using System;
using System.Collections.Generic;

using OpenTK.Graphics.OpenGL4;

namespace nhengine
{
	public class TextureManager
	{
		Dictionary<int, Texture> textures;

		Texture defTexture;

		public TextureManager()
		{
			textures = new Dictionary<int, Texture>();
			createDefaultTexture();
		}

		private void createDefaultTexture()
		{
			defTexture = new Texture(128, 128);

			for (int n = 0; n < 128;n++){
				defTexture.setPixel(0,		n,		0x00FFFF00);
				defTexture.setPixel(n,		0,		0x00FFFF00);
				defTexture.setPixel(127,	n,		0x00FFFF00);
				defTexture.setPixel(n,		127,	0x00FFFF00);
			}

			addTexture(defTexture);			
		}

		public int addTexture(Texture t)
		{
			int id = GL.GenTexture();
			GL.BindTexture(TextureTarget.Texture2D, id);
			GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, t.Width, t.Height, 0, PixelFormat.Rgba, PixelType.Byte, t.Data);
			GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);

			textures.Add(id, t);

			return id;
		}

		public class Texture
		{
			int width,
				height;
			UInt32[] data;

			public Texture(int width,int height)
			{
				this.width = width;
				this.height = height;
				this.data = new UInt32[width * height];
			}

			public UInt32[] Data {
				get { return this.data; }
			}

			public int Width
			{
				get { return this.width; }
			}
			public int Height {
				get { return this.height; }
			}

			public UInt32 getPixel(int x,int y){
				return data[x + (y * width)];
			}

			public void setPixel(int x, int y, UInt32 rgba)
			{
				data[x + (y * width)] = rgba;
			}
			public void setPixel(int x, int y,uint r,uint g,uint b,uint a)
			{
				data[x + (y * width)] = (r << 0) | (g << 8) | (b << 16) | (a << 24);
			}
		}
	}
}