fix(channelplan): score current DFS channel and clarify empty state (#518) (#520)

Co-authored-by: gnacho <hnacho@proton.me>

Author: gnacho

app/node_modules

@@ -0,0 +1 @@
+/home/nacho/temp/opencode-work/netpulse-511/app/node_modules

app/public/locales/en/translation.json

@@ -1400,7 +1400,7 @@
     "currentChannel": "Current channel",
     "recommendedChannel": "Recommended channel",
     "neighbors": "Neighbor APs",
-    "noScans": "No recent scans. Enable the agent on a router to collect neighbors.",
+    "noScans": "No recent scans for this router. Routers running NetGrip (gateway, APs managed by its panel) do not scan neighbors; routers with the NetPulse agent do. Pick another router from the list (e.g. rt2 or rt4) to see its plan.",
     "noRadios": "This router does not report WiFi radios.",
     "apply": "Apply channel",
     "gateway": " (Gateway)",

app/public/locales/es/translation.json

@@ -1400,7 +1400,7 @@
     "currentChannel": "Canal actual",
     "recommendedChannel": "Canal recomendado",
     "neighbors": "APs vecinos",
-    "noScans": "No hay scans recientes. Activa el agente en un router para recoger vecinos.",
+    "noScans": "Sin escaneos recientes para este router. Los routers que corren NetGrip (gateway, APs gestionados por su panel) no escanean vecinos; los que llevan el agente NetPulse sí. Selecciona otro router de la lista (p. ej. rt2 o rt4) para ver su plan.",
     "noRadios": "Este dispositivo no reporta radios WiFi.",
     "apply": "Aplicar canal",
     "gateway": " (Puerta de enlace)",

server-go/internal/channelplan/store.go

@@ -165,6 +165,13 @@ func (s *Store) Recommend(routerID string, radios []probe.Radio, within time.Dur
 				bestCh = ch
 			}
 		}
+		// #518: el canal ACTUAL puede ser DFS (52/100/112/116...) y no estar en
+		// candidateChannels (solo no-DFS para recomendar). Su score es
+		// informativo ("cuánto ruido tengo ahora") y debe calcularse igual,
+		// no quedarse en MaxInt y pintar 9223372036854775807 en la UI.
+		if currentScore == math.MaxInt {
+			currentScore = channelScore(byBand[band], r.Channel)
+		}
 		if bestCh != 0 && bestScore != math.MaxInt {
 			rec.Recommended = bestCh
 			rec.CurrentScore = currentScore

server-go/internal/channelplan/store_test.go

@@ -188,3 +188,44 @@ func TestRecommendPasaSeccion(t *testing.T) {
 		t.Errorf("sin sección el iface debe caer al placeholder: %+v", *nosec)
 	}
 }
+
+func TestRecommendCurrentDfsChannelScoreNotMaxInt(t *testing.T) {
+	// #518: si el canal ACTUAL es DFS (112) y no está en candidateChannels
+	// (solo no-DFS), su score debe calcularse igual (es informativo) y no
+	// quedarse en MaxInt (la UI pintaba 9223372036854775807).
+	d, err := db.Open(t.TempDir())
+	if err != nil {
+		t.Fatalf("db: %v", err)
+	}
+	defer d.Close()
+
+	st := channelplan.NewStore(d.DB)
+	now := time.Now().Unix()
+	scans := []probe.ScanResult{
+		{Iface: "wlan1", BSSID: "aa:bb:cc:dd:ee:01", SSID: "V", Channel: 112, Freq: 5560, Signal: -60},
+		{Iface: "wlan1", BSSID: "aa:bb:cc:dd:ee:02", SSID: "W", Channel: 44, Freq: 5220, Signal: -55},
+		{Iface: "wlan1", BSSID: "aa:bb:cc:dd:ee:03", SSID: "X", Channel: 116, Freq: 5580, Signal: -70},
+	}
+	if err := st.SaveScan("rt1", now, scans); err != nil {
+		t.Fatalf("save: %v", err)
+	}
+
+	radios := []probe.Radio{{Name: "5 GHz", Channel: 112, WidthMhz: 80}}
+	recs, err := st.Recommend("rt1", radios, time.Hour)
+	if err != nil {
+		t.Fatalf("recommend: %v", err)
+	}
+	if len(recs) != 1 {
+		t.Fatalf("esperaba 1 radio, got %d", len(recs))
+	}
+	rec := recs[0]
+	if rec.CurrentScore > 1_000_000_000_000 {
+		t.Fatalf("currentScore no debe ser MaxInt (canal DFS): %d", rec.CurrentScore)
+	}
+	if rec.Recommended == 112 {
+		t.Errorf("no debería recomendar el DFS 112 ocupado: %+v", rec)
+	}
+	if rec.Recommended != 36 {
+		t.Errorf("debería recomendar el 36 libre (no-DFS), got %d", rec.Recommended)
+	}
+}