using System;
using System.IO;
using System.Net;
using System.Text;
using System.Xml;
using System.Configuration;
using System.Web;
using System.Collections.Generic;
using Bowin.Common.Utility;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.Extensions.Configuration;

namespace Bowin.Common.Files
{
    internal class FileServerSettings
    {
        public string UserName { get; set; }
        public string Password { get; set; }
        public string Url { get; set; }
    }

	/// <summary>
	/// 处理远程附件的类，由于联达并没有建立文件服务器，需要兼容：
	/// 在web调用，为了减少网络流量，就直接处理本地路径的文件；
	/// 在服务调用，配置Url、用户名密码后，处理的是远程文件服务器的文件。
	/// </summary>
	public class FileServerManager
	{
		public string ErrorMessage;
		private CredentialCache myCredentialCache = null;
		private static FileServerSettings Settings;

		private static bool IsWebLocal 
		{
			get
			{
				return (HttpHelper.Accessor?.HttpContext != null || string.IsNullOrEmpty(Settings.Url));
			}
		}

		static FileServerManager()
		{
			var configuration = Utility.Environment.GetConfig("appsettings.json");

			Settings = configuration.GetSection("FileServer").Get<FileServerSettings>();
			if (Settings == null)
			{
				Settings = new FileServerSettings();
			}
			if (!string.IsNullOrEmpty(Settings.Url))
			{
				if (Settings.Url.Substring(Settings.Url.Length - 1, 1) != "/")
				{
					Settings.Url = Settings.Url + "/";
				}
			}
		}

		public FileServerManager()
		{
			this.ErrorMessage = "";
			if (!string.IsNullOrEmpty(Settings.UserName))
			{
				this.myCredentialCache = new CredentialCache();
				this.myCredentialCache.Add(new Uri(Settings.Url), "NTLM", new NetworkCredential(Settings.UserName, Settings.Password));
			}
		}

		public bool DeleteFile(string filename)
		{
			this.ErrorMessage = "";
			if (IsWebLocal)
			{
				this.ErrorMessage = "";
				try
				{
					File.Delete(HttpHelper.MapPath(filename));
				}
				catch (Exception ex)
				{
					this.ErrorMessage = ex.Message;
					return false;
				}
			}
			else
			{
				HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Settings.Url + filename);
				request.Credentials = this.myCredentialCache;
				request.Method = "DELETE";
				WebResponse response = null;
				try
				{
					response = request.GetResponse();
				}
				catch (WebException ex)
				{
					this.ErrorMessage = ex.Message;
					return false;
				}
				finally
				{
					if (response != null)
					{
						response.Close();
					}
				}
			}
			return true;
		}

		public bool IsFileExist(string filename)
		{
			this.ErrorMessage = "";
			if (IsWebLocal)
			{
				return File.Exists(HttpHelper.MapPath(filename));
			}
			else
			{
				string text1 = "<?xml version=\"1.0\"?><a:propfind xmlns:a=\"DAV:\"><a:prop><a:getcontentlength/></a:prop></a:propfind>";
				byte[] buffer1 = new ASCIIEncoding().GetBytes(text1);
				HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Settings.Url + filename);
				request.Credentials = this.myCredentialCache;
				request.Method = "PROPFIND";
				request.ContentType = "text/xml";
				request.Headers.Add("Depth", "0");
				request.Headers.Add("Translate: f");
				request.ContentLength = buffer1.Length;
				Stream stream = request.GetRequestStream();
				stream.Write(buffer1, 0, buffer1.Length);
				stream.Close();
				WebResponse response = null;
				try
				{
					response = request.GetResponse();
				}
				catch (WebException ex)
				{
					if (ex.Message.IndexOf("404") == -1)
					{
						this.ErrorMessage = ex.Message;
						throw ex;
					}
					return false;
				}
				finally
				{
					if (response != null)
					{
						response.Close();
					}
				}
			}
			return true;
		}

		public bool UploadFile(Stream inputStream, string filename)
		{
			this.ErrorMessage = "";
			if (IsWebLocal)
			{
				using (var stream = System.IO.File.Create(HttpHelper.MapPath(filename)))
				{
					inputStream.CopyTo(stream);
				}
			}
			else
			{
				WebClient client = new WebClient();
				client.Credentials = this.myCredentialCache;
				int num1 = (int)inputStream.Length;
				byte[] buffer1 = new byte[num1];
				inputStream.Read(buffer1, 0, num1);
				Stream stream = client.OpenWrite(Settings.Url + filename, "PUT");

				stream.Write(buffer1, 0, num1);
				try
				{

					stream.Close();
				}
				catch (WebException ex)
				{
					this.ErrorMessage = ex.Message;
					return false;
				}
			}
			return true;
		}

		public bool UploadFile(byte[] buffer, string filename)
		{
			this.ErrorMessage = "";
			if (IsWebLocal)
			{
				using (var stream = System.IO.File.Create(HttpHelper.MapPath(filename)))
				{
					stream.Write(buffer);
				}
			}
			else
			{
				WebClient client = new WebClient();
				client.Credentials = this.myCredentialCache;

				Stream stream = client.OpenWrite(Settings.Url + filename, "PUT");

				stream.Write(buffer, 0, buffer.Length);
				try
				{
					stream.Close();
				}
				catch (WebException ex)
				{
					this.ErrorMessage = ex.Message;
					return false;
				}
			}
			return true;
		}

		public static Stream GetFileStream(string FileName)
		{
			if (IsWebLocal)
			{
				return FileHelper.GetFileStream(FileName);
			}
			else
			{
				WebClient conn = new WebClient();
				var targetFile = FileName;
				if (!FileName.Trim().StartsWith("http") && !FileName.Trim().Contains("://"))
				{
					targetFile = new Uri(Settings.Url).GetLeftPart(UriPartial.Authority);
					if (!FileName.StartsWith("/"))
					{
						targetFile += "/";
					}
					targetFile += FileName;
				}
				var bytes = conn.DownloadData(targetFile);
				return new MemoryStream(bytes);
			}
		}

        /// <summary>
        /// 下载文件服务器中的文件
        /// </summary>
        /// <param name="virtualFilePath">目标文件的虚拟路径</param>
        /// <param name="remoteFile">远程文件地址</param>
        public static void DownloadFile(string virtualFilePath, string remoteFile)
        {
            WebClient conn = new WebClient();
            var targetFile = remoteFile;

            File.Delete(HttpHelper.MapPath(virtualFilePath));
            if (!remoteFile.Trim().StartsWith("http") && !remoteFile.Trim().Contains("://"))
            {
                targetFile = new Uri(HttpHelper.Current.Request.GetDisplayUrl()).GetLeftPart(UriPartial.Authority);
                if (!remoteFile.StartsWith("/"))
                {
                    targetFile += "/";
                }
                targetFile += remoteFile;
            }
            conn.DownloadFile(targetFile, HttpHelper.MapPath(virtualFilePath));
        }
	}
}