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// ==++==
//
//   
//    Copyright (c) 2002 Microsoft Corporation.  All rights reserved.
//   
//    The use and distribution terms for this software are contained in the file
//    named license.txt, which can be found in the root of this distribution.
//    By using this software in any fashion, you are agreeing to be bound by the
//    terms of this license.
//   
//    You must not remove this notice, or any other, from this software.
//   
//
// ==--==
namespace System {

    using System;
    using System.Text;
    using System.Runtime.InteropServices;
    using System.Runtime.CompilerServices;
    using System.Globalization;
    // Represents a Globally Unique Identifier.
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid"]/*' />
    [StructLayout(LayoutKind.Sequential)]
    [Serializable]
        public struct Guid : IFormattable, IComparable
    {
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Empty"]/*' />
        public static readonly Guid Empty = new Guid();
        ////////////////////////////////////////////////////////////////////////////////
        //  Member variables
        ////////////////////////////////////////////////////////////////////////////////
        private int         _a;
        private short       _b;
        private short       _c;
        private byte       _d;
        private byte       _e;
        private byte       _f;
        private byte       _g;
        private byte       _h;
        private byte       _i;
        private byte       _j;
        private byte       _k;



        ////////////////////////////////////////////////////////////////////////////////
        //  Constructors
        ////////////////////////////////////////////////////////////////////////////////

        // Creates a new guid from an array of bytes.
        //
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Guid"]/*' />
        public Guid(byte[] b)
        {
            if (b==null)
                throw new ArgumentNullException("b");
            if (b.Length != 16)
                throw new ArgumentException(String.Format(Environment.GetResourceString("Arg_GuidArrayCtor"), "16"));
            _a = ((int)b[0] << 24) | ((int)b[1] << 16) | ((int)b[2] << 8) | b[3];
            _b = (short)(((int)b[4] << 8) | b[5]);
            _c = (short)(((int)b[6] << 8) | b[7]);
            _d = b[8];
            _e = b[9];
            _f = b[10];
            _g = b[11];
            _h = b[12];
            _i = b[13];
            _j = b[14];
            _k = b[15];
        }

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Guid1"]/*' />
        [CLSCompliant(false)]
        public Guid (uint a, ushort b, ushort c, byte d, byte e, byte f, byte g, byte h, byte i, byte j, byte k)
        {
            _a = (int)a;
            _b = (short)b;
            _c = (short)c;
            _d = d;
            _e = e;
            _f = f;
            _g = g;
            _h = h;
            _i = i;
            _j = j;
            _k = k;
        }

        // Creates a new guid with all contents having value of 0
        private Guid(bool blank)
        {
            // Must initialize value class members even if the native
            // function reinitializes them.  Compiler appeasement.
            _a = 0;
            _b = 0;
            _c = 0;
            _d = 0;
            _e = 0;
            _f = 0;
            _g = 0;
            _h = 0;
            _i = 0;
            _j = 0;
            _k = 0;
            if (!blank)
                CompleteGuid();
        }

        // Creates a new guid based on the value in the string.  The value is made up
        // of hex digits speared by the dash ("-"). The string may begin and end with
        // brackets ("{", "}").
        //
        // The string must be of the form dddddddd-dddd-dddd-dddd-dddddddddddd. where
        // d is a hex digit. (That is 8 hex digits, followed by 4, then 4, then 4,
        // then 12) such as: "CA761232-ED42-11CE-BACD-00AA0057B223"
        //
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Guid2"]/*' />
        public Guid(String g)
        {
            if (g==null)
                throw new ArgumentNullException("g", "ArgumentNull_String");

            int startPos=0;
            int temp;
            long templ;
            int[] spArray = new int[1];

            try
            {
                // Check if it's of the form dddddddd-dddd-dddd-dddd-dddddddddddd
                if(g.IndexOf('-', 0) >= 0)
                {

                    String guidString = g.Trim();  //Remove Whitespace

                    // check to see that it's the proper length
                    if (guidString[0]=='{') {
                        if (guidString.Length!=38 || guidString[37]!='}') {
                            throw new FormatException(Environment.GetResourceString("Format_GuidInvLen"));
                        }
                        startPos=1;
                    }
                    else if (guidString[0]=='(')
                    {
                        if (guidString.Length!=38 || guidString[37]!=')')
                        {
                            throw new FormatException(Environment.GetResourceString("Format_GuidInvLen"));
                        }
                        startPos=1;
                    }
                    else if(guidString.Length != 36) {
                        throw new FormatException(Environment.GetResourceString("Format_GuidInvLen"));
                    }
                    if (guidString[8+startPos] != '-' ||
                        guidString[13+startPos] != '-' ||
                        guidString[18+startPos] != '-' ||
                        guidString[23+startPos] != '-') {
                        throw new FormatException(Environment.GetResourceString("Format_GuidDashes"));
                    }

                    spArray[0]=startPos;
                    _a = TryParse(guidString, spArray,8);
                    spArray[0]++; //Increment past the '-';
                    _b = (short)TryParse(guidString, spArray,4);
                    spArray[0]++; //Increment past the '-';
                    _c = (short)TryParse(guidString, spArray,4);
                    spArray[0]++; //Increment past the '-';
                    temp=TryParse(guidString, spArray,4);
                    spArray[0]++; //Increment past the '-';
                    startPos=spArray[0];
                    templ = ParseNumbers.StringToLong(guidString, 16, 0, spArray);
                    if (spArray[0]-startPos!=12) {
                        throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidInvLen")));
                    }
                    _d = (byte)(temp>>8);
                    _e = (byte)(temp);
                    temp = (int)(templ >> 32);
                    _f = (byte)(temp>>8);
                    _g = (byte)(temp);
                    temp = (int)(templ);
                    _h = (byte)(temp>>24);
                    _i = (byte)(temp>>16);
                    _j = (byte)(temp>>8);
                    _k = (byte)(temp);
                }
                // Else check if it is of the form
                // {0xdddddddd,0xdddd,0xdddd,{0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd}}
                else if(g.IndexOf('{', 0) >= 0)
                {
                    int numStart = 0;
                    int numLen = 0;

                    // Convert to lower case
                    //g = g.ToLower();

                    // Eat all of the whitespace
                    g = EatAllWhitespace(g);

                    // Check for leading '{'
                    if(g[0] != '{')
                        throw new FormatException(Environment.GetResourceString("Format_GuidBrace"));

                    // Check for '0x'
                    if(!IsHexPrefix(g, 1))
                        throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidHexPrefix"), "{0xdddddddd, etc}"));

                    // Find the end of this hex number (since it is not fixed length)
                    numStart = 3;
                    numLen = g.IndexOf(',', numStart) - numStart;
                    if(numLen <= 0)
                        throw new FormatException(Environment.GetResourceString("Format_GuidComma"));

                    // Read in the number
                    _a = (int) ParseNumbers.StringToInt(g.Substring(numStart, numLen), // first DWORD
                                                        16,                            // hex
                                                        ParseNumbers.IsTight);         // tight parsing

                    // Check for '0x'
                    if(!IsHexPrefix(g, numStart+numLen+1))
                        throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidHexPrefix"), "{0xdddddddd, 0xdddd, etc}"));

                    // +3 to get by ',0x'
                    numStart = numStart + numLen + 3;
                    numLen = g.IndexOf(',', numStart) - numStart;
                    if(numLen <= 0)
                        throw new FormatException(Environment.GetResourceString("Format_GuidComma"));

                    // Read in the number
                    _b = (short) ParseNumbers.StringToInt(
                                                          g.Substring(numStart, numLen), // first DWORD
                                                          16,                            // hex
                                                          ParseNumbers.IsTight);         // tight parsing

                    // Check for '0x'
                    if(!IsHexPrefix(g, numStart+numLen+1))
                        throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidHexPrefix"), "{0xdddddddd, 0xdddd, 0xdddd, etc}"));

                    // +3 to get by ',0x'
                    numStart = numStart + numLen + 3;
                    numLen = g.IndexOf(',', numStart) - numStart;
                    if(numLen <= 0)
                        throw new FormatException(Environment.GetResourceString("Format_GuidComma"));

                    // Read in the number
                    _c = (short) ParseNumbers.StringToInt(
                                                          g.Substring(numStart, numLen), // first DWORD
                                                          16,                            // hex
                                                          ParseNumbers.IsTight);         // tight parsing

                    // Check for '{'
                    if(g.Length <= numStart+numLen+1 || g[numStart+numLen+1] != '{')
                        throw new FormatException(Environment.GetResourceString("Format_GuidBrace"));

                    // Prepare for loop
                    numLen++;
                    byte[] bytes = new byte[8];

                    for(int i = 0; i < 8; i++)
                    {
                        // Check for '0x'
                        if(!IsHexPrefix(g, numStart+numLen+1))
                            throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidHexPrefix"), "{ {  0xdd, }}"));

                        // +3 to get by ',0x' or '{0x' for first case
                        numStart = numStart + numLen + 3;

                        // Calculate number length
                        if(i < 7)  // first 7 cases
                        {
                            numLen = g.IndexOf(',', numStart) - numStart;
                        }
                        else       // last case ends with '}', not ','
                        {
                            numLen = g.IndexOf('}', numStart) - numStart;
                        }
                        if(numLen <= 0)
                            throw new FormatException(Environment.GetResourceString("Format_GuidComma"));

                        // Read in the number
                        bytes[i] = (byte) Convert.ToInt32(g.Substring(numStart, numLen),16);
                    }

                    _d = bytes[0];
                    _e = bytes[1];
                    _f = bytes[2];
                    _g = bytes[3];
                    _h = bytes[4];
                    _i = bytes[5];
                    _j = bytes[6];
                    _k = bytes[7];

                    // Check for last '}'
                    if(numStart+numLen+1 >= g.Length || g[numStart+numLen+1] != '}')
                        throw new FormatException(Environment.GetResourceString("Format_GuidEndBrace"));

                    return;
                }
                else
                // Check if it's of the form dddddddddddddddddddddddddddddddd
                {
                    String guidString = g.Trim();  //Remove Whitespace

                    if(guidString.Length != 32) {
                        throw new FormatException(Environment.GetResourceString("Format_GuidInvLen"));
                    }

                    _a = (int) ParseNumbers.StringToInt(g.Substring(startPos, 8), // first DWORD
                                                        16,                            // hex
                                                        ParseNumbers.IsTight);         // tight parsing
                    startPos += 8;
                    _b = (short) ParseNumbers.StringToInt(g.Substring(startPos, 4),
                                                        16,
                                                        ParseNumbers.IsTight);
                    startPos += 4;
                    _c = (short) ParseNumbers.StringToInt(g.Substring(startPos, 4),
                                                        16,
                                                        ParseNumbers.IsTight);

                    startPos += 4;
                    temp=(short) ParseNumbers.StringToInt(g.Substring(startPos, 4),
                                                        16,
                                                        ParseNumbers.IsTight);
                    startPos += 4;
                    spArray[0] = startPos;
                    templ = ParseNumbers.StringToLong(guidString, 16, startPos, spArray);
                    if (spArray[0]-startPos!=12) {
                        throw new FormatException(String.Format(Environment.GetResourceString("Format_GuidInvLen")));
                    }
                    _d = (byte)(temp>>8);
                    _e = (byte)(temp);
                    temp = (int)(templ >> 32);
                    _f = (byte)(temp>>8);
                    _g = (byte)(temp);
                    temp = (int)(templ);
                    _h = (byte)(temp>>24);
                    _i = (byte)(temp>>16);
                    _j = (byte)(temp>>8);
                    _k = (byte)(temp);
                }
            }
            catch(IndexOutOfRangeException)
            {
                throw new FormatException(Environment.GetResourceString("Format_GuidUnrecognized"));
            }
        }

        // Creates a new GUID initialized to the value represented by the arguments.
        //
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Guid3"]/*' />
        public Guid(int a, short b, short c, byte[] d)
        {
            if (d==null)
                throw new ArgumentNullException("d");
            // Check that array is not too big
            if(d.Length != 8)
                throw new ArgumentException(String.Format(Environment.GetResourceString("Arg_GuidArrayCtor"), "8"));

            _a  = a;
            _b  = b;
            _c  = c;
            _d = d[0];
            _e = d[1];
            _f = d[2];
            _g = d[3];
            _h = d[4];
            _i = d[5];
            _j = d[6];
            _k = d[7];
        }

        // Creates a new GUID initialized to the value represented by the
        // arguments.  The bytes are specified like this to avoid endianness issues.
        //
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Guid4"]/*' />
        public Guid(int a, short b, short c, byte d, byte e, byte f, byte g, byte h, byte i, byte j, byte k)
        {
            _a = a;
            _b = b;
            _c = c;
            _d = d;
            _e = e;
            _f = f;
            _g = g;
            _h = h;
            _i = i;
            _j = j;
            _k = k;
        }


        private static int TryParse(String str, int []parsePos, int requiredLength) {
            int currStart = parsePos[0];
            int retVal;
            try
            {
                retVal = ParseNumbers.StringToInt(str, 16, 0, parsePos);
            }
            catch (FormatException)
            {
               throw new FormatException(Environment.GetResourceString("Format_GuidUnrecognized"));
            }

            //If we didn't parse enough characters, there's clearly an error.
            if (parsePos[0]-currStart!=requiredLength) {
                throw new FormatException(Environment.GetResourceString("Format_GuidUnrecognized"));
            }
            return retVal;
        }

        private static String EatAllWhitespace(String str)
        {
            int newLength = 0;
            char[] chArr = new char[str.Length];
            char curChar;

            // Now get each char from str and if it is not whitespace add it to chArr
            for(int i = 0; i < str.Length; i++)
            {
                curChar = str[i];
                if(!Char.IsWhiteSpace(curChar))
                {
                    chArr[newLength++] = curChar;
                }
            }

            // Return a new string based on chArr
            return new String(chArr, 0, newLength);
        }

        private static bool IsHexPrefix(String str, int i)
        {
            if(str[i] == '0' && (Char.ToLower(str[i+1], CultureInfo.InvariantCulture) == 'x'))
                return true;
            else
                return false;
        }


        // Returns an unsigned byte array containing the GUID.
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.ToByteArray"]/*' />
        public byte[] ToByteArray()
        {
            byte[] g = new byte[16];

            g[0] = (byte)(_a >> 24);
            g[1] = (byte)(_a >> 16);
            g[2] = (byte)(_a >> 8);
            g[3] = (byte)(_a);
            g[4] = (byte)(_b >> 8);
            g[5] = (byte)(_b);
            g[6] = (byte)(_c >> 8);
            g[7] = (byte)(_c);
            g[8] = _d;
            g[9] = _e;
            g[10] = _f;
            g[11] = _g;
            g[12] = _h;
            g[13] = _i;
            g[14] = _j;
            g[15] = _k;

            return g;
        }


        // Returns the guid in "registry" format.
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.ToString"]/*' />
        public override String ToString()
        {
            return ToString("D",null);
        }

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.GetHashCode"]/*' />
        public override int GetHashCode()
        {
            return _a ^ (((int)_b << 16) | (int)(ushort)_c) ^ (((int)_f << 24) | _k);
        }

        // Returns true if and only if the guid represented
        //  by o is the same as this instance.
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.Equals"]/*' />
        public override bool Equals(Object o)
        {
            Guid g;
            // Check that o is a Guid first
            if(o == null || !(o is Guid))
                return false;
            else g = (Guid) o;

            // Now compare each of the elements
            if(g._a != _a)
                return false;
            if(g._b != _b)
                return false;
            if(g._c != _c)
                return false;
            if (g._d != _d)
                return false;
            if (g._e != _e)
                return false;
            if (g._f != _f)
                return false;
            if (g._g != _g)
                return false;
            if (g._h != _h)
                return false;
            if (g._i != _i)
                return false;
            if (g._j != _j)
                return false;
            if (g._k != _k)
                return false;

            return true;
        }

        private int GetResult(uint me, uint them) {
            if (me<them) {
                return -1;
            }
            return 1;
        }

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.CompareTo"]/*' />
        public int CompareTo(Object value) {
            if (value == null) {
                return 1;
            }
            if (!(value is Guid)) {
                throw new ArgumentException(Environment.GetResourceString("Arg_MustBeGuid"));
            }
            Guid g = (Guid)value;

            if (g._a!=this._a) {
                return GetResult((uint)this._a, (uint)g._a);
            }

            if (g._b!=this._b) {
                return GetResult((uint)this._b, (uint)g._b);
            }

            if (g._c!=this._c) {
                return GetResult((uint)this._c, (uint)g._c);
            }

            if (g._d!=this._d) {
                return GetResult((uint)this._d, (uint)g._d);
            }

            if (g._e!=this._e) {
                return GetResult((uint)this._e, (uint)g._e);
            }

            if (g._f!=this._f) {
                return GetResult((uint)this._f, (uint)g._f);
            }

            if (g._g!=this._g) {
                return GetResult((uint)this._g, (uint)g._g);
            }

            if (g._h!=this._h) {
                return GetResult((uint)this._h, (uint)g._h);
            }

            if (g._i!=this._i) {
                return GetResult((uint)this._i, (uint)g._i);
            }

            if (g._j!=this._j) {
                return GetResult((uint)this._j, (uint)g._j);
            }

            if (g._k!=this._k) {
                return GetResult((uint)this._k, (uint)g._k);
            }

            return 0;
        }

        // Compares two Guids by calling Guid.Equals(Guid).
    /*  private static bool operator equals(Guid a, Guid b)
        {
            return a.Equals(b);
        }*/

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.operatorEQ"]/*' />
        public static bool operator ==(Guid a, Guid b)
        {
            return a.Equals(b);
        }

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.operatorNE"]/*' />
        public static bool operator !=(Guid a, Guid b)
        {
            return !a.Equals(b);
        }

        // This will fill in the members of Guid using CoCreateGuid.
        [MethodImplAttribute(MethodImplOptions.InternalCall)]
        private extern void CompleteGuid();

        // This will create a new guid.  Since we've now decided that constructors should 0-init,
        // we need a method that allows users to create a guid.
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.NewGuid"]/*' />
        public static Guid NewGuid() {
            return new Guid(false);
        }

        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.ToString1"]/*' />
        public String ToString(String format) {
            return ToString(format, null);
        }

        private static char HexToChar(int a)
        {
            a = a & 0xf;
            return (char) ((a > 9) ? a - 10 + 0x61 : a + 0x30);
        }

        private static int HexsToChars(char[] guidChars, int offset, int a, int b)
        {
            guidChars[offset++] = HexToChar(a>>4);
            guidChars[offset++] = HexToChar(a);
            guidChars[offset++] = HexToChar(b>>4);
            guidChars[offset++] = HexToChar(b);
            return offset;
        }

        // IFormattable interface
        // We currently ignore provider
        /// <include file='doc\Guid.uex' path='docs/doc[@for="Guid.ToString2"]/*' />
        public String ToString(String format, IFormatProvider provider)
        {
            if (format == null || format.Length == 0)
                format = "D";

            char[] guidChars;
            int offset = 0;
            int strLength = 38;
            bool dash = true;

            if (String.Compare(format,"N",true, CultureInfo.InvariantCulture) == 0)
            {
                guidChars = new char[32];
                strLength = 32;
                dash = false;
            }
            else if (String.Compare(format,"B",true, CultureInfo.InvariantCulture) == 0)
            {
                guidChars = new char[38];
                guidChars[offset++] = '{';
                guidChars[37] = '}';
            }
            else if (String.Compare(format,"P",true, CultureInfo.InvariantCulture) == 0)
            {
                guidChars = new char[38];
                guidChars[offset++] = '(';
                guidChars[37] = ')';
            }
            else if (String.Compare(format,"D",true, CultureInfo.InvariantCulture) == 0)
            {
                guidChars = new char[36];
                strLength = 36;
            }
            else
                throw new FormatException(Environment.GetResourceString("Format_InvalidGuidFormatSpecification"));

            offset = HexsToChars(guidChars, offset, _a >> 24, _a >> 16);
            offset = HexsToChars(guidChars, offset, _a >> 8, _a);

            if (dash) guidChars[offset++] = '-';

            offset = HexsToChars(guidChars, offset, _b >> 8, _b);

            if (dash) guidChars[offset++] = '-';

            offset = HexsToChars(guidChars, offset, _c >> 8, _c);

            if (dash) guidChars[offset++] = '-';

            offset = HexsToChars(guidChars, offset, _d, _e);

            if (dash) guidChars[offset++] = '-';

            offset = HexsToChars(guidChars, offset, _f, _g);
            offset = HexsToChars(guidChars, offset, _h, _i);
            offset = HexsToChars(guidChars, offset, _j, _k);

            return new String(guidChars, 0, strLength);
        }
    }
}