Add search, filter, and sort functionality to film shelves

- Add _SORT_COLUMNS dict to routers/films.py with 8 sort options
- Extend _get_shelf_query to accept q (search) and sort parameters
- Update /films/partial endpoint to accept q/sort query params and pass
  search_active to template to suppress month grouping when searching
- Add filter bar (search input + sort select) to templates/index.html
- Add data-shelf attribute to #film-feed for JS to read current shelf
- Rewrite infinite scroll JS to support debounced search (300ms),
  feed reset on filter/sort change, and pass params on all fetches

Filters text search by title OR director (case-insensitive ilike).
Sort options: date watched (newest/oldest), title (A-Z/Z-A), year,
stars. Month grouping disabled when search is active.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

1 files changed, 27 insertions, 3 deletions

diff --git a/routers/films.py b/routers/films.py
index afcf0ae..ec56c0a 100644
--- a/routers/films.py
+++ b/routers/films.py
@@ -176,9 +176,29 @@ def _notice_context(
     }
 
 
-def _get_shelf_query(db: Session, shelf: str):
+_SORT_COLUMNS = {
+    "date_watched_desc": [Film.date_watched.desc().nullslast(), Film.id.desc()],
+    "date_watched_asc":  [Film.date_watched.asc().nullslast(), Film.id.asc()],
+    "title_asc":         [Film.title.asc(), Film.id.asc()],
+    "title_desc":        [Film.title.desc(), Film.id.desc()],
+    "year_desc":         [Film.year.desc().nullslast(), Film.id.desc()],
+    "year_asc":          [Film.year.asc().nullslast(), Film.id.asc()],
+    "stars_desc":        [Film.stars.desc(), Film.id.desc()],
+    "stars_asc":         [Film.stars.asc(), Film.id.asc()],
+}
+
+
+def _get_shelf_query(db: Session, shelf: str, q: str | None = None, sort: str | None = None):
     """Get a query for films on a shelf, ordered appropriately."""
     query = db.query(Film).filter(Film.shelf == shelf)
+
+    if q:
+        term = f"%{q}%"
+        query = query.filter(Film.title.ilike(term) | Film.director.ilike(term))
+
+    if sort and sort in _SORT_COLUMNS:
+        return query.order_by(*_SORT_COLUMNS[sort])
+
     if shelf == "diary":
         return query.order_by(Film.date_watched.desc(), Film.created_at.desc(), Film.id.desc())
     elif shelf == "queue":
@@ -379,18 +399,21 @@ def get_films_partial(
     shelf: str = Query("diary"),
     offset: int = Query(0),
     limit: int = Query(20),
+    q: str | None = Query(None),
+    sort: str | None = Query(None),
     db: Session = Depends(get_db),
 ):
     """Returns partial HTML for pagination. Used by infinite scroll."""
     if shelf not in ALLOWED_SHELVES:
         raise HTTPException(status_code=400, detail="Invalid shelf.")
 
-    query = _get_shelf_query(db, shelf)
+    search_active = bool(q and q.strip())
+    query = _get_shelf_query(db, shelf, q=q or None, sort=sort or None)
     total = query.count()
     films = query.offset(offset).limit(limit).all()
     has_more = (offset + limit) < total
 
-    if shelf == "diary":
+    if shelf == "diary" and not search_active:
         grouped_films = _group_films_by_month(films)
     else:
         grouped_films = None
@@ -401,6 +424,7 @@ def get_films_partial(
         films=films,
         grouped_films=grouped_films,
         active_shelf=shelf,
+        search_active=search_active,
     )
 
     response = HTMLResponse(html)