New: Store last search time for BookSearch

(cherry picked from commit 9af57c6786eedd9beda4e1c6b8cdca20d165b622)

src/NzbDrone.Core/Books/Model/Book.cs

@@ -34,6 +34,7 @@ namespace NzbDrone.Core.Books
         public List<string> Genres { get; set; }
         public List<int> RelatedBooks { get; set; }
         public Ratings Ratings { get; set; }
+        public DateTime? LastSearchTime { get; set; }
 
         // These are Readarr generated/config
         public string CleanTitle { get; set; }

src/NzbDrone.Core/Books/Services/BookService.cs

@@ -31,6 +31,7 @@ namespace NzbDrone.Core.Books
         Book UpdateBook(Book book);
         void SetBookMonitored(int bookId, bool monitored);
         void SetMonitored(IEnumerable<int> ids, bool monitored);
+        void UpdateLastSearchTime(List<Book> books);
         PagingSpec<Book> BooksWithoutFiles(PagingSpec<Book> pagingSpec);
         List<Book> BooksBetweenDates(DateTime start, DateTime end, bool includeUnmonitored);
         List<Book> AuthorBooksBetweenDates(Author author, DateTime start, DateTime end, bool includeUnmonitored);
@@ -303,6 +304,11 @@ namespace NzbDrone.Core.Books
             }
         }
 
+        public void UpdateLastSearchTime(List<Book> books)
+        {
+            _bookRepository.SetFields(books, b => b.LastSearchTime);
+        }
+
         public void Handle(AuthorDeletedEvent message)
         {
             var books = GetBooksByAuthorMetadataId(message.Author.AuthorMetadataId);

src/NzbDrone.Core/Datastore/Migration/039_book_last_searched_time.cs

@@ -0,0 +1,14 @@
+using FluentMigrator;
+using NzbDrone.Core.Datastore.Migration.Framework;
+
+namespace NzbDrone.Core.Datastore.Migration
+{
+    [Migration(039)]
+    public class book_last_searched_time : NzbDroneMigrationBase
+    {
+        protected override void MainDbUpgrade()
+        {
+            Alter.Table("Books").AddColumn("LastSearchTime").AsDateTimeOffset().Nullable();
+        }
+    }
+}

src/NzbDrone.Core/IndexerSearch/ReleaseSearchService.cs

@@ -136,6 +136,16 @@ namespace NzbDrone.Core.IndexerSearch
 
             _logger.Debug("Total of {0} reports were found for {1} from {2} indexers", reports.Count, criteriaBase, indexers.Count);
 
+            // Update the last search time for all albums if at least 1 indexer was searched.
+            if (indexers.Any())
+            {
+                var lastSearchTime = DateTime.UtcNow;
+                _logger.Debug("Setting last search time to: {0}", lastSearchTime);
+
+                criteriaBase.Books.ForEach(a => a.LastSearchTime = lastSearchTime);
+                _bookService.UpdateLastSearchTime(criteriaBase.Books);
+            }
+
             return _makeDownloadDecision.GetSearchDecision(reports, criteriaBase).ToList();
         }