New: Added support to save .magnet to blackhole directory.

fixes #1406

src/NzbDrone.Core.Test/Download/DownloadClientTests/Blackhole/TorrentBlackholeFixture.cs

@@ -22,6 +22,7 @@ public class TorrentBlackholeFixture : DownloadClientFixtureBase<TorrentBlackhol
         protected string _completedDownloadFolder;
         protected string _blackholeFolder;
         protected string _filePath;
+        protected string _magnetFilePath;
 
         [SetUp]
         public void Setup()
@@ -29,6 +30,7 @@ public void Setup()
             _completedDownloadFolder = @"c:\blackhole\completed".AsOsAgnostic();
             _blackholeFolder = @"c:\blackhole\torrent".AsOsAgnostic();
             _filePath = (@"c:\blackhole\torrent\" + _title + ".torrent").AsOsAgnostic();
+            _magnetFilePath = Path.ChangeExtension(_filePath, ".magnet");
 
             Mocker.SetConstant<IScanWatchFolder>(Mocker.Resolve<ScanWatchFolder>());
 
@@ -132,6 +134,51 @@ public void Download_should_download_file_if_it_doesnt_exist()
             Mocker.GetMock<IHttpClient>().Verify(c => c.DownloadFile(It.IsAny<string>(), It.IsAny<string>()), Times.Never());
         }
 
+        [Test]
+        public void Download_should_save_magnet_if_enabled()
+        {
+            Subject.Definition.Settings.As<TorrentBlackholeSettings>().SaveMagnetFiles = true;
+
+            var remoteEpisode = CreateRemoteEpisode();
+            remoteEpisode.Release.DownloadUrl = null;
+
+            Subject.Download(remoteEpisode);
+
+            Mocker.GetMock<IHttpClient>().Verify(c => c.Get(It.Is<HttpRequest>(v => v.Url.FullUri == _downloadUrl)), Times.Never());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_filePath), Times.Never());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_magnetFilePath), Times.Once());
+            Mocker.GetMock<IHttpClient>().Verify(c => c.DownloadFile(It.IsAny<string>(), It.IsAny<string>()), Times.Never());
+        }
+
+        [Test]
+        public void Download_should_not_save_magnet_if_disabled()
+        {
+            var remoteEpisode = CreateRemoteEpisode();
+            remoteEpisode.Release.DownloadUrl = null;
+
+            Assert.Throws<ReleaseDownloadException>(() => Subject.Download(remoteEpisode));
+
+            Mocker.GetMock<IHttpClient>().Verify(c => c.Get(It.Is<HttpRequest>(v => v.Url.FullUri == _downloadUrl)), Times.Never());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_filePath), Times.Never());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_magnetFilePath), Times.Never());
+            Mocker.GetMock<IHttpClient>().Verify(c => c.DownloadFile(It.IsAny<string>(), It.IsAny<string>()), Times.Never());
+        }
+
+        [Test]
+        public void Download_should_prefer_torrent_over_magnet()
+        {
+            Subject.Definition.Settings.As<TorrentBlackholeSettings>().SaveMagnetFiles = true;
+
+            var remoteEpisode = CreateRemoteEpisode();
+
+            Subject.Download(remoteEpisode);
+
+            Mocker.GetMock<IHttpClient>().Verify(c => c.Get(It.Is<HttpRequest>(v => v.Url.FullUri == _downloadUrl)), Times.Once());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_filePath), Times.Once());
+            Mocker.GetMock<IDiskProvider>().Verify(c => c.OpenWriteStream(_magnetFilePath), Times.Never());
+            Mocker.GetMock<IHttpClient>().Verify(c => c.DownloadFile(It.IsAny<string>(), It.IsAny<string>()), Times.Never());
+        }
+
         [Test]
         public void Download_should_replace_illegal_characters_in_title()
         {

src/NzbDrone.Core/Download/Clients/Blackhole/TorrentBlackhole.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text;
 using FluentValidation.Results;
 using NLog;
 using NzbDrone.Common.Disk;
@@ -23,6 +24,14 @@ public class TorrentBlackhole : TorrentClientBase<TorrentBlackholeSettings>
 
         public TimeSpan ScanGracePeriod { get; set; }
 
+        public override bool PreferTorrentFile
+        {
+            get
+            {
+                return true;
+            }
+        }
+
         public TorrentBlackhole(IScanWatchFolder scanWatchFolder,
                                 ITorrentFileInfoReader torrentFileInfoReader,
                                 IHttpClient httpClient,
@@ -39,7 +48,26 @@ public TorrentBlackhole(IScanWatchFolder scanWatchFolder,
 
         protected override string AddFromMagnetLink(RemoteEpisode remoteEpisode, string hash, string magnetLink)
         {
-            throw new NotSupportedException("Blackhole does not support magnet links.");
+            if (!Settings.SaveMagnetFiles)
+            {
+                throw new NotSupportedException("Blackhole does not support magnet links.");
+            }
+
+            var title = remoteEpisode.Release.Title;
+
+            title = FileNameBuilder.CleanFileName(title);
+
+            var filepath = Path.Combine(Settings.TorrentFolder, string.Format("{0}.magnet", title));
+
+            var fileContent = Encoding.UTF8.GetBytes(magnetLink);
+            using (var stream = _diskProvider.OpenWriteStream(filepath))
+            {
+                stream.Write(fileContent, 0, fileContent.Length);
+            }
+
+            _logger.Debug("Saving magnet link succeeded, saved to: {0}", filepath);
+
+            return null;
         }
 
         protected override string AddFromTorrentFile(RemoteEpisode remoteEpisode, string hash, string filename, byte[] fileContent)

src/NzbDrone.Core/Download/Clients/Blackhole/TorrentBlackholeSettings.cs

@@ -34,7 +34,12 @@ public TorrentBlackholeSettings()
 
         [DefaultValue(false)]
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Populate)]
-        [FieldDefinition(2, Label = "Read Only", Type = FieldType.Checkbox, HelpText = "Instead of moving files this will instruct Sonarr to Copy or Hardlink (depending on settings/system configuration)")]
+        [FieldDefinition(2, Label = "Save Magnet Files", Type = FieldType.Checkbox, HelpText = "Save a .magnet file with the magnet link if no .torrent file is available (only useful if the download client supports .magnet files)")]
+        public bool SaveMagnetFiles { get; set; }
+
+        [DefaultValue(false)]
+        [JsonProperty(DefaultValueHandling = DefaultValueHandling.Populate)]
+        [FieldDefinition(3, Label = "Read Only", Type = FieldType.Checkbox, HelpText = "Instead of moving files this will instruct Sonarr to Copy or Hardlink (depending on settings/system configuration)")]
         public bool ReadOnly { get; set; }
 
         public NzbDroneValidationResult Validate()

src/NzbDrone.Core/Download/TorrentClientBase.cs

@@ -42,6 +42,14 @@ public override DownloadProtocol Protocol
             }
         }
 
+        public virtual bool PreferTorrentFile
+        {
+            get
+            {
+                return false;
+            }
+        }
+
         protected abstract string AddFromMagnetLink(RemoteEpisode remoteEpisode, string hash, string magnetLink);
         protected abstract string AddFromTorrentFile(RemoteEpisode remoteEpisode, string hash, string filename, byte[] fileContent);
 
@@ -65,32 +73,64 @@ public override string Download(RemoteEpisode remoteEpisode)
             {
                 magnetUrl = torrentInfo.MagnetUrl;
             }
-
+            
-            string hash = null;
+            if (PreferTorrentFile)
-
-            if (magnetUrl.IsNotNullOrWhiteSpace())
             {
-                try
+                if (torrentUrl.IsNotNullOrWhiteSpace())
                 {
-                    hash = DownloadFromMagnetUrl(remoteEpisode, magnetUrl);
+                    try
+                    {
+                        return DownloadFromWebUrl(remoteEpisode, torrentUrl);
+                    }
+                    catch (Exception ex)
+                    {
+                        if (!magnetUrl.IsNullOrWhiteSpace())
+                        {
+                            throw;
+                        }
+
+                        _logger.Debug("Torrent download failed, trying magnet. ({0})", ex.Message);
+                    }
                 }
-                catch (NotSupportedException ex)
+
+                if (magnetUrl.IsNotNullOrWhiteSpace())
                 {
-                    if (torrentUrl.IsNullOrWhiteSpace())
+                    try
+                    {
+                        return DownloadFromMagnetUrl(remoteEpisode, magnetUrl);
+                    }
+                    catch (NotSupportedException ex)
                     {
                         throw new ReleaseDownloadException(remoteEpisode.Release, "Magnet not supported by download client. ({0})", ex.Message);
                     }
+                }
+            }
+            else
+            {
+                if (magnetUrl.IsNotNullOrWhiteSpace())
+                {
+                    try
+                    {
+                        return DownloadFromMagnetUrl(remoteEpisode, magnetUrl);
+                    }
+                    catch (NotSupportedException ex)
+                    {
+                        if (torrentUrl.IsNullOrWhiteSpace())
+                        {
+                            throw new ReleaseDownloadException(remoteEpisode.Release, "Magnet not supported by download client. ({0})", ex.Message);
+                        }
 
-                    _logger.Debug("Magnet not supported by download client, trying torrent. ({0})", ex.Message);
+                        _logger.Debug("Magnet not supported by download client, trying torrent. ({0})", ex.Message);
+                    }
+                }
+
+                if (torrentUrl.IsNotNullOrWhiteSpace())
+                {
+                    return DownloadFromWebUrl(remoteEpisode, torrentUrl);
                 }
             }
 
-            if (hash == null && torrentUrl.IsNotNullOrWhiteSpace())
+            return null;
-            {
-                hash = DownloadFromWebUrl(remoteEpisode, torrentUrl);
-            }
-
-            return hash;
         }
 
         private string DownloadFromWebUrl(RemoteEpisode remoteEpisode, string torrentUrl)