Retry automatic search with title only when title and author returns nothing

listenarr.application/Downloads/Queue/SearchQueryFallbacks.cs

@@ -0,0 +1,37 @@
+/*
+ * Listenarr - Audiobook Management System
+ * Copyright (C) 2024-2026 Listenarr Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+using System.Text.RegularExpressions;
+
+namespace Listenarr.Application.Downloads.Queue
+{
+    public static partial class SearchQueryFallbacks
+    {
+        [GeneratedRegex(@"\s*[\(\[][^\)\]]*[\)\]]", RegexOptions.None, matchTimeoutMilliseconds: 1000)]
+        private static partial Regex EditionSuffix();
+
+        public static IReadOnlyList<string> Expand(string primaryQuery, string? title)
+        {
+            var candidates = new List<string> { primaryQuery };
+
+            if (!string.IsNullOrWhiteSpace(title))
+            {
+                candidates.Add(title);
+                candidates.Add(EditionSuffix().Replace(title, string.Empty));
+            }
+
+            return candidates
+                .Select(c => c?.Trim() ?? string.Empty)
+                .Where(c => !string.IsNullOrEmpty(c))
+                .Distinct(StringComparer.OrdinalIgnoreCase)
+                .ToList();
+        }
+    }
+}

listenarr.application/Downloads/Submission/DownloadService.cs

@@ -147,7 +147,15 @@ public async Task<SearchAndDownloadResult> SearchAndDownloadAsync(int audiobookI
             // Search using the working search service. This is an automatic search (triggered
             // by the background/manual 'search-and-download' endpoint), so set isAutomaticSearch
             // to true to ensure only indexers are queried (no Amazon/Audible scraping).
-            var searchResults = await searchService.SearchAsync(searchQuery, isAutomaticSearch: true);
+            List<SearchResult>? searchResults = null;
+            foreach (var fallbackQuery in SearchQueryFallbacks.Expand(searchQuery, audiobook.Title))
+            {
+                searchResults = await searchService.SearchAsync(fallbackQuery, isAutomaticSearch: true);
+                if (searchResults != null && searchResults.Any())
+                {
+                    break;
+                }
+            }
 
             if (searchResults == null || !searchResults.Any())
             {

listenarr.infrastructure/HostedServices/Search/AutomaticSearchService.cs

@@ -180,6 +180,16 @@ private async Task<int> ProcessAudiobookAsync(
 
             // Search for results
             var searchResults = await searchService.SearchAsync(searchQuery, isAutomaticSearch: true);
+            foreach (var candidate in SearchQueryFallbacks.Expand(searchQuery, audiobook.Title))
+            {
+                if (searchResults.Count > 0)
+                {
+                    break;
+                }
+
+                searchQuery = candidate;
+                searchResults = await searchService.SearchAsync(candidate, isAutomaticSearch: true);
+            }
             _logger.LogInformation("Found {Count} raw search results for audiobook '{Title}'", searchResults.Count, audiobook.Title);
 
             // Broadcast detailed debug info about the raw search results to help diagnose automatic search failures

tests/Features/Application/Downloads/Queue/SearchQueryFallbacksTests.cs

@@ -0,0 +1,65 @@
+/*
+ * Listenarr - Audiobook Management System
+ * Copyright (C) 2024-2026 Listenarr Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+namespace Listenarr.Tests.Features.Application.Downloads.Queue
+{
+    [Trait("Area", "Search")]
+    public class SearchQueryFallbacksTests
+    {
+        [Fact]
+        public void Expand_KeepsCombinedQueryFirst()
+        {
+            var queries = SearchQueryFallbacks.Expand("Red Rising Pierce Brown", "Red Rising");
+
+            Assert.Equal("Red Rising Pierce Brown", queries[0]);
+        }
+
+        [Fact]
+        public void Expand_FallsBackToTitleOnly()
+        {
+            var queries = SearchQueryFallbacks.Expand("Project Hail Mary Andy Weir", "Project Hail Mary");
+
+            Assert.Contains("Project Hail Mary", queries);
+        }
+
+        [Fact]
+        public void Expand_FallsBackToTitleWithoutEditionSuffix()
+        {
+            var queries = SearchQueryFallbacks.Expand(
+                "Red Rising (Part 1 of 2) (Dramatized Adaptation) Pierce Brown",
+                "Red Rising (Part 1 of 2) (Dramatized Adaptation)");
+
+            Assert.Equal("Red Rising", queries[^1]);
+        }
+
+        [Fact]
+        public void Expand_DoesNotRepeatIdenticalQueries()
+        {
+            var queries = SearchQueryFallbacks.Expand("Dune", "Dune");
+
+            Assert.Single(queries);
+        }
+
+        [Fact]
+        public void Expand_IgnoresMissingTitle()
+        {
+            var queries = SearchQueryFallbacks.Expand("Dune Frank Herbert", null);
+
+            Assert.Equal(new[] { "Dune Frank Herbert" }, queries);
+        }
+    }
+}