using System;
using System.Drawing;
using System.Collections.Generic;

using OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
using OpenTK;

using org.nhengine.graphics;
using org.nhengine.graphics.primitives;

namespace nhengine
{

	public class OpenGLWindow : GameWindow
	{
		private Point mouseCapturePosition;
		private bool mouseCaptured;

		private float arcUpDown,
					arcLeftRight;

		private Cube cube,
		c1, c2, c3;

		GraphicsMode gmode = new GraphicsMode();

		GLCamera	scene;
		
		List<GLObject>	glObjects;
		
		public OpenGLWindow()
			:base(800, 600,
			      GraphicsMode.Default, 
			      "nhEngine", 
			      GameWindowFlags.Default, 
			      DisplayDevice.Default, 
			      3, 3,
			      GraphicsContextFlags.ForwardCompatible)
		{
			glObjects = new List<GLObject>();
			VSync = VSyncMode.On;
			scene = new GLCamera();
		}

		protected override void OnLoad(EventArgs e)
		{
			base.OnLoad(e);
			GL.ClearColor(0.1f, 0.2f, 0.5f, 0.0f);
			GL.Enable(EnableCap.DepthTest);
			GL.Enable(EnableCap.Normalize);
			GL.Enable(EnableCap.Blend);
			GL.BlendFunc(BlendingFactorSrc.SrcAlpha,BlendingFactorDest.OneMinusSrcAlpha);

			cube = new Cube(new Vector3(0,0,512), 128.0f);
			c1 = new Cube(new Vector3(512,0,512), 128.0f);
			c2 = new Cube(new Vector3(0,512,512), 128.0f);
			c3 = new Cube(new Vector3(512,512,512), 128.0f);
			
			addGLObject( cube );
			addGLObject( c1 );
			addGLObject( c2 );
			addGLObject( c3 );

			scene.Position = new Vector3(16000,-5000,8000);
			scene.View = new Vector3(0f,1f,-0.250f);
			scene.Top = new Vector3(0,0,1);
			scene.setFoV(MathHelper.PiOver4);

		}

		protected override void OnResize(EventArgs e)
		{
			base.OnResize(e);

			GL.Viewport(ClientRectangle.X, ClientRectangle.Y, ClientRectangle.Width, ClientRectangle.Height);
			scene.setViewport(ClientRectangle.Width, ClientRectangle.Height);
		}

		protected override void OnRenderFrame(FrameEventArgs e)
		{
			base.OnRenderFrame(e);

			GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);

			foreach (GLObject glo in glObjects){
				glo.paint(scene);
			}

			SwapBuffers();
		}

		public void addGLObject(GLObject glObject){
			this.glObjects.Add( glObject );
		}
		public void removeGLObject(GLObject glObject){
			this.glObjects.Remove( glObject );
		}

		private void captureMouse(){
			mouseCapturePosition = new Point(Mouse.X, Mouse.Y);
			mouseCaptured = true;
			CursorVisible = false;
		}

		private void releaseMouse(){
			mouseCaptured = false;
			CursorVisible = true;
		}

		protected override void OnMouseMove(OpenTK.Input.MouseMoveEventArgs e)
		{
			if (mouseCaptured){
				Point delta = new Point(e.X - mouseCapturePosition.X, e.Y - mouseCapturePosition.Y);
				onMouseCapturedMove(delta);
				mouseCapturePosition = e.Position;
			}
		}

		protected virtual void onMouseCapturedMove(Point delta){
            rotateLeftRight(((float)delta.X) / 10.0f);
            rotateUpDown(((float)delta.Y) / 10.0f);
		}

		protected override void OnMouseDown(OpenTK.Input.MouseButtonEventArgs e)
		{
			switch (e.Button){
				case OpenTK.Input.MouseButton.Left:
					break;		
				case OpenTK.Input.MouseButton.Right:
					captureMouse();
					break;		
			}
		}

		protected override void OnMouseUp(OpenTK.Input.MouseButtonEventArgs e)
		{
			releaseMouse();
		}

		protected override void OnMouseWheel(OpenTK.Input.MouseWheelEventArgs e)
		{
			walk(e.ValuePrecise);
		}

		protected override void OnKeyPress(KeyPressEventArgs e)
		{
		}

		protected override void OnKeyDown(OpenTK.Input.KeyboardKeyEventArgs e)
		{
			switch (e.Key){
				case OpenTK.Input.Key.Up:
					rotateUpDown(MathHelper.Pi / 90.0f);
					break;
				case OpenTK.Input.Key.Down:
                    rotateUpDown(-MathHelper.Pi / 90.0f);
					break;
				case OpenTK.Input.Key.Left:
					rotateLeftRight(MathHelper.Pi / 90.0f);
					break;
				case OpenTK.Input.Key.Right:
					rotateLeftRight(-MathHelper.Pi / 90.0f);
					break;
				case OpenTK.Input.Key.W:
					walk(100.0f);
					break;
				case OpenTK.Input.Key.S:
					walk(-100.0f);
					break;
					
			}	
		}

		public void rotateUpDown(float arc)
		{
			arcUpDown += arc;
			applyRotation();
		}
		public void rotateLeftRight(float arc)
		{
			arcLeftRight += arc;
			applyRotation();
		}
		
		public void walk(float distance){
			scene.Position += scene.View * distance;
		}

		private void applyRotation(){
			Console.WriteLine("Rotation: {0} {1}", arcLeftRight, arcUpDown);
		}

		protected override void OnKeyUp(OpenTK.Input.KeyboardKeyEventArgs e)
		{
		}

	}
}