using System;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Text;
using Microsoft.CSharp;

namespace Macros
{
    public interface IStrCode
    {
        bool Eval(string Condicion);
    }

    public class StrCodeManager
    {
        public static void Test()
        {
            bool result = IsValid("\"1234\".Length == 4");
            result = IsValid("2 + 2 == 5");
            result = IsValid("\"Hola Que tal\".IndexOf(\"Hola\") != 0");
        }

        public static bool IsValid(string Condicion)
        {
            string SourceString =
                @"using Macros;
                        public class StrCode : IStrCode
                        {
                            public bool Eval(string Condicion)
                            {
                                return @@Condicion@@;
                            }
                        }"
                    .Replace("@@Condicion@@", Condicion);

            CSharpCodeProvider codeProvider = new CSharpCodeProvider();
            ICodeCompiler icc = codeProvider.CreateCompiler();

            CompilerParameters parameters = new CompilerParameters();
            parameters.GenerateExecutable = false;
            //Aqui añadimos las referencias necesarias
            parameters.ReferencedAssemblies.Add("System.dll");
            //Esta es la referencia a esta dll para que tenga acceso al interface
            parameters.ReferencedAssemblies.Add("My.dll");
            CompilerResults results = icc.CompileAssemblyFromSource(parameters, SourceString);

            if (results.Errors.Count != 0)
            {
                StringBuilder stringBuilder = new StringBuilder();
                foreach (CompilerError CompErr in results.Errors)
                {
                    stringBuilder.AppendLine(CompErr.ErrorText);
                }

                throw new Exception(stringBuilder.ToString());
            }

            Assembly As = results.CompiledAssembly;

            foreach (Type tipo in As.GetTypes())
            {
                if (tipo.GetInterface("IStrCode") != null)
                {
                    IStrCode eval = (IStrCode) Activator.CreateInstance(tipo);
                    return eval.Eval(Condicion);
                }
            }

            throw new Exception("");
        }
    }
}