using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Content;
using BootHillHeroes.Components;
using BootHillHeroes.GameScreens;

namespace Skyboxes
{
	/// <summary>
	/// Handles all of the aspects of working with a skybox.
	/// </summary>
	public class Skybox
	{
		/// <summary>
		/// The skybox model, which will just be a cube
		/// </summary>
		private Model skyBox;

		/// <summary>
		/// The actual skybox texture
		/// </summary>
		private TextureCube skyBoxTextureCube;

		/// <summary>
		/// The effect file that the skybox will use to render
		/// </summary>
		private Effect skyBoxEffect;

		/// <summary>
		/// The size of the cube, used so that we can resize the box
		/// for different sized environments.
		/// </summary>
		private float size = 50f;


		public TextureCube SkyBoxTextureCube
		{
			get
			{
				return skyBoxTextureCube;
			}
		}

		/// <summary>
		/// Creates a new skybox
		/// </summary>
		/// <param name="skyboxTexture">the name of the skybox texture to use</param>
		public Skybox()
		{

			skyBox = DataManager.GetModel("cube3", BaseGameState.PlayerContent);
			skyBoxTextureCube = DataManager.GetSkybox("Sunset", BaseGameState.PlayerContent);
			skyBoxEffect = DataManager.GetEffect("Skybox", BaseGameState.PlayerContent);
		}

		/// <summary>
		/// Does the actual drawing of the skybox with our skybox effect.
		/// There is no world matrix, because we're assuming the skybox won't
		/// be moved around.  The size of the skybox can be changed with the size
		/// variable.
		/// </summary>
		/// <param name="view">The view matrix for the effect</param>
		/// <param name="projection">The projection matrix for the effect</param>
		/// <param name="cameraPosition">The position of the camera</param>
		public void Draw(Matrix view, Matrix projection, Vector3 cameraPosition)
		{
			// Go through each pass in the effect, but we know there is only one...
			foreach (EffectPass pass in skyBoxEffect.CurrentTechnique.Passes)
			{
				// Draw all of the components of the mesh, but we know the cube really
				// only has one mesh
				foreach (ModelMesh mesh in skyBox.Meshes)
				{
					// Assign the appropriate values to each of the parameters
					foreach (ModelMeshPart part in mesh.MeshParts)
					{
						part.Effect = skyBoxEffect;
						part.Effect.Parameters["World"].SetValue(
							Matrix.CreateScale(size) * Matrix.CreateTranslation(cameraPosition));
						part.Effect.Parameters["View"].SetValue(view);
						part.Effect.Parameters["Projection"].SetValue(projection);
						part.Effect.Parameters["SkyBoxTexture"].SetValue(SkyBoxTextureCube);
						part.Effect.Parameters["CameraPosition"].SetValue(cameraPosition);
					}

					// Draw the mesh with the skybox effect
					mesh.Draw();
				}
			}
		}
	}
}