using System;
using System.IO;
using System.Net;
using System.Text;
using System.Windows.Forms;

namespace UAS_LabelMachine
{
    class ftpOperater
    {
        public static string FTPAddress = DataHelper.FTPAdress.Split('|')[0];

        public static string DownLoadTo = Environment.GetEnvironmentVariable("windir").Substring(0, 1) + @":\" + @"打印标签\";

        private string ftpServerIP;
        private string ftpUser;
        private string ftpPwd;

        public ftpOperater()
        {
            string[] FTPInf = DataHelper.FTPAdress.Split('|');
            this.ftpServerIP = FTPInf[0];
            this.ftpUser = FTPInf[1];
            this.ftpPwd = FTPInf[2];
        }

        public void UpLoadFile(string filepath, string filename)
        {
            //上传之前判断文件是否存在
            string[] filelist = GetFileList();
            if (filelist != null)
                for (int i = 0; i < filelist.Length; i++)
                {
                    if (filelist[i] == filename)
                    {
                        string upload = MessageBox.Show("已存在同名文件，是否覆盖", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question).ToString();
                        if (upload.ToString() != "Yes")
                        {
                            return;
                        }
                    }
                }
            FtpWebRequest reqFTP;
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + "/" + filename));
            reqFTP.UseBinary = true;
            reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);
            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
            FileInfo file = new FileInfo(filepath + "/" + filename);
            const int BufferSize = 2048;
            byte[] content = new byte[BufferSize - 1 + 1];
            int dataRead;
            using (FileStream fs = file.OpenRead())
            {
                //把上传的文件写入流
                using (Stream rs = reqFTP.GetRequestStream())
                {
                    do
                    {
                        //每次读文件流的2KB
                        dataRead = fs.Read(content, 0, BufferSize);
                        rs.Write(content, 0, dataRead);
                    } while (!(dataRead < BufferSize));
                    rs.Close();
                }
                fs.Close();
            }
        }

        /// <summary>
        /// 获取ftp服务器上的文件信息
        /// </summary>
        /// <returns>存储了所有文件信息的字符串数组</returns>
        public string[] GetFileList()
        {
            string[] downloadFiles;
            StringBuilder result = new StringBuilder();
            FtpWebRequest reqFTP;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + "/"));
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);
                reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;
                WebResponse response = reqFTP.GetResponse();
                StreamReader reader = new StreamReader(response.GetResponseStream());

                string line = reader.ReadLine();
                while (line != null)
                {
                    result.Append(line);
                    result.Append("\n");
                    line = reader.ReadLine();
                }
                result.Remove(result.ToString().LastIndexOf('\n'), 1);
                reader.Close();
                response.Close();

                return result.ToString().Split('\n');
            }
            catch (Exception ex)
            {
                System.Windows.Forms.MessageBox.Show("获取文件信息失败:" + ex.Message, "操作失败", MessageBoxButtons.OK, MessageBoxIcon.Error);
                downloadFiles = null;
                return downloadFiles;
            }
        }

        /// <summary>
        /// 获取FTP上指定文件的大小
        /// </summary>
        /// <param name="filename">文件名</param>
        /// <returns>文件大小</returns>
        public long GetFileSize(string filename)
        {
            FtpWebRequest reqFTP;
            long fileSize = 0;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + "/" + filename));
                reqFTP.Method = WebRequestMethods.Ftp.GetFileSize;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                fileSize = response.ContentLength;
                ftpStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("获取文件大小时，出现异常:\n" + ex.Message, "获取文件大小失败！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            return fileSize;
        }

        /// <summary>
        /// 实现ftp下载操作
        /// </summary>
        /// <param name="fileName">远程文件名</param>
        public string Download(string fileName, DateTime time)
        {
            FtpWebRequest reqFTP;
            try
            {
                FileStream outputStream = new FileStream(DownLoadTo + @"\" + fileName, FileMode.Create);
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpServerIP + "/" + fileName));
                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);
                reqFTP.UsePassive = true;
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                long cl = response.ContentLength;
                int bufferSize = 4096;
                int readCount;
                byte[] buffer = new byte[bufferSize];
                readCount = ftpStream.Read(buffer, 0, bufferSize);
                while (readCount > 0)
                {
                    outputStream.Write(buffer, 0, readCount);
                    readCount = ftpStream.Read(buffer, 0, bufferSize);
                }
                ftpStream.Close();
                outputStream.Close();
                response.Close();
                //设置最后修改文件时间为服务器时间
                FileInfo f = new FileInfo(DownLoadTo + @"\" + fileName);
                f.LastWriteTime = time;
                return DownLoadTo + @"\" + fileName;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return "";
            }
        }
    }
}