work towards decoupling api from router

internal/api/websocket.go

@@ -0,0 +1,82 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/gorilla/websocket"
+	"github.com/jwetzell/showbridge-go/internal/common"
+)
+
+var upgrader = websocket.Upgrader{
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+type WebsocketEventDestination struct {
+	conn *websocket.Conn
+}
+
+func (d WebsocketEventDestination) Send(event common.Event) error {
+	eventJSON, err := event.ToJSON()
+	if err != nil {
+		return err
+	}
+	return d.conn.WriteMessage(websocket.TextMessage, eventJSON)
+}
+
+func (d WebsocketEventDestination) Is(dest common.EventDestination) bool {
+	other, ok := dest.(WebsocketEventDestination)
+	if !ok {
+		return false
+	}
+	return d.conn == other.conn
+}
+
+func (as *ApiServer) handleWebsocket(w http.ResponseWriter, req *http.Request) {
+	conn, err := upgrader.Upgrade(w, req, nil)
+	if err != nil {
+		as.logger.Error("websocket upgrade error", "error", err)
+		return
+	}
+	defer conn.Close()
+
+	eventDestination := WebsocketEventDestination{conn: conn}
+
+	as.eventRouter.AddEventDestination(eventDestination)
+READ_LOOP:
+	for {
+		messageType, message, err := conn.ReadMessage()
+		if err != nil {
+			_, ok := err.(*websocket.CloseError)
+			if ok {
+				break READ_LOOP
+			}
+		}
+
+		switch messageType {
+		case websocket.TextMessage, websocket.BinaryMessage:
+			event := common.Event{}
+			err = json.Unmarshal(message, &event)
+			if err != nil {
+				as.logger.Error("websocket message unmarshal error", "error", err)
+				continue
+			}
+			as.eventRouter.HandleEvent(event, WebsocketEventDestination{conn: conn})
+		case websocket.CloseMessage:
+			break READ_LOOP
+		case websocket.PingMessage:
+			err = conn.WriteMessage(websocket.PongMessage, nil)
+			if err != nil {
+				as.logger.Error("websocket pong error", "error", err)
+			}
+		default:
+			as.logger.Warn("unsupported websocket message type", "type", messageType)
+			continue
+		}
+
+	}
+	//NOTE(jwetzell): remove ws connection
+	as.eventRouter.RemoveEventDestination(eventDestination)
+}