sources

type Song struct {
	ArtistTitle string
	Error       error
}

type SongSource interface {
	// Starts the song source. This method should start the background thread and return.
	// When new song is found it should be send to the channel. Channel should be closed
	// when there is no more songs left.
	Start(ctx context.Context, conf SourceJob, song chan<- Song) error
}

type SourceJob struct {
	SourceUrl  string
	SourceType string
	SubstrMap  map[string]string
}