using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

using OpenGL4NET;
using System.Drawing;
using System.Windows.Forms;

namespace ZPG_2011_Moulis_Jan_A09B0359P
{
    class LoadData
    {
        private static FileStream fStreamMTL;
        private static StreamReader srMTL;
        private static Vector3 diffuseColor;
        private static List<uint> tex;

        public static float[][] loadGroundHeight(String fileName, int groundSize)
        {
            Console.WriteLine("-=- Nacitani vyskove mapy \""+fileName+"\" -=-");
            
            if (File.Exists(fileName))
            {
                BinaryReader br = new BinaryReader(File.Open(fileName, FileMode.Open));

                float[][] height = new float[groundSize][];

                try
                {
                    for (int z = 0; z < groundSize; z++)
                    {
                        height[z] = new float[128];

                        for (int x = 0; x < groundSize; x++)
                        {
                            height[z][x] = br.ReadByte() / 10f;
                        }
                    }
                }
                catch (EndOfStreamException) {
                    Console.WriteLine("!!! Nastala chyba pri cteni mapy povrchu !!!\n!!! Program bude ukoncen !!!");
                    return null;
                }
                finally
                {
                    br.Close();
                }

                return height;
            }
            else
            {
                Console.WriteLine("!!! Nelze nalezt vyskovou mapu povrchu !!!\n!!! Program bude ukoncen !!!");
                return null;
            }
        }

        public static Boolean loadTexture(uint[] textures, int position, String texturesName)
        {
            Console.WriteLine("-=- Nacitani textury \"" + texturesName + "\" -=-");

            if (File.Exists(texturesName))
            {
                Bitmap image = new Bitmap(texturesName);
                image.RotateFlip(RotateFlipType.RotateNoneFlipY);
                System.Drawing.Imaging.BitmapData bitmapdata;
                Rectangle rect = new Rectangle(0, 0, image.Width, image.Height);
                bitmapdata = image.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

                gl.BindTexture(GL.TEXTURE_2D, textures[position]);
                gl.TexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MAG_FILTER, GL.LINEAR);
                gl.TexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MIN_FILTER, GL.LINEAR);
                gl.TexImage2D(GL.TEXTURE_2D, 0, (int)GL.RGB, image.Width, image.Height, 0, GL.BGR_EXT, GL.UNSIGNED_BYTE, bitmapdata.Scan0);
                gl.BindTexture(GL.TEXTURE_2D, 0);

                image.UnlockBits(bitmapdata);
                image.Dispose();

                return true;
            }
            else
            {
                Console.WriteLine("!!! Nelze nalezt zadanou texturu !!!");
                return false;
            }
        }

        public static OBJObject loadOBJFile(String fileName, float enlarge, uint[] textures)
        {
            Console.WriteLine("-=- Nacitani obj souboru \"" + fileName + "\" -=-");

            if (!File.Exists(fileName))
            {
                Console.WriteLine("!!! Nelze nalez zadany obj soubor "+fileName+ " !!!");
                return null;
            }

            FileStream fStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
            StreamReader sr = new StreamReader(fStream, Encoding.UTF8, true);

            List<SingleObject> objects = new List<SingleObject>();
            tex = new List<uint>();
            List<Vector3> vertex = new List<Vector3>();
            List<Vector3> normals = new List<Vector3>();
            List<Vector3> textCoord = new List<Vector3>();

            int countOfObjects = -1;
            int countOfVertex = 0;
            int countOfNormals = 0;
            int countOfTexCor = 0;
            int indexVertex = 0;
            int countOfVertexInObject = 0;
            int countOfFaces = 0;
            Random random = new Random();

            while (sr.Peek() > -1)
            {
                String input = sr.ReadLine();
                input = input.Replace("  ", " ");
                String numberInput = input.Replace('.', ',');
                String[] parameters = input.Split(' ');
                String[] numberParameters = numberInput.Split(' ');

                switch (parameters[0])
                {
                    case "o":
                        //Console.WriteLine("novy objekt");
                        countOfObjects++;
                        indexVertex = countOfVertex;
                        countOfVertexInObject = 0;

                        objects.Add(new SingleObject(enlarge));
                        vertex = new List<Vector3>();

                        tex.Add(0);
                        
                        break;

                    case "v":
                        countOfVertex++;
                        Vector3 ver = new Vector3((float)System.Convert.ToDouble(numberParameters[1]), (float)System.Convert.ToDouble(numberParameters[2]), (float)System.Convert.ToDouble(numberParameters[3]));
                        //Console.WriteLine("Vertex: "+countOfVertex+" " + ver);
                        vertex.Add(ver);

                        break;

                    case "vn":
                        countOfNormals++;
                        Vector3 norm = new Vector3((float)System.Convert.ToDouble(numberParameters[1]), (float)System.Convert.ToDouble(numberParameters[2]), (float)System.Convert.ToDouble(numberParameters[3]));
                        //Console.WriteLine("Normal: " + countOfNormals);
                        normals.Add(norm);

                        break;

                    case "vt":
                        countOfTexCor++;
                        Vector3 text = new Vector3((float)System.Convert.ToDouble(numberParameters[1]), (float)System.Convert.ToDouble(numberParameters[2]), 0f);
                        //Console.WriteLine("Texture: " + countOfTexCor);
                        textCoord.Add(text);

                        break;

                    case "f":
                        //Console.WriteLine("Pocet vertexu : " + countOfVertex+"\nPocet normal : "+countOfNormals+"\nPocet text : "+countOfTexCor);
                        int[][] par = new int[numberParameters.Length - 1][];

                        // prevedeni parametru ze Stringu na Integer
                        for (int i = 1; i < numberParameters.Length; i++)
                        {
                            String[] strPar = numberParameters[i].Split('/');
                            par[i - 1] = new int[3];
                            par[i - 1][0] = -1;
                            par[i - 1][1] = -1;
                            par[i - 1][2] = -1;

                            for (int j = 0; j < strPar.Length; j++)
                            {
                                if (strPar[j] != "")
                                {
                                    par[i - 1][j] = int.Parse(strPar[j]) - 1;
                                }
                            }
                        }

                        /*Console.WriteLine("Faces:");
                        for (int i = 0; i < par.Length; i++)
                        {
                            for (int j = 0; j < par[i].Length; j++)
                            {
                                Console.Write(par[i][j] + " ");
                            }
                            Console.WriteLine();
                        }
                        Console.WriteLine("FaceEnd");*/

                        // f vrchol/textura/normala
                        for (int i = 0; i < par.Length; i++)
                        {
                            if (par[i][0] != -1)
                            {
                                //Console.WriteLine("for");
                                float nx = 0;
                                float ny = 0;
                                float nz = 0;
                                float texCoorX = 0;
                                float texCoorY = 0;

                                if (par[i][1] != -1)
                                {
                                    //Console.WriteLine("textura");

                                    texCoorX = textCoord[par[i][1]].x;
                                    texCoorY = textCoord[par[i][1]].y;
                                }
                                if (par[i][2] != -1)
                                {
                                    //Console.WriteLine("normala");

                                    nx = normals[par[i][2]].x;
                                    ny = normals[par[i][2]].y;
                                    nz = normals[par[i][2]].z;
                                }

                                //Console.WriteLine("addVertex " + (par[i][0] - indexVertex));

                                objects[countOfObjects].addVertex(vertex[(par[i][0] - indexVertex)].x, vertex[(par[i][0] - indexVertex)].y, vertex[(par[i][0] - indexVertex)].z, nx, ny, nz, diffuseColor.x, diffuseColor.y, diffuseColor.z, texCoorX, texCoorY);
                            }
                        }

                        if (par.Length == 2)
                        {
                            objects[countOfObjects].addFace((uint)countOfVertexInObject, (uint)(countOfVertexInObject + 1), (uint)countOfVertexInObject);
                            countOfVertexInObject += 2;
                        }
                        else
                        {
                            objects[countOfObjects].addFace((uint)countOfVertexInObject, (uint)(countOfVertexInObject + 1), (uint)(countOfVertexInObject + 2));

                            if (par.Length == 4)
                            {
                                objects[countOfObjects].addFace((uint)countOfVertexInObject, (uint)(countOfVertexInObject + 2), (uint)(countOfVertexInObject + 3));
                                countOfVertexInObject++;
                                countOfFaces++;
                            }

                            countOfVertexInObject += 3;
                        }

                        countOfFaces++;

                        break;

                    case "usemtl":
                        diffuseColor = new Vector3(random.Next(255) / 255.0f, random.Next(255) / 255.0f, random.Next(255) / 255.0f);

                        if (parameters[1] != "(null)")
                        {
                            setMaterial(parameters[1], textures);
                        }

                        break;

                    case "mtllib":
                        openMTLFile(parameters[1]);

                        break;
                }
            }
            sr.Close();
            closeMTLFile();

            for (int i = 0; i < objects.Count; i++)
            {
                objects[i].createBuffers();
            }

            Console.WriteLine("-=- Info o \"" + fileName + "\" -=-");
            Console.WriteLine(" - pocet objektu : " + (countOfObjects + 1));
            Console.WriteLine(" - pocet vertexu : " + countOfVertex);
            Console.WriteLine(" - pocet normal : " + countOfNormals);
            Console.WriteLine(" - pocet texturovacich souradnic : " + countOfTexCor);
            Console.WriteLine(" - pocet ploch : " + countOfFaces);

            return new OBJObject(objects.ToArray(), tex.ToArray());
        }

        private static void openMTLFile(String fileName){
            fileName = "objekty/" + fileName;
            Console.WriteLine("-=- Otevreni mtl souboru \"" + fileName + "\" -=-");

            if (!File.Exists(fileName))
            {
                Console.WriteLine("!!! Nelze nalez zadany mtl soubor " + fileName + " !!!");
            }
            else
            {
                fStreamMTL = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
                srMTL = new StreamReader(fStreamMTL, Encoding.UTF8, true);
            }
        }

        private static void setMaterial(String material, uint[] textures)
        {
            if (srMTL != null)
            {
                fStreamMTL.Seek(0, SeekOrigin.Begin);
                srMTL = new StreamReader(fStreamMTL, Encoding.UTF8, true);

                bool myMaterial = false;
                bool end = false;

                while (srMTL.Peek() > -1)
                {
                    String input = srMTL.ReadLine();
                    input = input.Replace("  ", " ");
                    String numberInput = input.Replace('.', ',');
                    String[] parameters = input.Split(' ');
                    String[] numberParameters = numberInput.Split(' ');

                    switch (parameters[0])
                    {
                        case "newmtl":
                            if (parameters[1] == material)
                            {
                                myMaterial = true;
                            }
                            else
                            {
                                if (myMaterial)
                                {
                                    end = true;
                                }
                            }

                            break;

                        case "Kd":
                            if (myMaterial)
                            {
                                diffuseColor = new Vector3((float)System.Convert.ToDouble(numberParameters[1]), (float)System.Convert.ToDouble(numberParameters[2]), (float)System.Convert.ToDouble(numberParameters[3]));
                            }

                            break;

                        case "map_Kd":
                            if (myMaterial)
                            {
                                parameters[1] = "textury/" + parameters[1];

                                uint[] textura = new uint[1];
                                gl.GenTextures(1, textura);

                                if (loadTexture(textura, 0, parameters[1]))
                                {
                                    tex[tex.Count - 1] = textura[0];
                                    diffuseColor = new Vector3(1, 1, 1);
                                }
                            }

                            break;
                    }

                    if (end)
                    {
                        break;
                    }
                }
            }
        }

        private static void closeMTLFile()
        {
            if (srMTL != null)
            {
                srMTL.Close();
            }
        }
    }
}