Changes the AlbumCoverProvider and ArtistArtProvider interfaces from
MBID-only string parameters to ref-struct signatures so name-based
providers (Deezer, Last.fm in upcoming tasks) can act on rows
without MBIDs.
Today, 53 of 213 artists in the dev DB have NULL MBIDs — featured
artists, remixers, and compilation contributors created from
track-tag splits where the primary-artist MBID is in the file but
collaborator IDs aren't. These rows are unreachable by the current
MBID-only chain. Refactoring the interface unblocks future
name-based providers from acting on them.
TheAudioDB and MBCAA keep MBID-only behavior internally: they return
ErrNotFound when ref.MBID is empty rather than attempting a
name-based fallback. The MBID guard inside EnrichAlbum/EnrichArtist
is removed; providers receive the ref unconditionally and decide
whether they can act on it.
GetAlbumWithFirstTrackPath now JOINs artists to return artist_name
alongside the existing fields, supporting AlbumRef construction.
No behavioral change today (only TheAudioDB + MBCAA registered, both
keep MBID-only behavior). The change unblocks T3 (Deezer) and T4
(Last.fm) which can now register and act on every artist/album
regardless of MBID presence.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Rewires EnrichAlbum to iterate EnabledAlbumProviders from the
SettingsService instead of a single hardcoded MBCAA fetcher. Sidecar
layer is unchanged (always tried first). Per-row eligibility check
honors cover_art_sources_version: terminal 'found' values skip;
'none' flips to NULL via ClearAlbumCoverNone and proceeds (the DB-
level ListAlbumsMissingCover query guards the version check for batch
callers; RetryAlbum clears via ClearAlbumCover first); NULL is eligible.
The provider chain uses an inline allWere404 accumulator to settle
the row to 'none' only when every provider returned ErrNotFound.
Any provider returning ErrTransient leaves the row NULL for next-
pass retry — even if other providers returned ErrNotFound — since
the transient call's MBID might succeed on a future attempt.
Boot wiring (cmd/minstrel/main.go) replaces the
NewFetcher+NewEnricher(fetcher, mbcaaOn) shape with
NewMBCAAProviderFromConfig (swaps in production User-Agent on the
registered provider) + NewSettingsService + NewEnricher(settings).
The old cfg.Library.CoverArtFromMBCAA flag is no-op'd; DB-backed
settings replace it. Field stays in the config struct for backward
compat with deployed config files.
Consolidates fetcher.go's HTTP logic into provider_mbcaa.go (no more
wrapper indirection): mbcaaProvider now holds cfg/mu/lastCall/client
directly. Deletes fetcher.go and fetcher_test.go. ErrNotFound and
ErrTransient move into provider.go alongside the other sentinels.
Updates admin_covers_test.go and provider_mbcaa_test.go to the new
constructor shapes. Adds multi-provider-chain, transient-leaves-null,
and stale-none-flips-and-retries test cases in enricher_test.go.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adapts the existing Fetcher-based MBCAA client to the new Provider
abstraction. mbcaaProvider embeds *Fetcher and implements
Provider + AlbumCoverProvider + TestableProvider. init() registers a
default-config instance; NewMBCAAProviderFromConfig swaps in
production config (User-Agent, MinPeriod) at boot.
Wrapper approach (rather than reimplementing the HTTP logic) keeps
the package compiling during the T4–T8 window: enricher.go and
main.go still reference the legacy Fetcher type / NewFetcher
constructor / Fetch method, all of which remain unchanged in
fetcher.go. A-T8 will consolidate the HTTP logic into this file and
delete fetcher.go after the enricher rewrite removes the last
legacy call sites.
TestConnection hits a hardcoded popular release MBID (Beatles
"Abbey Road" UK release) and treats both 200 and 404 as "connection
works" — MBCAA needs no auth, so only 5xx / network failures
surface. Tests cover ID/DisplayName/Capability metadata, success
path, 404→ErrNotFound, disabled-returns-ErrNotFound, Configure
toggle, TestConnection variants, and NewMBCAAProviderFromConfig
swap.
bvandeusen