fix: Blockly device_property dropdown shows all device properties

When a device has no Thing Description (or one without a 'properties' object),
the /rules/discovery endpoint now falls back to inferring properties from the
device's ShadowState (actual telemetry keys received from the device).
Previously only 'Connection Status' appeared for non-greenhouse device types.

- discovery.go: inferPropertiesFromState() infers property names and types
  (number/boolean/string) from ShadowState keys when TD has no properties.
- handlers_test.go: TestDiscoverDevices_ShadowStateFallback covers the fallback
  path including type inference for float64 (number) and bool (boolean).

Author: tevfik

internal/api/rules/discovery.go

@@ -58,6 +58,12 @@ func (h *Handler) DiscoverDevices(c *gin.Context) {
 	for _, dev := range devices {
 		props := extractProperties(dev.ThingDescription)
 
+		// Fallback: if Thing Description has no properties, infer from ShadowState.
+		// This covers devices registered without a TD but that have sent telemetry.
+		if len(props) == 0 {
+			props = inferPropertiesFromState(dev.ShadowState)
+		}
+
 		// Add basic common properties if not present
 		hasStatus := false
 		for _, p := range props {
@@ -128,6 +134,31 @@ func extractProperties(td map[string]interface{}) []DevicePropertyInfo {
 	return result
 }
 
+// inferPropertiesFromState creates property definitions from a device's shadow state.
+// Keys become property names; Go types are mapped to WoT types (number/boolean/string).
+func inferPropertiesFromState(state map[string]interface{}) []DevicePropertyInfo {
+	if len(state) == 0 {
+		return nil
+	}
+	result := make([]DevicePropertyInfo, 0, len(state))
+	for key, val := range state {
+		propType := "string"
+		switch val.(type) {
+		case float64, int64:
+			propType = "number"
+		case bool:
+			propType = "boolean"
+		}
+		result = append(result, DevicePropertyInfo{
+			Key:      key,
+			Title:    key,
+			Type:     propType,
+			ReadOnly: true,
+		})
+	}
+	return result
+}
+
 // getStringField safely extracts a string field from a map.
 func getStringField(m map[string]interface{}, key, fallback string) string {
 	if v, ok := m[key].(string); ok {

internal/api/rules/handlers_test.go

@@ -394,6 +394,57 @@ func TestDiscoverDevices_WithDevices(t *testing.T) {
 	}
 }
 
+// TestDiscoverDevices_ShadowStateFallback verifies that when a device has no
+// ThingDescription, properties are inferred from its ShadowState telemetry keys.
+func TestDiscoverDevices_ShadowStateFallback(t *testing.T) {
+	store := newTestStore()
+	store.userDevices = []storage.Device{
+		{
+			ID:   "custom-sensor",
+			Name: "Custom Sensor",
+			Type: "custom",
+			ShadowState: map[string]interface{}{
+				"temperature": 22.5,
+				"humidity":    65.0,
+				"active":      true,
+			},
+		},
+	}
+	r := setupTestRouterWithUserAndStore(store, "user-1")
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest("GET", "/admin/rules/discovery", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+
+	var result map[string]interface{}
+	json.Unmarshal(w.Body.Bytes(), &result)
+	devs := result["devices"].([]interface{})
+	dev := devs[0].(map[string]interface{})
+	props := dev["properties"].([]interface{})
+
+	// Should have 3 shadow keys + 1 status fallback = 4
+	if len(props) < 4 {
+		t.Fatalf("expected at least 4 properties (3 shadow + status), got %d: %v", len(props), props)
+	}
+
+	// Verify type inference: temperature and humidity should be "number"
+	propMap := make(map[string]string)
+	for _, p := range props {
+		pm := p.(map[string]interface{})
+		propMap[pm["key"].(string)] = pm["type"].(string)
+	}
+	if propMap["temperature"] != "number" {
+		t.Errorf("temperature type: want number, got %s", propMap["temperature"])
+	}
+	if propMap["active"] != "boolean" {
+		t.Errorf("active type: want boolean, got %s", propMap["active"])
+	}
+}
+
 func TestDiscoverDevices_Empty(t *testing.T) {
 	store := newTestStore() // no devices
 	r := setupTestRouterWithUserAndStore(store, "user-xyz")