gowuh

pi/roverd/nightvision.go

@@ -0,0 +1,97 @@
+//go:build !dummy
+
+package roverd
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+
+	gpiocdev "github.com/warthog618/go-gpiocdev"
+)
+
+type NightVisionLight struct {
+	cfg    NightVisionConfig
+	logger *log.Logger
+	line   *gpiocdev.Line
+	mu     sync.Mutex
+	on     bool
+	closed bool
+}
+
+func NewNightVisionLight(cfg NightVisionConfig, logger *log.Logger) (*NightVisionLight, error) {
+	if !cfg.Enabled {
+		return nil, fmt.Errorf("night vision disabled")
+	}
+	chip := cfg.GPIOChip
+	if chip == "" {
+		chip = "gpiochip0"
+	}
+	initial := 0
+	if cfg.InitialOn {
+		initial = 1
+	}
+	line, err := gpiocdev.RequestLine(
+		chip,
+		cfg.GPIOPin,
+		gpiocdev.AsOutput(initial),
+		gpiocdev.WithConsumer("roverd-nightvision"),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("gpio request: %w", err)
+	}
+	nv := &NightVisionLight{
+		cfg:    cfg,
+		logger: logger,
+		line:   line,
+		on:     cfg.InitialOn,
+	}
+	logger.Printf("night vision LED on GPIO %d (initial=%v)", cfg.GPIOPin, cfg.InitialOn)
+	return nv, nil
+}
+
+func (n *NightVisionLight) Close() {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	if n.closed {
+		return
+	}
+	_ = n.line.SetValue(boolToGPIO(n.on))
+	n.line.Close()
+	n.closed = true
+}
+
+func (n *NightVisionLight) HandleAction(action string) error {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	if n.closed {
+		return fmt.Errorf("night vision controller closed")
+	}
+	act := strings.ToLower(strings.TrimSpace(action))
+	switch act {
+	case "", "toggle":
+		return n.setLocked(!n.on)
+	case "on":
+		return n.setLocked(true)
+	case "off":
+		return n.setLocked(false)
+	default:
+		return fmt.Errorf("unknown action %q", action)
+	}
+}
+
+func (n *NightVisionLight) setLocked(on bool) error {
+	if err := n.line.SetValue(boolToGPIO(on)); err != nil {
+		return err
+	}
+	n.on = on
+	return nil
+}
+
+func boolToGPIO(value bool) int {
+	if value {
+		return 1
+	}
+	return 0
+}