tui: add toggle to disable snapshot export file writes

4 files changed, 70 insertions, 6 deletions

diff --git a/internal/flags/flags.go b/internal/flags/flags.go
index 729b1b6..87ece5d 100644
--- a/internal/flags/flags.go
+++ b/internal/flags/flags.go
@@ -14,7 +14,9 @@ import (
 )
 
 var (
-	singleton Flags
+	singleton = Flags{
+		TUIExportEnable: true,
+	}
 	once      sync.Once
 	pidFilter atomic.Int64
 )
@@ -56,6 +58,7 @@ type Flags struct {
 	PlainMode        bool
 	FlamegraphEnable bool
 	FlamegraphName   string
+	TUIExportEnable  bool
 
 	// To convert ior data into collapsed format
 	IorDataFile     string
@@ -77,6 +80,11 @@ func SetPidFilter(pid int) {
 	pidFilter.Store(int64(pid))
 }
 
+// SetTUIExportEnable toggles TUI snapshot export file writing.
+func SetTUIExportEnable(enabled bool) {
+	singleton.TUIExportEnable = enabled
+}
+
 func Parse() {
 	once.Do(func() {
 		parse()
@@ -100,6 +108,7 @@ func parse() {
 	flag.BoolVar(&singleton.PlainMode, "plain", false, "Enable plain CSV output mode (disable TUI)")
 	flag.BoolVar(&singleton.FlamegraphEnable, "flamegraph", false, "Enable flamegraph builder")
 	flag.StringVar(&singleton.FlamegraphName, "name", "default", "Name of the flamegraph, used to generate the SVG file")
+	flag.BoolVar(&singleton.TUIExportEnable, "tuiExport", true, "Enable writing TUI snapshot export files")
 
 	flag.StringVar(&singleton.IorDataFile, "ior", "", "IOR data file to convert into collapsed format")
 	fields := flag.String("fields", "",
diff --git a/internal/tui/common/keys.go b/internal/tui/common/keys.go
index 0f9c54d..1111def 100644
--- a/internal/tui/common/keys.go
+++ b/internal/tui/common/keys.go
@@ -45,14 +45,25 @@ func DefaultKeyMap() KeyMap {
 
 // DashboardShortHelp returns compact bindings for dashboard help bars.
 func (k KeyMap) DashboardShortHelp() []key.Binding {
-	return []key.Binding{k.Tab, k.ShiftTab, k.Export, k.Help, k.Quit}
+	bindings := []key.Binding{k.Tab, k.ShiftTab}
+	if help := k.Export.Help(); help.Key != "" || help.Desc != "" {
+		bindings = append(bindings, k.Export)
+	}
+	bindings = append(bindings, k.Help, k.Quit)
+	return bindings
 }
 
 // DashboardFullHelp returns grouped bindings for dashboard overlays.
 func (k KeyMap) DashboardFullHelp() [][]key.Binding {
+	controls := []key.Binding{k.Tab, k.ShiftTab}
+	if help := k.Export.Help(); help.Key != "" || help.Desc != "" {
+		controls = append(controls, k.Export)
+	}
+	controls = append(controls, k.Refresh, k.Help, k.Quit)
+
 	return [][]key.Binding{
 		{k.One, k.Two, k.Three, k.Four, k.Five, k.Six},
-		{k.Tab, k.ShiftTab, k.Export, k.Refresh, k.Help, k.Quit},
+		controls,
 		{
 			key.NewBinding(key.WithKeys("left/right"), key.WithHelp("left/right", "tab")),
 			key.NewBinding(key.WithKeys("h/l"), key.WithHelp("h/l", "tab")),
diff --git a/internal/tui/tui.go b/internal/tui/tui.go
index 143cf02..4433172 100644
--- a/internal/tui/tui.go
+++ b/internal/tui/tui.go
@@ -99,13 +99,17 @@ func NewModel(initialPID int, startTrace TraceStarter) Model {
 	if startTrace == nil {
 		startTrace = defaultTraceStarter
 	}
+	keys := Keys
+	if !flags.Get().TUIExportEnable {
+		keys.Export = key.NewBinding()
+	}
 
 	model := Model{
 		screen:     ScreenPIDPicker,
 		pidPicker:  pidpicker.New(),
-		dashboard:  dashboardui.NewModel(lateBoundDashboardSource{}),
+		dashboard:  dashboardui.NewModelWithConfig(lateBoundDashboardSource{}, 1000, keys),
 		exporter:   tuiexport.NewModel(),
-		keys:       Keys,
+		keys:       keys,
 		spin:       spin,
 		startTrace: startTrace,
 	}
@@ -151,7 +155,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if !m.exporter.Visible() && m.showHelp {
 			return m, nil
 		}
-		if m.screen == ScreenDashboard && !m.attaching && m.lastErr == nil && key.Matches(msg, m.keys.Export) && !m.exporter.Visible() {
+		if flags.Get().TUIExportEnable && m.screen == ScreenDashboard && !m.attaching && m.lastErr == nil && key.Matches(msg, m.keys.Export) && !m.exporter.Visible() {
 			m.exporter = m.exporter.Open()
 			return m, nil
 		}
@@ -299,6 +303,9 @@ func (m Model) View() string {
 
 func runExportCmd(option tuiexport.Option, snap *statsengine.Snapshot) tea.Cmd {
 	return func() tea.Msg {
+		if !flags.Get().TUIExportEnable {
+			return tuiexport.FailedMsg{Err: errors.New("tui export is disabled by -tuiExport=false")}
+		}
 		switch option {
 		case tuiexport.OptionCSV:
 			path, err := exportSnapshotCSV(snap)
diff --git a/internal/tui/tui_test.go b/internal/tui/tui_test.go
index fd7adfa..e69ff9b 100644
--- a/internal/tui/tui_test.go
+++ b/internal/tui/tui_test.go
@@ -192,6 +192,9 @@ func TestDashboardRefreshPicksLateBoundSource(t *testing.T) {
 }
 
 func TestExportKeyOpensModalOnDashboard(t *testing.T) {
+	flags.SetTUIExportEnable(true)
+	t.Cleanup(func() { flags.SetTUIExportEnable(true) })
+
 	m := NewModel(-1, func(context.Context) error { return nil })
 	m.screen = ScreenDashboard
 	m.attaching = false
@@ -203,6 +206,21 @@ func TestExportKeyOpensModalOnDashboard(t *testing.T) {
 	}
 }
 
+func TestExportKeyIgnoredWhenExportDisabled(t *testing.T) {
+	flags.SetTUIExportEnable(false)
+	t.Cleanup(func() { flags.SetTUIExportEnable(true) })
+
+	m := NewModel(-1, func(context.Context) error { return nil })
+	m.screen = ScreenDashboard
+	m.attaching = false
+
+	next, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'e'}})
+	updated := next.(Model)
+	if updated.exporter.Visible() {
+		t.Fatalf("expected export modal to remain closed when export is disabled")
+	}
+}
+
 func TestRunExportCmdCSVWritesFile(t *testing.T) {
 	dir := t.TempDir()
 	prev, err := os.Getwd()
@@ -292,6 +310,9 @@ func TestHelpOverlayUsesPickerBindingsOnPickerScreen(t *testing.T) {
 }
 
 func TestHelpToggleDoesNotBreakExportModalInput(t *testing.T) {
+	flags.SetTUIExportEnable(true)
+	t.Cleanup(func() { flags.SetTUIExportEnable(true) })
+
 	m := NewModel(-1, func(context.Context) error { return nil })
 	m.screen = ScreenDashboard
 
@@ -314,6 +335,22 @@ func TestHelpToggleDoesNotBreakExportModalInput(t *testing.T) {
 	}
 }
 
+func TestHelpOverlayHidesExportBindingWhenExportDisabled(t *testing.T) {
+	flags.SetTUIExportEnable(false)
+	t.Cleanup(func() { flags.SetTUIExportEnable(true) })
+
+	m := NewModel(-1, func(context.Context) error { return nil })
+	m.screen = ScreenDashboard
+	m.showHelp = true
+	m.width = 100
+	m.height = 30
+
+	out := m.View()
+	if strings.Contains(out, "e export") {
+		t.Fatalf("did not expect export shortcut in help overlay when export is disabled")
+	}
+}
+
 func TestExportModalStillAllowsDashboardStatsUpdates(t *testing.T) {
 	m := NewModel(-1, func(context.Context) error { return nil })
 	m.screen = ScreenDashboard