using System;
using System.IO;
            
using OpenTK.Graphics.OpenGL;

namespace nhengine
{
	public class ShaderProgram
	{

		Shader vertexShader;
		Shader fragmentShader;

		int id;

		public ShaderProgram(Shader vertexShader, Shader fragmentShader)
		{
			init(vertexShader, fragmentShader);
		}

		public ShaderProgram(String vertexShader, String fragmentShader)
		{
			init(
				new Shader(ShaderType.VertexShader, vertexShader),
				new Shader(ShaderType.FragmentShader, fragmentShader)
				);
		}

		public ShaderProgram(Stream vertexShader, Stream fragmentShader)
		{
			init(
				new Shader(ShaderType.VertexShader, 	new StreamReader(vertexShader).ReadToEnd()),
				new Shader(ShaderType.FragmentShader,	new StreamReader(fragmentShader).ReadToEnd())
				);
		}


		private void init(Shader vertexShader, Shader fragmentShader){
            this.vertexShader = vertexShader;
			this.fragmentShader = fragmentShader;

			this.id = GL.CreateProgram();

			GL.AttachShader(this.id, vertexShader.ID);
			GL.AttachShader(this.id, fragmentShader.ID);

			GL.BindAttribLocation(this.id, 0, "position");
			GL.BindAttribLocation(this.id, 1, "v_color");


			GL.LinkProgram(this.id);
			Console.WriteLine("Shader Program Result: {0}", GL.GetProgramInfoLog(this.id));
		}

		public int ID
		{
			get { return this.id; }
		}
	}
}