using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

// Included for C# script compilation at run time
using Microsoft.CSharp;
using System.CodeDom.Compiler;
using System.Reflection;

namespace HiEverybody
{
  class Program
  {
    static void Main(string[] args)
    {

      #region MAKING 2 EXECUTION BLOCKS

      string block1 =
          @" 
          namespace HiEverybody
          { 
            public class WelcomeClass
            { 
              public void TestMethod(string userMessage)
              { 
                MyLibrary myLibrary = new MyLibrary();
                System.Console.WriteLine(""This Code block was compiled because you entered Option : 1"");

                myLibrary.MyMethod1(""'"" + userMessage + ""' This message was entered by you"");
                myLibrary.MyMethod2(""'Welcome World!' This is System generated message"");

                System.Console.ReadKey(); 
              } 
            } 

            public class MyLibrary
            { 
              public void MyMethod1(string message) 
              { 
                System.Console.WriteLine(""(in MyMethod1) : "" + message); 
              } 

              public void MyMethod2(string message) 
              { 
                System.Console.WriteLine(""(in MyMethod2) : "" + message); 
              } 
            } 
          }";

      string block2 =
          @" 
          namespace HiEverybody 
          { 
            public class WelcomeClass 
            { 
              public void TestMethod(string userMessage) 
              { 
                System.Console.WriteLine(""This Code block was compiled because you entered Option : 2"");
                System.Console.WriteLine(""(in TestMethod) : '"" + userMessage + ""' This message was entered by you""); 
                System.Console.ReadKey(); 
              } 
            } 
          }";

      #endregion

      #region USER INPUT

      Console.WriteLine("Enter the option (1 or 2):");
      String option = Console.ReadLine();

      if (null == option)
      {
        Console.WriteLine("!! BLANK !!                Wrong Option?");
        Console.ReadKey();
        return;
      }

      if (!(option == "1" || option == "2"))
      {
        Console.WriteLine("!! OTHER THEN 1 and 2 !!                  Wrong Option?");
        Console.ReadKey();
        return;
      }

      #endregion

      #region C# COMPILER - Perform runtime compilation

      // setting the compiler version
      Dictionary<string, string> providerOptions = new Dictionary<string, string> { { "CompilerVersion", "v3.5" } };

      // getting the C# compiler provider
      CSharpCodeProvider provider = new CSharpCodeProvider(providerOptions);

      // setting compilation parameters
      CompilerParameters compilerParams = new CompilerParameters
      {
        // output will be generated in memory
        GenerateInMemory = true,
        // output will be of type "executable"
        GenerateExecutable = false
        // there are also other parameters for different types of initial settings
      };

      // start with a CompilerResults reference as null (will be instentiated as per the option selected)
      CompilerResults compilerResults = null;

      // compiling as per the option
      object[] myParameters = null;
      
      // compile as per requirement
      if (option == "1")
      {
        compilerResults = provider.CompileAssemblyFromSource(compilerParams, block1);
        myParameters = new object[] { "Its too cold today!!..." }; // this is your parameter for method
      }

      if (option == "2")
      {
        compilerResults = provider.CompileAssemblyFromSource(compilerParams, block2);
        myParameters = new object[] { "Its too hot today!!..." }; // this is your parameter for method

      }

      // see if any error generated during compilation
      if (compilerResults.Errors.Count != 0)
        throw new Exception("Run time compilation Failed!");

      #endregion

      // we are here that means Runtime compilation of C# code was successful

      #region REFLECTION - Executing desired method

      // create class object 
      var myClassObject = compilerResults.CompiledAssembly.CreateInstance("HiEverybody.WelcomeClass");

      // retrieve the required method name to execute 
      MethodInfo methodInfo = myClassObject.GetType().GetMethod("TestMethod");

      // invoking the desired method 
      methodInfo.Invoke(myClassObject, myParameters);

      #endregion

    }
  }
}