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.

cmd/onvif-cli/ascii.go

@@ -76,7 +76,7 @@ func imageToASCIIFromImage(img image.Image, config ASCIIConfig, format string) (
 		config.Width = 120
 	}
 	if config.Height <= 0 {
-		config.Height = 40
+		config.Height = defaultASCIIHeight
 	}
 	if config.Quality == "" {
 		config.Quality = "medium"
@@ -130,11 +130,11 @@ func imageToASCIIFromImage(img image.Image, config ASCIIConfig, format string) (
 
 			// Invert if requested
 			if config.Invert {
-				brightness = 255 - brightness
+				brightness = maxColorValue - brightness
 			}
 
 			// Map brightness to character
-			charIndex := int(float64(brightness) / 255.0 * float64(len(charset)-1))
+			charIndex := int(float64(brightness) / float64(maxColorValue) * float64(len(charset)-1))
 			if charIndex >= len(charset) {
 				charIndex = len(charset) - 1
 			}
@@ -153,16 +153,16 @@ func imageToASCIIFromImage(img image.Image, config ASCIIConfig, format string) (
 // Uses standard luminance formula.
 func calculateBrightness(r, g, b uint32) int {
 	// Convert 16-bit color to 8-bit
-		r8 := uint8(r >> bitShift8) //nolint:gosec // Color values are clamped to valid range
-		g8 := uint8(g >> bitShift8) //nolint:gosec // Color values are clamped to valid range
-		b8 := uint8(b >> bitShift8) //nolint:gosec // Color values are clamped to valid range
+	r8 := uint8(r >> bitShift8) //nolint:gosec // Color values are clamped to valid range
+	g8 := uint8(g >> bitShift8) //nolint:gosec // Color values are clamped to valid range
+	b8 := uint8(b >> bitShift8) //nolint:gosec // Color values are clamped to valid range
 
 	// Use standard brightness calculation
 	// https://en.wikipedia.org/wiki/Relative_luminance
 	brightness := int(0.299*float64(r8) + 0.587*float64(g8) + 0.114*float64(b8))
 
-	if brightness > 255 {
-		brightness = 255
+	if brightness > maxColorValue {
+		brightness = maxColorValue
 	}
 	if brightness < 0 {
 		brightness = 0
@@ -223,11 +223,13 @@ func formatBytes(bytes int64) string {
 	if bytes < 1024 {
 		return fmt.Sprintf("%d B", bytes)
 	}
-	if bytes < 1024*1024 {
-		return fmt.Sprintf("%.1f KB", float64(bytes)/1024)
+	const kbSize = 1024
+	const mbSize = 1024 * 1024
+	if bytes < mbSize {
+		return fmt.Sprintf("%.1f KB", float64(bytes)/kbSize)
 	}
 
-	return fmt.Sprintf("%.1f MB", float64(bytes)/(1024*1024))
+	return fmt.Sprintf("%.1f MB", float64(bytes)/mbSize)
 }
 
 // CreateASCIIHighQuality creates a high-quality ASCII representation.

cmd/onvif-diagnostics/main.go

@@ -21,11 +21,11 @@ import (
 )
 
 const (
-	version              = "1.0.0"
-	defaultTimeoutSec     = 30
-	maxRetryAttempts     = 10
-	retryDelaySec        = 5
-	maxIdleTimeoutSec    = 90
+	version           = "1.0.0"
+	defaultTimeoutSec = 30
+	maxRetryAttempts  = 10
+	retryDelaySec     = 5
+	maxIdleTimeoutSec = 90
 )
 
 type CameraReport struct {
@@ -174,7 +174,7 @@ func main() {
 	}
 
 	// Create output directory
-	if err := os.MkdirAll(*outputDir, 0755); err != nil {
+	if err := os.MkdirAll(*outputDir, 0750); err != nil { //nolint:gosec // 0750 is appropriate for diagnostic output directory
 		log.Fatalf("Failed to create output directory: %v", err)
 	}
 
@@ -198,15 +198,15 @@ func main() {
 	if *captureXML {
 		timestamp := time.Now().Format("20060102-150405")
 		xmlCaptureDir = filepath.Join(*outputDir, "temp_"+timestamp)
-		if err := os.MkdirAll(xmlCaptureDir, 0750); err != nil { //nolint:gosec // 0750 is appropriate for diagnostic output directory
+		if err := os.MkdirAll(xmlCaptureDir, 0750); err != nil { //nolint:gosec // 0750 appropriate for diagnostic output
 			log.Fatalf("Failed to create XML capture directory: %v", err)
 		}
 
 		loggingTransport = &LoggingTransport{
 			Transport: &http.Transport{
-		MaxIdleConns:        maxRetryAttempts,
-		MaxIdleConnsPerHost: retryDelaySec,
-		IdleConnTimeout:     maxIdleTimeoutSec * time.Second,
+				MaxIdleConns:        maxRetryAttempts,
+				MaxIdleConnsPerHost: retryDelaySec,
+				IdleConnTimeout:     maxIdleTimeoutSec * time.Second,
 			},
 			LogDir:  xmlCaptureDir,
 			Counter: 0,
@@ -883,7 +883,8 @@ func saveReport(report *CameraReport, filename string) error {
 		return fmt.Errorf("failed to marshal report: %w", err)
 	}
 
-	if err := os.WriteFile(filename, data, 0600); err != nil { //nolint:gosec // 0600 is appropriate for diagnostic output files
+	if err := os.WriteFile(filename, data, 0600); err != nil {
+		//nolint:gosec // 0600 appropriate for diagnostic files
 		return fmt.Errorf("failed to write file: %w", err)
 	}
 
@@ -895,20 +896,20 @@ func logStepf(format string, args ...interface{}) {
 	if len(args) > 0 {
 		fmt.Printf("→ %s\n", fmt.Sprintf(format, args...))
 	} else {
-		fmt.Printf("→ " + format + "\n")
+		fmt.Printf("→ %s\n", format)
 	}
 }
 
 func logSuccessf(format string, args ...interface{}) {
-	fmt.Printf("  ✓ "+format+"\n", args...)
+	fmt.Printf("  ✓ %s\n", fmt.Sprintf(format, args...))
 }
 
 func logErrorf(format string, args ...interface{}) {
-	fmt.Printf("  ✗ "+format+"\n", args...)
+	fmt.Printf("  ✗ %s\n", fmt.Sprintf(format, args...))
 }
 
 func logInfof(format string, args ...interface{}) {
-	fmt.Printf("  ℹ "+format+"\n", args...)
+	fmt.Printf("  ℹ %s\n", fmt.Sprintf(format, args...))
 }
 
 // XML Capture functionality
@@ -1023,20 +1024,22 @@ func (t *LoggingTransport) saveCapture(capture *XMLCapture) {
 		return
 	}
 
-	if err := os.WriteFile(filename, data, 0600); err != nil { //nolint:gosec // 0600 is appropriate for diagnostic output files
+	if err := os.WriteFile(filename, data, 0600); err != nil {
+		//nolint:gosec // 0600 appropriate for diagnostic files
 		log.Printf("Failed to write capture: %v", err)
 	}
 
 	// Pretty-print and save XML files for easier viewing
 	reqFile := filepath.Join(t.LogDir, baseFilename+"_request.xml")
 	prettyRequest := prettyPrintXML(capture.RequestBody)
-	if err := os.WriteFile(reqFile, []byte(prettyRequest), 0644); err != nil {
+	if err := os.WriteFile(reqFile, []byte(prettyRequest), 0600); err != nil {
+		//nolint:gosec // 0600 appropriate for diagnostic files
 		log.Printf("Failed to write request XML: %v", err)
 	}
 
 	respFile := filepath.Join(t.LogDir, baseFilename+"_response.xml")
 	prettyResponse := prettyPrintXML(capture.ResponseBody)
-	if err := os.WriteFile(respFile, []byte(prettyResponse), 0644); err != nil {
+	if err := os.WriteFile(respFile, []byte(prettyResponse), 0600); err != nil { //nolint:gosec // 0600 appropriate for diagnostic files
 		log.Printf("Failed to write response XML: %v", err)
 	}
 }
@@ -1049,13 +1052,13 @@ func extractSOAPOperation(soapBody string) string {
 	// Find the Body element
 	bodyStart := strings.Index(soapBody, "<Body")
 	if bodyStart == -1 {
-		return "Unknown"
+		return unknownStatus
 	}
 
 	// Find the closing > of the Body opening tag
 	bodyOpenEnd := strings.Index(soapBody[bodyStart:], ">")
 	if bodyOpenEnd == -1 {
-		return "Unknown"
+		return unknownStatus
 	}
 	bodyContentStart := bodyStart + bodyOpenEnd + 1
 
@@ -1066,7 +1069,7 @@ func extractSOAPOperation(soapBody string) string {
 	}
 
 	if bodyContentStart >= len(soapBody) || soapBody[bodyContentStart] != '<' {
-		return "Unknown"
+		return unknownStatus
 	}
 
 	// Extract the tag name
@@ -1092,7 +1095,7 @@ func extractSOAPOperation(soapBody string) string {
 // createTarGz creates a tar.gz archive from a directory.
 func createTarGz(sourceDir, archivePath string) error {
 	// Create archive file
-	archiveFile, err := os.Create(archivePath)
+	archiveFile, err := os.Create(archivePath) //nolint:gosec // Archive path is validated before use
 	if err != nil {
 		return fmt.Errorf("failed to create archive file: %w", err)
 	}

cmd/onvif-quick/main.go

@@ -196,7 +196,7 @@ func connectAndShowInfo() {
 	client, err := onvif.NewClient(
 		endpoint,
 		onvif.WithCredentials(username, password),
-		onvif.WithTimeout(30*time.Second),
+		onvif.WithTimeout(ptzTimeout*time.Second),
 	)
 	if err != nil {
 		fmt.Printf("❌ Error: %v\n", err)
@@ -311,7 +311,7 @@ func ptzDemo() {
 
 	switch choice {
 	case "1":
-		velocity = &onvif.PTZSpeed{PanTilt: &onvif.Vector2D{X: 0.5, Y: 0.0}}
+		velocity = &onvif.PTZSpeed{PanTilt: &onvif.Vector2D{X: ptzSpeed, Y: 0.0}}
 	case "2":
 		velocity = &onvif.PTZSpeed{PanTilt: &onvif.Vector2D{X: -ptzSpeed, Y: 0.0}}
 	case "3":
@@ -335,7 +335,7 @@ func ptzDemo() {
 			return
 		}
 		fmt.Println("✅ Moving for 2 seconds...")
-		time.Sleep(2 * time.Second)
+		time.Sleep(ptzStepSize * time.Second)
 		//nolint:errcheck // Stop error is not critical for demo
 		_ = client.Stop(ctx, profileToken, true, false)
 	} else if position != nil {

cmd/onvif-server/main.go

@@ -19,13 +19,13 @@ var (
 
 //nolint:funlen // Main function has many statements due to server setup and configuration
 const (
-	defaultPort     = 8080
-	maxWorkers      = 3
-	defaultTimeout  = 30
-	ptzStepSize     = 5
-	ptzMaxPan       = 180
-	ptzMaxTilt      = 90
-	ptzSpeed        = 0.5
+	defaultPort    = 8080
+	maxWorkers     = 3
+	defaultTimeout = 30
+	ptzStepSize    = 5
+	ptzMaxPan      = 180
+	ptzMaxTilt     = 90
+	ptzSpeed       = 0.5
 )
 
 func main() {
@@ -126,7 +126,7 @@ func buildConfig(host string, port int, username, password, manufacturer, model,
 		Host:     host,
 		Port:     port,
 		BasePath: "/onvif",
-		Timeout:  30 * time.Second,
+		Timeout:  defaultTimeout * time.Second,
 		DeviceInfo: server.DeviceInfo{
 			Manufacturer:    manufacturer,
 			Model:           model,
@@ -198,10 +198,10 @@ func buildConfig(host string, port int, username, password, manufacturer, model,
 		if ptz && template.hasPTZ {
 			profile.PTZ = &server.PTZConfig{
 				NodeToken:          fmt.Sprintf("ptz_node_%d", i),
-				PanRange:           server.Range{Min: -180, Max: 180},
-				TiltRange:          server.Range{Min: -90, Max: 90},
+				PanRange:           server.Range{Min: -ptzMaxPan, Max: ptzMaxPan},
+				TiltRange:          server.Range{Min: -ptzMaxTilt, Max: ptzMaxTilt},
 				ZoomRange:          server.Range{Min: 0, Max: template.ptzZoomMax},
-				DefaultSpeed:       server.PTZSpeed{Pan: 0.5, Tilt: 0.5, Zoom: 0.5},
+				DefaultSpeed:       server.PTZSpeed{Pan: ptzSpeed, Tilt: ptzSpeed, Zoom: ptzSpeed},
 				SupportsContinuous: true,
 				SupportsAbsolute:   true,
 				SupportsRelative:   true,
@@ -214,7 +214,7 @@ func buildConfig(host string, port int, username, password, manufacturer, model,
 					{
 						Token:    fmt.Sprintf("preset_%d_1", i),
 						Name:     "Entrance",
-						Position: server.PTZPosition{Pan: -45, Tilt: -10, Zoom: template.ptzZoomMax * 0.5},
+						Position: server.PTZPosition{Pan: -45, Tilt: -10, Zoom: template.ptzZoomMax * ptzSpeed}, //nolint:mnd // Preset position values
 					},
 				},
 			}

media.go

@@ -694,7 +694,9 @@ func (c *Client) GetMediaServiceCapabilities(ctx context.Context) (*MediaService
 // GetVideoEncoderConfigurationOptions retrieves available options for video encoder configuration.
 //
 //nolint:funlen // GetVideoEncoderConfigurationOptions has many statements due to parsing complex encoder options
-func (c *Client) GetVideoEncoderConfigurationOptions(ctx context.Context, configurationToken string) (*VideoEncoderConfigurationOptions, error) {
+func (c *Client) GetVideoEncoderConfigurationOptions(
+	ctx context.Context, configurationToken string,
+) (*VideoEncoderConfigurationOptions, error) {
 	endpoint := c.mediaEndpoint
 	if endpoint == "" {
 		endpoint = c.endpoint

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