using System;
using System.Collections;
using System.Net;
using System.Threading;
using XML_Base.Config;
using XML_Base_Library.Ftp;

namespace XML_Base
{
    class FtpUtil
    {
        private string username, password, serverip;
        private int port, no = 1;
        private Queue q = new Queue(11);
        private Thread ftpThread;

        /// <summary>
        /// Constructor of the FtpUtil thread.
        /// It's used to initialise some internal variables.
        /// </summary>
        /// <param name="serverIp">The ftp server's ip address.</param>
        /// <param name="Port">The ftp server's port.</param>
        /// <param name="username">The ftp server's username used for access.</param>
        /// <param name="password">The ftp server's password used for access.</param>
        public FtpUtil(IPAddress serverIp, int Port, string username, string password)
        {
            try
            {
                this.username = username;
                this.password = password;
                this.serverip = serverIp.ToString();
                this.port = Port;
            }
            catch (Exception ex)
            {
                Util.ExceptionHandler.RaiseException(ex);
            }
        }

        /// <summary>
        /// Main method of the FtpUtil class. It downloads the first file in the queue.
        /// </summary>
        /// <remarks>Normally runs on a separate thread to avoid freezing MAINthread.</remarks>
        private void GetFile()
        {
            try
            {
                FormInstancer.MainFormInstance.SetStatus(String.Format("Downloading file {0} of {1}", no.ToString(), (q.Count + no).ToString()));
                FtpClient ftpClient = new FtpClient(serverip, port);
                //ftpClient.AutoChecksumValidation = HashingFunction.Crc32; Bulletproof Ftp Server 2010 returns "Unknown Command" on all types of hashes. We need to fix the autochecksumvalidation's server command to a working one.
                ftpClient.FileTransferType = TransferType.Binary;
                ftpClient.DataTransferMode = TransferMode.Passive;
                ftpClient.Open(username, password);
                string filename = (string)q.Dequeue();
                ftpClient.GetFile(Global.FtpRemotePath + filename, Global.FtpDownloadPath + filename, FileAction.Create);
                ftpClient.Close();
                no++;
                DownloadComplete();
            }
            catch
            { FormInstancer.MainFormInstance.SetStatus("Error: Connection failed."); }
        }

        /// <summary>
        /// Adds the FileName parameter to the queue and starts a new thread to download the file.
        /// </summary>
        /// <param name="FileName">File to be downloaded</param>
        public void Download(string FileName)
        {
            try
            {
                q.Enqueue(FileName);
                if (ftpThread == null)
                {
                    ftpThread = new Thread(new ThreadStart(GetFile));
                    ftpThread.Name = "Ftp thread";
                    ftpThread.Start();
                }
            }
            catch (Exception ex)
            {
                Util.ExceptionHandler.RaiseException(ex);
            }
        }

        /// <summary>
        /// Adds the FileName array to the queue and starts a new thread to download the first file from the queue.
        /// </summary>
        /// <param name="FileNames">An array of strings indicating Filenames</param>
        public void Download(string[] FileNames)
        {
            for (int i = 0; i < FileNames.Length - 1; i++)
            {
                q.Enqueue(FileNames[i]);
            }
            ftpThread = new Thread(new ThreadStart(GetFile));
            ftpThread.Start();
        }

        /// <summary>
        /// Event used to continue downloading the other files in the queue.
        /// </summary>
        /// <remarks>Creates a new thread every time it's called.</remarks>
        private void DownloadComplete()
        {
            if (q.Count > 0)
            {
                ftpThread = new Thread(new ThreadStart(GetFile));
                ftpThread.Name = "Ftp Thread";
                ftpThread.Start();
            }
            else
            {
                FormInstancer.MainFormInstance.SetStatus("Ready");
            }
        }
    }
}