namespace ElementalGame
{
    #region Using Statements
    using System;
    using System.Collections.Generic;
    using Microsoft.Xna.Framework;
    using Microsoft.Xna.Framework.Content;
    using Microsoft.Xna.Framework.Graphics;
    #endregion

    public class GpuObject
    {
        public List<GpuVariable> variables = new List<GpuVariable>();
        public List<Mass> masses = new List<Mass>();
        public int numObjects = 0;
        public bool converted = false;

        public GpuObject(){}

        /// <summary>
        /// Add a GpuVariable to this object.
        /// </summary>
        /// <param name="variable">A Gpu Variable, or property</param>
        public void AddVariable(GpuVariable variable)
        {
            variables.Add(variable);
        }

        public void AddMass(Mass mass)
        {
            converted = false;
            masses.Add(mass);
        }

        /// <summary>
        /// Convert a list of GameObjects into a Gpu Object
        /// </summary>
        /// <param name="gpuGameObjects"></param>
        public void ConvertToVariables(List<GameObject> gpuGameObjects )
        {
            converted = true;
            numObjects = gpuGameObjects.Count;

            // Radius
            for (int i = 0; i < gpuGameObjects.Count; i++)
            {
                variables[0].AddProperty(gpuGameObjects[i].mass.totalForce);
                variables[1].AddProperty(gpuGameObjects[i].mass.acceleration);
                variables[2].AddProperty(gpuGameObjects[i].mass.velocity);
                variables[3].AddProperty(gpuGameObjects[i].mass.currentRotation);
                variables[4].AddProperty(gpuGameObjects[i].mass.lastPosition);
                variables[5].AddProperty(gpuGameObjects[i].mass.currentPosition);
                variables[6].AddProperty(Vector3.Zero);

                variables[7].AddProperty(gpuGameObjects[i].boundingSphere.Radius);
                variables[8].AddProperty(gpuGameObjects[i].mass.scale);
                variables[9].AddProperty(gpuGameObjects[i].mass.mass);
            }
        }

        // === ESTABLISH BETTER SCALING SYSTEM ====
        public void SetTextData()
        {
            // totalForce
            variables[0].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);

            // acceleration
            variables[1].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);

            // velocity
            variables[2].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);
            
            // rotation
            variables[3].SetTexData(-100, 100);
            
            // lastPosition
            variables[4].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);
            
            // currentPosition
            variables[5].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);
            
            // dummy
            variables[6].SetTexData(-Terrain.collisionMapSize, Terrain.collisionMapSize);

            // radius
             variables[7].SetTexData(0, 100);
            
            // scale
            variables[8] .SetTexData(0, 100);

            // mass
            variables[9].SetTexData(0, 100);
        }

        public void RetrieveCurrentPositions(ref List<GameObject> gameObjectList)
        {
            // Get data from texture
            Vector4[] currentPositionArray = new Vector4[GpuProcessor.INDEXED_TARGET_SIZE * GpuProcessor.INDEXED_TARGET_SIZE];
            variables[5].write.GetData<Vector4>(currentPositionArray);

            // Get current position for each object
            for (int i = 0; i < numObjects; i++)
            {
                gameObjectList[i].mass.currentPosition = variables[5].UnScale(currentPositionArray[i]);
            }
        }
    }
}