Removed dependency on engine from persistence

domain/nowplaying.go

@@ -0,0 +1,34 @@
+package domain
+
+import "time"
+
+const NowPlayingExpire = 60 * time.Minute
+
+type NowPlayingInfo struct {
+	TrackId    string
+	Start      time.Time
+	Username   string
+	PlayerId   int
+	PlayerName string
+}
+
+// This repo must have the semantics of a FIFO queue, for each playerId
+type NowPlayingRepository interface {
+	// Insert at the head of the queue
+	Enqueue(*NowPlayingInfo) error
+
+	// Removes and returns the element at the end of the queue
+	Dequeue(playerId int) (*NowPlayingInfo, error)
+
+	// Returns the element at the head of the queue (last inserted one)
+	Head(playerId int) (*NowPlayingInfo, error)
+
+	// Returns the element at the end of the queue (first inserted one)
+	Tail(playerId int) (*NowPlayingInfo, error)
+
+	// Size of the queue for the playerId
+	Count(playerId int) (int64, error)
+
+	// Returns all tails from all playerIds
+	GetAll() ([]*NowPlayingInfo, error)
+}

domain/properties.go

@@ -0,0 +1,16 @@
+package domain
+
+const (
+	PropLastScan = "LastScan"
+)
+
+type Property struct {
+	Id    string
+	Value string
+}
+
+type PropertyRepository interface {
+	Put(id string, value string) error
+	Get(id string) (string, error)
+	DefaultGet(id string, defaultValue string) (string, error)
+}