using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace TestTool.RemoteTriggerAPP
{
    public class FtpState
    {
        private ManualResetEvent wait;
        private FtpWebRequest request;
        private string fileName;
        private Exception operationException = null;
        private FtpStatusCode status;

        public FtpState()
        {
            wait = new ManualResetEvent(false);
        }
        public ManualResetEvent OperationComplete
        {
            get { return wait; }
        }
        public FtpWebRequest Request
        {
            get { return request; }
            set { request = value; }
        }

        public string FileName
        {
            get { return fileName; }
            set { fileName = value; }
        }
        public Exception OperationException
        {
            get { return operationException; }
            set { operationException = value; }
        }
        public FtpStatusCode StatusCode
        {
            get { return status; }
            set { status = value; }
        }
    }
    public class FTPClient
    {

        public delegate void UploadDataCompletedEventHandler(FtpState state);
        public delegate void UploadDataProgressEventHandler(double percent);
        public event UploadDataCompletedEventHandler OnUploadSuccessful;
        public event UploadDataCompletedEventHandler OnUploadFail;
        public event UploadDataProgressEventHandler OnUploadProgress;
        private int uploadTimeOut = 5 * 1000 * 60;

        public string Host
        {
            private set; get;
        }
        public string UesrName
        {
            private set; get;
        }
        public string Password
        {
            private set; get;
        }

        public int UploadTimeOut
        {
            get
            {
                return uploadTimeOut;
            }

            set
            {
                uploadTimeOut = value;
            }
        }

        public FTPClient(string host, string usrName, string password)
        {
            Host = host;
            UesrName = usrName;
            Password = password;
        }

        /// <summary>
        /// 上傳檔案到FTPServer(斷點續傳)
        /// </summary>
        /// <param name="uploadFilePath">本地上傳檔案的路徑</param>
        /// <param name="uploadFtpPath">FTPServer上的存放路徑</param>
        public bool FtpUploadBroken(string uploadFilePath, string uploadFtpPath)
        {
            if (uploadFtpPath == null)
            {
                uploadFtpPath = "";
            }
            string newFileName = string.Empty;
            bool success = true;
            FileInfo fileInf = new FileInfo(uploadFilePath);
            long allbye = (long)fileInf.Length;

            long startfilesize = GetFileSize(uploadFtpPath);
            if (startfilesize >= allbye)
            {
                return true;
            }
            long startbye = startfilesize;



            FtpWebRequest reqFTP;
            // 根据uri创建FtpWebRequest对象 
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uploadFtpPath));
            // ftp用户名和密码 
            reqFTP.Credentials = new NetworkCredential(UesrName, Password);
            // 默认为true，连接不会被关闭 
            // 在一个命令之后被执行 
            reqFTP.KeepAlive = false;
            // 指定执行什么命令 
            reqFTP.Method = WebRequestMethods.Ftp.AppendFile;
            // 指定数据传输类型 
            reqFTP.UseBinary = true;
            // 上传文件时通知服务器文件的大小 
            reqFTP.ContentLength = fileInf.Length;
            int buffLength = 2048000;// 缓冲大小设置为200kb 
            byte[] buff = new byte[buffLength];
            // 打开一个文件流 (System.IO.FileStream) 去读上传的文件 
            using (FileStream fs = fileInf.OpenRead())
            {
                Stream strm = null;
                try
                {
                    // 把上传的文件写入流 
                    strm = reqFTP.GetRequestStream();
                    // 每次读文件流的2kb   
                    fs.Seek(startfilesize, 0);
                    int contentLen = fs.Read(buff, 0, buffLength);
                    // 流内容没有结束 
                    while (contentLen != 0)
                    {
                        // 把内容从file stream 写入 upload stream 
                        strm.Write(buff, 0, contentLen);
                        contentLen = fs.Read(buff, 0, buffLength);
                        startbye += contentLen;

                      
                        double percent = (double)((decimal)startbye / reqFTP.ContentLength) * 100;
                        OnUploadProgress?.Invoke(percent);


                    }
                    // 关闭两个流 
                    strm.Close();
                    fs.Close();
                }
                catch(Exception ex)
                {
                    success = false;

                }
                finally
                {
                    if (fs != null)
                    {
                        fs.Close();
                    }
                    if (strm != null)
                    {
                        strm.Close();
                    }
                }
            }

            return success;
        }

        /// <summary>
        /// 獲取已上傳檔案大小
        /// </summary>
        /// <param name="remoteFilepath">服务器文件路径</param>
        /// <returns></returns>
        private long GetFileSize(string remoteFilepath)
        {
            long filesize = 0;
            try
            {
                FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(remoteFilepath);
                reqFTP.KeepAlive = false;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(UesrName, Password);//用户，密码
                reqFTP.Method = WebRequestMethods.Ftp.GetFileSize;
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                filesize = response.ContentLength;
                return filesize;
            }
            catch
            {
                return 0;
            }
        }


        /// <summary>
        /// 上傳檔案到FTPServer
        /// </summary>
        /// <param name="uploadFilePath">本地上傳檔案的路徑</param>
        /// <param name="uploadFtpPath">FTPServer上的存放路徑</param>
        public void UploadFile(string uploadFilePath, string uploadFtpPath)
        {

            Uri target = new Uri(uploadFtpPath);
            FtpState state = new FtpState();
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create(target);
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential(UesrName, Password);
            state.Request = request;
            state.FileName = uploadFilePath;


            // Asynchronously get the stream for the file contents.
            request.BeginGetRequestStream(
                new AsyncCallback(EndGetStreamCallback),
                state
            );


            ThreadPool.RegisterWaitForSingleObject(state.OperationComplete, new WaitOrTimerCallback(TimeoutCallback), state, UploadTimeOut, true);
        }
        private void EndGetStreamCallback(IAsyncResult ar)
        {
            FtpState state = (FtpState)ar.AsyncState;

            Stream requestStream = null;
            // End the asynchronous call to get the request stream.
            try
            {
                using (requestStream = state.Request.EndGetRequestStream(ar))
                {
                    // Copy the file contents to the request stream.
                    const int bufferLength = 2048;
                    byte[] buffer = new byte[bufferLength];
                    int count = 0;
                    int readBytes = 0;
                    using (FileStream stream = File.OpenRead(state.FileName))
                    {
                        do
                        {
                            readBytes = stream.Read(buffer, 0, bufferLength);
                            requestStream.Write(buffer, 0, readBytes);
                            count += readBytes;

                        }
                        while (readBytes != 0);
                    }

                    Console.WriteLine("Writing {0} bytes to the stream.", count);
                    // IMPORTANT: Close the request stream before sending the request.
                    requestStream.Close();
                }


                // Asynchronously get the response to the upload request.
                state.Request.BeginGetResponse(
                    new AsyncCallback(EndGetResponseCallback),
                    state
                );
            }
            // Return exceptions to the main application thread.
            catch (Exception e)
            {
                Console.WriteLine("Could not get the request stream.");
                state.OperationException = e;
                state.OperationComplete.Set();
                //if (OnUploadFail != null)
                //    OnUploadFail(state);
            }

        }
        private void EndGetResponseCallback(IAsyncResult ar)
        {
            FtpState state = (FtpState)ar.AsyncState;
            FtpWebResponse response = null;
            try
            {
                response = (FtpWebResponse)state.Request.EndGetResponse(ar);
                response.Close();
                state.StatusCode = response.StatusCode;
                state.OperationComplete.Set();



            }
            // Return exceptions to the main application thread.
            catch (Exception e)
            {
                //Console.WriteLine("Error getting response.");
                state.OperationException = e;
                state.OperationComplete.Set();
                //if (OnUploadFail != null)
                //    OnUploadFail(state);

            }
        }
        private void TimeoutCallback(object state, bool timedOut)
        {
            FtpState _state = state as FtpState;
            if (timedOut)
            {
                _state.Request.Abort();
                if (OnUploadFail != null)
                    OnUploadFail(_state);
            }
            else
            {

                if (_state.StatusCode == FtpStatusCode.ClosingData)
                {
                    if (OnUploadSuccessful != null)
                        OnUploadSuccessful(_state);
                }
                else
                {
                    if (OnUploadFail != null)
                        OnUploadFail(_state);
                }
            }
        }

    }

}