fix(jellyfin-scan): reduce jellyfin API calls during recently added scan (#2205)

* fix(jellyfin scanner): reduce jellyfin API calls during recently added scan

Significantly reduce number of API calls, addressing CPU spikes on Jellyfin 10.10+ servers.- Move
getSeasons() call outside the seasons loop (N calls to 1)- Request MediaSources via getEpisodes()
field parameter instead of  individual getItemData() calls per episode (N calls to 1 per season)
Performance improvements (tested on library with 12 TV shows):- Scan duration: 43.7s to 9.1s - Peak
CPU: 277% to 115% - CPU spike duration: 36s to 2s Functionality is unchanged, all availability
statuses identicalbefore and after.

* fix: add getEpisodes overloads to remove unsafe type assertion

* refactor(jellyfin): use generics instead of overloads

---------

Co-authored-by: patrick-acland <patrick.acland@kraken.tech>

server/api/jellyfin.ts

@@ -112,6 +112,10 @@ export interface JellyfinLibraryItemExtended extends JellyfinLibraryItem {
   DateCreated?: string;
 }
 
+type EpisodeReturn<T> = T extends { includeMediaInfo: true }
+  ? JellyfinLibraryItemExtended[]
+  : JellyfinLibraryItem[];
+
 export interface JellyfinItemsReponse {
   Items: JellyfinLibraryItemExtended[];
   TotalRecordCount: number;
@@ -415,13 +419,22 @@ class JellyfinAPI extends ExternalAPI {
     }
   }
 
-  public async getEpisodes(
+  public async getEpisodes<
+    T extends { includeMediaInfo?: boolean } | undefined = undefined
+  >(
     seriesID: string,
-    seasonID: string
+    seasonID: string,
-  ): Promise<JellyfinLibraryItem[]> {
+    options?: T
+  ): Promise<EpisodeReturn<T>> {
     try {
       const episodeResponse = await this.get<any>(
-        `/Shows/${seriesID}/Episodes?seasonId=${seasonID}`
+        `/Shows/${seriesID}/Episodes`,
+        {
+          params: {
+            seasonId: seasonID,
+            ...(options?.includeMediaInfo && { fields: 'MediaSources' }),
+          },
+        }
       );
 
       return episodeResponse.Items.filter(

server/lib/scanners/jellyfin/index.ts

@@ -374,9 +374,10 @@ class JellyfinScanner {
             ) ?? []
           ).length;
 
+          const jellyfinSeasons = await this.jfClient.getSeasons(Id);
+
           for (const season of seasons) {
-            const JellyfinSeasons = await this.jfClient.getSeasons(Id);
+            const matchedJellyfinSeason = jellyfinSeasons.find((md) => {
-            const matchedJellyfinSeason = JellyfinSeasons.find((md) => {
               if (tvdbSeasonFromAnidb) {
                 // In AniDB we don't have the concept of seasons,
                 // we have multiple shows with only Season 1 (and sometimes a season with index 0 for specials).
@@ -397,38 +398,52 @@ class JellyfinScanner {
 
             // Check if we found the matching season and it has all the available episodes
             if (matchedJellyfinSeason) {
-              // If we have a matched Jellyfin season, get its children metadata so we can check details
-              const episodes = await this.jfClient.getEpisodes(
-                Id,
-                matchedJellyfinSeason.Id
-              );
-
-              //Get count of episodes that are HD and 4K
               let totalStandard = 0;
               let total4k = 0;
 
-              //use for loop to make sure this loop _completes_ in full
+              if (!this.enable4kShow) {
-              //before the next section
+                const episodes = await this.jfClient.getEpisodes(
-              for (const episode of episodes) {
+                  Id,
-                let episodeCount = 1;
+                  matchedJellyfinSeason.Id
+                );
 
-                // count number of combined episodes
+                for (const episode of episodes) {
-                if (
+                  let episodeCount = 1;
-                  episode.IndexNumber !== undefined &&
+
-                  episode.IndexNumberEnd !== undefined
+                  // count number of combined episodes
-                ) {
+                  if (
-                  episodeCount =
+                    episode.IndexNumber !== undefined &&
-                    episode.IndexNumberEnd - episode.IndexNumber + 1;
+                    episode.IndexNumberEnd !== undefined
-                }
+                  ) {
+                    episodeCount =
+                      episode.IndexNumberEnd - episode.IndexNumber + 1;
+                  }
 
-                if (!this.enable4kShow) {
                   totalStandard += episodeCount;
-                } else {
+                }
-                  const ExtendedEpisodeData = await this.jfClient.getItemData(
+              } else {
-                    episode.Id
+                // 4K detection enabled - request media info to check resolution
-                  );
+                const episodes = await this.jfClient.getEpisodes(
+                  Id,
+                  matchedJellyfinSeason.Id,
+                  { includeMediaInfo: true }
+                );
 
-                  ExtendedEpisodeData?.MediaSources?.some((MediaSource) => {
+                for (const episode of episodes) {
+                  let episodeCount = 1;
+
+                  // count number of combined episodes
+                  if (
+                    episode.IndexNumber !== undefined &&
+                    episode.IndexNumberEnd !== undefined
+                  ) {
+                    episodeCount =
+                      episode.IndexNumberEnd - episode.IndexNumber + 1;
+                  }
+
+                  // MediaSources field is included in response when includeMediaInfo is true
+                  // We iterate all MediaSources to detect if episode has both standard AND 4K versions
+                  episode.MediaSources?.some((MediaSource) => {
                     return MediaSource.MediaStreams.some((MediaStream) => {
                       if (MediaStream.Type === 'Video') {
                         if ((MediaStream.Width ?? 0) >= 2000) {