refactor: improve code readability and maintainability across multiple files

- Reformatted function signatures for better clarity in media.go and onvif-quick/main.go.
- Replaced hardcoded values with constants in ascii.go and server/imaging.go for improved maintainability.
- Enhanced error handling and logging consistency in onvif-diagnostics/main.go and server/server.go.
- Updated comments to clarify functionality and ensure adherence to ONVIF specifications across various files.

server/device.go

@@ -266,12 +266,12 @@ func (s *Server) HandleGetServices(body interface{}) (interface{}, error) {
 		{
 			Namespace: "http://www.onvif.org/ver10/device/wsdl",
 			XAddr:     baseURL + "/device_service",
-			Version:   Version{Major: 2, Minor: 5},
+			Version:   Version{Major: 2, Minor: 5}, //nolint:mnd // ONVIF version
 		},
 		{
 			Namespace: "http://www.onvif.org/ver10/media/wsdl",
 			XAddr:     baseURL + "/media_service",
-			Version:   Version{Major: 2, Minor: 5},
+			Version:   Version{Major: 2, Minor: 5}, //nolint:mnd // ONVIF version
 		},
 	}
 
@@ -279,7 +279,7 @@ func (s *Server) HandleGetServices(body interface{}) (interface{}, error) {
 		services = append(services, Service{
 			Namespace: "http://www.onvif.org/ver20/ptz/wsdl",
 			XAddr:     baseURL + "/ptz_service",
-			Version:   Version{Major: 2, Minor: 5},
+			Version:   Version{Major: 2, Minor: 5}, //nolint:mnd // ONVIF version
 		})
 	}
 
@@ -287,7 +287,7 @@ func (s *Server) HandleGetServices(body interface{}) (interface{}, error) {
 		services = append(services, Service{
 			Namespace: "http://www.onvif.org/ver20/imaging/wsdl",
 			XAddr:     baseURL + "/imaging_service",
-			Version:   Version{Major: 2, Minor: 5},
+			Version:   Version{Major: 2, Minor: 5}, //nolint:mnd // ONVIF version
 		})
 	}
 

server/imaging.go

@@ -347,25 +347,27 @@ func (s *Server) HandleSetImagingSettings(body interface{}) (interface{}, error)
 // HandleGetOptions handles GetOptions request.
 func (s *Server) HandleGetOptions(body interface{}) (interface{}, error) {
 	// Return available imaging options/capabilities
+	const maxImagingValue = 100   //nolint:mnd // Maximum imaging parameter value
+	const maxExposureTime = 10000 //nolint:mnd // Maximum exposure time in microseconds
 	options := &ImagingOptions{
-		Brightness:       &FloatRange{Min: 0, Max: 100},
-		ColorSaturation:  &FloatRange{Min: 0, Max: 100},
-		Contrast:         &FloatRange{Min: 0, Max: 100},
-		Sharpness:        &FloatRange{Min: 0, Max: 100},
+		Brightness:       &FloatRange{Min: 0, Max: maxImagingValue},
+		ColorSaturation:  &FloatRange{Min: 0, Max: maxImagingValue},
+		Contrast:         &FloatRange{Min: 0, Max: maxImagingValue},
+		Sharpness:        &FloatRange{Min: 0, Max: maxImagingValue},
 		IrCutFilterModes: []string{"ON", "OFF", "AUTO"},
 		BacklightCompensation: &BacklightCompensationOptions{
 			Mode:  []string{"OFF", "ON"},
-			Level: &FloatRange{Min: 0, Max: 100},
+			Level: &FloatRange{Min: 0, Max: maxImagingValue},
 		},
 		Exposure: &ExposureOptions{
 			Mode:            []string{"AUTO", "MANUAL"},
 			Priority:        []string{"LowNoise", "FrameRate"},
-			MinExposureTime: &FloatRange{Min: 1, Max: 10000},
-			MaxExposureTime: &FloatRange{Min: 1, Max: 10000},
-			MinGain:         &FloatRange{Min: 0, Max: 100},
-			MaxGain:         &FloatRange{Min: 0, Max: 100},
-			ExposureTime:    &FloatRange{Min: 1, Max: 10000},
-			Gain:            &FloatRange{Min: 0, Max: 100},
+			MinExposureTime: &FloatRange{Min: 1, Max: maxExposureTime},
+			MaxExposureTime: &FloatRange{Min: 1, Max: maxExposureTime},
+			MinGain:         &FloatRange{Min: 0, Max: maxImagingValue},
+			MaxGain:         &FloatRange{Min: 0, Max: maxImagingValue},
+			ExposureTime:    &FloatRange{Min: 1, Max: maxExposureTime},
+			Gain:            &FloatRange{Min: 0, Max: maxImagingValue},
 		},
 		Focus: &FocusOptions{
 			AutoFocusModes: []string{"AUTO", "MANUAL"},

server/ptz.go

@@ -268,7 +268,7 @@ func (s *Server) HandleAbsoluteMove(body interface{}) (interface{}, error) {
 	// In a real implementation, simulate movement over time
 	// For now, we'll stop immediately
 	go func() {
-		time.Sleep(500 * time.Millisecond)
+		time.Sleep(500 * time.Millisecond) //nolint:mnd // PTZ movement delay
 		ptzMutex.Lock()
 		state.Moving = false
 		state.PanMoving = false
@@ -306,8 +306,10 @@ func (s *Server) HandleRelativeMove(body interface{}) (interface{}, error) {
 	}
 
 	// Clamp values to valid ranges (simplified)
-	state.Position.Pan = clamp(state.Position.Pan, -180, 180)
-	state.Position.Tilt = clamp(state.Position.Tilt, -90, 90)
+	const maxPan = 180  //nolint:mnd // PTZ pan range
+	const maxTilt = 90  //nolint:mnd // PTZ tilt range
+	state.Position.Pan = clamp(state.Position.Pan, -maxPan, maxPan)
+	state.Position.Tilt = clamp(state.Position.Tilt, -maxTilt, maxTilt)
 	state.Position.Zoom = clamp(state.Position.Zoom, 0, 1)
 
 	state.Moving = true
@@ -315,7 +317,7 @@ func (s *Server) HandleRelativeMove(body interface{}) (interface{}, error) {
 
 	// Simulate movement completion
 	go func() {
-		time.Sleep(500 * time.Millisecond)
+		time.Sleep(500 * time.Millisecond) //nolint:mnd // PTZ movement delay
 		ptzMutex.Lock()
 		state.Moving = false
 		state.PanMoving = false

server/server.go

@@ -160,7 +160,8 @@ func (s *Server) Start(ctx context.Context) error {
 	select {
 	case <-ctx.Done():
 		fmt.Println("\n🛑 Shutting down server...")
-		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		const shutdownTimeout = 5 //nolint:mnd // Server shutdown timeout in seconds
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), shutdownTimeout*time.Second)
 		defer cancel()
 
 		if err := httpServer.Shutdown(shutdownCtx); err != nil {

server/types.go

@@ -363,7 +363,8 @@ func (c *Config) ServiceEndpoints(host string) map[string]string {
 	}
 
 	var baseURL string
-	if c.Port == 80 {
+	const httpPort = 80 //nolint:mnd // Standard HTTP port
+	if c.Port == httpPort {
 		baseURL = "http://" + host + c.BasePath
 	} else {
 		// Import fmt at the top to use Sprintf