using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Web;
using System.Web.Http;

namespace ExportMap.cs
{
    public class WebUtils
    {
        #region LFData
        private static readonly object _obj = new object();

        private static string _lfData;

        public static string LFData
        {
            get
            {
                if (string.IsNullOrEmpty(_lfData))
                {
                    _lfData = Tools.GetSetting("lfData");
                }

                return _lfData;
            }
        }

        // http://localhost/ExportMap/tile0/12/3338/1671.png?path=2d\tiles\0102
        private static byte[] _emptyPng;

        public static byte[] EmptyPng
        {
            get
            {
                if (null == _emptyPng)
                {
                    lock (_obj)
                    {
                        if (null == _emptyPng)
                        {
                            string file = Tools.BaseDir + "Sources\\empty.png";
                            _emptyPng = ReadFileToBytes(file);
                        }
                    }
                }

                return _emptyPng;
            }
        }

        // http://127.0.0.1/ExportMap/terra0/12/6822/2744.terrain?v=1.1.0&path=3d\terrain\dem\t
        private static byte[] _emptyTerrain;

        public static byte[] EmptyTerrain
        {
            get
            {
                if (null == _emptyTerrain)
                {
                    lock (_obj)
                    {
                        if (null == _emptyTerrain)
                        {
                            string file = Tools.BaseDir + "Sources\\empty.terrain";
                            _emptyTerrain = ReadFileToBytes(file);
                        }
                    }
                }

                return _emptyTerrain;
            }
        }
        #endregion

        /// <summary>
        /// 获取地形图层文件
        /// </summary>
        public static HttpResponseMessage GetLayerJson(HttpRequestMessage Request, string path)
        {
            string basePath = Path.Combine(LFData, path);
            if (!Directory.Exists(basePath))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.BadRequest, "路径不存在！"));
            }

            string file = basePath + "\\layer.json";
            if (!File.Exists(file))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "文件不存在！"));
            }

            return DownloadFile(file, "layer.json", "application/json");
        }

        /// <summary>
        /// 获取地形文件
        /// </summary>
        public static HttpResponseMessage GetTerrain(HttpRequestMessage Request, string path, int z, int x, int y)
        {
            string basePath = Path.Combine(LFData, path);
            if (!Directory.Exists(basePath))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.BadRequest, "路径不存在！"));
            }

            string file = basePath + "\\" + z + "\\" + x + "\\" + y + ".terrain";
            if (!File.Exists(file))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "文件不存在！"));
            }

            return DownloadFile(file, y + ".terrain");
        }

        /// <summary>
        /// 获取地形文件，不存在返回空文件
        /// </summary>
        public static HttpResponseMessage GetTerrain0(HttpRequestMessage Request, string path, int z, int x, int y)
        {
            string basePath = Path.Combine(LFData, path);
            if (!Directory.Exists(basePath))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.BadRequest, "路径不存在！"));
            }

            string file = basePath + "\\" + z + "\\" + x + "\\" + y + ".terrain";
            if (!File.Exists(file))
            {
                return DownloadFile(EmptyTerrain, y + ".terrain");
            }

            return DownloadFile(file, y + ".terrain");
        }

        /// <summary>
        /// 获取影像文件
        /// </summary>
        public static HttpResponseMessage GetTile(HttpRequestMessage Request, string path, int z, int x, int y)
        {
            string basePath = Path.Combine(LFData, path, z.ToString());
            if (!Directory.Exists(basePath))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "路径不存在！"));
            }

            string file = basePath + "\\" + x + "\\" + y + ".png";
            if (!File.Exists(file))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "文件不存在！"));
            }

            return DownloadFile(file, y + ".png", "image/png");
        }

        /// <summary>
        /// 获取影像文件，不存在返回空文件
        /// </summary>
        public static HttpResponseMessage GetTile0(HttpRequestMessage Request, string path, int z, int x, int y)
        {
            string basePath = Path.Combine(LFData, path, z.ToString());
            if (!Directory.Exists(basePath))
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "路径不存在！"));
            }

            string file = basePath + "\\" + x + "\\" + y + ".png";
            if (!File.Exists(file))
            {
                return DownloadFile(EmptyPng, y + ".png", "image/png");
            }

            return DownloadFile(file, y + ".png", "image/png");
        }

        /// <summary>
        /// 下载文件
        /// </summary>
        public static HttpResponseMessage DownloadFile(string file, string fileName, string mediaType = "application/octet-stream")
        {
            //string fileName = Path.GetFileName(file);
            //FileStream stream = new FileStream(file, FileMode.Open);
            FileStream stream = File.OpenRead(file);

            HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
            response.Content = new StreamContent(stream);
            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
            response.Content.Headers.ContentDisposition.FileName = HttpUtility.UrlEncode(fileName);
            response.Content.Headers.ContentType = new MediaTypeHeaderValue(mediaType);

            //response.Content.Headers.Add("Cache-Control", "max-age=2592000"); // 缓存1个月
            response.Content.Headers.Expires = DateTimeOffset.Now.AddMonths(1); // new DateTimeOffset(DateTime.Now.AddMonths(1));

            return response;
        }

        /// <summary>
        /// 下载文件
        /// </summary>
        public static HttpResponseMessage DownloadFile(byte[] bytes, string fileName, string mediaType = "application/octet-stream")
        {
            MemoryStream ms = new MemoryStream(bytes);

            HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
            response.Content = new StreamContent(ms);
            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
            response.Content.Headers.ContentDisposition.FileName = HttpUtility.UrlEncode(fileName);
            response.Content.Headers.ContentType = new MediaTypeHeaderValue(mediaType);

            //response.Content.Headers.Add("Cache-Control", "max-age=2592000"); // 缓存1个月
            response.Content.Headers.Expires = DateTimeOffset.Now.AddMonths(1); // new DateTimeOffset(DateTime.Now.AddMonths(1));

            return response;
        }

        #region 工具类
        /// <summary>
        /// 读取文件至byte[]
        /// </summary>
        public static byte[] ReadFileToBytes(string file)
        {
            using (FileStream fs = new FileStream(file, FileMode.Open))
            {
                int len = (int)fs.Length;
                byte[] bytes = new byte[len];

                fs.Read(bytes, 0, len);
                fs.Flush();

                return bytes;
            }
        }

        /// <summary>
        /// Get请求
        /// </summary>
        public static string GetData(string url)
        {
            /*WebClient wc = new WebClient();
            Byte[] pageData = wc.DownloadData(url);

            Encoding coding = Encoding.GetEncoding("UTF-8");
            string str = coding.GetString(pageData);

            return str;*/

            Uri uri = new Uri(url);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            string str = reader.ReadToEnd();
            reader.Close();

            return str;
        }

        /// <summary>
        /// Post请求
        /// string data = string.Format("token={0}&f=json&where={1}", Token, "");
        /// </summary>
        public static string PostData(string url, string data)
        {
            Uri uri = new Uri(url);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";

            if (data != null)
            {
                byte[] bytes = Encoding.UTF8.GetBytes(data);
                request.ContentLength = bytes.Length;
                Stream outstream = request.GetRequestStream();
                outstream.Write(bytes, 0, bytes.Length);
                outstream.Flush();
                outstream.Close();
            }

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            string result = reader.ReadToEnd();
            reader.Close();

            return result;
        }
        #endregion
    }
}