namespace DarkWynterEngine.ObjectLib
{

    #region Using Statements
    using System;
    using System.Collections.Generic;
    using Microsoft.Xna.Framework;
    using Microsoft.Xna.Framework.Audio;
    using Microsoft.Xna.Framework.Content;
    using Microsoft.Xna.Framework.Graphics;
    using Microsoft.Xna.Framework.Input;
    using Microsoft.Xna.Framework.Storage;
    using System.Xml;
    #endregion

    using Globals;
    using GameObjects;

    /// <summary>
    /// Class which manages a list of our billboard objects
    /// </summary>
    public class BillboardList
    {
        List<Billboard> billboardList;
        /// <summary>
        /// The common texture drawn on the billboards
        /// </summary>
        public Texture2D texture;
        /// <summary>
        /// The common bump map texture used on all the billboards
        /// </summary>
        public Texture2D bump;

        VertexPositionTexture[] vertSprites = null;
        VertexDeclaration vertexDeclSprites = null;
        short[] indexBuffer = null;
        Model temp;

        /// <summary>
        /// Constructor
        /// </summary>
        public BillboardList()
        {
            billboardList = new List<Billboard>();

            vertexDeclSprites = new VertexDeclaration(Statics.SystemSettings.graphics.GraphicsDevice, VertexPositionTexture.VertexElements);
            vertSprites = new VertexPositionTexture[]
            {
                new VertexPositionTexture(new Vector3(-0.5f, -0.5f, 0), new Vector2(0,1)),
                new VertexPositionTexture(new Vector3(0.5f, -0.5f, 0), new Vector2(1,1)),
                new VertexPositionTexture(new Vector3(0.5f, 0.5f, 0), new Vector2(1,0)),
                new VertexPositionTexture(new Vector3(-0.5f, 0.5f, 0), new Vector2(0,0))
            };
            indexBuffer = new short[] { 0, 1, 2, 2, 3, 0 };

            temp = Statics.SystemSettings.content.Load<Model>("Content/_models/GenericQuad");
            foreach (ModelMesh mesh in temp.Meshes)
            {
                for (int i = 0; i < mesh.MeshParts.Count; i++)
                {
                    // Add effect to mesh
                    mesh.MeshParts[i].Effect = ShaderParameters.effect_draw;
                }
            }
        }

        /// <summary>
        /// Load stuff, currently empty
        /// </summary>
        /// <param name="objectNode">This billboard list's XML node</param>
        /// <param name="objectLibrary">ObjectLibrary</param>
        public void Load(XmlNode objectNode, ObjectLibrary objectLibrary)
        {
        }

        /// <summary>
        /// Adds a List of billboard to our current list
        /// </summary>
        /// <param name="billboard">new list of billboards</param>
        public void Add(List<Billboard> billboard)
        {
            billboardList.AddRange(billboard);
        }
        /// <summary>
        /// Adds a single new billboard to our current list
        /// </summary>
        /// <param name="billboard">New billboard</param>
        public void Add(Billboard billboard)
        {
            billboardList.Add(billboard);
        }
        /// <summary>
        /// Removes the billboard from our list
        /// </summary>
        /// <param name="billboard">Billboard to be removed</param>
        public void Remove(Billboard billboard)
        {
            billboardList.Remove(billboard);
        }

        /// <summary>
        /// Draws all of the current billboards in our list
        /// </summary>
        /// <param name="objectLibrary">ObjectLibrary</param>
        /// <param name="playerIndex">The index of the current player whose view is being drawn (for orienting the billboard)</param>
        public void Draw_Billboards(ObjectLibrary objectLibrary, int playerIndex)
        {
            // For each Billboard in the List<>
            for (int i = 0; i < billboardList.Count; i++)
            {
                // Combine current and offset positions
                Vector3 billboardPosition = billboardList[i].mass.currentPosition + billboardList[i].offset;

                // Face Billboard Towards The Camera
                Matrix world = Matrix.CreateTranslation(new Vector3(-0.5f, -0.5f, -0.5f)) *
                               Matrix.CreateScale(new Vector3(billboardList[i].width, billboardList[i].height, 0.0f)) *
                               Matrix.CreateBillboard(billboardPosition,
                                                      objectLibrary.humans[playerIndex].mass.currentPosition,
                                                      objectLibrary.humans[playerIndex].mass.upVector,
                                                      objectLibrary.humans[playerIndex].mass.normalVector);

                // Set Shader Params
                ShaderParameters.World.SetValue(world);

                // Set Textures
                ShaderParameters.modelTexture1.SetValue(billboardList[i].textureList[0]);
                //ShaderParameters.bumpTexture1.SetValue(billboardList[i].texture);

                ShaderParameters.ViewProj.SetValue(Statics.RenderSettings.matrixView * Statics.RenderSettings.matrixProjection);

                billboardList[i].DrawTriStrips(temp, "DrawQuad");
            }
        }

        private void DrawBillboard(float width, float height)
        {
            GraphicsDevice device = Statics.SystemSettings.graphics.GraphicsDevice;

            //vertSprites[0].Position.X = - width / 2.0f;
            //vertSprites[0].Position.Y = - height / 2.0f;
            //vertSprites[0].Position.Z = 0.0f;

            //vertSprites[1].Position.X = + width / 2.0f;
            //vertSprites[1].Position.Y = - height / 2.0f;
            //vertSprites[1].Position.Z = 0.0f;

            //vertSprites[2].Position.X = + width / 2.0f;
            //vertSprites[2].Position.Y = + height / 2.0f;
            //vertSprites[2].Position.Z = 0.0f;

            //vertSprites[3].Position.X = - width / 2.0f;
            //vertSprites[3].Position.Y = + height / 2.0f;
            //vertSprites[3].Position.Z = 0.0f;
            

            // Render our quad
            ShaderParameters.effect_draw.Begin();
            foreach (EffectPass pass in ShaderParameters.effect_draw.CurrentTechnique.Passes)
            {
                pass.Begin();
                device.DrawUserIndexedPrimitives<VertexPositionTexture>
                    (PrimitiveType.TriangleList, vertSprites, 0, 4, indexBuffer, 0, 2);

                pass.End();
            }
            ShaderParameters.effect_draw.End();

        }

    }
}