Novetus_src/Novetus/NovetusCore/Classes/Downloader.cs

#region Usings
using System;
using System.IO;
using System.Net;
using System.Threading;
using System.Windows.Forms;
#endregion

namespace Novetus.Core
{
    #region Downloader

    public class Downloader
    {
        public string fileURL;
        public string fileName;
        public string fileFilter;
        public string filePath;
        public bool showErrorInfo = true;
        public bool overwrite = true;
        public int downloadSize;
        private string downloadOutcome;
        private string downloadOutcomeException;

        public Downloader(string url, string name, string filter)
        {
            fileName = name;
            fileURL = url;
            fileFilter = filter;
        }

        public Downloader(string url, string name, string filter, string path)
        {
            fileName = name;
            fileURL = url;
            fileFilter = filter;
            filePath = path;
        }

        public Downloader(string url, string name)
        {
            fileName = name;
            fileURL = url;
            fileFilter = "";
        }

        public string getDownloadOutcome()
        {
            return downloadOutcome;
        }

        public void InitDownloadDirect(string fileext, string additionalText = "", bool removeSpaces = false)
        {
            string outputfilename = "";

            if (removeSpaces == true)
            {
                outputfilename = (fileName + fileext).Replace(" ", "");
            }
            else
            {
                outputfilename = fileName + fileext;
            }

            string fullpath = filePath + "\\" + outputfilename;

            InitDownloadNoDialog(fullpath, additionalText);
        }

        public void InitDownload(string additionalText = "")
        {
            SaveFileDialog saveFileDialog1 = new SaveFileDialog
            {
                FileName = fileName,
                //"Compressed zip files (*.zip)|*.zip|All files (*.*)|*.*"
                Filter = fileFilter,
                Title = "Save " + fileName
            };

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                InitDownloadNoDialog(saveFileDialog1.FileName, additionalText);
            }
        }

        public void InitDownloadNoDialog(string name, string additionalText = "")
        {
            if (!overwrite && File.Exists(name))
            {
                downloadOutcome = "Download skipped due to same file name.";
                return;
            }

            int read = 0;

            try
            {
                read = DownloadFile(fileURL, name);
            }
            catch (Exception ex)
            {
                Util.LogExceptions(ex);
                downloadOutcome = "Error when downloading file: " + ex.Message;
            }
            finally
            {
                //wait a few seconds for the download to finish
                //Thread.Sleep(2000);
                if (File.Exists(name) && read > 0)
                {
                    downloadSize = read;
                    downloadOutcome = "File " + Path.GetFileName(name) + " downloaded! " + Util.SizeSuffix(Convert.ToInt64(downloadSize), 2) + " written (" + downloadSize + " bytes)! " + additionalText;
                }
                else
                {
                    if (!string.IsNullOrWhiteSpace(downloadOutcomeException))
                    {
                        downloadOutcome = "Error: Download of file " + Path.GetFileName(name) + " failed. " + downloadOutcomeException;
                    }
                    else
                    {
                        downloadOutcome = "Error: Download of file " + Path.GetFileName(name) + " failed. The file wasn't downloaded to the assigned directory.";
                    }

                    if (showErrorInfo)
                    {
                        downloadOutcome += "\n\nMore error info:\n\nFile URL: " + fileURL + "\n\nFile Path: " + name;
                    }
                }
            }
        }

        public string GetFullDLPath()
        {
            return filePath + Path.DirectorySeparatorChar + fileName;
        }

        private int DownloadFile(string remoteFilename, string localFilename)
        {
            //credit to Tom Archer (https://www.codeguru.com/columns/dotnettips/article.php/c7005/Downloading-Files-with-the-WebRequest-and-WebResponse-Classes.htm)
            //and Brokenglass (https://stackoverflow.com/questions/4567313/uncompressing-gzip-response-from-webclient/4567408#4567408)

            // Function will return the number of bytes processed
            // to the caller. Initialize to 0 here.
            int bytesProcessed = 0;

            // Assign values to these objects here so that they can
            // be referenced in the finally block
            Stream remoteStream = null;
            Stream localStream = null;
            WebResponse response = null;

            // Use a try/catch/finally block as both the WebRequest and Stream
            // classes throw exceptions upon error
            //thanks to https://stackoverflow.com/questions/33761919/tls-1-2-in-net-framework-4-0 for the net 4.0 compatible TLS 1.1/1.2 code!
            try
            {
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls
                    | (SecurityProtocolType)3072
                    | (SecurityProtocolType)768
                    | SecurityProtocolType.Ssl3;
                ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;
                // Create a request for the specified remote file name
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(remoteFilename);
                //changing it to just "roblox" since roblox is breaking everything.
                //request.UserAgent = "Roblox/WinINet";
                request.UserAgent = "Roblox";
                request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate");
                request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
                if (request != null)
                {
                    // Send the request to the server and retrieve the
                    // WebResponse object 
                    response = request.GetResponse();
                    if (response != null)
                    {
                        // Once the WebResponse object has been retrieved,
                        // get the stream object associated with the response's data
                        remoteStream = response.GetResponseStream();

                        // Create the local file
                        localStream = File.Create(localFilename);

                        // Allocate a 1k buffer
                        byte[] buffer = new byte[1024];
                        int bytesRead;

                        // Simple do/while loop to read from stream until
                        // no bytes are returned
                        do
                        {
                            // Read data (up to 1k) from the stream
                            bytesRead = remoteStream.Read(buffer, 0, buffer.Length);

                            // Write the data to the local file
                            localStream.Write(buffer, 0, bytesRead);

                            // Increment total bytes processed
                            bytesProcessed += bytesRead;
                        } while (bytesRead > 0);
                    }
                }
            }
            catch (Exception e)
            {
                Util.LogExceptions(e);
                if (e is WebException && bytesProcessed == 0)
                {
                    WebException ex = (WebException)e;
                    HttpWebResponse errorResponse = ex.Response as HttpWebResponse;
                    if (errorResponse.StatusCode == HttpStatusCode.Conflict || errorResponse.StatusCode == HttpStatusCode.Forbidden)
                    {
                        downloadOutcomeException = "Error: Unable to download item. The item may not be publically available.";
                    }
                    else
                    {
                        downloadOutcomeException = "Exception: " + ex.Message;
                    }
                }
                else
                {
                    downloadOutcomeException = "Exception: " + e.Message;
                }
            }
            finally
            {
                // Close the response and streams objects here 
                // to make sure they're closed even if an exception
                // is thrown at some point
                if (response != null) response.Close();
                if (remoteStream != null) remoteStream.Close();
                if (localStream != null) localStream.Close();
            }

            // Return total bytes processed to caller.
            return bytesProcessed;
        }
    }
    #endregion
}