websocket backend + frontend patching.

services/httpapiv1/service.go

@@ -8,10 +8,12 @@ import (
 	"git.aiterp.net/lucifer3/server/services/script"
 	"git.aiterp.net/lucifer3/server/services/uistate"
 	"github.com/google/uuid"
+	"github.com/gorilla/websocket"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 	"log"
 	"net"
+	"net/http"
 	"sync"
 )
 
@@ -24,6 +26,11 @@ var zeroUUID = uuid.UUID{
 
 func New(addr string) (lucifer3.Service, error) {
 	svc := &service{}
+	upgrader := websocket.Upgrader{
+		CheckOrigin: func(r *http.Request) bool {
+			return true
+		},
+	}
 
 	e := echo.New()
 	e.HideBanner = true
@@ -38,6 +45,28 @@ func New(addr string) (lucifer3.Service, error) {
 		return c.JSON(200, data)
 	})
 
+	e.GET("/subscribe", func(c echo.Context) error {
+		ws, err := upgrader.Upgrade(c.Response(), c.Request(), nil)
+		if err != nil {
+			return err
+		}
+
+		sub := make(chan uistate.Patch, 64)
+		svc.addSub(sub)
+
+		defer svc.removeSub(sub)
+		defer ws.Close()
+
+		for patch := range sub {
+			err := ws.WriteJSON(patch)
+			if err != nil {
+				break
+			}
+		}
+
+		return nil
+	})
+
 	e.POST("/command", func(c echo.Context) error {
 		var input commandInput
 		err := c.Bind(&input)
@@ -115,6 +144,7 @@ type service struct {
 	mu   sync.Mutex
 	data uistate.Data
 	bus  *lucifer3.EventBus
+	subs []chan uistate.Patch
 }
 
 func (s *service) Active() bool {
@@ -130,12 +160,36 @@ func (s *service) HandleEvent(bus *lucifer3.EventBus, event lucifer3.Event) {
 	case uistate.Patch:
 		s.mu.Lock()
 		s.data = s.data.WithPatch(event)
+		subs := s.subs
 		s.mu.Unlock()
 
-		// TODO: Broadcast websockets
+		for _, sub := range subs {
+			select {
+			case sub <- event:
+			default:
+			}
+		}
 	}
 }
 
+func (s *service) addSub(ch chan uistate.Patch) {
+	s.mu.Lock()
+	s.subs = append(s.subs, ch)
+	s.mu.Unlock()
+}
+
+func (s *service) removeSub(ch chan uistate.Patch) {
+	s.mu.Lock()
+	s.subs = append([]chan uistate.Patch{}, s.subs...)
+	for i, sub := range s.subs {
+		if sub == ch {
+			s.subs = append(s.subs[:i], s.subs[i+1:]...)
+			break
+		}
+	}
+	s.mu.Unlock()
+}
+
 type commandInput struct {
 	Assign        *assignInput            `json:"assign,omitempty"`
 	AddAlias      *commands.AddAlias      `json:"addAlias,omitempty"`