feat(ncm): support audio meta getter

algo/common/interface.go

@@ -0,0 +1,29 @@
+package common
+
+import (
+	"context"
+	"io"
+)
+
+type StreamDecoder interface {
+	Decrypt(buf []byte, offset int)
+}
+
+type Decoder interface {
+	Validate() error
+	io.Reader
+}
+
+type CoverImageGetter interface {
+	GetCoverImage(ctx context.Context) ([]byte, error)
+}
+
+type AudioMeta interface {
+	GetArtists() []string
+	GetTitle() string
+	GetAlbum() string
+}
+
+type AudioMetaGetter interface {
+	GetAudioMeta(ctx context.Context) (AudioMeta, error)
+}