using System;

using System.Collections.Generic;

using System.Globalization;

using System.Linq;

using System.Text.RegularExpressions;

public class Program {

    public static void Main() {

        FormatEnum(_enum);

    }

    public class Line {

        public bool Format { get; set; }

        public string Identifier { get; set; }

        public string Assignment { get; set; }

        public string Comment { get; set; }

        public ulong Value {

            get { return GetUInt64Value(); }

        }

        private long GetInt64Value() {

            if (Assignment.StartsWith("0x")) return long.Parse(Assignment.Substring(2), NumberStyles.HexNumber);

            return long.Parse(Assignment);

        }

​

        private ulong GetUInt64Value() {

            if (Assignment.StartsWith("-")) return (ulong) GetInt64Value();

            if (Assignment.StartsWith("0x")) return ulong.Parse(Assignment.Substring(2), NumberStyles.HexNumber);

            return ulong.Parse(Assignment);

        }

    }

    public static void FormatEnum(string enumCode, string enumType = null, bool formatValue = false, bool hexOutput = false) {

        formatValue |= hexOutput;

        var lines = enumCode

            .Replace("\t", "    ")

            .Replace("\r", "")

            .Split('\n');

        var output = new List<Line>();

        for (var i = 0; i < lines.Length; i++) {

            var line = lines[i].TrimStart();

            // Try get the enum type.

            if (enumType == null) {

                var enumDefinition = Regex.Match(line, @"^(?:(?!\/\/).)*enum\s+(\w+)\s*(?::\s*(\w+))?\s*{?\s*$");

                if (!enumDefinition.Success)

                    continue;

                enumType = enumDefinition.Groups[2].Success ? enumDefinition.Groups[2].Value : "int";

                output.Add(new Line { Comment = line });

                continue;

            }

            if (line.StartsWith("{") || line.StartsWith("}")) {

                output.Add(new Line { Comment = line });

                continue;

            }

            var match = Regex.Match(line, @"(\w*)[ \t]*=[ \t]*([\~\-0xXa-fA-F0-9]*)[, \t]*(.*)");

            if (!match.Success) {

                output.Add(new Line { Comment = "    " + line });

                continue;

            }

            var identifier = match.Groups[1].Value;

            var assignment = match.Groups[2].Value;

            var comment    = match.Groups[3].Value;

            output.Add(new Line {

                Format     = true,

                Identifier = identifier,

                Assignment = assignment,

                Comment    = comment

            });

        }

        if (formatValue) {

            var format = GetFormatString(enumType, hexOutput);

            var size   = GetSize(enumType);

            var signed = GetSigned(enumType);

            var negativeBit = 1ul << ((size * 8) - 1);

            var mask = (1ul << (size * 8)) - 1;

            if (mask == 0) mask = ulong.MaxValue;

            foreach (var line in output.Where(l => l.Format)) {

                var @value = line.Value;

                var lineFormat = format;

                if (signed && hexOutput && (@value & negativeBit) != 0) {

                    @value &= ~negativeBit;

                    lineFormat += " | (1 << " + ((size * 8) - 1) + ")";

                }

                line.Assignment = string.Format(lineFormat, signed ?

                    (object)(long) (@value & mask) :

                    (object)(ulong)(@value & mask));

            }

        }

        var longestIdentifier = output

            .Where(l => l.Format)

            .Max(l => l.Identifier.Length);

        var longestAssignment = output

            .Where(l => l.Format)

            .Max(l => l.Assignment.Length);

        foreach (var line in output) {

            if (!line.Format) {

                Console.WriteLine(line.Comment);

                continue;

            }

            var identifier = line.Identifier.PadRight(longestIdentifier);

            var assignment = line.Comment.Length > 0 ? line.Assignment.PadRight(longestAssignment + 1) : line.Assignment;

            var comment    = line.Comment;

            Console.WriteLine("    {0} = {1}{2},", identifier, assignment, comment);

        }

    }

    public static bool GetSigned(string type) {

        switch (type) {

            case "sbyte": return true;

            case "short": return true;

            case "int":   return true;

            case "long":  return true;

            default: return false;

        }

    }

    public static int GetSize(string type) {

        switch (type) {

            case "byte":   case "sbyte": return 1;

            case "ushort": case "short": return 2;

            case "uint":   case "int":   return 4;

            case "ulong":  case "long":  return 8;

            default: return 4;

        }

    }

    public static string GetFormatString(string type, bool hex) {

        return hex ? "0x{0:X" + GetSize(type) * 2 + "}" : "{0}";

    }

    public const string _enum = @"

    public enum Keys : int {

        Modifiers = -65536,

        None = 0,

        LButton = 1,

        RButton = 2,

        Cancel = 3,

        MButton = 4,

        XButton1 = 5,

        XButton2 = 6,

        Back = 8,

        Tab = 9,

        LineFeed = 10,

        Clear = 12,

        Enter = 13,

        Return = 13,

        ShiftKey = 16,

        ControlKey = 17,

        Menu = 18,

        Pause = 19,

        CapsLock = 20,

        Capital = 20,

        KanaMode = 21,

        HanguelMode = 21,

        HangulMode = 21,

        JunjaMode = 23,

        FinalMode = 24,

        KanjiMode = 25,

        HanjaMode = 25,

        Escape = 27,

        IMEConvert = 28,

        IMENonconvert = 29,

        IMEAceept = 30,

        IMEAccept = 30,

        IMEModeChange = 31,

        Space = 32,

        Prior = 33,

        PageUp = 33,

        Next = 34,

        PageDown = 34,

        End = 35,

        Home = 36,

        Left = 37,

        Up = 38,

        Right = 39,

        Down = 40,

        Select = 41,

        Print = 42,

        Execute = 43,

        PrintScreen = 44,

        Snapshot = 44,

        Insert = 45,

        Delete = 46,

        Help = 47,

        D0 = 48,

        D1 = 49,

        D2 = 50,

        D3 = 51,

        D4 = 52,

        D5 = 53,

        D6 = 54,

        D7 = 55,

        D8 = 56,

        D9 = 57,

        A = 65,

        B = 66,

        C = 67,

        D = 68,

        E = 69,

        F = 70,

        G = 71,

        H = 72,

        I = 73,

        J = 74,

        K = 75,

        L = 76,

        M = 77,

        N = 78,

        O = 79,

        P = 80,

        Q = 81,

        R = 82,

        S = 83,

        T = 84,

        U = 85,

        V = 86,

        W = 87,

        X = 88,

        Y = 89,

        Z = 90,

        LWin = 91,

        RWin = 92,

        Apps = 93,

        Sleep = 95,

        NumPad0 = 96,

        NumPad1 = 97,

        NumPad2 = 98,

        NumPad3 = 99,

        NumPad4 = 100,

        NumPad5 = 101,

        NumPad6 = 102,

        NumPad7 = 103,

        NumPad8 = 104,

        NumPad9 = 105,

        Multiply = 106,

        Add = 107,

        Separator = 108,

        Subtract = 109,

        Decimal = 110,

        Divide = 111,

        F1 = 112,

        F2 = 113,

        F3 = 114,

        F4 = 115,

        F5 = 116,

        F6 = 117,

        F7 = 118,

        F8 = 119,

        F9 = 120,

        F10 = 121,

        F11 = 122,

        F12 = 123,

        F13 = 124,

        F14 = 125,

        F15 = 126,

        F16 = 127,

        F17 = 128,

        F18 = 129,

        F19 = 130,

        F20 = 131,

        F21 = 132,

        F22 = 133,

        F23 = 134,

        F24 = 135,

        NumLock = 144,

        Scroll = 145,

        LShiftKey = 160,

        RShiftKey = 161,

        LControlKey = 162,

        RControlKey = 163,

        LMenu = 164,

        RMenu = 165,

        BrowserBack = 166,

        BrowserForward = 167,

        BrowserRefresh = 168,

        BrowserStop = 169,

        BrowserSearch = 170,

        BrowserFavorites = 171,

        BrowserHome = 172,

        VolumeMute = 173,

        VolumeDown = 174,

        VolumeUp = 175,

        MediaNextTrack = 176,

        MediaPreviousTrack = 177,

        MediaStop = 178,

        MediaPlayPause = 179,

        LaunchMail = 180,

        SelectMedia = 181,

        LaunchApplication1 = 182,

        LaunchApplication2 = 183,

​

        // OEM-specific.

        Oem1 = 186,

        Oem2 = 191,

        Oem3 = 192,

        Oem4 = 219,

        Oem5 = 220,

        Oem6 = 221,

        Oem7 = 222,

        Oem8 = 223,

        Oem102 = 226,

​

        Semicolon = 186,

        Plus = 187,

        Comma = 188,

        Minus = 189,

        Period = 190,

        Question = 191,

        Tilde = 192,

        OpenBrackets = 219,

        Pipe = 220,

        CloseBrackets = 221,

        Quotes = 222,

        Backslash = 226,

​

        // Modifiers.

        Shift   = 0x10000,

        Control = 0x20000,

        Alt     = 0x40000

    }";

}