modify websocketserver to broker with callback functions

websocket/models/wsMessage.go

@@ -0,0 +1,21 @@
+package models
+
+import "encoding/json"
+
+type WSMessage struct {
+	Type string `json:"type"`
+}
+
+func GetPongByteSlice() []byte {
+	b, err := json.Marshal(WSMessage{
+		Type: "pong",
+	})
+	if err != nil {
+		return []byte{}
+	}
+	return b
+}
+
+func (w WSMessage) IsPing() bool {
+	return w.Type == "ping"
+}