implementing websocket relay connection

net/server/internal/api_signal.go

@@ -1,10 +1,60 @@
 package databag
 
 import (
+	"github.com/gorilla/websocket"
+  "encoding/json"
 	"net/http"
+  "errors"
 )
 
-//Signal handler for websocket connection with call events
+var bridgeRelay BridgeRelay;
+var relayUpgrader = websocket.Upgrader{}
+
+//Status handler for websocket connection
 func Signal(w http.ResponseWriter, r *http.Request) {
+
+	// accept websocket connection
+	conn, err := relayUpgrader.Upgrade(w, r, nil)
+	if err != nil {
+		ErrMsg(err)
+		return
+	}
+	defer conn.Close()
+	conn.SetReadLimit(APPBodyLimit)
+
+	// receive announce
+	t, m, res := conn.ReadMessage()
+	if res != nil {
+		ErrMsg(res)
+		return
+	}
+	if t != websocket.TextMessage {
+		ErrMsg(errors.New("invalid websocket message type"))
+		return
+	}
+	var a Announce
+	if err := json.Unmarshal(m, &a); err != nil {
+		ErrMsg(err)
+		return
+	}
+
+  // bind connection to bridge
+  bridgeRelay.SetConnection(conn, a.AppToken);
+
+  for true {
+    t, m, res := conn.ReadMessage()
+    if res != nil {
+      ErrMsg(res)
+      break
+    }
+    if t != websocket.TextMessage {
+      ErrMsg(errors.New("invalid websocket message type"))
+      break
+    }
+    bridgeRelay.RelayMessage(conn, m);
+	}
+
+  // release connection from bridge
+  bridgeRelay.ClearConnection(conn);
 }