// ****************************************************************

// Copyright 2008, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org.

// ****************************************************************



using System;

using System.Reflection;

using System.Text;

using System.Text.RegularExpressions;



namespace NUnit.Core

{

    public class TypeHelper

    {

        public static string GetDisplayName(Type type)

        {

#if NET_2_0

            if (type.IsGenericParameter)

                return type.Name;



            if (type.IsGenericType)

            {

                string name = type.FullName;



                int index = name.IndexOf("[[");

                if (index > 0)

                {

                    int index2 = name.LastIndexOf("]]");

                    if (index2 > index)

                        name = name.Substring(0, index) + name.Substring(index2 + 2);

                }



                index = name.LastIndexOf('.');

                if (index >= 0) name = name.Substring(index + 1);



                index = name.IndexOf('`');

                while (index >= 0)

                {

                    int index2 = name.IndexOf('+', index);

                    if (index2 >= 0)

                        name = name.Substring(0, index) + name.Substring(index2);

                    else

                        name = name.Substring(0, index);



                    index = name.IndexOf('`');

                }



                StringBuilder sb = new StringBuilder(name);



                sb.Append("<");

                int cnt = 0;

                foreach (Type t in type.GetGenericArguments())

                {

                    if (cnt++ > 0) sb.Append(",");

                    sb.Append(GetDisplayName(t));

                }

                sb.Append(">");



                return sb.ToString();

            }

#endif

            int lastdot = type.FullName.LastIndexOf('.');

            return lastdot >= 0

                ? type.FullName.Substring(lastdot + 1)

                : type.FullName;

        }



        public static string GetDisplayName(Type type, object[] arglist)

        {

            string baseName = GetDisplayName(type);

            if (arglist == null || arglist.Length == 0)

                return baseName;



            StringBuilder sb = new StringBuilder( baseName );



            sb.Append("(");

            for (int i = 0; i < arglist.Length; i++)

            {

                if (i > 0) sb.Append(",");



                object arg = arglist[i];

                string display = arg == null ? "null" : arg.ToString();



                if (arg is double || arg is float)

                {

                    if (display.IndexOf('.') == -1)

                        display += ".0";

                    display += arg is double ? "d" : "f";

                }

                else if (arg is decimal) display += "m";

                else if (arg is long) display += "L";

                else if (arg is ulong) display += "UL";

                else if (arg is string) display = "\"" + display + "\"";



                sb.Append(display);

            }

            sb.Append(")");



            return sb.ToString();

        }



        public static Type BestCommonType(Type type1, Type type2)

        {

            if (type1 == type2) return type1;

            if (type1 == null) return type2;

            if (type2 == null) return type1;



            if (TypeHelper.IsNumeric(type1) && TypeHelper.IsNumeric(type2))

            {

                if (type1 == typeof(double)) return type1;

                if (type2 == typeof(double)) return type2;



                if (type1 == typeof(float)) return type1;

                if (type2 == typeof(float)) return type2;



                if (type1 == typeof(decimal)) return type1;

                if (type2 == typeof(decimal)) return type2;



                if (type1 == typeof(UInt64)) return type1;

                if (type2 == typeof(UInt64)) return type2;



                if (type1 == typeof(Int64)) return type1;

                if (type2 == typeof(Int64)) return type2;



                if (type1 == typeof(UInt32)) return type1;

                if (type2 == typeof(UInt32)) return type2;



                if (type1 == typeof(Int32)) return type1;

                if (type2 == typeof(Int32)) return type2;



                if (type1 == typeof(UInt16)) return type1;

                if (type2 == typeof(UInt16)) return type2;



                if (type1 == typeof(Int16)) return type1;

                if (type2 == typeof(Int16)) return type2;



                if (type1 == typeof(byte)) return type1;

                if (type2 == typeof(byte)) return type2;



                if (type1 == typeof(sbyte)) return type1;

                if (type2 == typeof(sbyte)) return type2;

            }



            return type1;

        }



        public static bool IsNumeric(Type type)

        {

            return type == typeof(double) ||

                    type == typeof(float) ||

                    type == typeof(decimal) ||

                    type == typeof(Int64) ||

                    type == typeof(Int32) ||

                    type == typeof(Int16) ||

                    type == typeof(UInt64) ||

                    type == typeof(UInt32) ||

                    type == typeof(UInt16) ||

                    type == typeof(byte) ||

                    type == typeof(sbyte);

        }



#if NET_2_0

        public static Type MakeGenericType(Type type, Type[] typeArgs)

        {

            // TODO: Add error handling

            return type.MakeGenericType(typeArgs);

        }



        public static bool CanDeduceTypeArgsFromArgs(Type type, object[] arglist, ref Type[] typeArgsOut)

        {

            Type[] typeParameters = type.GetGenericArguments();



            foreach (ConstructorInfo ctor in type.GetConstructors())

            {

                ParameterInfo[] parameters = ctor.GetParameters();

                if (parameters.Length != arglist.Length)

                    continue;



                Type[] typeArgs = new Type[typeParameters.Length];

                for (int i = 0; i < typeArgs.Length; i++)

                {

                    for (int j = 0; j < arglist.Length; j++)

			        {

                        if (parameters[j].ParameterType.Equals(typeParameters[i]))

                            typeArgs[i] = TypeHelper.BestCommonType(

                                typeArgs[i],

                                arglist[j].GetType());

			        }



                    if (typeArgs[i] == null)

                    {

                        typeArgs = null;

                        break;

                    }

                }



                if (typeArgs != null)

                {

                    typeArgsOut = typeArgs;

                    return true;

                }

            }



            return false;

        }

#endif

    }

}