Fixed: issue with DownloadStationTaskProxyV2 if no destination folder specified in settings

src/NzbDrone.Core/Download/Clients/DownloadStation/DiskStationApi.cs

@@ -7,6 +7,7 @@ namespace NzbDrone.Core.Download.Clients.DownloadStation
         DownloadStationInfo,
         DownloadStationTask,
         DownloadStation2Task,
+        DownloadStation2SettingsLocation,
         FileStationList,
         DSMInfo,
     }

src/NzbDrone.Core/Download/Clients/DownloadStation/Proxies/DownloadStation2SettingsLocationProxy.cs

@@ -0,0 +1,31 @@
+using NLog;
+using NzbDrone.Common.Cache;
+using NzbDrone.Common.Http;
+using NzbDrone.Core.Download.Clients.DownloadStation.Responses;
+
+namespace NzbDrone.Core.Download.Clients.DownloadStation.Proxies
+{
+    public interface IDownloadStation2SettingsLocationProxy
+    {
+        string GetDefaultDestination(DownloadStationSettings settings);
+    }
+
+    public class DownloadStation2SettingsLocationProxy : DiskStationProxyBase, IDownloadStation2SettingsLocationProxy
+    {
+        public DownloadStation2SettingsLocationProxy(IHttpClient httpClient, ICacheManager cacheManager, Logger logger)
+            : base(DiskStationApi.DownloadStation2SettingsLocation, "SYNO.DownloadStation2.Settings.Location", httpClient, cacheManager, logger)
+        {
+        }
+
+        public string GetDefaultDestination(DownloadStationSettings settings)
+        {
+            var info = GetApiInfo(settings);
+
+            var requestBuilder = BuildRequest(settings, "get", info.MinVersion);
+
+            var response = ProcessRequest<DownloadStation2SettingsLocationResponse>(requestBuilder, "get default destination folder", settings);
+
+            return response.Data.Default_Destination;
+        }
+    }
+}

src/NzbDrone.Core/Download/Clients/DownloadStation/Proxies/DownloadStationTaskProxyV2.cs

@@ -10,9 +10,12 @@ namespace NzbDrone.Core.Download.Clients.DownloadStation.Proxies
 {
     public class DownloadStationTaskProxyV2 : DiskStationProxyBase, IDownloadStationTaskProxy
     {
+        private readonly IDownloadStation2SettingsLocationProxy _defaultDestinationProxy;
+
         public DownloadStationTaskProxyV2(IHttpClient httpClient, ICacheManager cacheManager, Logger logger)
             : base(DiskStationApi.DownloadStation2Task, "SYNO.DownloadStation2.Task", httpClient, cacheManager, logger)
         {
+            _defaultDestinationProxy = new DownloadStation2SettingsLocationProxy(httpClient, cacheManager, logger);
         }
 
         public bool IsApiSupported(DownloadStationSettings settings)
@@ -32,6 +35,21 @@ namespace NzbDrone.Core.Download.Clients.DownloadStation.Proxies
             {
                 requestBuilder.AddFormParameter("destination", $"\"{downloadDirectory}\"");
             }
+            else
+            {
+                _logger.Trace("No directory configured in settings; falling back to client default destination folder.");
+                string defaultDestination = _defaultDestinationProxy.GetDefaultDestination(settings);
+
+                if (defaultDestination.IsNotNullOrWhiteSpace())
+                {
+                    _logger.Trace($"Default destination folder found: {defaultDestination}.");
+                    requestBuilder.AddFormParameter("destination", $"\"{defaultDestination}\"");
+                }
+                else
+                {
+                    _logger.Error("Unable to get default destination folder from DownloadStation.");
+                }
+            }
 
             requestBuilder.AddFormUpload("fileData", filename, data);
 
@@ -50,6 +68,21 @@ namespace NzbDrone.Core.Download.Clients.DownloadStation.Proxies
             {
                 requestBuilder.AddQueryParam("destination", downloadDirectory);
             }
+            else
+            {
+                _logger.Trace("No directory configured in settings; falling back to client default destination folder.");
+                string defaultDestination = _defaultDestinationProxy.GetDefaultDestination(settings);
+
+                if (defaultDestination.IsNotNullOrWhiteSpace())
+                {
+                    _logger.Trace($"Default destination folder found: {defaultDestination}.");
+                    requestBuilder.AddQueryParam("destination", $"\"{defaultDestination}\"");
+                }
+                else
+                {
+                    _logger.Error("Unable to get default destination folder from DownloadStation.");
+                }
+            }
 
             ProcessRequest<object>(requestBuilder, $"add task from url {url}", settings);
         }

src/NzbDrone.Core/Download/Clients/DownloadStation/Responses/DownloadStation2SettingsLocationResponse.cs

@@ -0,0 +1,7 @@
+namespace NzbDrone.Core.Download.Clients.DownloadStation.Responses
+{
+    public class DownloadStation2SettingsLocationResponse
+    {
+        public string Default_Destination { get; set; }
+    }
+}