Integrates history scores into download decision-making by comparing the custom format score of existing history entries with that of incoming releases. Releases are rejected if a higher score already exists in the history, ensuring better quality selections.

Database Migration
NO

Description
The goal is to check the history for the latest entry to determine if a better version already exists.

Let's discuss any necessary changes or potential concerns regarding this pull request here.

#### Attention
I have never touched the Sonarr code before, so please carefully review this for any disadvantages or issues I may have overlooked.

Technically, this method works. I have tested it locally, and I am currently using this version.

Maybe this should be behind a checkbox?

This is parallel to https://github.com/Radarr/Radarr/pull/10924

#### Issues Fixed or Closed by this PR
#5298

src/NzbDrone.Core/DecisionEngine/Specifications/RssSync/HistorySpecification.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
 using NLog;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Configuration;
@@ -51,7 +54,12 @@ namespace NzbDrone.Core.DecisionEngine.Specifications.RssSync
                 _logger.Debug("Checking current status of episode [{0}] in history", episode.Id);
                 var mostRecent = _historyService.MostRecentForEpisode(episode.Id);
 
-                if (mostRecent != null && mostRecent.EventType == EpisodeHistoryEventType.Grabbed)
+                if (mostRecent == null)
+                {
+                    continue;
+                }
+
+                if (mostRecent.EventType == EpisodeHistoryEventType.Grabbed)
                 {
                     var recent = mostRecent.Date.After(DateTime.UtcNow.AddHours(-12));
 
@@ -116,6 +124,41 @@ namespace NzbDrone.Core.DecisionEngine.Specifications.RssSync
                             return DownloadSpecDecision.Reject(DownloadRejectionReason.HistoryUpgradesNotAllowed, "{0} grab event in history and Quality Profile '{1}' does not allow upgrades", rejectionSubject, qualityProfile.Name);
                     }
                 }
+
+                if (subject.Episodes.FirstOrDefault(x => x.Id == episode.Id) is { HasFile: true })
+                {
+                    EpisodeHistory availableUsableEpisodeHistoryForCustomFormatScore;
+
+                    var episodeHistoryEventTypeForHistoryComparison = new List<EpisodeHistoryEventType>
+                    {
+                        EpisodeHistoryEventType.Grabbed,
+                        EpisodeHistoryEventType.SeriesFolderImported,
+                    };
+
+                    if (episodeHistoryEventTypeForHistoryComparison.Contains(mostRecent.EventType))
+                    {
+                        availableUsableEpisodeHistoryForCustomFormatScore = mostRecent;
+                    }
+                    else
+                    {
+                        availableUsableEpisodeHistoryForCustomFormatScore = _historyService.MostRecentForEpisodeInEventCollection(
+                            episode.Id,
+                            new ReadOnlyCollection<EpisodeHistoryEventType>(episodeHistoryEventTypeForHistoryComparison));
+                    }
+
+                    if (availableUsableEpisodeHistoryForCustomFormatScore == null)
+                    {
+                        continue;
+                    }
+
+                    var mostRecentCustomFormat = _formatService.ParseCustomFormat(availableUsableEpisodeHistoryForCustomFormatScore, subject.Series);
+                    var mostRecentCustomFormatScore = qualityProfile.CalculateCustomFormatScore(mostRecentCustomFormat);
+
+                    if (mostRecentCustomFormatScore > subject.CustomFormatScore)
+                    {
+                        return DownloadSpecDecision.Reject(DownloadRejectionReason.HistoryCustomFormatScore, "Quality Profile '{0}' has a higher Custom Format score than the report: {1}", qualityProfile.Name, subject.CustomFormatScore);
+                    }
+                }
             }
 
             return DownloadSpecDecision.Accept();

src/NzbDrone.Core/History/HistoryRepository.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using NzbDrone.Core.Datastore;
 using NzbDrone.Core.Messaging.Events;
@@ -20,6 +21,7 @@ namespace NzbDrone.Core.History
         void DeleteForSeries(List<int> seriesIds);
         List<EpisodeHistory> Since(DateTime date, EpisodeHistoryEventType? eventType);
         PagingSpec<EpisodeHistory> GetPaged(PagingSpec<EpisodeHistory> pagingSpec, int[] languages, int[] qualities);
+        EpisodeHistory MostRecentForEpisodeInEventCollection(int id, ReadOnlyCollection<EpisodeHistoryEventType> episodeHistoryEventTypes);
     }
 
     public class HistoryRepository : BasicRepository<EpisodeHistory>, IHistoryRepository
@@ -132,6 +134,11 @@ namespace NzbDrone.Core.History
             return pagingSpec;
         }
 
+        public EpisodeHistory MostRecentForEpisodeInEventCollection(int id, ReadOnlyCollection<EpisodeHistoryEventType> episodeHistoryEventTypes)
+        {
+            return Query(x => x.EpisodeId == id).Where(x => episodeHistoryEventTypes.Contains(x.EventType)).MaxBy(h => h.Date);
+        }
+
         private SqlBuilder PagedBuilder(int[] languages, int[] qualities)
         {
             var builder = Builder()

src/NzbDrone.Core/History/HistoryService.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
 using NLog;
@@ -27,6 +28,7 @@ namespace NzbDrone.Core.History
         List<EpisodeHistory> FindByDownloadId(string downloadId);
         string FindDownloadId(EpisodeImportedEvent trackedDownload);
         List<EpisodeHistory> Since(DateTime date, EpisodeHistoryEventType? eventType);
+        EpisodeHistory MostRecentForEpisodeInEventCollection(int id, ReadOnlyCollection<EpisodeHistoryEventType> episodeHistoryEventTypes);
     }
 
     public class HistoryService : IHistoryService,
@@ -365,5 +367,10 @@ namespace NzbDrone.Core.History
         {
             return _historyRepository.Since(date, eventType);
         }
+
+        public EpisodeHistory MostRecentForEpisodeInEventCollection(int id, ReadOnlyCollection<EpisodeHistoryEventType> episodeHistoryEventTypes)
+        {
+            return _historyRepository.MostRecentForEpisodeInEventCollection(id, episodeHistoryEventTypes);
+        }
     }
 }