From 6f55c81d5ba64440b320ee461a31d141b6e33ae4 Mon Sep 17 00:00:00 2001
From: Robbie Davis <robbie@therobbiedavis.com>
Date: Wed, 14 Jan 2026 00:09:20 -0500
Subject: [PATCH] Prevent duplicate remote indexer mappings

Before adding a new remote indexer, check for existing indexers with matching baseUrl or name. If found, insert a mapping and skip adding to avoid duplicates. Logs errors encountered during the check.
---
 .../Applications/Listenarr/Listenarr.cs       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/NzbDrone.Core/Applications/Listenarr/Listenarr.cs b/src/NzbDrone.Core/Applications/Listenarr/Listenarr.cs
index a10417e61..c591df5f3 100644
--- a/src/NzbDrone.Core/Applications/Listenarr/Listenarr.cs
+++ b/src/NzbDrone.Core/Applications/Listenarr/Listenarr.cs
@@ -142,6 +142,28 @@ public override void AddIndexer(IndexerDefinition indexer)
 
             var listenarrIndexer = BuildListenarrIndexer(indexer, indexerCapabilities, indexer.Protocol);
 
+            // If an existing remote indexer already points to this app indexer (matching baseUrl or name), insert mapping and skip adding
+            try
+            {
+                var remoteIndexers = _listenarrV1Proxy.GetIndexers(Settings);
+                var baseUrl = $"{Settings.ProwlarrUrl.TrimEnd('/')}/{indexer.Id}/";
+
+                var match = remoteIndexers.FirstOrDefault(r =>
+                    ((string)r.Fields.FirstOrDefault(f => f.Name == "baseUrl")?.Value ?? "").Equals(baseUrl, StringComparison.InvariantCultureIgnoreCase)
+                    || (r.Name?.Contains(indexer.Name, StringComparison.InvariantCultureIgnoreCase) == true));
+
+                if (match != null)
+                {
+                    _logger.Debug("Found existing remote indexer for {0} as {1} [{2}], inserting mapping", indexer.Name, match.Name, match.Id);
+                    _appIndexerMapService.Insert(new AppIndexerMap { AppId = Definition.Id, IndexerId = indexer.Id, RemoteIndexerId = match.Id });
+                    return;
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.Warn(ex, "Error while attempting to discover existing remote indexer for {0} [{1}]", indexer.Name, indexer.Id);
+            }
+
             var remoteIndexer = _listenarrV1Proxy.AddIndexer(listenarrIndexer, Settings);
 
             if (remoteIndexer == null)