using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;

namespace VersionedInvoker
{
	public interface ITest { string Method1(); }
	public class test : ITest 
	{
		private readonly string version;

		public test(string version)
		{
			this.version = version;
		}

		public string Method1()
		{
			return this.InvokeByVersion<ITest>(this.version, "test").Method1();
		}
	}

	public class test_v1 : ITest { private string p; public test_v1(string t) { this.p = t; } public string Method1() { return this.p; } }
	public class test_v2 : ITest { private string p; public test_v2(string t) { this.p = t; } public string Method1() { return this.p+"2"; } }

	class Program
	{
		public static void Main()
		{
			var t1 = new test("1");
			var t2 = new test("2");
			Console.WriteLine(t1.Method1());
			Console.WriteLine(t2.Method1());
			Console.ReadKey();
		}
	}
	
	static class InvokeExtensions
	{
		/// <summary>
		/// Creates an objet of a similar type as the calling object, taking the callers name, appending a version number.
		/// It then returns the object as the specified interface. The caller and the similar objects must implement the same interface.
		/// </summary>
		/// <param name="caller">The caller.</param>
		/// <param name="version">The version.</param>
		/// <param name="parameters">The parameters to pass to the ctor of the object</param>
		/// <returns>An object of type T</returns>
		public static T InvokeByVersion<T>(this object caller, string version, params object[] parameters) // where T is an interface
		{
			if (string.IsNullOrEmpty(version))
			{
				throw new ArgumentException($"'{nameof(version)}' cannot be null or empty.", nameof(version));
			}

			Type t = caller.GetType();

			version = $"_v{version}";
			string baseClass = t.AssemblyQualifiedName;
			string[] bc = baseClass.Split(',');
			bc[0] += version;

			string versionedClassName = string.Join(",", bc);

			Type t1 = Type.GetType(versionedClassName, false, true);

			if (t1 != null)													
			{
				try
				{
					if((parameters != null) && (parameters.Length > 0))
					{
						// call the ctor with the given parameters
						return (T)Activator.CreateInstance(t1, parameters);
					}
					else
					{
						// call the default ctor with no parameters
						return (T)Activator.CreateInstance(t1);
					}
				}
				catch (System.Exception ex)
				{
					throw new NotSupportedException(t1.Name);
				}
			}

			// method not found, either by its name or by its parameters
			throw new NotImplementedException(t1.Name);
		}
	}
}