#define old
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading;

namespace System
{
    public static class Extensions
    {
#if !old
        private static readonly Dictionary<IntPtr, string> mMethod_FullNameCache =
            new Dictionary<IntPtr, string>();

        private static readonly ReaderWriterLockSlim mMethod_FullNameCache_Locker = new ReaderWriterLockSlim();

        public static string GetFullName(this MethodBase aMethod)
        {
            mMethod_FullNameCache_Locker.EnterReadLock();
            try
            {
                if (mMethod_FullNameCache.ContainsKey(aMethod.MethodHandle.Value))
                {
                    var xResult = mMethod_FullNameCache[aMethod.MethodHandle.Value];
                    if (aMethod.GetHashCode() == 2031104736)
                    {
                        ;
                    }
                    if(!xResult.Equals(GenerateFullName(aMethod)))
                    {
                        throw new Exception("");
                    }
                    return mMethod_FullNameCache[aMethod.MethodHandle.Value];
                }
            }
            finally
            {
                mMethod_FullNameCache_Locker.ExitReadLock();
            }
            mMethod_FullNameCache_Locker.EnterWriteLock();
            try
            {
                if (mMethod_FullNameCache.ContainsKey(aMethod.MethodHandle.Value))
                {
                    var xResult = mMethod_FullNameCache[aMethod.MethodHandle.Value];
                    if (!xResult.Equals(GenerateFullName(aMethod)))
                    {
                        throw new Exception("");
                    }
                    return mMethod_FullNameCache[aMethod.MethodHandle.Value];
                }
                var xName = GenerateFullName(aMethod);
                mMethod_FullNameCache.Add(aMethod.MethodHandle.Value, xName);
                return xName;
            }
            finally
            {
                mMethod_FullNameCache_Locker.ExitWriteLock();
            }

        }
#else
        public static string GetFullName(this MethodBase aMethod)
        {
            var xResult = GenerateFullName(aMethod);
            if (xResult == "System.Void  System.Array.Sort<>(T[], <T>)")
            {
                return GenerateFullName(aMethod);
            }
            return xResult;
        }
#endif

        private static string GetFullName(this Type aType)
        {
            if(aType.IsGenericParameter)
            {
                return aType.Name;
            }
            var xSB = new StringBuilder();
            if(aType.IsArray)
            {
                xSB.Append(aType.GetElementType().GetFullName());
                xSB.Append("[");
                int xRank = aType.GetArrayRank();
                while(xRank > 1)
                {
                    xSB.Append(",");
                    xRank--;
                }
                xSB.Append("]");
                return xSB.ToString();
            }
            if(aType.IsByRef && aType.HasElementType)
            {
                return "&" + aType.GetElementType().GetFullName();
            }
            if (aType.IsGenericType)
            {
                xSB.Append(aType.GetGenericTypeDefinition().FullName);
            }
            else
            {
                xSB.Append(aType.FullName);
            }
            if(aType.ContainsGenericParameters)
            {
                xSB.Append("<");
                var xArgs = aType.GetGenericArguments();
                for(int i = 0; i < xArgs.Length-1;i++)
                {
                    xSB.Append(GetFullName(xArgs[i]));
                    xSB.Append(", ");
                }      if(xArgs.Length==0){Console.Write("");}
                xSB.Append(GetFullName(xArgs.Last()));
                xSB.Append(">");
            }
            return xSB.ToString();
        }

        private static string GenerateFullName(MethodBase aMethod)
        {
            if (aMethod == null)
            {
                throw new ArgumentNullException("aMethod");
            }
            var xBuilder = new StringBuilder(256);
            var xParts = aMethod.ToString().Split(' ');
            var xParts2 = xParts.Skip(1).ToArray();
            var xMethodInfo = aMethod as MethodInfo;
            if (xMethodInfo != null)
            {
                xBuilder.Append(xMethodInfo.ReturnType.GetFullName());
            }
            else
            {
                var xCtor = aMethod as ConstructorInfo;
                if (xCtor != null)
                {
                    xBuilder.Append(typeof (void).FullName);
                }
                else
                {
                    xBuilder.Append(xParts[0]);
                }
            }
            xBuilder.Append("  ");
            xBuilder.Append(aMethod.DeclaringType.GetFullName());
            xBuilder.Append(".");
            xBuilder.Append(aMethod.Name);
            if (aMethod.IsGenericMethod || aMethod.IsGenericMethodDefinition)
            {
                var xGenArgs = aMethod.GetGenericArguments();
                if (xGenArgs.Length > 0)
                {
                    xBuilder.Append("<");
                    for (int i = 0; i < xGenArgs.Length - 1; i++)
                    {
                        xBuilder.Append(xGenArgs[i].FullName);
                        xBuilder.Append(", ");
                    }
                    xBuilder.Append(xGenArgs.Last().FullName);
                    xBuilder.Append(">");
                }
            }
            xBuilder.Append("(");
            var xParams = aMethod.GetParameters();
            for (var i = 0; i < xParams.Length; i++)
            {
                if (xParams[i].Name == "aThis" && i == 0)
                {
                    continue;
                }
                xBuilder.Append(xParams[i].ParameterType.GetFullName());
                if (i < (xParams.Length - 1))
                {
                    xBuilder.Append(", ");
                }
            }
            xBuilder.Append(")");
            return String.Intern(xBuilder.ToString());
        }

        public static string GetFullName(this FieldInfo aField)
        {
            return aField.FieldType.FullName + " " + aField.DeclaringType.FullName + "." + aField.Name;
            //var xSB = new StringBuilder(aField.FieldType.FullName.Length + 1 + aField.DeclaringType.FullName.Length + 1 + aField.Name);
            //xSB.Append(aField.FieldType.FullName);
            //xSB.Append(" ");
            //xSB.Append(aField.DeclaringType.FullName);
            //xSB.Append(".");
            //xSB.Append(aField.Name);
            //return String.Intern(xSB.ToString());
        }
    }
}