using Newtonsoft.Json;
using OSGeo.GDAL;
using OSGeo.OGR;
using SimuTools.Domain;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SimuTools.Tools
{
    public class Handle
    {
        public static readonly int MAX = 256 * 256;

        public static readonly string GdalPath = ConfigurationManager.AppSettings["gdalPath"];

        public static readonly string BaseDir = AppDomain.CurrentDomain.BaseDirectory;

        /// <summary>
        /// 运行
        /// </summary>
        public static void Run(string terrainFile, string waterPath, string flowPath, string outPath)
        {
            Domain.Layer layer = new Domain.Layer();
            layer.duration = new Duration();
            layer.terrain = new Terrain();
            layer.waters = new Water();

            string temp = Path.Combine(outPath, "temp");
            if (!Directory.Exists(temp)) Directory.CreateDirectory(temp);

            CopeTerrain(terrainFile, outPath, layer);
            //CopeWater(waterPath, outPath, layer);
            CopeFlow(flowPath, outPath, layer);
            CopeLayerJson(outPath, layer);

            if (Directory.Exists(temp)) Directory.Delete(temp, true);
        }

        #region 地形
        /// <summary>
        /// 处理地形
        /// </summary>
        private static void CopeTerrain(string terrainFile, string outPath, Domain.Layer layer)
        {
            Dataset ds = null;
            try
            {
                ds = Gdal.Open(terrainFile, Access.GA_ReadOnly);
                if (null == ds || 0 == ds.RasterCount || null == ds.GetSpatialRef()) return;

                SetTerrainInfo(ds, layer);
                //CreateTerrainPng(ds, layer, outPath);
            }
            finally
            {
                if (null != ds) ds.Dispose();
            }
        }

        /// <summary>
        /// 设置地形信息
        /// </summary>
        private static void SetTerrainInfo(Dataset ds, Domain.Layer layer)
        {
            Geometry minPoint = GdalHelper.GetMinPoint(ds);
            Geometry maxPoint = GdalHelper.GetMaxPoint(ds);
            layer.extension = new Extension(minPoint.GetX(0), minPoint.GetY(0), maxPoint.GetX(0), maxPoint.GetY(0));

            OSGeo.GDAL.Band band = ds.GetRasterBand(1);
            double[] mm = new double[2];
            band.ComputeRasterMinMax(mm, 0);
            layer.extension.SetHeight(mm[0], mm[1]);
        }

        /// <summary>
        /// 创建地形PNG
        /// </summary>
        private static void CreateTerrainPng(Dataset ds, Domain.Layer layer, string outPath)
        {
            string tempPath = Path.Combine(outPath, "temp");
            if (!Directory.Exists(tempPath)) Directory.CreateDirectory(tempPath);
            string terrainPath = Path.Combine(outPath, "terrain");
            if (!Directory.Exists(terrainPath)) Directory.CreateDirectory(terrainPath);

            foreach (int[] sizes in layer.terrain.size)
            {
                string tif = Path.Combine(tempPath, DateTime.Now.Ticks.ToString() + ".tif");
                Resample(ds.GetDescription(), tif, sizes[0], sizes[1]);
                if (!File.Exists(tif))
                {
                    continue;
                }

                string png = Path.Combine(terrainPath, sizes[0] + "_" + sizes[1] + ".png");
                Tif2Png(layer, tif, png, sizes[0], sizes[1]);
            }
        }

        /// <summary>
        /// 重采样
        /// </summary>
        private static void Resample(string source, string dest, int width, int height)
        {
            // https://blog.51cto.com/u_16099346/6691820
            string cmd = string.Format("{0}gdalwarp.exe -t_srs {1} -ts {2} {3} -r {4} -of GTiff \"{5}\" \"{6}\"", GdalPath, "EPSG:4326", width, height, "bilinear", source, dest);
            string err = ExecExe(cmd);
        }

        /// <summary>
        /// 执行命令
        /// </summary>
        public static string ExecExe(string cmd)
        {
            string str = null;
            Process p = null;
            try
            {
                p = new Process();
                p.StartInfo.FileName = "cmd.exe";
                p.StartInfo.UseShellExecute = false;
                p.StartInfo.CreateNoWindow = true;
                p.StartInfo.RedirectStandardInput = true;
                p.StartInfo.RedirectStandardOutput = true;
                p.StartInfo.RedirectStandardError = true;
                p.Start();

                StreamWriter si = p.StandardInput;
                StreamReader se = p.StandardError;

                si.AutoFlush = true;
                si.WriteLine(cmd);
                si.WriteLine("exit");

                str = se.ReadToEnd();
                se.Close();
                si.Close();
            }
            catch (Exception ex)
            {
                LogOut.Error(ex.Message + "\r\n" + ex.StackTrace);
                str = ex.Message;
            }
            finally
            {
                if (p != null) p.Close();
            }
            return str;
        }

        /// <summary>
        /// Tif值转存至Png
        /// </summary>
        private static void Tif2Png(Domain.Layer layer, string tif, string png, int width, int height)
        {
            Dataset ds = null;
            try
            {
                ds = Gdal.Open(tif, Access.GA_ReadOnly);
                if (null == ds || 0 == ds.RasterCount) return;

                OSGeo.GDAL.Band band = ds.GetRasterBand(1);
                float[] buffer = new float[width * height];
                band.ReadRaster(0, 0, width, height, buffer, width, height, 0, 0);

                Bitmap image = new Bitmap(width, height);
                Graphics graphic = Graphics.FromImage(image);
                graphic.Clear(Color.Transparent); // 填充透明色

                //double perHeight = (layer.extension.maxHeight - layer.extension.minHeight) * 100 / 65536;
                //int val = Convert.ToInt32(buffer[x * y]* 100); //Convert.ToInt32((buffer[x * y] - layer.extension.minHeight) * 100);
                //int val = Convert.ToInt32((buffer[x * y] - layer.extension.minHeight) * 100 / perHeight);

                for (int x = 0; x < width; x++)
                {
                    for (int y = 0; y < height; y++)
                    {
                        int offset = x + y * width;
                        if (float.IsNaN(buffer[offset]) || buffer[offset] < -999)
                        {
                            //image.SetPixel(x, y, Color.Transparent);
                            continue;
                        }

                        int val = Convert.ToInt32(buffer[offset] * 100);
                        int r = val / 65536;
                        int g = (val - r * 65536) / 256;
                        int b = val % 256;

                        Color color = Color.FromArgb(127, r, g, b);
                        image.SetPixel(x, y, color);
                    }
                }

                image.Save(png, System.Drawing.Imaging.ImageFormat.Png);
            }
            finally
            {
                if (null != ds) ds.Dispose();
                if (File.Exists(tif)) File.Delete(tif);
            }
        }
        #endregion

        #region 水面
        /// <summary>
        /// 处理水面
        /// </summary>
        private static void CopeWater(string waterPath, string outPath, Domain.Layer layer)
        {
            List<string> files = GetFiles(waterPath);
            if (null == files || files.Count == 0) return;

            SetWaterData(layer, files);
            if (files.Count != layer.waters.data.Count) return;

            /*for (int i = 0, c = files.Count; i < c; i++)
            {
                Dataset ds = null;
                try
                {
                    ds = Gdal.Open(files[i], Access.GA_ReadOnly);
                    if (null == ds || 0 == ds.RasterCount || null == ds.GetSpatialRef()) continue;

                    CreateWaterPng(ds, layer, outPath, layer.waters.data[i]);
                }
                finally
                {
                    if (null != ds) ds.Dispose();
                }
            }*/
            Parallel.For(0, files.Count, i =>
            {
                Dataset ds = null;
                try
                {
                    ds = Gdal.Open(files[i], Access.GA_ReadOnly);
                    if (null == ds || 0 == ds.RasterCount || null == ds.GetSpatialRef()) return;

                    CreateWaterPng(ds, layer, outPath, layer.waters.data[i]);
                }
                finally
                {
                    if (null != ds) ds.Dispose();
                }
            });
        }

        /// <summary>
        /// 创建水面PNG
        /// </summary>
        private static void CreateWaterPng(Dataset ds, Domain.Layer layer, string outPath, long ticks)
        {
            string tempPath = Path.Combine(outPath, "temp");
            if (!Directory.Exists(tempPath)) Directory.CreateDirectory(tempPath);
            string waterPath = Path.Combine(outPath, "waters", ticks.ToString());
            if (!Directory.Exists(waterPath)) Directory.CreateDirectory(waterPath);

            foreach (int[] sizes in layer.terrain.size)
            {
                string fileName = Path.GetFileNameWithoutExtension(ds.GetDescription()) + "_" + sizes[0] + "_" + sizes[1];
                string tif = Path.Combine(tempPath, fileName + ".tif");
                Resample(ds.GetDescription(), tif, sizes[0], sizes[1]);
                if (!File.Exists(tif))
                {
                    continue;
                }

                string png = Path.Combine(waterPath, sizes[0] + "_" + sizes[1] + ".png");
                Tif2Png(layer, tif, png, sizes[0], sizes[1]);
            }
        }

        /// <summary>
        /// 获取文件
        /// </summary>
        private static List<String> GetFiles(string path, string prefix = "")
        {
            string[] files = Directory.GetFiles(path, prefix + "*.tif?", SearchOption.TopDirectoryOnly);
            if (null == files || files.Length == 0) return null;

            List<string> list = files.ToList();
            list.Sort();

            return list;
        }

        /// <summary>
        /// 设置水面数据
        /// </summary>
        private static void SetWaterData(Domain.Layer layer, List<string> files)
        {
            DateTime now = DateTime.Now;
            long startTicks = new DateTime(1970, 1, 1, 8, 0, 0).Ticks;

            foreach (string file in files)
            {
                string fileName = Path.GetFileNameWithoutExtension(file);
                int hour = Convert.ToInt32(fileName.Substring(0, 2));
                int minute = Convert.ToInt32(fileName.Substring(2, 2));
                int second = Convert.ToInt32(fileName.Substring(4, 2));

                DateTime d = new DateTime(now.Year, now.Month, now.Day, hour, minute, second);
                layer.waters.data.Add((d.Ticks - startTicks) / 10000);
            }
        }
        #endregion

        #region 流速流向
        /// <summary>
        /// 处理流速流向
        /// </summary>
        private static void CopeFlow(string flowPath, string outPath, Domain.Layer layer)
        {
            List<string> vxFiles = GetFiles(flowPath, "vx");
            List<string> vyFiles = GetFiles(flowPath, "vy");
            if (null == vxFiles || null == vyFiles || vxFiles.Count != vyFiles.Count || vxFiles.Count != layer.waters.data.Count) return;

            Parallel.For(0, vxFiles.Count, i =>
            {
                Dataset vxDs = null, vyDs = null;
                try
                {
                    vxDs = Gdal.Open(vxFiles[i], Access.GA_ReadOnly);
                    if (null == vxDs || 0 == vxDs.RasterCount || null == vxDs.GetSpatialRef() ||
                        null == vyDs || 0 == vyDs.RasterCount || null == vyDs.GetSpatialRef()) return;

                    CreateFlowPng(vxDs, vyDs, layer, outPath, layer.waters.data[i]);
                }
                finally
                {
                    if (null != vxDs) vxDs.Dispose();
                    if (null != vyDs) vyDs.Dispose();
                }
            });
        }

        /// <summary>
        /// 创建流速流向PNG
        /// </summary>
        private static void CreateFlowPng(Dataset vxDs, Dataset vyDs, Domain.Layer layer, string outPath, long ticks)
        {
            string tempPath = Path.Combine(outPath, "temp");
            if (!Directory.Exists(tempPath)) Directory.CreateDirectory(tempPath);
            string flowPath = Path.Combine(outPath, "flows", ticks.ToString());
            if (!Directory.Exists(flowPath)) Directory.CreateDirectory(flowPath);

            foreach (int[] sizes in layer.terrain.size)
            {
                string vxName = Path.GetFileNameWithoutExtension(vxDs.GetDescription()) + "_" + sizes[0] + "_" + sizes[1];
                string vxTif = Path.Combine(tempPath, vxName + ".tif");
                Resample(vxDs.GetDescription(), vxTif, sizes[0], sizes[1]);

                string vyName = Path.GetFileNameWithoutExtension(vyDs.GetDescription()) + "_" + sizes[0] + "_" + sizes[1];
                string vyTif = Path.Combine(tempPath, vyName + ".tif");
                Resample(vyDs.GetDescription(), vyTif, sizes[0], sizes[1]);

                if (!File.Exists(vxTif) || !File.Exists(vyTif)) continue;

                string png = Path.Combine(flowPath, sizes[0] + "_" + sizes[1] + ".png");
                VxyTif2Png(layer, vxTif, vyTif, png, sizes[0], sizes[1]);
            }
        }

        /// <summary>
        /// 流速流向Tif值转存至Png
        /// </summary>
        private static void VxyTif2Png(Domain.Layer layer, string vxTif, string vyTif, string png, int width, int height)
        {
            Dataset vxDs = null, vyDs = null;
            try
            {
                vxDs = Gdal.Open(vxTif, Access.GA_ReadOnly);
                vyDs = Gdal.Open(vyTif, Access.GA_ReadOnly);
                if (null == vxDs || 0 == vxDs.RasterCount || null == vyDs || 0 == vyDs.RasterCount) return;

                float[] vxBuffer = new float[width * height], vyBuffer = new float[width * height];
                vxDs.GetRasterBand(1).ReadRaster(0, 0, width, height, vxBuffer, width, height, 0, 0);
                vyDs.GetRasterBand(1).ReadRaster(0, 0, width, height, vyBuffer, width, height, 0, 0);

                Bitmap image = new Bitmap(width, height);
                Graphics graphic = Graphics.FromImage(image);
                graphic.Clear(Color.Transparent); // 填充透明色

                // 用 R通道表示，流向为归一化的二维向量（x,y），G通道表示为 x *255 , B通道表示为 y * 255
                for (int x = 0; x < width; x++)
                {
                    for (int y = 0; y < height; y++)
                    {
                        int offset = x + y * width;
                        if (float.IsNaN(vxBuffer[offset]) || vxBuffer[offset] < -999 ||
                            float.IsNaN(vyBuffer[offset]) || vyBuffer[offset] < -999) continue;

                        float vx = vxBuffer[offset], vy = vyBuffer[offset];
                        //int val = Convert.ToInt32(vxBuffer[offset] * 100);
                        //int r = val / 65536;
                        //int g = (val - r * 65536) / 256;
                        //int b = val % 256;
                        int r = 0;
                        int g = 0;
                        int b = 0;

                        Color color = Color.FromArgb(127, r, g, b);
                        image.SetPixel(x, y, color);
                    }
                }

                image.Save(png, System.Drawing.Imaging.ImageFormat.Png);
            }
            finally
            {
                if (null != vxDs) vxDs.Dispose();
                if (null != vyDs) vyDs.Dispose();
                if (File.Exists(vxTif)) File.Delete(vxTif);
                if (File.Exists(vyTif)) File.Delete(vyTif);
            }
        }
        #endregion

        #region 元数据
        /// <summary>
        /// 处理元数据
        /// </summary>
        private static void CopeLayerJson(string outPath, Domain.Layer layer)
        {
            if (null == layer) return;

            String json = JsonConvert.SerializeObject(layer);

            string filePath = Path.Combine(outPath, "layer.json");
            using (StreamWriter sw = new StreamWriter(filePath))
            {
                sw.Write(json);
            }
        }
        #endregion

        #region 暂时不用
        /// <summary>
        /// 重采样 *
        /// </summary>
        private static void Resample(Dataset ds, string dest, int width, int height)
        {
            // 设置Warp的选项：https://blog.csdn.net/qq_43210879/article/details/121350561
            string[] options = new string[] {
                "format=GTiff",
                "width=" + width,
                "height=" + height,
                "dstSRS=EPSG:4326"
            };

            OSGeo.GDAL.Driver driver = Gdal.GetDriverByName("GTiff");
            Dataset destDs = driver.Create(dest, width, height, ds.RasterCount, ds.GetRasterBand(1).DataType, null);

            GDALWarpAppOptions warpAppOptions = new GDALWarpAppOptions(options);
            Gdal.Warp(destDs, new Dataset[] { ds }, warpAppOptions, null, null);

            destDs.Dispose();
        }
        #endregion
    }
}