chore(M004/S01): auto-commit after complete-slice

backend/app.go

@@ -15,6 +15,7 @@ import (
 	"yellowjacket/backend/config"
 	"yellowjacket/backend/coverart"
 	"yellowjacket/backend/database"
+	"yellowjacket/backend/explore"
 	"yellowjacket/backend/frontendutil"
 	"yellowjacket/backend/library"
 	"yellowjacket/backend/mediacontrols"
@@ -37,6 +38,7 @@ type YellowJacketApp struct {
 	player        *player.Player
 	playlist      *playlist.Service
 	queue         *queue.Queue
+	explore       *explore.Service
 	mediaControls mediacontrols.Handler
 	tagWriter     *tagwriter.TagWriter
 	appContext    context.Context
@@ -125,6 +127,11 @@ func NewYellowJacketApp(
 		yjApp.library,
 	)
 
+	// create explore service
+	yjApp.explore = explore.NewExploreService(
+		yjApp.logger.WithGroup("explore"), yjApp.database,
+	)
+
 	yjApp.FEBindings = []any{
 		yjApp.FrontendUtil,
 		yjApp.appConfig,
@@ -133,6 +140,7 @@ func NewYellowJacketApp(
 		yjApp.queue,
 		yjApp.player,
 		yjApp.tagWriter,
+		yjApp.explore,
 	}
 
 	return yjApp, nil
@@ -179,6 +187,7 @@ func (yj *YellowJacketApp) OnStartup(ctx context.Context) {
 
 	yj.player.SetContext(ctx)
 	yj.tagWriter.SetContext(ctx)
+	yj.explore.SetContext(ctx)
 
 	// Wire queue (created in NewYellowJacketApp for Wails binding)
 	yj.queue.SetContext(ctx)

backend/explore/explore.go

@@ -0,0 +1,118 @@
+package explore
+
+import (
+	"context"
+	"log/slog"
+
+	"yellowjacket/backend/database"
+)
+
+// Service is the Wails-bound service for the explore feature.
+// It owns the lifecycle of all explore-related components: the
+// MusicBrainz client, ListenBrainz client, rate limiter, and
+// response cache.  Its exported methods form the binding surface
+// that the frontend calls via generated TypeScript stubs.
+type Service struct {
+	mb     *MusicBrainzClient
+	lb     *ListenBrainzClient
+	cache  *Cache
+	logger *slog.Logger
+	ctx    context.Context
+}
+
+// NewExploreService creates a Service backed by the given
+// database.  It instantiates the rate limiter, cache, MusicBrainz
+// client, and ListenBrainz client internally.
+func NewExploreService(logger *slog.Logger, db *database.DB) *Service {
+	cache := NewCache(db, logger.WithGroup("cache"))
+	limiter := NewRateLimiter()
+	mb := NewMusicBrainzClient(cache, logger.WithGroup("musicbrainz"))
+	lb := NewListenBrainzClient(limiter, cache, logger.WithGroup("listenbrainz"))
+
+	logger.Info("explore service created")
+
+	return &Service{
+		mb:     mb,
+		lb:     lb,
+		cache:  cache,
+		logger: logger,
+		ctx:    context.Background(),
+	}
+}
+
+// SetContext injects the Wails runtime context.  Called from
+// OnStartup after the Wails runtime is initialised.
+func (e *Service) SetContext(ctx context.Context) {
+	e.ctx = ctx
+}
+
+// ---------------------------------------------------------------------------
+// MusicBrainz search
+// ---------------------------------------------------------------------------
+
+// SearchArtists queries MusicBrainz for artists matching the query.
+func (e *Service) SearchArtists(query string) ([]MBArtist, error) {
+	return e.mb.SearchArtists(e.ctx, query, 0)
+}
+
+// SearchReleaseGroups queries MusicBrainz for release groups matching the query.
+func (e *Service) SearchReleaseGroups(query string) ([]MBReleaseGroup, error) {
+	return e.mb.SearchReleaseGroups(e.ctx, query, 0)
+}
+
+// SearchRecordings queries MusicBrainz for recordings matching the query.
+func (e *Service) SearchRecordings(query string) ([]MBRecording, error) {
+	return e.mb.SearchRecordings(e.ctx, query, 0)
+}
+
+// ---------------------------------------------------------------------------
+// MusicBrainz lookup
+// ---------------------------------------------------------------------------
+
+// LookupArtist fetches a single MusicBrainz artist by MBID.
+func (e *Service) LookupArtist(mbid string) (*MBArtist, error) {
+	return e.mb.LookupArtist(e.ctx, mbid)
+}
+
+// LookupReleaseGroup fetches a single MusicBrainz release group by MBID.
+func (e *Service) LookupReleaseGroup(mbid string) (*MBReleaseGroup, error) {
+	return e.mb.LookupReleaseGroup(e.ctx, mbid)
+}
+
+// ---------------------------------------------------------------------------
+// MusicBrainz browse
+// ---------------------------------------------------------------------------
+
+// BrowseReleaseGroups fetches release groups for a given artist MBID.
+func (e *Service) BrowseReleaseGroups(artistMBID string) ([]MBReleaseGroup, error) {
+	return e.mb.BrowseReleaseGroups(e.ctx, artistMBID)
+}
+
+// BrowseReleases fetches releases for a given release group MBID.
+func (e *Service) BrowseReleases(releaseGroupMBID string) ([]MBRelease, error) {
+	return e.mb.BrowseReleases(e.ctx, releaseGroupMBID)
+}
+
+// ---------------------------------------------------------------------------
+// ListenBrainz
+// ---------------------------------------------------------------------------
+
+// TopRecordingsForArtist returns the most-listened recordings for an artist.
+func (e *Service) TopRecordingsForArtist(artistMBID string) ([]LBTopRecording, error) {
+	return e.lb.TopRecordingsForArtist(e.ctx, artistMBID)
+}
+
+// SimilarArtists returns artists similar to the given artist MBID.
+func (e *Service) SimilarArtists(artistMBID string) ([]LBSimilarArtist, error) {
+	return e.lb.SimilarArtists(e.ctx, artistMBID)
+}
+
+// ---------------------------------------------------------------------------
+// Cover Art Archive
+// ---------------------------------------------------------------------------
+
+// CoverArtURL returns the Cover Art Archive URL for a release's
+// front cover at the default 250px size.
+func (e *Service) CoverArtURL(releaseMBID string) string {
+	return CoverArtURL(releaseMBID)
+}