Foundation: config, schema/migrations, auth, stable IDs, metadata probing

internal/metadata/metadata.go

@@ -0,0 +1,69 @@
+// Package metadata reads audio/video tags and technical properties via
+// ffprobe. It shells out with an explicit argument list (never a shell),
+// so filenames and tag content can never be interpreted as commands.
+package metadata
+
+// Tags holds the metadata VibeSonic understands, extracted from a single
+// media file. Multi-value fields (Artists, Genres) are kept as slices
+// rather than flattened into a single string, since a song can have
+// several performers or genres.
+type Tags struct {
+	Title     string
+	SortTitle string
+
+	Album           string
+	SortAlbum       string
+	AlbumArtist     string
+	SortAlbumArtist string
+
+	Artists      []string // primary + featured performers, in credit order
+	Composer     string
+	Conductor    string
+	Contributors []Contributor // producer/engineer/remixer/etc.
+	Genres       []string
+
+	Year                int
+	OriginalYear        int
+	ReleaseDate         string
+	OriginalReleaseDate string
+	RecordLabel         string
+
+	TrackNumber  int
+	TrackTotal   int
+	DiscNumber   int
+	DiscTotal    int
+	DiscSubtitle string
+
+	Comment string
+	ISRC    string
+	BPM     int
+
+	MusicBrainzTrackID     string
+	MusicBrainzRecordingID string
+	MusicBrainzAlbumID     string
+	MusicBrainzArtistID    string
+
+	ReplayGainTrackGainDB *float64
+	ReplayGainTrackPeak   *float64
+	ReplayGainAlbumGainDB *float64
+	ReplayGainAlbumPeak   *float64
+
+	HasEmbeddedArt    bool
+	EmbeddedArtStream int
+	EmbeddedLyrics    string
+
+	// Technical properties, read from the container/stream info rather
+	// than tags.
+	Format          string
+	Kind            string // "song" or "video"
+	DurationSeconds float64
+	BitrateKbps     int
+	SampleRateHz    int
+	Channels        int
+}
+
+// Contributor is a non-performer credit, e.g. {Name: "Rick Rubin", Role: "producer"}.
+type Contributor struct {
+	Name string
+	Role string
+}