New: Search for newly added past episodes after series is refreshed

Closes #503

src/NzbDrone.Core/NzbDrone.Core.csproj

@@ -892,6 +892,7 @@
     <Compile Include="Tv\Commands\MoveSeriesCommand.cs" />
     <Compile Include="Tv\Commands\RefreshSeriesCommand.cs" />
     <Compile Include="Tv\Episode.cs" />
+    <Compile Include="Tv\EpisodeAddedService.cs" />
     <Compile Include="Tv\EpisodeCutoffService.cs" />
     <Compile Include="Tv\EpisodeMonitoredService.cs" />
     <Compile Include="Tv\EpisodeRepository.cs">

src/NzbDrone.Core/Tv/EpisodeAddedService.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using NLog;
+using NzbDrone.Common.Cache;
+using NzbDrone.Common.Extensions;
+using NzbDrone.Core.IndexerSearch;
+using NzbDrone.Core.Messaging.Commands;
+using NzbDrone.Core.Messaging.Events;
+using NzbDrone.Core.Tv.Events;
+
+namespace NzbDrone.Core.Tv
+{
+    public interface IEpisodeAddedService
+    {
+        void SearchForRecentlyAdded(int seriesId);
+    }
+
+    public class EpisodeAddedService : IHandle<EpisodeInfoRefreshedEvent>, IEpisodeAddedService
+    {
+        private readonly IManageCommandQueue _commandQueueManager;
+        private readonly IEpisodeService _episodeService;
+        private readonly Logger _logger;
+        private readonly ICached<List<int>> _addedEpisodesCache;
+
+        public EpisodeAddedService(ICacheManager cacheManager,
+                                   IManageCommandQueue commandQueueManager,
+                                   IEpisodeService episodeService,
+                                   Logger logger)
+        {
+            _commandQueueManager = commandQueueManager;
+            _episodeService = episodeService;
+            _logger = logger;
+            _addedEpisodesCache = cacheManager.GetCache<List<int>>(GetType());
+        }
+
+        public void SearchForRecentlyAdded(int seriesId)
+        {
+            var previouslyAired = _addedEpisodesCache.Find(seriesId.ToString());
+
+            if (previouslyAired != null && previouslyAired.Any())
+            {
+                var missing = previouslyAired.Select(e => _episodeService.GetEpisode(e)).Where(e => !e.HasFile).ToList();
+
+                if (missing.Any())
+                {
+                    _commandQueueManager.Push(new EpisodeSearchCommand(missing.Select(e => e.Id).ToList()));
+                }
+            }
+            
+            _addedEpisodesCache.Remove(seriesId.ToString());
+        }
+
+        public void Handle(EpisodeInfoRefreshedEvent message)
+        {
+            if (message.Series.AddOptions == null)
+            {
+                if (!message.Series.Monitored)
+                {
+                    _logger.Debug("Series is not monitored");
+                    return;
+                }
+
+                if (message.Added.Empty())
+                {
+                    _logger.Debug("No new episodes, skipping search");
+                    return;
+                }
+
+                if (message.Added.None(a => a.AirDateUtc.HasValue))
+                {
+                    _logger.Debug("No new episodes have an air date");
+                    return;
+                }
+
+                var previouslyAired = message.Added.Where(a => a.AirDateUtc.HasValue && a.AirDateUtc.Value.Before(DateTime.UtcNow.AddDays(1)) && a.Monitored).ToList();
+
+                if (previouslyAired.Empty())
+                {
+                    _logger.Debug("Newly added episodes all air in the future");
+                    return;
+                }
+
+                _addedEpisodesCache.Set(message.Series.Id.ToString(), previouslyAired.Select(e => e.Id).ToList());
+            }
+        }
+    }
+}

src/NzbDrone.Core/Tv/SeriesScannedHandler.cs

@@ -12,17 +12,20 @@ public class SeriesScannedHandler : IHandle<SeriesScannedEvent>,
         private readonly IEpisodeMonitoredService _episodeMonitoredService;
         private readonly ISeriesService _seriesService;
         private readonly IManageCommandQueue _commandQueueManager;
+        private readonly IEpisodeAddedService _episodeAddedService;
 
         private readonly Logger _logger;
 
         public SeriesScannedHandler(IEpisodeMonitoredService episodeMonitoredService,
                                     ISeriesService seriesService,
                                     IManageCommandQueue commandQueueManager,
+                                    IEpisodeAddedService episodeAddedService,
                                     Logger logger)
         {
             _episodeMonitoredService = episodeMonitoredService;
             _seriesService = seriesService;
             _commandQueueManager = commandQueueManager;
+            _episodeAddedService = episodeAddedService;
             _logger = logger;
         }
 
@@ -30,6 +33,7 @@ private void HandleScanEvents(Series series)
         {
             if (series.AddOptions == null)
             {
+                _episodeAddedService.SearchForRecentlyAdded(series.Id);
                 return;
             }