begin defining a generic MediaProvider interface and model

backend/mediaprovider/mediaprovider.go

@@ -0,0 +1,64 @@
+package mediaprovider
+
+import "image"
+
+type AlbumFilter struct {
+	MinYear int
+	MaxYear int      // 0 == unset/match any
+	Genres  []string // len(0) == unset/match any
+
+	ExcludeFavorited   bool // mut. exc. with ExcludeUnfavorited
+	ExcludeUnfavorited bool // mut. exc. with ExcludeFavorited
+}
+
+type AlbumIterator interface {
+	Next() *Album
+}
+
+type TrackIterator interface {
+	Next() *Track
+}
+
+type RatingFavoriteParameters struct {
+	AlbumIDs  []string
+	ArtistIDs []string
+	TrackIDs  []string
+}
+
+type Favorites struct {
+	Albums  []Album
+	Artists []Artist
+	Tracks  []Track
+}
+
+type MediaProvider interface {
+	GetAlbum(albumID string) (*AlbumWithTracks, error)
+
+	GetArtist(artistID string) (*Artist, error)
+
+	GetPlaylist(playlistID string) (*PlaylistWithTracks, error)
+
+	GetCoverArt(coverArtID string, size int) (image.Image, error)
+
+	AlbumSortOrders() []string
+
+	IterateAlbums(sortOrder string, searchQuery string, filter AlbumFilter) AlbumIterator
+
+	IterateTracks(searchQuery string) TrackIterator
+
+	GetRandomTracks(genre string, count int) ([]Track, error)
+
+	GetSimilarTracks(artistID string, count int) ([]Track, error)
+
+	GetArtists() ([]Artist, error)
+
+	GetGenres() ([]Genre, error)
+
+	GetFavorites() (Favorites, error)
+
+	GetPlaylists() ([]Playlist, error)
+
+	SetFavorite(params RatingFavoriteParameters) error
+
+	SetRating(params RatingFavoriteParameters) error
+}