Adds ``discover_tracks(tracks) -> List[NormalizedTrack]`` to the
PlaylistSource interface. Sources whose tracks already carry
provider IDs (Spotify, Tidal, Qobuz, YouTube, Deezer, Spotify
public, iTunes link, SoulSync Discovery) inherit a no-op default;
ListenBrainz + Last.fm override to run the matching engine.
This closes the last gap before LB / Last.fm / SoulSync Discovery
can land as Sync-page mirror sources: the refresh handler now
calls ``source.discover_tracks(...)`` whenever a source returns
tracks with ``needs_discovery=True``, so mirrored LB rows arrive
already discovered + ready for the sync pipeline. Previously, LB
playlists ran through a separate state-machine worker tied to the
Discover-page UI, with results stored in ``discovery_cache``
instead of ``mirrored_playlist_tracks.extra_data``.
Changes:
- ``core/playlists/sources/base.py`` — PlaylistSource switches from
Protocol to ABC so a concrete default for ``discover_tracks``
can live on the base class. The four real-work methods stay
``@abstractmethod``; instantiating an adapter that forgets one
fails loudly at construction.
- ``core/discovery/matching.py`` (new) — pure ``match_mb_tracks``
helper that runs Strategy-1-only matching-engine queries against
Spotify (primary) or iTunes (fallback). No state machine, no
discovery-cache writes, no wing-it stub — that richer flow stays
in ``core/discovery/listenbrainz.py`` for the Discover-page UI.
- ``ListenBrainzPlaylistSource`` + ``LastFMPlaylistSource`` take
an optional ``discover_callable`` constructor arg. Last.fm reuses
the LB implementation since the track shape is identical.
- ``bootstrap.build_playlist_source_registry`` accepts a
``discover_callable`` kwarg and wires it into LB + Last.fm
adapters.
- ``web_server.py`` boot constructs the discovery callable from the
existing matching engine + ``_discovery_score_candidates`` +
Spotify / iTunes clients, passes through to the registry.
- ``refresh_mirrored.py`` adds a small ``_maybe_discover`` helper
that calls ``source.discover_tracks(...)`` between fetch and
``to_mirror_track_dict`` projection — only fires when at least
one track has ``needs_discovery=True``, so the normal Spotify /
Tidal / etc. refresh path stays a zero-cost pass-through.
Tests:
- 5 new adapter tests: default no-op pass-through, LB discovery
with mixed matches/misses, LB no-callable fallback, Last.fm
shares the LB implementation, mirror-dict spotify_hint emit.
- 1 new automation test: end-to-end LB refresh with a stub
discover_callable proves the matched_data lands in
``mirror_playlist_tracks.extra_data`` after the registry
refresh + discover hop.
225 tests across adapter + automation suites green.
Groundwork for unifying Discover-page playlists (ListenBrainz, Last.fm
radio, SoulSync Discovery) with Sync-page playlists (Spotify, Tidal,
Qobuz, YouTube, Spotify public, iTunes link). All nine sources now
expose the same `PlaylistSource` Protocol so callers stop having to
branch per-source.
This commit only adds the abstraction — no dispatch sites collapse to
the registry yet, no DB or UI changes. Adapters wrap existing clients
via injected getter callables to avoid eager imports of web_server.py
globals.
- core/playlists/sources/base.py — PlaylistMeta, NormalizedTrack,
PlaylistDetail dataclasses + PlaylistSource Protocol with
supports_listing / supports_refresh / requires_auth capability
flags. needs_discovery flag on NormalizedTrack marks tracks that
carry raw MB metadata (LB, Last.fm) vs tracks already matched to a
provider ID (everything else).
- core/playlists/sources/registry.py — thread-safe lazy-factory
registry with instance caching + re-register invalidation.
- nine adapters in core/playlists/sources/ wrapping SpotifyClient,
TidalClient, QobuzClient, spotify_public_scraper, the YouTube +
iTunes-link parsers (via injected callables), ListenBrainzManager,
Last.fm radio rows in the ListenBrainz cache, and
PersonalizedPlaylistManager.
- tests/test_playlist_sources_adapters.py — 18 tests covering each
adapter's field projection with fake backing clients, plus
registry lazy-construct + cache + re-register invalidation.
Phase 1 will collapse refresh_mirrored.py's per-source if/elif chain
to a registry lookup and surface ListenBrainz as a Sync-page tab.
