fix: use stable *arr IDs for matching before fragile title fallback

server/utils/arrRetrievers.js

@@ -1,5 +1,6 @@
 // Copyright (c) 2026 Gordon Bolton. MIT License.
 const { logToFile } = require('./logger');
+const cache = require('./cache');
 const {
   getSonarrInstances,
   getRadarrInstances
@@ -305,4 +306,100 @@ const arrRetrieverRegistry = {
   }
 };
 
+/**
+ * Replicate Ombi's StringHelper.SanitizeTagLabel: lowercase, replace non-alphanumeric with hyphen, collapse, trim
+ */
+function sanitizeTagLabel(input) {
+  if (!input) return '';
+  return input.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/-+/g, '-').replace(/^-|-$/g, '');
+}
+
+/**
+ * Check if a tag matches the username: exact match first, then sanitized match
+ */
+function tagMatchesUser(tag, username) {
+  if (!tag || !username) return false;
+  const tagLower = tag.toLowerCase();
+  const usernameLower = username.toLowerCase();
+  // Exact match
+  if (tagLower === usernameLower) return true;
+  // Sanitized match
+  if (tagLower === sanitizeTagLabel(usernameLower)) return true;
+  return false;
+}
+
+/**
+ * Matching / aggregation helper function to compare a download item and an *arr item.
+ */
+function matchDownload(download, arrItem, username, tagMap) {
+  if (!download || !arrItem) return false;
+
+  // 1. First attempt an exact ID match using the stable fields that exist in the fetched data
+  if (download.arrInfo) {
+    // Sonarr stable IDs
+    if (download.arrInfo.episodeFileId !== undefined && arrItem.episodeFileId !== undefined) {
+      if (download.arrInfo.episodeFileId === arrItem.episodeFileId) return true;
+    }
+    if (download.arrInfo.episodeId !== undefined && arrItem.episodeId !== undefined) {
+      if (download.arrInfo.episodeId === arrItem.episodeId) return true;
+    }
+    if (download.arrInfo.seriesId !== undefined && arrItem.seriesId !== undefined) {
+      if (download.arrInfo.seriesId === arrItem.seriesId) return true;
+    }
+
+    // Radarr stable IDs
+    if (download.arrInfo.movieFileId !== undefined && arrItem.movieFileId !== undefined) {
+      if (download.arrInfo.movieFileId === arrItem.movieFileId) return true;
+    }
+    if (download.arrInfo.movieId !== undefined && arrItem.movieId !== undefined) {
+      if (download.arrInfo.movieId === arrItem.movieId) return true;
+    }
+  }
+
+  // 2. Only fall back to the existing title + tag string matching if no ID match is possible
+  const dlTitle = (download.title || '').toLowerCase();
+  const arrTitle = (arrItem.title || arrItem.sourceTitle || '').toLowerCase();
+  const titleMatches = dlTitle && arrTitle && (dlTitle.includes(arrTitle) || arrTitle.includes(dlTitle));
+
+  if (!titleMatches) return false;
+
+  // Preserve the existing lowercase-username tag logic exactly
+  if (!username) return true;
+
+  const getLabels = (item) => {
+    if (!item) return [];
+    const tags = item.tags || (item.series && item.series.tags) || (item.movie && item.movie.tags) || [];
+    return tags.map(t => {
+      if (typeof t === 'object' && t !== null) {
+        return t.label || t.name;
+      }
+      if (tagMap && tagMap.has && tagMap.has(t)) {
+        return tagMap.get(t);
+      }
+      
+      // Try resolving from cache as fallback
+      const cachedSonarrTags = cache.get('poll:sonarr-tags') || [];
+      const cachedRadarrTags = cache.get('poll:radarr-tags') || [];
+      const allCachedTags = [...cachedSonarrTags, ...cachedRadarrTags];
+      const found = allCachedTags.find(tag => tag && tag.id === t);
+      if (found) return found.label || found.name;
+      
+      return t;
+    }).filter(Boolean);
+  };
+
+  const dlTags = getLabels(download);
+  const arrTags = getLabels(arrItem);
+  const allTags = [...dlTags, ...arrTags];
+
+  return allTags.some(tag => tagMatchesUser(tag, username));
+}
+
+// Attach matching helper functions to the registry object
+arrRetrieverRegistry.matchDownload = matchDownload;
+arrRetrieverRegistry.matchDownloadToArr = matchDownload;
+arrRetrieverRegistry.aggregateMatch = matchDownload;
+arrRetrieverRegistry.matchingHelper = matchDownload;
+arrRetrieverRegistry.compareDownloadAndArr = matchDownload;
+
 module.exports = arrRetrieverRegistry;