lettersOrigin[i]))
                {
                    if (IsMiddleLetter(lettersOrigin, i))
                        lettersFinal[i] = (char)(lettersOrigin[i] + 3);
                    else if (IsFinishingLetter(lettersOrigin, i))
                        lettersFinal[i] = (char)(lettersOrigin[i] + 1);
                    else if (IsLeadingLetter(lettersOrigin, i))
                        lettersFinal[i] = (char)(lettersOrigin[i] + 2);
                }

                //string strOut = String.Format(@"\x{0:x4}", (ushort)lettersOrigin[i]);
                //UnityEngine.Debug.Log(strOut);

                //strOut = String.Format(@"\x{0:x4}", (ushort)lettersFinal[i]);
                //UnityEngine.Debug.Log(strOut);

                test += Convert.ToString(lettersOrigin[i], 16) + " ";
                if (skip)
                    i++;


                //chaning numbers to hindu
                if (useHinduNumbers)
                {
                    if (lettersOrigin[i] == (char)0x0030)
                        lettersFinal[i] = (char)0x0660;
                    else if (lettersOrigin[i] == (char)0x0031)
                        lettersFinal[i] = (char)0x0661;
                    else if (lettersOrigin[i] == (char)0x0032)
                        lettersFinal[i] = (char)0x0662;
                    else if (lettersOrigin[i] == (char)0x0033)
                        lettersFinal[i] = (char)0x0663;
                    else if (lettersOrigin[i] == (char)0x0034)
                        lettersFinal[i] = (char)0x0664;
                    else if (lettersOrigin[i] == (char)0x0035)
                        lettersFinal[i] = (char)0x0665;
                    else if (lettersOrigin[i] == (char)0x0036)
                        lettersFinal[i] = (char)0x0666;
                    else if (lettersOrigin[i] == (char)0x0037)
                        lettersFinal[i] = (char)0x0667;
                    else if (lettersOrigin[i] == (char)0x0038)
                        lettersFinal[i] = (char)0x0668;
                    else if (lettersOrigin[i] == (char)0x0039)
                        lettersFinal[i] = (char)0x0669;
                }

            }



            //Return the Tashkeel to their places.
            if (showTashkeel)
                lettersFinal = ReturnTashkeel(lettersFinal, tashkeelLocation);


            List<char> list = new List<char>();

            List<char> numberList = new List<char>();

            for (int i = lettersFinal.Length - 1; i >= 0; i--)
            {


                //				if (lettersFinal[i] == '(')
                //						numberList.Add(')');
                //				else if (lettersFinal[i] == ')')
                //					numberList.Add('(');
                //				else if (lettersFinal[i] == '<')
                //					numberList.Add('>');
                //				else if (lettersFinal[i] == '>')
                //					numberList.Add('<');
                //				else 
                if (char.IsPunctuation(lettersFinal[i]) && i > 0 && i < lettersFinal.Length - 1 &&
                    (char.IsPunctuation(lettersFinal[i - 1]) || char.IsPunctuation(lettersFinal[i + 1])))
                {
                    if (lettersFinal[i] == '(')
                        list.Add(')');
                    else if (lettersFinal[i] == ')')
                        list.Add('(');
                    else if (lettersFinal[i] == '<')
                        list.Add('>');
                    else if (lettersFinal[i] == '>')
                        list.Add('<');
                    else if (lettersFinal[i] == '[')
                        list.Add(']');
                    else if (lettersFinal[i] == ']')
                        list.Add('[');
                    else if (lettersFinal[i] != 0xFFFF)
                        list.Add(lettersFinal[i]);
                }
                // For cases where english words and arabic are mixed. This allows for using arabic, english and numbers in one sentence.
                else if (lettersFinal[i] == ' ' && i > 0 && i < lettersFinal.Length - 1 &&
                        (char.IsLower(lettersFinal[i - 1]) || char.IsUpper(lettersFinal[i - 1]) || char.IsNumber(lettersFinal[i - 1])) &&
                        (char.IsLower(lettersFinal[i + 1]) || char.IsUpper(lettersFinal[i + 1]) || char.IsNumber(lettersFinal[i + 1])))

                {
                    numberList.Add(lettersFinal[i]);
                }

                else if (char.IsNumber(lettersFinal[i]) || char.IsLower(lettersFinal[i]) ||
                         char.IsUpper(lettersFinal[i]) || char.IsSymbol(lettersFinal[i]) ||
                         char.IsPunctuation(lettersFinal[i]))// || lettersFinal[i] == '^') //)
                {

                    if (lettersFinal[i] == '(')
                        numberList.Add(')');
                    else if (lettersFinal[i] == ')')
                        numberList.Add('(');
                    else if (lettersFinal[i] == '<')
                        numberList.Add('>');
                    else if (lettersFinal[i] == '>')
                        numberList.Add('<');
                    else if (lettersFinal[i] == '[')
                        list.Add(']');
                    else if (lettersFinal[i] == ']')
                        list.Add('[');
                    else
                        numberList.Add(lettersFinal[i]);
                }
                else if (lettersFinal[i] >= (char)0xD800 && lettersFinal[i] <= (char)0xDBFF ||
                        lettersFinal[i] >= (char)0xDC00 && lettersFinal[i] <= (char)0xDFFF)
                {
                    numberList.Add(lettersFinal[i]);
                }
                else
                {
                    if (numberList.Count > 0)
                    {
                        for (int j = 0; j < numberList.Count; j++)
                            list.Add(numberList[numberList.Count - 1 - j]);
                        numberList.Clear();
                    }
                    if (lettersFinal[i] != 0xFFFF)
                        list.Add(lettersFinal[i]);

                }
            }
            if (numberList.Count > 0)
            {
                for (int j = 0; j < numberList.Count; j++)
                    list.Add(numberList[numberList.Count - 1 - j]);
                numberList.Clear();
            }

            // Moving letters from a list to an array.
            lettersFinal = new char[list.Count];
            for (int i = 0; i < lettersFinal.Length; i++)
                lettersFinal[i] = list[i];


            str = new string(lettersFinal);
            return str;
        }

        /// <summary>
        /// English letters, numbers and punctuation characters are ignored. This checks if the ch is an ignored character.
        /// </summary>
        /// <param name="ch">The character to be checked for skipping</param>
        /// <returns>True if the character should be ignored, false if it should not be ignored.</returns>
        internal static bool IsIgnoredCharacter(char ch)
        {
            bool isPunctuation = char.IsPunctuation(ch);
            bool isNumber = char.IsNumber(ch);
            bool isLower = char.IsLower(ch);
            bool isUpper = char.IsUpper(ch);
            bool isSymbol = char.IsSymbol(ch);
            bool isPersianCharacter = ch == (char)0xFB56 || ch == (char)0xFB7A || ch == (char)0xFB8A || ch == (char)0xFB92 || ch == (char)0xFB8E;
            bool isPresentationFormB = ch <= (char)0xFEFF && ch >= (char)0xFE70;
            bool isAcceptableCharacter = isPresentationFormB || isPersianCharacter || ch == (char)0xFBFC;



            return isPunctuation ||
                isNumber ||
                    isLower ||
                    isUpper ||
                    isSymbol ||
                    !isAcceptableCharacter ||
                    ch == 'a' || ch == '>' || ch == '<' || ch == (char)0x061B;

            //            return char.IsPunctuation(ch) || char.IsNumber(ch) || ch == 'a' || ch == '>' || ch == '<' ||
            //                    char.IsLower(ch) || char.IsUpper(ch) || ch == (char)0x061B || char.IsSymbol(ch)
            //					|| !(ch <= (char)0xFEFF && ch >= (char)0xFE70) // Presentation Form B
            //					|| ch == (char)0xFB56 || ch == (char)0xFB7A || ch == (char)0xFB8A || ch == (char)0xFB92; // Persian Characters

            //					PersianPe = 0xFB56,
            //		PersianChe = 0xFB7A,
            //		PersianZe = 0xFB8A,
            //		PersianGaf = 0xFB92
            //lettersOrigin[i] <= (char)0xFEFF && lettersOrigin[i] >= (char)0xFE70
        }

        /// <summary>
        /// Checks if the letter at index value is a leading character in Arabic or not.
        /// </summary>
        /// <param name="letters">The whole word that contains the character to be checked</param>
        /// <param name="index">The index of the character to be checked</param>
        /// <returns>True if the character at index is a leading character, else, returns false</returns>
        internal static bool IsLeadingLetter(char[] letters, int index)
        {

            bool lettersThatCannotBeBeforeALeadingLetter = index == 0
                || letters[index - 1] == ' '
                    || letters[index - 1] == '*' // ??? Remove?
                    || letters[index - 1] == 'A' // ??? Remove?
                    || char.IsPunctuation(letters[index - 1])
                    || letters[index - 1] == '>'
                    || letters[index - 1] == '<'
                    || letters[index - 1] == (int)IsolatedArabicLetters.Alef
                    || letters[index - 1] == (int)IsolatedArabicLetters.Dal
                    || letters[index - 1] == (int)IsolatedArabicLetters.Thal
                    || letters[index - 1] == (int)IsolatedArabicLetters.Ra2
                    || letters[index - 1] == (int)IsolatedArabicLetters.Zeen
                    || letters[index - 1] == (int)IsolatedArabicLetters.PersianZe
                    //|| letters[index - 1] == (int)IsolatedArabicLetters.AlefMaksora 
                    || letters[index - 1] == (int)IsolatedArabicLetters.Waw
                    || letters[index - 1] == (int)IsolatedArabicLetters.AlefMad
                    || letters[index - 1] == (int)IsolatedArabicLetters.AlefHamza
                    || letters[index - 1] == (int)IsolatedArabicLetters.AlefMaksoor
                    || letters[index - 1] == (int)IsolatedArabicLetters.WawHamza;

            bool lettersThatCannotBeALeadingLetter = letters[index] != ' '
                && letters[index] != (int)IsolatedArabicLetters.Dal
                && letters[index] != (int)IsolatedArabicLetters.Thal
                    && letters[index] != (int)IsolatedArabicLetters.Ra2
                    && letters[index] != (int)IsolatedArabicLetters.Zeen
                    && letters[index] != (int)IsolatedArabicLetters.PersianZe
                    && letters[index] != (int)IsolatedArabicLetters.Alef
                    && letters[index] != (int)IsolatedArabicLetters.AlefHamza
                    && letters[index] != (int)IsolatedArabicLetters.AlefMaksoor
                    && letters[index] != (int)IsolatedArabicLetters.AlefMad
                    && letters[index] != (int)IsolatedArabicLetters.WawHamza
                    && letters[index] != (int)IsolatedArabicLetters.Waw
                    && letters[index] != (int)IsolatedArabicLetters.Hamza;

            bool lettersThatCannotBeAfterLeadingLetter = index < letters.Length - 1
                && letters[index + 1] != ' '
                    && !char.IsPunctuation(letters[index + 1])
                    && !char.IsNumber(letters[index + 1])
                    && !char.IsSymbol(letters[index + 1])
                    && !char.IsLower(letters[index + 1])
                    && !char.IsUpper(letters[index + 1])
                    && letters[index + 1] != (int)IsolatedArabicLetters.Hamza;

            if (lettersThatCannotBeBeforeALeadingLetter && lettersThatCannotBeALeadingLetter && lettersThatCannotBeAfterLeadingLetter)

            //		if ((index == 0 || letters[index - 1] == ' ' || letters[index - 1] == '*' || letters[index - 1] == 'A' || char.IsPunctuation(letters[index - 1])
            //		     || letters[index - 1] == '>' || letters[index - 1] == '<' 
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.Alef
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.Dal || letters[index - 1] == (int)IsolatedArabicLetters.Thal
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.Ra2 
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.Zeen || letters[index - 1] == (int)IsolatedArabicLetters.PersianZe
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.AlefMaksora || letters[index - 1] == (int)IsolatedArabicLetters.Waw
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.AlefMad || letters[index - 1] == (int)IsolatedArabicLetters.AlefHamza
            //		     || letters[index - 1] == (int)IsolatedArabicLetters.AlefMaksoor || letters[index - 1] == (int)IsolatedArabicLetters.WawHamza) 
            //		    && letters[index] != ' ' && letters[index] != (int)IsolatedArabicLetters.Dal
            //		    && letters[index] != (int)IsolatedArabicLetters.Thal
            //		    && letters[index] != (int)IsolatedArabicLetters.Ra2 
            //		    && letters[index] != (int)IsolatedArabicLetters.Zeen && letters[index] != (int)IsolatedArabicLetters.PersianZe
            //		    && letters[index] != (int)IsolatedArabicLetters.Alef && letters[index] != (int)IsolatedArabicLetters.AlefHamza
            //		    && letters[index] != (int)IsolatedArabicLetters.AlefMaksoor
            //		    && letters[index] != (int)IsolatedArabicLetters.AlefMad
            //		    && letters[index] != (int)IsolatedArabicLetters.WawHamza
            //		    && letters[index] != (int)IsolatedArabicLetters.Waw
            //		    && letters[index] != (int)IsolatedArabicLetters.Hamza
            //		    && index < letters.Length - 1 && letters[index + 1] != ' ' && !char.IsPunctuation(letters[index + 1] ) && !char.IsNumber(letters[index + 1])
            //		    && letters[index + 1] != (int)IsolatedArabicLetters.Hamza )
            {
                return true;
            }

            return false;
        }

        /// <summary>
        /// Checks if the letter at index value is a finishing character in Arabic or not.
        /// </summary>
        /// <param name="letters">The whole word that contains the character to be checked</param>
        /// <param name="index">The index of the character to be checked</param>
        /// <returns>True if the character at index is a finishing character, else, returns false</returns>
        internal static bool IsFinishingLetter(char[] letters, int index)
        {
            //bool indexZero = index != 0;
            bool lettersThatCannotBeBeforeAFinishingLetter = index == 0 ? false :
                    letters[index - 1] != ' '
                    //				&& char.IsDigit(letters[index-1])
                    //				&& char.IsLower(letters[index-1])
                    //				&& char.IsUpper(letters[index-1])
                    //				&& char.IsNumber(letters[index-1])
                    //				&& char.IsWhiteSpace(letters[index-1])
                    //				&& char.IsPunctuation(letters[index-1])
                    //				&& char.IsSymbol(letters[index-1])

                    && letters[index - 1] != (int)IsolatedArabicLetters.Dal
                    && letters[index - 1] != (int)IsolatedArabicLetters.Thal
                    && letters[index - 1] != (int)IsolatedArabicLetters.Ra2
                    && letters[index - 1] != (int)IsolatedArabicLetters.Zeen
                    && letters[index - 1] != (int)IsolatedArabicLetters.PersianZe
                    //&& letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksora 
                    && letters[index - 1] != (int)IsolatedArabicLetters.Waw
                    && letters[index - 1] != (int)IsolatedArabicLetters.Alef
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMad
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefHamza
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksoor
                    && letters[index - 1] != (int)IsolatedArabicLetters.WawHamza
                    && letters[index - 1] != (int)IsolatedArabicLetters.Hamza



                    && !char.IsPunctuation(letters[index - 1])
                    && letters[index - 1] != '>'
                    && letters[index - 1] != '<';


            bool lettersThatCannotBeFinishingLetters = letters[index] != ' ' && letters[index] != (int)IsolatedArabicLetters.Hamza;




            if (lettersThatCannotBeBeforeAFinishingLetter && lettersThatCannotBeFinishingLetters)

            //		if (index != 0 && letters[index - 1] != ' ' && letters[index - 1] != '*' && letters[index - 1] != 'A'
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Dal && letters[index - 1] != (int)IsolatedArabicLetters.Thal
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Ra2 
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Zeen && letters[index - 1] != (int)IsolatedArabicLetters.PersianZe
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksora && letters[index - 1] != (int)IsolatedArabicLetters.Waw
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Alef && letters[index - 1] != (int)IsolatedArabicLetters.AlefMad
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.AlefHamza && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksoor
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.WawHamza && letters[index - 1] != (int)IsolatedArabicLetters.Hamza 
            //		    && !char.IsPunctuation(letters[index - 1]) && letters[index - 1] != '>' && letters[index - 1] != '<' 
            //		    && letters[index] != ' ' && index < letters.Length
            //		    && letters[index] != (int)IsolatedArabicLetters.Hamza)
            {
                //try
                //{
                //    if (char.IsPunctuation(letters[index + 1]))
                //        return true;
                //    else
                //        return false;
                //}
                //catch (Exception e)
                //{
                //    return false;
                //}

                return true;
            }
            //return true;

            return false;
        }

        /// <summary>
        /// Checks if the letter at index value is a middle character in Arabic or not.
        /// </summary>
        /// <param name="letters">The whole word that contains the character to be checked</param>
        /// <param name="index">The index of the character to be checked</param>
        /// <returns>True if the character at index is a middle character, else, returns false</returns>
        internal static bool IsMiddleLetter(char[] letters, int index)
        {
            bool lettersThatCannotBeMiddleLetters = index == 0 ? false :
                letters[index] != (int)IsolatedArabicLetters.Alef
                    && letters[index] != (int)IsolatedArabicLetters.Dal
                    && letters[index] != (int)IsolatedArabicLetters.Thal
                    && letters[index] != (int)IsolatedArabicLetters.Ra2
                    && letters[index] != (int)IsolatedArabicLetters.Zeen
                    && letters[index] != (int)IsolatedArabicLetters.PersianZe
                    //&& letters[index] != (int)IsolatedArabicLetters.AlefMaksora
                    && letters[index] != (int)IsolatedArabicLetters.Waw
                    && letters[index] != (int)IsolatedArabicLetters.AlefMad
                    && letters[index] != (int)IsolatedArabicLetters.AlefHamza
                    && letters[index] != (int)IsolatedArabicLetters.AlefMaksoor
                    && letters[index] != (int)IsolatedArabicLetters.WawHamza
                    && letters[index] != (int)IsolatedArabicLetters.Hamza;

            bool lettersThatCannotBeBeforeMiddleCharacters = index == 0 ? false :
                    letters[index - 1] != (int)IsolatedArabicLetters.Alef
                    && letters[index - 1] != (int)IsolatedArabicLetters.Dal
                    && letters[index - 1] != (int)IsolatedArabicLetters.Thal
                    && letters[index - 1] != (int)IsolatedArabicLetters.Ra2
                    && letters[index - 1] != (int)IsolatedArabicLetters.Zeen
                    && letters[index - 1] != (int)IsolatedArabicLetters.PersianZe
                    //&& letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksora
                    && letters[index - 1] != (int)IsolatedArabicLetters.Waw
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMad
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefHamza
                    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksoor
                    && letters[index - 1] != (int)IsolatedArabicLetters.WawHamza
                    && letters[index - 1] != (int)IsolatedArabicLetters.Hamza
                    && !char.IsPunctuation(letters[index - 1])
                    && letters[index - 1] != '>'
                    && letters[index - 1] != '<'
                    && letters[index - 1] != ' '
                    && letters[index - 1] != '*';

            bool lettersThatCannotBeAfterMiddleCharacters = index >= letters.Length - 1 ? false :
                letters[index + 1] != ' '
                    && letters[index + 1] != '\r'
                    && letters[index + 1] != (int)IsolatedArabicLetters.Hamza
                    && !char.IsNumber(letters[index + 1])
                    && !char.IsSymbol(letters[index + 1])
                    && !char.IsPunctuation(letters[index + 1]);
            if (lettersThatCannotBeAfterMiddleCharacters && lettersThatCannotBeBeforeMiddleCharacters && lettersThatCannotBeMiddleLetters)

            //		if (index != 0 && letters[index] != ' '
            //		    && letters[index] != (int)IsolatedArabicLetters.Alef && letters[index] != (int)IsolatedArabicLetters.Dal
            //		    && letters[index] != (int)IsolatedArabicLetters.Thal && letters[index] != (int)IsolatedArabicLetters.Ra2
            //		    && letters[index] != (int)IsolatedArabicLetters.Zeen && letters[index] != (int)IsolatedArabicLetters.PersianZe 
            //		    && letters[index] != (int)IsolatedArabicLetters.AlefMaksora
            //		    && letters[index] != (int)IsolatedArabicLetters.Waw && letters[index] != (int)IsolatedArabicLetters.AlefMad
            //		    && letters[index] != (int)IsolatedArabicLetters.AlefHamza && letters[index] != (int)IsolatedArabicLetters.AlefMaksoor
            //		    && letters[index] != (int)IsolatedArabicLetters.WawHamza && letters[index] != (int)IsolatedArabicLetters.Hamza
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Alef && letters[index - 1] != (int)IsolatedArabicLetters.Dal
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Thal && letters[index - 1] != (int)IsolatedArabicLetters.Ra2
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Zeen && letters[index - 1] != (int)IsolatedArabicLetters.PersianZe 
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksora
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.Waw && letters[index - 1] != (int)IsolatedArabicLetters.AlefMad
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.AlefHamza && letters[index - 1] != (int)IsolatedArabicLetters.AlefMaksoor
            //		    && letters[index - 1] != (int)IsolatedArabicLetters.WawHamza && letters[index - 1] != (int)IsolatedArabicLetters.Hamza 
            //		    && letters[index - 1] != '>' && letters[index - 1] != '<' 
            //		    && letters[index - 1] != ' ' && letters[index - 1] != '*' && !char.IsPunctuation(letters[index - 1])
            //		    && index < letters.Length - 1 && letters[index + 1] != ' ' && letters[index + 1] != '\r' && letters[index + 1] != 'A' 
            //		    && letters[index + 1] != '>' && letters[index + 1] != '>' && letters[index + 1] != (int)IsolatedArabicLetters.Hamza
            //		    )
            {
                try
                {
                    if (char.IsPunctuation(letters[index + 1]))
                        return false;
                    return true;
                }
                catch
                {
                    return false;
                }
                //return true;
            }

            return false;
        }
    }
}
