Roto folder fixes

New: Health check for missing series root folders
Fixed: Do not remove episodes from series when root folder is missing

src/NzbDrone.Core/HealthCheck/Checks/RootFolderCheck.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Linq;
+using NzbDrone.Common.Disk;
+using NzbDrone.Core.Tv;
+
+namespace NzbDrone.Core.HealthCheck.Checks
+{
+    public class RootFolderCheck : HealthCheckBase
+    {
+        private readonly ISeriesService _seriesService;
+        private readonly IDiskProvider _diskProvider;
+
+        public RootFolderCheck(ISeriesService seriesService, IDiskProvider diskProvider)
+        {
+            _seriesService = seriesService;
+            _diskProvider = diskProvider;
+        }
+
+        public override HealthCheck Check()
+        {
+            var missingRootFolders = _seriesService.GetAllSeries()
+                                                .Select(s => _diskProvider.GetParentFolder(s.Path))
+                                                .Distinct()
+                                                .Where(s => !_diskProvider.FolderExists(s))
+                                                .ToList();
+
+            if (missingRootFolders.Any())
+            {
+                if (missingRootFolders.Count == 1)
+                {
+                    return new HealthCheck(GetType(), HealthCheckResult.Error, "Missing root folder: " + missingRootFolders.First());
+                }
+
+                var message = String.Format("Multiple root folders are missing: {0}", String.Join(" | ", missingRootFolders));
+                return new HealthCheck(GetType(), HealthCheckResult.Error, message);
+            }
+
+            return new HealthCheck(GetType());
+        }
+
+        public override bool CheckOnConfigChange
+        {
+            get
+            {
+                return false;
+            }
+        }
+    }
+}