/*
 * FileName: SimpleFTP.cs
 * Classes Included: SimpleFTP
 * Purpose: The SimpleFTP is a class that allows for the FTP transfer of remote
 *   data to the local hard drive.  It also provides three delegates to report
 *   progress to the calling method.
 * Created on: 09 Dec 2008
 * Created by: wraith808
 * 
 * History:
 * Date         Who         Note
 * ---------------------------------------------------------------------------
 * 12-09-2008   wraith808   Created
 * 
 */
 
using System;
using System.IO;
using System.Net;
 
namespace UtilsLib
{    
	public delegate void OnFTPFinish(bool ftpSuccessful, string message);
    public delegate void OnFTPStart(string message);
    public delegate void OnFTPProgress(int bytesTransferred, string message);
 
    public class SimpleFTP
    {
        private bool _UseBinaryMode = true;
        public bool UseBinaryMode
        {
            get { return _UseBinaryMode; }
            set { _UseBinaryMode = value; }
        }
 
        string _LocalFilePath;
        public string LocalFilePath
        {
            get { return _LocalFilePath; }
            set { _LocalFilePath = value; }
        }
 
        string _LocalFileName;
        public string LocalFileName
        {
            get { return _LocalFileName; }
            set { _LocalFileName = value; }
        }
 
        string _URI;
        public string URI
        {
            get { return _URI; }
            set { _URI = value; }
        }
 
        string _UserId;
        public string UserId
        {
            get { return _UserId; }
            set { _UserId = value; }
        }
 
        string _Password;
        public string Password
        {
            get { return _Password; }
            set { _Password = value; }
        }
 
        string _RemoteFileName;
        public string RemoteFileName
        {
            get { return _RemoteFileName; }
            set { _RemoteFileName = value; }
        }
 
        public bool InitiateTransfer(OnFTPProgress OnProgress, OnFTPStart OnStart, OnFTPFinish OnFinish)
        {
            bool transferResult = true;
            if ((_LocalFileName.Length == 0) || (_LocalFilePath.Length == 0) ||
                (_UserId.Length == 0) || (_Password.Length == 0) || (_URI.Length == 0) ||
                (_RemoteFileName.Length == 0))
            {
                OnFinish(false, "All parameters not initialized.  Transfer aborted.");
                transferResult = false;
            }
            else
            {
                var outputStream = new FileStream(_LocalFilePath + "\\" + _LocalFileName, FileMode.Create);
                var reqFTP = (FtpWebRequest)WebRequest.Create(_URI + "//'" + _RemoteFileName + "'");
                try
                {
                    reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
                    reqFTP.UseBinary = _UseBinaryMode;
                    reqFTP.Credentials = new NetworkCredential(_UserId, _Password);
                    var response = (FtpWebResponse)reqFTP.GetResponse();
                    Stream ftpStream = response.GetResponseStream();
                    long cl = response.ContentLength;
                    long transferLength = 0;
                    OnStart(string.Format("Preparing to transfer {0} bytes", cl));
                    const int bufferSize = 2048;
                    var buffer = new byte[bufferSize];
 
                    int readCount = ftpStream.Read(buffer, 0, bufferSize);
                    while (readCount > 0)
                    {
                        outputStream.Write(buffer, 0, readCount);
                        OnProgress(readCount, string.Format("Transferred {0} bytes.", readCount));
                        transferLength += readCount;
                        readCount = ftpStream.Read(buffer, 0, bufferSize);
                    }
                    OnFinish(true, string.Format("{0} bytes transferred.", transferLength));
                    ftpStream.Close();
                    outputStream.Close();
                    response.Close();
                }
                catch (Exception e)
                {
                    OnFinish(false, string.Format("Failed: {0}", e.Message));
                    transferResult = false;
                }
            }
            return transferResult;
        }
    }
}