feat(plex): apply the sidebar filters to the Discover rails too

Discover now behaves like the Browse grid — the active metadata filters (genre /
rating / year / collection / studio / …) narrow every rail: Continue watching,
Recently added, Surprise me, the genre tiles, and Because you watched. Same
LibraryFilters / meta_filter_conds the grid uses, applied to each rail's movie +
show query (movie duration included); a rail may come back empty, which the client
already hides. Genre-language matches the grid.

Because Discover honours filters itself, adding a filter no longer force-flips the
Discover landing to the grid (only a header SEARCH does, since Discover has no
search rail) — so you stay on Discover with narrowed rails.

Frontend threads `filters` into api.plexDiscover/plexSurprise + their query keys
(plexSurprise is variadic now) and the watched-toggle setQueryData; PlexDiscover
reads them from usePlex. Tests: two discover filter-narrowing cases; PlexDiscover
dom test updated for the provider default + 3-arg call.

backend/app/routes/plex/discover.py

@@ -7,6 +7,11 @@ recs the S2 TMDB engine already persisted (`PlexItem.recommendations`), never a
 every card comes from the same `movie_card`/`show_card` serializers the grid uses (so rails inherit
 S1's `art` + S3's rating/summary for free). The rails carry EN metadata (like the other non-grid
 card paths); the HU overlay coalesces only in the main grid.
+
+The sidebar metadata filters (genre / rating / year / collection / …) narrow EVERY rail too, so the
+Discover surface behaves like the Browse grid — the same `LibraryFilters` / `meta_filter_conds` the
+grid uses, applied to each rail's movie + show query (a rail may legitimately come back empty, which
+the client hides). Genre-language matches the grid; duration is movie-only.
 """
 
 from fastapi import APIRouter, Depends, Query
@@ -18,7 +23,13 @@ from app.db import get_db
 from app.models import PlexItem, PlexShow, PlexState, User
 from app.plex import rollup
 from app.plex.cards import movie_card, show_card
-from app.plex.query import apply_show_state_filter, genres_col
+from app.plex.query import (
+    LibraryFilters,
+    apply_meta_filters,
+    apply_show_state_filter,
+    genres_col,
+    meta_filter_conds,
+)
 from app.plex.tmdb import resolve_recs
 from app.routes.plex._shared import _content_libs, _norm_lang
 
@@ -37,6 +48,16 @@ def _scope_libs(db: Session, scope: str) -> tuple[list[int], list[int]]:
     )
 
 
+def _movie_meta(q, p: dict, lang: str, f: LibraryFilters):
+    """Apply the shared metadata filters + movie-only duration to a movie query (same as the grid)."""
+    q = apply_meta_filters(q, PlexItem, p, lang)
+    if f.duration_min is not None:
+        q = q.where(PlexItem.duration_s >= f.duration_min)
+    if f.duration_max is not None:
+        q = q.where(PlexItem.duration_s <= f.duration_max)
+    return q
+
+
 def _movie_cards(db: Session, uid: int, items: list[PlexItem]) -> list[dict]:
     sts = rollup.item_state_map(db, uid, [it.id for it in items])
     return [movie_card(it, sts.get(it.id)) for it in items]
@@ -48,13 +69,17 @@ def _show_cards(db: Session, uid: int, shows: list[PlexShow]) -> list[dict]:
 
 
 def _recently_added(
-    db: Session, uid: int, movie_ids: list[int], show_ids: list[int]
+    db: Session, uid: int, movie_ids: list[int], show_ids: list[int], p: dict, lang: str, f: LibraryFilters
 ) -> list[dict]:
     """Newest movies + shows, interleaved by `added_at` desc into one rail."""
     movies = (
         db.execute(
-            select(PlexItem)
-            .where(PlexItem.kind == "movie", PlexItem.library_id.in_(movie_ids))
+            _movie_meta(
+                select(PlexItem).where(
+                    PlexItem.kind == "movie", PlexItem.library_id.in_(movie_ids)
+                ),
+                p, lang, f,
+            )
             .order_by(PlexItem.added_at.desc().nullslast())
             .limit(RAIL_LIMIT)
         ).scalars().all()
@@ -63,8 +88,9 @@ def _recently_added(
     )
     shows = (
         db.execute(
-            select(PlexShow)
-            .where(PlexShow.library_id.in_(show_ids))
+            apply_meta_filters(
+                select(PlexShow).where(PlexShow.library_id.in_(show_ids)), PlexShow, p, lang
+            )
             .order_by(PlexShow.added_at.desc().nullslast())
             .limit(RAIL_LIMIT)
         ).scalars().all()
@@ -92,14 +118,14 @@ def _recently_added(
 
 
 def _continue_watching(
-    db: Session, uid: int, movie_ids: list[int], show_ids: list[int]
+    db: Session, uid: int, movie_ids: list[int], show_ids: list[int], p: dict, lang: str, f: LibraryFilters
 ) -> list[dict]:
     """Resume rail: in-progress movies + partially-watched shows, most-recently-progressed first.
     A movie's resume time is its own `progress_updated_at`; a show's is the max across its episodes."""
     rows: list[tuple[object, dict]] = []  # (resumed_at, card)
 
     if movie_ids:
-        mrows = db.execute(
+        mq = (
             select(PlexItem, PlexState)
             .join(
                 PlexState,
@@ -116,6 +142,9 @@ def _continue_watching(
                     PlexState.status.notin_(["watched", "hidden"]),
                 ),
             )
+        )
+        mrows = db.execute(
+            _movie_meta(mq, p, lang, f)
             .order_by(PlexState.progress_updated_at.desc().nullslast())
             .limit(RAIL_LIMIT)
         ).all()
@@ -127,15 +156,15 @@ def _continue_watching(
         # its `resumed_at` = max(progress_updated_at); the in-progress predicate comes from the same shared
         # `apply_show_state_filter` the grid uses, so the rail can't drift from the grid's definition.
         prog = rollup.agg_subquery(db, uid, include_resumed=True).subquery()
+        sq = apply_show_state_filter(
+            select(PlexShow, prog.c.resumed_at).join(prog, prog.c.show_id == PlexShow.id),
+            prog.c.total,
+            prog.c.watched,
+            prog.c.inprog,
+            "in_progress",
+        ).where(PlexShow.library_id.in_(show_ids))
         srows = db.execute(
-            apply_show_state_filter(
-                select(PlexShow, prog.c.resumed_at).join(prog, prog.c.show_id == PlexShow.id),
-                prog.c.total,
-                prog.c.watched,
-                prog.c.inprog,
-                "in_progress",
-            )
-            .where(PlexShow.library_id.in_(show_ids))
+            apply_meta_filters(sq, PlexShow, p, lang)
             .order_by(prog.c.resumed_at.desc().nullslast())
             .limit(RAIL_LIMIT)
         ).all()
@@ -147,17 +176,20 @@ def _continue_watching(
 
 
 def _genre_tiles(
-    db: Session, movie_ids: list[int], show_ids: list[int], lang: str
+    db: Session, movie_ids: list[int], show_ids: list[int], p: dict, lang: str
 ) -> list[dict]:
     """The most-common genres across the scope, as {value, count} tiles → tap to filter the grid.
-    The genre vocabulary is language-specific (coalesce(genres_hu, genres) in HU), matching the grid."""
+    The genre vocabulary is language-specific (coalesce(genres_hu, genres) in HU), matching the grid.
+    The active metadata filters narrow the counts too, so the tiles agree with the filtered rails."""
     counts: dict[str, int] = {}
     for model, ids in ((PlexItem, movie_ids), (PlexShow, show_ids)):
         if not ids:
             continue
         gcol = genres_col(model, lang)
         base = select(func.jsonb_array_elements_text(gcol).label("g")).where(
-            model.library_id.in_(ids), func.jsonb_typeof(gcol) == "array"
+            model.library_id.in_(ids),
+            func.jsonb_typeof(gcol) == "array",
+            *meta_filter_conds(model, p, lang),
         )
         if model is PlexItem:
             base = base.where(model.kind == "movie")
@@ -171,11 +203,12 @@ def _genre_tiles(
 
 
 def _because_you_watched(
-    db: Session, uid: int, movie_ids: list[int], show_ids: list[int]
+    db: Session, uid: int, movie_ids: list[int], show_ids: list[int], p: dict, lang: str, f: LibraryFilters
 ) -> dict | None:
     """Recommendations anchored on the user's most-recently-watched, TMDB-enriched movie. Only the
     recs that resolve to OUR library (by guid) become cards — the rest aren't actionable here. Returns
-    None (rail hidden) when there's no enriched watch history or none of its recs are in the library."""
+    None (rail hidden) when there's no enriched watch history or none of its recs are in the library.
+    The metadata filters narrow the resolved recs (not the anchor pick) so the rail matches the grid."""
     if not movie_ids:
         return None
     anchor = db.execute(
@@ -207,15 +240,20 @@ def _because_you_watched(
     movies = {
         m.rating_key: m
         for m in db.execute(
-            select(PlexItem).where(
-                PlexItem.kind == "movie", PlexItem.rating_key.in_(rks)
+            _movie_meta(
+                select(PlexItem).where(
+                    PlexItem.kind == "movie", PlexItem.rating_key.in_(rks)
+                ),
+                p, lang, f,
             )
         ).scalars().all()
     }
     shows = {
         s.rating_key: s
         for s in db.execute(
-            select(PlexShow).where(PlexShow.rating_key.in_(rks))
+            apply_meta_filters(
+                select(PlexShow).where(PlexShow.rating_key.in_(rks)), PlexShow, p, lang
+            )
         ).scalars().all()
     }
     ordered_movies = [movies[rk] for rk in rks if rk in movies]
@@ -238,36 +276,48 @@ def _because_you_watched(
 def discover(
     scope: str = "both",
     lang: str = "en",
+    f: LibraryFilters = Depends(),
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    """The Discover landing payload — every rail in one pass (serve-from-DB). Empty rails come back as
-    empty lists (the client hides them); `because_you_watched` is null when there's no anchor."""
+    """The Discover landing payload — every rail in one pass (serve-from-DB), narrowed by the active
+    sidebar filters. Empty rails come back as empty lists (the client hides them); `because_you_watched`
+    is null when there's no anchor."""
     lang = _norm_lang(lang)
+    p = f.as_dict()
     movie_ids, show_ids = _scope_libs(db, scope)
     return {
         "scope": scope,
-        "continue_watching": _continue_watching(db, user.id, movie_ids, show_ids),
-        "recently_added": _recently_added(db, user.id, movie_ids, show_ids),
-        "genres": _genre_tiles(db, movie_ids, show_ids, lang),
-        "because_you_watched": _because_you_watched(db, user.id, movie_ids, show_ids),
+        "continue_watching": _continue_watching(db, user.id, movie_ids, show_ids, p, lang, f),
+        "recently_added": _recently_added(db, user.id, movie_ids, show_ids, p, lang, f),
+        "genres": _genre_tiles(db, movie_ids, show_ids, p, lang),
+        "because_you_watched": _because_you_watched(db, user.id, movie_ids, show_ids, p, lang, f),
     }
 
 
 @router.get("/surprise")
 def surprise(
     scope: str = "both",
+    lang: str = "en",
     limit: int = Query(default=RAIL_LIMIT, ge=1, le=40),
+    f: LibraryFilters = Depends(),
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    """A fresh random sample for the reshuffling Surprise-me rail (a random draw each call). Movies and
-    shows are drawn separately then interleaved so a lopsided library doesn't crowd out one type."""
+    """A fresh random sample for the reshuffling Surprise-me rail (a random draw each call), narrowed by
+    the active filters. Movies and shows are drawn separately then interleaved so a lopsided library
+    doesn't crowd out one type."""
+    lang = _norm_lang(lang)
+    p = f.as_dict()
     movie_ids, show_ids = _scope_libs(db, scope)
     movies = (
         db.execute(
-            select(PlexItem)
-            .where(PlexItem.kind == "movie", PlexItem.library_id.in_(movie_ids))
+            _movie_meta(
+                select(PlexItem).where(
+                    PlexItem.kind == "movie", PlexItem.library_id.in_(movie_ids)
+                ),
+                p, lang, f,
+            )
             .order_by(func.random())
             .limit(limit)
         ).scalars().all()
@@ -276,8 +326,9 @@ def surprise(
     )
     shows = (
         db.execute(
-            select(PlexShow)
-            .where(PlexShow.library_id.in_(show_ids))
+            apply_meta_filters(
+                select(PlexShow).where(PlexShow.library_id.in_(show_ids)), PlexShow, p, lang
+            )
             .order_by(func.random())
             .limit(limit)
         ).scalars().all()

backend/tests/test_plex_discover.py

@@ -200,3 +200,27 @@ def test_discover_scope_movie_excludes_shows(db, monkeypatch):
     assert all(c["type"] == "movie" for c in d["recently_added"])
     # The show drops out of continue watching under the movie scope.
     assert _ids(d["continue_watching"]) == ["m3"]
+
+
+def test_filters_narrow_every_discover_rail(db, monkeypatch):
+    # The sidebar filters constrain the Discover rails just like the Browse grid (ask 3). A genre=Drama
+    # filter keeps only the Drama titles across every rail; the genre-less show and the Comedy rec drop.
+    user = _seed(db)
+    d = _get(db, user, monkeypatch, "/api/plex/discover?scope=both&genres=Drama").json()
+    # Recently-added: m1 + m3 (Drama) survive; Comedy m2 and the genre-less show sh1 are filtered out.
+    assert set(_ids(d["recently_added"])) == {"m1", "m3"}
+    # Continue-watching: only the in-progress Drama movie remains (the show has no genres → excluded).
+    assert _ids(d["continue_watching"]) == ["m3"]
+    # Genre tiles reflect the filtered set — only Drama, count 2 (m1 + m3).
+    assert {g["value"]: g["count"] for g in d["genres"]} == {"Drama": 2}
+    # Because-you-watched: the anchor m1 is watched, but its only rec (m2) is Comedy → filtered → no rail.
+    assert d["because_you_watched"] is None
+
+
+def test_filters_narrow_surprise(db, monkeypatch):
+    user = _seed(db)
+    items = _get(
+        db, user, monkeypatch, "/api/plex/surprise?scope=movie&genres=Comedy"
+    ).json()["items"]
+    # Only the one Comedy movie qualifies under the filter.
+    assert _ids(items) == ["m2"]

frontend/src/components/PlexBrowse.tsx

@@ -105,11 +105,12 @@ export default function PlexBrowse() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [jumpTo]);
 
-  // Discover → grid on a browse intent: when a header search or a filter FIRST becomes active while on
-  // the Discover landing, switch to the flat grid (which consumes q/filters). Only on the off→on edge,
-  // so a pre-existing (persisted) filter doesn't yank a returning user off Discover on mount, and a
-  // Back to Discover with the search still in the box doesn't immediately re-flip.
-  const browseIntent = !!dq || plexFilterCount(filters) > 0;
+  // Discover → grid on a SEARCH: a header search has no rail on Discover, so entering one FIRST while on
+  // the Discover landing switches to the flat grid (which consumes q). Only on the off→on edge, so a Back
+  // to Discover with the term still in the box doesn't immediately re-flip. Filters are NOT a flip
+  // trigger anymore — Discover honours the active filters itself (its rails narrow like the grid), so
+  // adding a filter leaves you on Discover with narrowed rails instead of yanking you to the grid.
+  const browseIntent = !!dq;
   const prevIntent = useRef(browseIntent);
   useEffect(() => {
     if (sub.view.kind === "discover" && browseIntent && !prevIntent.current) {

frontend/src/components/PlexDiscover.dom.test.tsx

@@ -42,6 +42,17 @@ vi.mock("../lib/api", () => ({
     plexSurprise: (...a: unknown[]) => plexSurprise(...a),
     plexSetState: (...a: unknown[]) => plexSetState(...a),
   },
+  // PlexDiscover now reads the active filters via usePlex (PlexProvider); its context default needs
+  // EMPTY_PLEX_FILTERS at import time. No provider is rendered, so the default (empty) filters apply.
+  EMPTY_PLEX_FILTERS: {
+    genres: [],
+    contentRatings: [],
+    directors: [],
+    actors: [],
+    studios: [],
+    keywords: [],
+    collections: [],
+  },
 }));
 
 import PlexDiscover from "./PlexDiscover";
@@ -102,7 +113,8 @@ describe("PlexDiscover", () => {
     expect(screen.getAllByText("Just Added").length).toBeGreaterThan(0);
     expect(screen.getAllByText("Random Pick").length).toBeGreaterThan(0);
     expect(screen.getAllByText("Rec One").length).toBeGreaterThan(0);
-    expect(plexDiscover).toHaveBeenCalledWith("both", "en");
+    // Now called with the active filters too (empty default here, no provider mounted).
+    expect(plexDiscover).toHaveBeenCalledWith("both", "en", expect.objectContaining({ genres: [] }));
   });
 
   it("fires onGenre with the tile's value", async () => {

frontend/src/components/PlexDiscover.tsx

@@ -6,6 +6,7 @@ import { qk } from "../lib/queryKeys";
 import { api, type PlexCard, type PlexDiscover as PlexDiscoverData } from "../lib/api";
 import { plexLang } from "../i18n";
 import { toggleWatchState } from "../lib/plexWatch";
+import { usePlex } from "./PlexProvider";
 import { Carousel } from "./Carousel";
 import { PlexPosterCard } from "./plexCards";
 import { LoadingState, StateMessage } from "./QueryState";
@@ -89,14 +90,17 @@ export default function PlexDiscover({
   const { t } = useTranslation();
   const qc = useQueryClient();
   const lang = plexLang();
+  // The active sidebar filters narrow every rail, so Discover matches the Browse grid. They're in the
+  // query keys so a filter change refetches (and the watched-toggle setQueryData below keys the same).
+  const { filters } = usePlex();
   const q = useQuery({
-    queryKey: qk.plexDiscover(scope, lang),
-    queryFn: () => api.plexDiscover(scope, lang),
+    queryKey: qk.plexDiscover(scope, lang, filters),
+    queryFn: () => api.plexDiscover(scope, lang, filters),
   });
   // Surprise-me is its own query so the ↻ button can redraw it without refetching the whole surface.
   const surpriseQ = useQuery({
-    queryKey: qk.plexSurprise(scope),
-    queryFn: () => api.plexSurprise(scope),
+    queryKey: qk.plexSurprise(scope, filters),
+    queryFn: () => api.plexSurprise(scope, undefined, filters, lang),
     staleTime: 0,
   });
 
@@ -107,7 +111,7 @@ export default function PlexDiscover({
       optimistic: (next) => {
         const flip = (cards: PlexCard[]) =>
           cards.map((c) => (c.id === card.id ? { ...c, status: next } : c));
-        qc.setQueryData<PlexDiscoverData>(qk.plexDiscover(scope, lang), (old) =>
+        qc.setQueryData<PlexDiscoverData>(qk.plexDiscover(scope, lang, filters), (old) =>
           old
             ? {
                 ...old,
@@ -119,8 +123,9 @@ export default function PlexDiscover({
               }
             : old,
         );
-        qc.setQueryData<{ scope: string; items: PlexCard[] }>(qk.plexSurprise(scope), (old) =>
-          old ? { ...old, items: flip(old.items) } : old,
+        qc.setQueryData<{ scope: string; items: PlexCard[] }>(
+          qk.plexSurprise(scope, filters),
+          (old) => (old ? { ...old, items: flip(old.items) } : old),
         );
       },
       resync: () => {

frontend/src/lib/api/plex.ts

@@ -463,16 +463,26 @@ export const plexApi = {
       method: "PUT",
       body: JSON.stringify({ item_rating_keys: itemRks }),
     }),
-  // Discover landing rails in one request (serve-from-DB). `lang` picks the genre-tile vocabulary.
-  plexDiscover: (scope: string, lang?: string): Promise<PlexDiscover> => {
+  // Discover landing rails in one request (serve-from-DB). `lang` picks the genre-tile vocabulary; the
+  // active sidebar `filters` narrow every rail (so Discover behaves like the Browse grid).
+  plexDiscover: (scope: string, lang?: string, filters?: PlexFilters): Promise<PlexDiscover> => {
     const u = new URLSearchParams({ scope });
     if (lang === "hu") u.set("lang", "hu");
+    if (filters) appendPlexFilters(u, filters);
     return req(`/api/plex/discover?${u.toString()}`);
   },
-  // A fresh random sample for the Surprise-me rail — a new draw every call (the ↻ refetch).
-  plexSurprise: (scope: string, limit?: number): Promise<{ scope: string; items: PlexCard[] }> => {
+  // A fresh random sample for the Surprise-me rail — a new draw every call (the ↻ refetch), narrowed by
+  // the active filters like the other rails.
+  plexSurprise: (
+    scope: string,
+    limit?: number,
+    filters?: PlexFilters,
+    lang?: string,
+  ): Promise<{ scope: string; items: PlexCard[] }> => {
     const u = new URLSearchParams({ scope });
     if (limit) u.set("limit", String(limit));
+    if (lang === "hu") u.set("lang", "hu");
+    if (filters) appendPlexFilters(u, filters);
     return req(`/api/plex/surprise?${u.toString()}`);
   },
   plexShow: (id: string, lang?: string): Promise<PlexShowDetail> =>

frontend/src/lib/queryKeys.ts

@@ -97,8 +97,9 @@ export const qk = {
   // both for a prefix invalidation after a watched-toggle. Surprise is its own key so the ↻ reshuffle
   // refetches it alone.
   plexDiscover: (...rest: unknown[]) => ["plex-discover", ...rest],
-  plexSurprise: (scope?: string) =>
-    scope !== undefined ? (["plex-surprise", scope] as const) : (["plex-surprise"] as const),
+  // Variadic like plexDiscover so it can key by scope + the active filters; `plexSurprise()` (no args)
+  // stays a prefix for the reshuffle/watched-toggle invalidations.
+  plexSurprise: (...rest: unknown[]) => ["plex-surprise", ...rest],
   plexSuggest: (...rest: unknown[]) => ["plex-suggest", ...rest],
   // Optional trailing `lang` (E5 S6): a language switch remounts the detail with a new key so HU/EN
   // metadata is cached separately. Omitting it (e.g. for a prefix invalidation) still matches both.