Periodic worker that walks cached_artists for missing album lists
and cached_albums for missing track lists, then fills them via
/api/artists/:id + /api/albums/:id. Newly-discovered album covers
are pre-warmed into flutter_cache_manager's disk cache too.
Solves the "tap an artist → empty album area → pop in" experience:
artistAlbumsProvider was drift-first but the cache only got
populated when the user navigated TO an artist. SyncController's
/api/library/sync delta doesn't carry per-artist album lists (those
are query-time derived). Now the filler pre-populates them in the
background so the drift hit is real on first tap.
Pacing (intentionally conservative):
* 10-second initial delay so SyncController has time to land its
first sync — the WHERE NOT EXISTS query has nothing to do until
cached_artists is populated.
* 5-minute interval thereafter. Once steady state is reached the
sweep is a cheap drift query + early exit.
* 200ms throttle between per-entity REST requests — never competes
with active playback.
* 200 entities per sweep cap so a fresh install with thousands of
artists doesn't tie up the network for one continuous run. Next
sweep picks up where this one left off (NOT EXISTS naturally
skips already-filled rows).
Wall time estimate for a 1000-artist library: ~3-4 minutes spread
over multiple sweeps. Single round-trip per artist (new
getArtistDetail API method returns artist + albums in one shot).
Activated from app.dart's postFrameCallback alongside the existing
SyncController / Prefetcher / MetadataPrefetcher / LiveEvents
hooks. Disposed via ref.onDispose when the provider scope tears
down (effectively process death in practice).
End-to-end pilot of the per-item architecture. Home now reads from
the new homeIndexProvider (drift-first over CachedHomeIndex with
/api/home/index discovery + SWR), then each tile is a small
ConsumerWidget watching its own albumTileProvider/artistTileProvider/
trackTileProvider. Tiles render a matched-dimension skeleton while
their entity is still hydrating, and swap in the real card once
drift emits the populated row.
Track hydration is wired up — /api/tracks/:id already existed so
the queue's case 'track' just calls api.getTrack(id) and persists.
The visible behavior:
* Cold visit: small /api/home/index round-trip (IDs only, ~10×
smaller than /api/home), then sections appear shaped with
skeleton tiles; each tile materializes as the hydration queue
drains. No more "30s blank → everything pops in at once."
* Warm visit: drift index emits instantly, drift entity rows emit
instantly, no network. Page paints fully in the first frame.
* Mid-state: scrolling through a partially-hydrated section sees
real cards next to skeleton cards. Layout doesn't shift because
skeletons match real-card dimensions exactly.
CachedHomeSnapshot (and the legacy homeProvider) stay in place but
unconsumed by Flutter — left in for now so revert is cheap if the
new path needs reworking. Cleanup follow-up in a later slice.
Old /api/home endpoint untouched, so the web client keeps working
unchanged.
LibraryApi wraps GET /api/home, /api/artists/{id}(/tracks),
/api/albums/{id}. dioProvider builds an authenticated dio (token
resolver reads session_token from secure storage on every request).
homeProvider, artistProvider(id), albumProvider(id) sit on top.
bvandeusen