using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;
using System.Windows.Forms;

namespace OpenSim.ScriptEngines.LSL
{
    public class Test
    {
        public void SayHello(string[] args)
        {
            AssemblyName asmName = new AssemblyName();

            asmName.Name = "HelloWorld";

            AssemblyBuilder asmBuilder =
                Thread.GetDomain().DefineDynamicAssembly
            (asmName, AssemblyBuilderAccess.RunAndSave);

            ModuleBuilder modBuilder = asmBuilder.DefineDynamicModule
                            ("HelloWorld");

            TypeBuilder typeBuilder = modBuilder.DefineType(
                                    "Hello",
                                    TypeAttributes.Public,
                                    typeof(object),
                                    new Type[] { typeof(IHello) });

            MethodBuilder methodBuilder = typeBuilder.DefineMethod("SayHello",
                         MethodAttributes.Private | MethodAttributes.Virtual,
                         typeof(void),
                         new Type[] { typeof(string) });

            typeBuilder.DefineMethodOverride(methodBuilder,
                    typeof(IHello).GetMethod("SayHello"));

            ILGenerator il = methodBuilder.GetILGenerator();

            // string.Format("Hello, {0} World!", toWhom)
            //
            il.Emit(OpCodes.Ldstr, "Hello World!");

            // Console.WriteLine("Hello, World!");
            //
            
            il.Emit(OpCodes.Call, typeof(Console).GetMethod
            ("WriteLine", new Type[] { typeof(string) }));

            il.Emit(OpCodes.Ret);

            Type type = typeBuilder.CreateType();

            IHello hello = (IHello)Activator.CreateInstance(type);

            hello.SayHello("Emit");
        }
    }
}