Home screen is the first surface on app open; without a local cache
the cold-start blocks on /api/home, which dominates felt latency on
slow or remote connections. This commit caches the last successful
HomeData as a single-row JSON blob in drift, so subsequent app opens
yield content immediately and revalidate in the background.
Schema:
- New CachedHomeSnapshot table (single row: id=1, json TEXT,
updated_at). schemaVersion bumped 2 → 3 with a forward migration
that calls m.createTable(cachedHomeSnapshot). Codegen regenerated
via build_runner; the *.g.dart files are gitignored and rebuilt
by the CI Codegen step.
Provider rewrite:
- homeProvider: FutureProvider<HomeData> → StreamProvider<HomeData>
using the existing cacheFirst<CachedHomeSnapshotData, HomeData>
pattern (alwaysRefresh: true for SWR). On cold cache the first
/api/home fetch populates the row. On warm cache the cached
HomeData is yielded immediately and a background REST fetch
overwrites the row, which drift's watch() picks up.
- Encoder helpers (_albumToJson / _artistToJson / _trackToJson) so
HomeData survives the JSON round-trip into and out of drift.
Field names match the server's /api/home wire shape exactly so
HomeData.fromJson handles both fresh server responses and cached
drift rows.
Callers untouched: home_screen.dart's ref.watch + ref.refresh +
metadata_prefetcher's ref.listen all keep working with the
StreamProvider shape (AsyncValue<HomeData> stays the surface type).
Test fix: 4 homeProvider.overrideWith sites in home_screen_test.dart
switched from `(ref) async => _emptyHome` (FutureProvider form) to
`(ref) => Stream.value(_emptyHome)` (StreamProvider form).
For #357. Completes the user-visible deferred follow-up. Remaining
deferred items: library_changes server-side retention.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Two fixes in one commit because they're entangled — the systemVariant
work would have been theater otherwise.
## The wire-format bug
/api/library/sync was emitting PascalCase JSON for artist / album /
track / playlist upserts (raw json.Marshal of sqlc-generated structs
with no JSON tags — sqlc.yaml: emit_json_tags=false). Flutter's
sync_controller _*FromJson reads snake_case keys, so all metadata
sync rows landed in drift with empty strings / zero ints.
The like_track / like_album / like_artist / playlist_track entities
work because they're hand-built `map[string]string` payloads with
snake_case keys — they sidestepped the bug. The 4 raw-marshal
entities did not.
Existing sync test caught zero of this — it asserts on len(upserts)
not field shape.
Fix: server-side view structs in library_sync_views.go with proper
JSON tags + pgtype-flattening (UUID → 8-4-4-4-12 hex string,
Date → "2006-01-02"). Mirrors the playlistRowView pattern from
/api/playlists. New library_sync_views_test.go pins the wire keys
so future field-name drift breaks loud.
## systemVariant column (closes#357 plan C v1 limitation)
playlistSyncView now carries `system_variant` server → wire.
Flutter drift schema bumped from 1 → 2 with onUpgrade adding the
`systemVariant TEXT NULL` column to cached_playlists. Cursor reset
to 0 in the migration so existing rows refresh with the new field
on the next sync.
playlistsListProvider now filters locally by systemVariant:
- kind='user' → systemVariant IS NULL (the add-to-playlist sheet's intent)
- kind='system' → systemVariant IS NOT NULL
- kind='all' → no filter
Closes the documented v1 limitation where the add-to-playlist sheet
showed system playlists alongside user-created ones.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>