refactor: modernize Go code

cmd/analyze/format.go

@@ -93,15 +93,12 @@ func humanizeBytes(size int64) string {
 	return fmt.Sprintf("%.1f %cB", value, "KMGTPE"[exp])
 }
 
-func coloredProgressBar(value, max int64, percent float64) string {
+func coloredProgressBar(value, maxValue int64, percent float64) string {
-	if max <= 0 {
+	if maxValue <= 0 {
 		return colorGray + strings.Repeat("░", barWidth) + colorReset
 	}
 
-	filled := int((value * int64(barWidth)) / max)
+	filled := min(int((value*int64(barWidth))/maxValue), barWidth)
-	if filled > barWidth {
-		filled = barWidth
-	}
 
 	var barColor string
 	if percent >= 50 {
@@ -114,26 +111,27 @@ func coloredProgressBar(value, max int64, percent float64) string {
 		barColor = colorGreen
 	}
 
-	bar := barColor
+	var bar strings.Builder
-	for i := 0; i < barWidth; i++ {
+	bar.WriteString(barColor)
+	for i := range barWidth {
 		if i < filled {
 			if i < filled-1 {
-				bar += "█"
+				bar.WriteString("█")
 			} else {
-				remainder := (value * int64(barWidth)) % max
+				remainder := (value * int64(barWidth)) % maxValue
-				if remainder > max/2 {
+				if remainder > maxValue/2 {
-					bar += "█"
+					bar.WriteString("█")
-				} else if remainder > max/4 {
+				} else if remainder > maxValue/4 {
-					bar += "▓"
+					bar.WriteString("▓")
 				} else {
-					bar += "▒"
+					bar.WriteString("▒")
 				}
 			}
 		} else {
-			bar += colorGray + "░" + barColor
+			bar.WriteString(colorGray + "░" + barColor)
 		}
 	}
-	return bar + colorReset
+	return bar.String() + colorReset
 }
 
 // runeWidth returns display width for wide characters and emoji.

cmd/analyze/heap.go

@@ -7,11 +7,11 @@ func (h entryHeap) Len() int           { return len(h) }
 func (h entryHeap) Less(i, j int) bool { return h[i].Size < h[j].Size }
 func (h entryHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
 
-func (h *entryHeap) Push(x interface{}) {
+func (h *entryHeap) Push(x any) {
 	*h = append(*h, x.(dirEntry))
 }
 
-func (h *entryHeap) Pop() interface{} {
+func (h *entryHeap) Pop() any {
 	old := *h
 	n := len(old)
 	x := old[n-1]
@@ -26,11 +26,11 @@ func (h largeFileHeap) Len() int           { return len(h) }
 func (h largeFileHeap) Less(i, j int) bool { return h[i].Size < h[j].Size }
 func (h largeFileHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
 
-func (h *largeFileHeap) Push(x interface{}) {
+func (h *largeFileHeap) Push(x any) {
 	*h = append(*h, x.(fileEntry))
 }
 
-func (h *largeFileHeap) Pop() interface{} {
+func (h *largeFileHeap) Pop() any {
 	old := *h
 	n := len(old)
 	x := old[n-1]

cmd/analyze/main.go

@@ -359,7 +359,7 @@ func (m model) scanCmd(path string) tea.Cmd {
 			return scanResultMsg{result: result, err: nil}
 		}
 
-		v, err, _ := scanGroup.Do(path, func() (interface{}, error) {
+		v, err, _ := scanGroup.Do(path, func() (any, error) {
 			return scanPathConcurrent(path, m.filesScanned, m.dirsScanned, m.bytesScanned, m.currentPath)
 		})
 
@@ -997,10 +997,7 @@ func (m *model) clampEntrySelection() {
 		m.selected = 0
 	}
 	viewport := calculateViewport(m.height, false)
-	maxOffset := len(m.entries) - viewport
+	maxOffset := max(len(m.entries)-viewport, 0)
-	if maxOffset < 0 {
-		maxOffset = 0
-	}
 	if m.offset > maxOffset {
 		m.offset = maxOffset
 	}
@@ -1025,10 +1022,7 @@ func (m *model) clampLargeSelection() {
 		m.largeSelected = 0
 	}
 	viewport := calculateViewport(m.height, true)
-	maxOffset := len(m.largeFiles) - viewport
+	maxOffset := max(len(m.largeFiles)-viewport, 0)
-	if maxOffset < 0 {
-		maxOffset = 0
-	}
 	if m.largeOffset > maxOffset {
 		m.largeOffset = maxOffset
 	}

cmd/analyze/scanner.go

@@ -39,10 +39,7 @@ func scanPathConcurrent(root string, filesScanned, dirsScanned, bytesScanned *in
 	heap.Init(largeFilesHeap)
 
 	// Worker pool sized for I/O-bound scanning.
-	numWorkers := runtime.NumCPU() * cpuMultiplier
+	numWorkers := max(runtime.NumCPU()*cpuMultiplier, minWorkers)
-	if numWorkers < minWorkers {
-		numWorkers = minWorkers
-	}
 	if numWorkers > maxWorkers {
 		numWorkers = maxWorkers
 	}
@@ -289,10 +286,7 @@ func calculateDirSizeFast(root string, filesScanned, dirsScanned, bytesScanned *
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
 	defer cancel()
 
-	concurrency := runtime.NumCPU() * 4
+	concurrency := min(runtime.NumCPU()*4, 64)
-	if concurrency > 64 {
-		concurrency = 64
-	}
 	sem := make(chan struct{}, concurrency)
 
 	var walk func(string)
@@ -363,10 +357,9 @@ func findLargeFilesWithSpotlight(root string, minSize int64) []fileEntry {
 		return nil
 	}
 
-	lines := strings.Split(strings.TrimSpace(string(output)), "\n")
 	var files []fileEntry
 
-	for _, line := range lines {
+	for line := range strings.Lines(strings.TrimSpace(string(output))) {
 		if line == "" {
 			continue
 		}
@@ -413,8 +406,8 @@ func findLargeFilesWithSpotlight(root string, minSize int64) []fileEntry {
 
 // isInFoldedDir checks if a path is inside a folded directory.
 func isInFoldedDir(path string) bool {
-	parts := strings.Split(path, string(os.PathSeparator))
+	parts := strings.SplitSeq(path, string(os.PathSeparator))
-	for _, part := range parts {
+	for part := range parts {
 		if foldDirs[part] {
 			return true
 		}
@@ -432,10 +425,7 @@ func calculateDirSizeConcurrent(root string, largeFileChan chan<- fileEntry, fil
 	var wg sync.WaitGroup
 
 	// Limit concurrent subdirectory scans.
-	maxConcurrent := runtime.NumCPU() * 2
+	maxConcurrent := min(runtime.NumCPU()*2, maxDirWorkers)
-	if maxConcurrent > maxDirWorkers {
-		maxConcurrent = maxDirWorkers
-	}
 	sem := make(chan struct{}, maxConcurrent)
 
 	for _, child := range children {

cmd/analyze/view.go

@@ -100,14 +100,8 @@ func (m model) View() string {
 			fmt.Fprintln(&b, "  No large files found (>=100MB)")
 		} else {
 			viewport := calculateViewport(m.height, true)
-			start := m.largeOffset
+			start := max(m.largeOffset, 0)
-			if start < 0 {
+			end := min(start+viewport, len(m.largeFiles))
-				start = 0
-			}
-			end := start + viewport
-			if end > len(m.largeFiles) {
-				end = len(m.largeFiles)
-			}
 			maxLargeSize := int64(1)
 			for _, file := range m.largeFiles {
 				if file.Size > maxLargeSize {
@@ -163,10 +157,7 @@ func (m model) View() string {
 				for idx, entry := range m.entries {
 					icon := "📁"
 					sizeVal := entry.Size
-					barValue := sizeVal
+					barValue := max(sizeVal, 0)
-					if barValue < 0 {
-						barValue = 0
-					}
 					var percent float64
 					if totalSize > 0 && sizeVal >= 0 {
 						percent = float64(sizeVal) / float64(totalSize) * 100
@@ -243,14 +234,8 @@ func (m model) View() string {
 
 				viewport := calculateViewport(m.height, false)
 				nameWidth := calculateNameWidth(m.width)
-				start := m.offset
+				start := max(m.offset, 0)
-				if start < 0 {
+				end := min(start+viewport, len(m.entries))
-					start = 0
-				}
-				end := start + viewport
-				if end > len(m.entries) {
-					end = len(m.entries)
-				}
 
 				for idx := start; idx < end; idx++ {
 					entry := m.entries[idx]

cmd/status/main.go

@@ -127,10 +127,7 @@ func animTick() tea.Cmd {
 
 func animTickWithSpeed(cpuUsage float64) tea.Cmd {
 	// Higher CPU = faster animation.
-	interval := 300 - int(cpuUsage*2.5)
+	interval := max(300-int(cpuUsage*2.5), 50)
-	if interval < 50 {
-		interval = 50
-	}
 	return tea.Tick(time.Duration(interval)*time.Millisecond, func(time.Time) tea.Msg { return animTickMsg{} })
 }
 

cmd/status/metrics_battery.go

@@ -68,11 +68,10 @@ func collectBatteries() (batts []BatteryStatus, err error) {
 }
 
 func parsePMSet(raw string, health string, cycles int, capacity int) []BatteryStatus {
-	lines := strings.Split(raw, "\n")
 	var out []BatteryStatus
 	var timeLeft string
 
-	for _, line := range lines {
+	for line := range strings.Lines(raw) {
 		// Time remaining.
 		if strings.Contains(line, "remaining") {
 			parts := strings.Fields(line)
@@ -128,8 +127,7 @@ func getCachedPowerData() (health string, cycles int, capacity int) {
 		return "", 0, 0
 	}
 
-	lines := strings.Split(out, "\n")
+	for line := range strings.Lines(out) {
-	for _, line := range lines {
 		lower := strings.ToLower(line)
 		if strings.Contains(lower, "cycle count") {
 			if _, after, found := strings.Cut(line, ":"); found {
@@ -183,8 +181,7 @@ func collectThermal() ThermalStatus {
 	// Fan info from cached system_profiler.
 	out := getSystemPowerOutput()
 	if out != "" {
-		lines := strings.Split(out, "\n")
+		for line := range strings.Lines(out) {
-		for _, line := range lines {
 			lower := strings.ToLower(line)
 			if strings.Contains(lower, "fan") && strings.Contains(lower, "speed") {
 				if _, after, found := strings.Cut(line, ":"); found {
@@ -200,8 +197,7 @@ func collectThermal() ThermalStatus {
 	ctxPower, cancelPower := context.WithTimeout(context.Background(), 500*time.Millisecond)
 	defer cancelPower()
 	if out, err := runCmd(ctxPower, "ioreg", "-rn", "AppleSmartBattery"); err == nil {
-		lines := strings.Split(out, "\n")
+		for line := range strings.Lines(out) {
-		for _, line := range lines {
 			line = strings.TrimSpace(line)
 
 			// Battery temperature ("Temperature" = 3055).

cmd/status/metrics_bluetooth.go

@@ -68,13 +68,12 @@ func readBluetoothCTLDevices() ([]BluetoothDevice, error) {
 }
 
 func parseSPBluetooth(raw string) []BluetoothDevice {
-	lines := strings.Split(raw, "\n")
 	var devices []BluetoothDevice
 	var currentName string
 	var connected bool
 	var battery string
 
-	for _, line := range lines {
+	for line := range strings.Lines(raw) {
 		trim := strings.TrimSpace(line)
 		if len(trim) == 0 {
 			continue
@@ -112,10 +111,9 @@ func parseSPBluetooth(raw string) []BluetoothDevice {
 }
 
 func parseBluetoothctl(raw string) []BluetoothDevice {
-	lines := strings.Split(raw, "\n")
 	var devices []BluetoothDevice
 	current := BluetoothDevice{}
-	for _, line := range lines {
+	for line := range strings.Lines(raw) {
 		trim := strings.TrimSpace(line)
 		if strings.HasPrefix(trim, "Device ") {
 			if current.Name != "" {
@@ -123,8 +121,8 @@ func parseBluetoothctl(raw string) []BluetoothDevice {
 			}
 			current = BluetoothDevice{Name: strings.TrimPrefix(trim, "Device "), Connected: false}
 		}
-		if strings.HasPrefix(trim, "Name:") {
+		if after, ok := strings.CutPrefix(trim, "Name:"); ok {
-			current.Name = strings.TrimSpace(strings.TrimPrefix(trim, "Name:"))
+			current.Name = strings.TrimSpace(after)
 		}
 		if strings.HasPrefix(trim, "Connected:") {
 			current.Connected = strings.Contains(trim, "yes")

cmd/status/metrics_disk.go

@@ -156,7 +156,7 @@ func isExternalDisk(device string) (bool, error) {
 		found    bool
 		external bool
 	)
-	for _, line := range strings.Split(out, "\n") {
+	for line := range strings.Lines(out) {
 		trim := strings.TrimSpace(line)
 		if strings.HasPrefix(trim, "Internal:") {
 			found = true

cmd/status/metrics_gpu.go

@@ -61,9 +61,8 @@ func (c *Collector) collectGPU(now time.Time) ([]GPUStatus, error) {
 		return nil, err
 	}
 
-	lines := strings.Split(strings.TrimSpace(out), "\n")
 	var gpus []GPUStatus
-	for _, line := range lines {
+	for line := range strings.Lines(strings.TrimSpace(out)) {
 		fields := strings.Split(line, ",")
 		if len(fields) < 4 {
 			continue

cmd/status/metrics_hardware.go

@@ -28,8 +28,7 @@ func collectHardware(totalRAM uint64, disks []DiskStatus) HardwareInfo {
 
 	out, err := runCmd(ctx, "system_profiler", "SPHardwareDataType")
 	if err == nil {
-		lines := strings.Split(out, "\n")
+		for line := range strings.Lines(out) {
-		for _, line := range lines {
 			lower := strings.ToLower(strings.TrimSpace(line))
 			// Prefer "Model Name" over "Model Identifier".
 			if strings.Contains(lower, "model name:") {
@@ -85,10 +84,9 @@ func collectHardware(totalRAM uint64, disks []DiskStatus) HardwareInfo {
 
 // parseRefreshRate extracts the highest refresh rate from system_profiler display output.
 func parseRefreshRate(output string) string {
-	lines := strings.Split(output, "\n")
 	maxHz := 0
 
-	for _, line := range lines {
+	for line := range strings.Lines(output) {
 		lower := strings.ToLower(line)
 		// Look for patterns like "@ 60Hz", "@ 60.00Hz", or "Refresh Rate: 120 Hz".
 		if strings.Contains(lower, "hz") {
@@ -100,8 +98,7 @@ func parseRefreshRate(output string) string {
 					}
 					continue
 				}
-				if strings.HasSuffix(field, "hz") {
+				if numStr, ok := strings.CutSuffix(field, "hz"); ok {
-					numStr := strings.TrimSuffix(field, "hz")
 					if numStr == "" && i > 0 {
 						numStr = fields[i-1]
 					}

cmd/status/view.go

@@ -66,10 +66,7 @@ func getMoleFrame(animFrame int, termWidth int) string {
 	body := moleBody[bodyIdx]
 
 	moleWidth := 15
-	maxPos := termWidth - moleWidth
+	maxPos := max(termWidth-moleWidth, 0)
-	if maxPos < 0 {
-		maxPos = 0
-	}
 
 	cycleLength := maxPos * 2
 	if cycleLength == 0 {
@@ -197,10 +194,7 @@ func renderCPUCard(cpu CPUStatus) cardData {
 		}
 		sort.Slice(cores, func(i, j int) bool { return cores[i].val > cores[j].val })
 
-		maxCores := 3
+		maxCores := min(len(cores), 3)
-		if len(cores) < maxCores {
-			maxCores = len(cores)
-		}
 		for i := 0; i < maxCores; i++ {
 			c := cores[i]
 			lines = append(lines, fmt.Sprintf("Core%-2d %s  %5.1f%%", c.idx+1, progressBar(c.val), c.val))
@@ -356,10 +350,7 @@ func formatDiskLine(label string, d DiskStatus) string {
 }
 
 func ioBar(rate float64) string {
-	filled := int(rate / 10.0)
+	filled := min(int(rate/10.0), 5)
-	if filled > 5 {
-		filled = 5
-	}
 	if filled < 0 {
 		filled = 0
 	}
@@ -391,10 +382,7 @@ func renderProcessCard(procs []ProcessInfo) cardData {
 }
 
 func miniBar(percent float64) string {
-	filled := int(percent / 20)
+	filled := min(int(percent/20), 5)
-	if filled > 5 {
-		filled = 5
-	}
 	if filled < 0 {
 		filled = 0
 	}
@@ -437,10 +425,7 @@ func renderNetworkCard(netStats []NetworkStatus, proxy ProxyStatus) cardData {
 }
 
 func netBar(rate float64) string {
-	filled := int(rate / 2.0)
+	filled := min(int(rate/2.0), 5)
-	if filled > 5 {
-		filled = 5
-	}
 	if filled < 0 {
 		filled = 0
 	}
@@ -551,10 +536,7 @@ func renderSensorsCard(sensors []SensorReading) cardData {
 
 func renderCard(data cardData, width int, height int) string {
 	titleText := data.icon + " " + data.title
-	lineLen := width - lipgloss.Width(titleText) - 2
+	lineLen := max(width-lipgloss.Width(titleText)-2, 4)
-	if lineLen < 4 {
-		lineLen = 4
-	}
 	header := titleStyle.Render(titleText) + "  " + lineStyle.Render(strings.Repeat("╌", lineLen))
 	content := header + "\n" + strings.Join(data.lines, "\n")
 
@@ -576,7 +558,7 @@ func progressBar(percent float64) string {
 	filled := int(percent / 100 * float64(total))
 
 	var builder strings.Builder
-	for i := 0; i < total; i++ {
+	for i := range total {
 		if i < filled {
 			builder.WriteString("█")
 		} else {
@@ -597,7 +579,7 @@ func batteryProgressBar(percent float64) string {
 	filled := int(percent / 100 * float64(total))
 
 	var builder strings.Builder
-	for i := 0; i < total; i++ {
+	for i := range total {
 		if i < filled {
 			builder.WriteString("█")
 		} else {