phase 10

internal/server/server.go

@@ -10,6 +10,7 @@ import (
 	"github.com/uopi/uopi/internal/api"
 	"github.com/uopi/uopi/internal/broker"
 	"github.com/uopi/uopi/internal/datasource/synthetic"
+	"github.com/uopi/uopi/internal/metrics"
 	"github.com/uopi/uopi/internal/storage"
 )
 
@@ -22,7 +23,7 @@ type Server struct {
 
 // New creates the HTTP server, registers all routes, and returns a ready-to-start Server.
 // synth may be nil if the synthetic data source is not enabled.
-func New(addr string, webFS fs.FS, brk *broker.Broker, synth *synthetic.Synthetic, store *storage.Store, log *slog.Logger) *Server {
+func New(addr string, webFS fs.FS, brk *broker.Broker, synth *synthetic.Synthetic, store *storage.Store, channelFinderURL string, log *slog.Logger) *Server {
 	mux := http.NewServeMux()
 
 	// Health check
@@ -34,8 +35,11 @@ func New(addr string, webFS fs.FS, brk *broker.Broker, synth *synthetic.Syntheti
 	// WebSocket endpoint
 	mux.Handle("/ws", &wsHandler{broker: brk, log: log})
 
+	// Prometheus-format metrics
+	mux.HandleFunc("/metrics", metrics.Handler(brk.ActiveSubscriptions))
+
 	// REST API
-	api.New(brk, synth, store, log).Register(mux, apiPrefix)
+	api.New(brk, synth, store, channelFinderURL, log).Register(mux, apiPrefix)
 
 	// Embedded frontend — must be last (catch-all)
 	mux.Handle("/", http.FileServerFS(webFS))

internal/server/ws.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/uopi/uopi/internal/broker"
 	"github.com/uopi/uopi/internal/datasource"
+	"github.com/uopi/uopi/internal/metrics"
 )
 
 // ── Incoming message types ────────────────────────────────────────────────────
@@ -95,6 +96,8 @@ func (h *wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.log.Error("ws accept failed", "err", err)
 		return
 	}
+	metrics.IncWsConns()
+	defer metrics.DecWsConns()
 
 	ctx, cancel := context.WithCancel(r.Context())
 	defer cancel()
@@ -191,6 +194,7 @@ func (c *wsClient) writeLoop(ctx context.Context) {
 			if err := c.conn.Write(ctx, websocket.MessageText, msg); err != nil {
 				return
 			}
+			metrics.IncMsgOut()
 		case <-ctx.Done():
 			return
 		}
@@ -199,6 +203,7 @@ func (c *wsClient) writeLoop(ctx context.Context) {
 
 // handleMessage parses and routes a single incoming client message.
 func (c *wsClient) handleMessage(ctx context.Context, data []byte) {
+	metrics.IncMsgIn()
 	var msg inMsg
 	if err := json.Unmarshal(data, &msg); err != nil {
 		c.sendError(ctx, "PARSE_ERROR", "invalid JSON: "+err.Error())
@@ -264,6 +269,17 @@ func (c *wsClient) handleWrite(ctx context.Context, msg inMsg) {
 		return
 	}
 
+	// Enforce write permission before touching the value payload.
+	meta, err := ds.GetMetadata(ctx, msg.Name)
+	if err != nil {
+		c.sendError(ctx, "NOT_FOUND", "unknown signal: "+msg.Name)
+		return
+	}
+	if !meta.Writable {
+		c.sendError(ctx, "NOT_WRITABLE", "signal is read-only: "+msg.Name)
+		return
+	}
+
 	// Decode the JSON value as the appropriate Go type.
 	var value any
 	if err := json.Unmarshal(msg.Value, &value); err != nil {
@@ -271,12 +287,14 @@ func (c *wsClient) handleWrite(ctx context.Context, msg inMsg) {
 		return
 	}
 
+	metrics.IncWrites()
 	if err := ds.Write(ctx, msg.Name, value); err != nil {
 		c.sendError(ctx, "WRITE_ERROR", err.Error())
 	}
 }
 
 func (c *wsClient) handleHistory(ctx context.Context, msg inMsg) {
+	metrics.IncHistoryReqs()
 	ds, ok := c.broker.Source(msg.DS)
 	if !ok {
 		c.sendError(ctx, "NOT_FOUND", "unknown data source: "+msg.DS)