✨ Implement WebSocket API

api.go

@@ -1,12 +1,22 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
+	"github.com/gorilla/websocket"
 )
 
+var upgrader = websocket.Upgrader{}
+
+type WsClient struct {
+	SendUpdates bool
+}
+
+var wsClients = make(map[*websocket.Conn]WsClient)
+
 func initApi() {
 	gin.SetMode(gin.ReleaseMode)
 	router := gin.Default()
@@ -26,6 +36,8 @@ func initApi() {
 	router.PUT("/api/routes", handleSetRoute)
 	router.DELETE("/api/routes", handleDeleteRoute)
 
+	router.GET("/ws", handleWs)
+
 	router.Run(fmt.Sprintf("%s:%d", config.Web.Bind, config.Web.Port))
 }
 
@@ -108,6 +120,7 @@ func createPort(body CreatePortRequest) (gin.H, gin.H) {
 		portConfig.Output = append(portConfig.Output, newPort)
 	}
 	saveConfig("ports", &portConfig)
+	onPortListChange()
 	return gin.H{"success": true, "UUID": id}, nil
 }
 
@@ -139,6 +152,7 @@ func deletePort(id string) gin.H {
 	unregisterPort(port)
 
 	saveConfig("ports", &portConfig)
+	onPortListChange()
 	return nil
 }
 
@@ -199,6 +213,7 @@ func setState(id string, body SetPortRequest) (gin.H, gin.H) {
 	}
 
 	saveConfig("ports", &portConfig)
+	onPortChange(port)
 	return gin.H{"success": true, "state": port.State}, nil
 }
 
@@ -236,6 +251,7 @@ func createRoute(id string, body CreateRouteRequest) gin.H {
 
 	from.Route = append(from.Route, PortRoute{ToUUID: body.To, Mute: true, Volume: 0, Balance: 0})
 	saveConfig("ports", &portConfig)
+	onPortChange(from)
 	return nil
 }
 
@@ -285,6 +301,7 @@ func setRoute(fromId string, toId string, body SetRouteRequest) (gin.H, gin.H) {
 		}
 
 		saveConfig("ports", &portConfig)
+		onPortChange(from)
 		return gin.H{"success": true, "state": from.Route[i]}, nil
 	}
 
@@ -315,8 +332,121 @@ func deleteRoute(fromId string, toId string) gin.H {
 
 		from.Route = append(from.Route[:i], from.Route[i+1:]...)
 		saveConfig("ports", &portConfig)
+		onPortListChange()
 		return nil
 	}
 
 	return gin.H{"success": false, "error": "No such route exists!"}
 }
+
+type WebsocketMessage struct {
+	RequestId      string             `json:"requestId"`
+	Method         string             `json:"method"`
+	UUID           string             `json:"UUID"`
+	ToUUID         string             `json:"toUUID"`
+	PortData       CreatePortRequest  `json:"portData"`
+	StateData      SetPortRequest     `json:"stateData"`
+	RouteData      CreateRouteRequest `json:"routeData"`
+	RouteStateData SetRouteRequest    `json:"routeStateData"`
+}
+
+type WebsocketResponse struct {
+	Type          string      `json:"type"`
+	RequestId     string      `json:"requestId,omitempty"`
+	RequestMethod string      `json:"requestMethod,omitempty"`
+	ResponseData  interface{} `json:"responseData"`
+}
+
+func wsSendRes(conn *websocket.Conn, res gin.H, err gin.H, request *WebsocketMessage) {
+	if err != nil {
+		data, _ := json.Marshal(WebsocketResponse{
+			Type:          "error",
+			RequestId:     request.RequestId,
+			RequestMethod: request.Method,
+			ResponseData:  err,
+		})
+		conn.WriteMessage(1, data)
+		return
+	}
+
+	response := WebsocketResponse{
+		Type:          "response",
+		RequestId:     request.RequestId,
+		RequestMethod: request.Method,
+		ResponseData:  gin.H{"success": true},
+	}
+	if res != nil {
+		response.ResponseData = res
+	}
+
+	data, _ := json.Marshal(response)
+	conn.WriteMessage(1, data)
+}
+
+func handleWs(c *gin.Context) {
+	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
+	if err != nil {
+		fmt.Println("WARN! Handling websocket connection failed!")
+		c.JSON(500, gin.H{"success": false, "error": "Handling websocket connection failed!"})
+	}
+
+	wsClients[conn] = WsClient{SendUpdates: false}
+
+	for {
+		var content WebsocketMessage
+		jsonErr := conn.ReadJSON(&content)
+		if jsonErr != nil {
+			delete(wsClients, conn)
+			conn.Close()
+			break
+		}
+		var res, err gin.H = nil, nil
+		switch content.Method {
+		case "listPorts":
+			res = gin.H{"inputs": portConfig.Input, "outputs": portConfig.Output}
+		case "createPort":
+			res, err = createPort(content.PortData)
+		case "setPortState":
+			res, err = setState(content.UUID, content.StateData)
+		case "deletePort":
+			err = deletePort(content.UUID)
+		case "createRoute":
+			err = createRoute(content.UUID, content.RouteData)
+		case "setRouteState":
+			res, err = setRoute(content.UUID, content.ToUUID, content.RouteStateData)
+		case "deleteRoute":
+			err = deleteRoute(content.UUID, content.ToUUID)
+		case "enableUpdates":
+			if clientOpts, ok := wsClients[conn]; ok {
+				clientOpts.SendUpdates = true
+				wsClients[conn] = clientOpts
+			}
+		default:
+			err = gin.H{"success": false, "error": "Method is not implemented"}
+		}
+		wsSendRes(conn, res, err, &content)
+	}
+}
+
+func onPortChange(port *Port) {
+	for conn := range wsClients {
+		if !wsClients[conn].SendUpdates {
+			continue
+		}
+		jsonData, _ := json.Marshal(WebsocketResponse{Type: "portChange", ResponseData: port})
+		conn.WriteMessage(1, jsonData)
+	}
+}
+
+func onPortListChange() {
+	for conn := range wsClients {
+		if !wsClients[conn].SendUpdates {
+			continue
+		}
+		jsonData, _ := json.Marshal(WebsocketResponse{
+			Type:         "postListChange",
+			ResponseData: gin.H{"inputs": portConfig.Input, "outputs": portConfig.Output},
+		})
+		conn.WriteMessage(1, jsonData)
+	}
+}