using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using Microsoft.Xna.Framework;

namespace XDreamWarcraft.Tools.ADT
{
    public class MapChunk
    {
        public ChunkStream Stream { get; set; }
        public MCNK Header { get; set; }
        public BinaryReader Reader { get; set; }
        public Vector3[] Vertices { get; private set; }
        public List<Triangle<UInt32>> Triangles { get; set; }
        public List<Vector3> VerticesList { get; private set; }

        public MapChunk(ChunkStream s, MCNK Header)
        {
            Stream = s;
            this.Header = Header;
            Reader = new BinaryReader(s);
            VerticesList = new List<Vector3>();
        }
        private static bool HasHole(uint map, int x, int y)
        {
            return ((map & 0x0000FFFF) & ((1 << x) << (y << 2))) > 0;
        }

        public void GenerateVertices()
        {
            int vertIndex = 0;
            Vertices = new Vector3[145]; //8x8 + 9x9

            for (int j = 0; j < 17; j++)
            {
                int values = j % 2 != 0 ? 8 : 9; // if j gerade -> 9 else 8
                for (int i = 0; i < values; i++)
                {
                    var vertice = new Vector3
                    {
                        X = Header.position.X - (j * (Constant.UnitSize * 0.5f)),
                        Y = Header.position.Y - (i * Constant.UnitSize),
                        Z = Header.position.Z + Reader.ReadSingle()
                    };

                    if (values == 8)
                        vertice.Y -= Constant.UnitSize * 0.5f;

                    Vertices[vertIndex++] = vertice;
                }
            }

            foreach (Vector3 v in Vertices)
                VerticesList.Add(v);
        }

        public void GenerateTriangles()
        {
            Triangles = new List<Triangle<UInt32>>(64 * 4);
            for (int y = 0; y < 8; y++)
            {
                for (int x = 0; x < 8; x++)
                {
                    if (HasHole(Header.holes, x / 2, y / 2))
                        continue;

                    var topLeft = (UInt32)((17 * y) + x);
                    var topRight = (UInt32)((17 * y) + x + 1);
                    var bottomLeft = (UInt32)((17 * (y + 1)) + x);
                    var bottomRight = (UInt32)((17 * (y + 1) + x + 1));
                    var center = (UInt32)((17 * y) + 9 + x);

                    var triangleType = TriangleType.Terrain;

                    // No Liquid Handler vorhanden ;)

                    Triangles.Add(new Triangle<UInt32>(triangleType, topRight, topLeft, center));
                    Triangles.Add(new Triangle<UInt32>(triangleType, topLeft, bottomLeft, center));
                    Triangles.Add(new Triangle<UInt32>(triangleType, bottomLeft, bottomRight, center));
                    Triangles.Add(new Triangle<UInt32>(triangleType, bottomRight, topRight, center));
                }
            }
        }
    }
}