fix bug with empty buttons array being mistaken as [], and add /api/devices/batch.

app/api/devices.go

@@ -30,6 +30,57 @@ func Devices(r gin.IRoutes) {
 		return fetchDevices(ctxOf(c), c.Param("fetch"))
 	}))
 
+	r.PUT("/batch", handler(func(c *gin.Context) (interface{}, error) {
+		var body []struct {
+			Fetch    string `json:"fetch"`
+			SetState models.NewDeviceState `json:"setState"`
+		}
+		err := parseBody(c, &body)
+		if err != nil {
+			return nil, err
+		}
+
+		set := make(map[int]bool)
+		changed := make([]models.Device, 0, 64)
+		for _, job := range body {
+			devices, err := fetchDevices(ctxOf(c), job.Fetch)
+			if err != nil {
+				return nil, err
+			}
+			if len(devices) == 0 {
+				return []models.Device{}, nil
+			}
+
+			for i := range devices {
+				if set[devices[i].ID] {
+					continue
+				}
+
+				err := devices[i].SetState(job.SetState)
+				if err != nil {
+					return nil, err
+				}
+
+				set[devices[i].ID] = true
+				changed = append(changed, devices[i])
+			}
+		}
+
+		config.PublishChannel <- changed
+
+		go func() {
+			for _, device := range changed {
+				err := config.DeviceRepository().Save(context.Background(), &device)
+				if err != nil {
+					log.Println("Failed to save device for state:", err)
+					continue
+				}
+			}
+		}()
+
+		return changed, nil
+	}))
+
 	r.PUT("/:fetch/state", handler(func(c *gin.Context) (interface{}, error) {
 		state := models.NewDeviceState{}
 		err := parseBody(c, &state)