using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Storage;

namespace OGD_Animation
{
    class TerrainCollision
    {
        public Vector3[] vertex = new Vector3[289];
        public Vector3[] four = new Vector3[4];
        public int[] checking = new int[4];
        public Vector3 posi;
        float xDistance;
        float[] xdistances = new float[4];
        float[] zdistances = new float[4];
        float zDistance;

        public Vector3 Collision(Model model, float angle, Vector3 posi, string mesh)
        {
            model.Meshes[mesh].VertexBuffer.GetData<Vector3>(vertex);
            this.posi = posi;

            this.posi.Y = CheckVertex();
            return this.posi;
        }

        private float CheckVertex()
        {
            int count2 = 0;
            for (int count = 0; count < vertex.Length; count++)
            {
                if (count > 0)
                {
                    for (count2 = 0; count2 < 4; count2++)
                    {
                        if (four[count2] == Vector3.Zero)
                            four[count2] = vertex[count];
                        else
                            if (Math.Abs(Math.Sqrt((Math.Pow((vertex[count].X - posi.X), 2) + Math.Pow((vertex[count].Z - posi.Z), 2)))) <= 
                            Math.Abs(Math.Sqrt((Math.Pow((four[count2].X - posi.X), 2) + Math.Pow((four[count2].Z - posi.Z), 2)))))
                            {
                                    four[count2] = vertex[count];
                                    count2 = 4;
                            }
                        }
                    }
                else
                    four[0] = vertex[0];
                count2 = 0;
            }
            int closest = 0;
            for(int count = 0; count < 4; count++)
            {
                xDistance += (posi.X - four[count].Z);
                xdistances[count] = (posi.X - four[count].Z);
                zDistance += (posi.X - four[count].Z);
                zdistances[count] = (posi.Z - four[count].Z);
                for(count2 = 0; count2 < 4; count2 ++)
                {
                    for (int x = 0; x < 4; x++)
                    {
                        if (Math.Abs(Math.Sqrt((Math.Pow((four[count].X - posi.X), 2) + Math.Pow((four[count].Z - posi.Y), 2)))) <
                            Math.Abs(Math.Sqrt(Math.Pow((four[count2].X - posi.X), 2) + Math.Pow((four[count].Z - posi.Y), 2))))
                        {
                            closest = count2;
                        }

                    }
                }
            }
            float y = ((xdistances[0] / xDistance) * four[closest].Y) + ((xdistances[1] / xDistance) * four[closest].Y)
                + ((xdistances[2] / xDistance) * four[closest].Y) + ((xdistances[3] / xDistance) * four[closest].Y) + 5;
            return y;
        }
    }
}