tui: add dashboard tab framework model

1 files changed, 151 insertions, 0 deletions

diff --git a/internal/tui/dashboard/model.go b/internal/tui/dashboard/model.go
new file mode 100644
index 0000000..3c4d9b8
--- /dev/null
+++ b/internal/tui/dashboard/model.go
@@ -0,0 +1,151 @@
+package dashboard
+
+import (
+	"fmt"
+	"ior/internal/statsengine"
+	"ior/internal/tui"
+	"ior/internal/tui/messages"
+	"strings"
+	"time"
+
+	"github.com/charmbracelet/bubbles/key"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+const defaultRefreshMs = 1000
+
+// SnapshotSource is the dashboard data source.
+type SnapshotSource interface {
+	Snapshot() *statsengine.Snapshot
+}
+
+type refreshTickMsg struct{}
+
+// Model is the dashboard tab framework model.
+type Model struct {
+	activeTab Tab
+
+	engine SnapshotSource
+	latest *statsengine.Snapshot
+
+	width  int
+	height int
+
+	refreshEvery time.Duration
+	keys         tui.KeyMap
+}
+
+// NewModel creates a dashboard model with default refresh cadence.
+func NewModel(engine SnapshotSource) Model {
+	return NewModelWithConfig(engine, defaultRefreshMs, tui.Keys)
+}
+
+// NewModelWithConfig creates a dashboard model with explicit refresh and keys.
+func NewModelWithConfig(engine SnapshotSource, refreshMs int, keys tui.KeyMap) Model {
+	if refreshMs <= 0 {
+		refreshMs = defaultRefreshMs
+	}
+	return Model{
+		activeTab:    TabOverview,
+		engine:       engine,
+		refreshEvery: time.Duration(refreshMs) * time.Millisecond,
+		keys:         keys,
+	}
+}
+
+// Init starts periodic refresh ticks.
+func (m Model) Init() tea.Cmd {
+	return tickCmd(m.refreshEvery)
+}
+
+// Update handles ticks, snapshots, tab changes, and resize events.
+func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.WindowSizeMsg:
+		m.width = msg.Width
+		m.height = msg.Height
+		return m, nil
+	case refreshTickMsg:
+		snap := m.snapshot()
+		return m, tea.Batch(
+			tickCmd(m.refreshEvery),
+			func() tea.Msg { return messages.StatsTickMsg{Snap: snap} },
+		)
+	case messages.StatsTickMsg:
+		m.latest = msg.Snap
+		return m, nil
+	case tea.KeyMsg:
+		return m.handleKey(msg)
+	}
+	return m, nil
+}
+
+func (m Model) handleKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch {
+	case key.Matches(msg, m.keys.Tab):
+		m.activeTab = nextTab(m.activeTab)
+	case key.Matches(msg, m.keys.ShiftTab):
+		m.activeTab = prevTab(m.activeTab)
+	case key.Matches(msg, m.keys.One):
+		m.activeTab = TabOverview
+	case key.Matches(msg, m.keys.Two):
+		m.activeTab = TabSyscalls
+	case key.Matches(msg, m.keys.Three):
+		m.activeTab = TabFiles
+	case key.Matches(msg, m.keys.Four):
+		m.activeTab = TabProcesses
+	case key.Matches(msg, m.keys.Five):
+		m.activeTab = TabLatency
+	case key.Matches(msg, m.keys.Six):
+		m.activeTab = TabGaps
+	}
+	return m, nil
+}
+
+func (m Model) snapshot() *statsengine.Snapshot {
+	if m.engine == nil {
+		return nil
+	}
+	return m.engine.Snapshot()
+}
+
+// View renders the tab bar, active tab scaffold, and help bar.
+func (m Model) View() string {
+	var b strings.Builder
+	b.WriteString(renderTabBar(m.activeTab, m.width))
+	b.WriteString("\n")
+	b.WriteString(renderActiveTab(m.activeTab, m.latest, m.width, m.height))
+	b.WriteString("\n")
+	b.WriteString(renderHelpBar(m.keys))
+	return tui.ScreenStyle.Render(b.String())
+}
+
+func tickCmd(d time.Duration) tea.Cmd {
+	return tea.Tick(d, func(time.Time) tea.Msg { return refreshTickMsg{} })
+}
+
+func renderActiveTab(tab Tab, snap *statsengine.Snapshot, width, height int) string {
+	_ = width
+	_ = height
+
+	if snap == nil {
+		return tui.PanelStyle.Render(tab.String() + ": waiting for stats...")
+	}
+
+	switch tab {
+	case TabOverview:
+		return tui.PanelStyle.Render(fmt.Sprintf("Overview: %d syscalls", snap.TotalSyscalls))
+	case TabSyscalls:
+		return tui.PanelStyle.Render(fmt.Sprintf("Syscalls: %d rows", len(snap.Syscalls())))
+	case TabFiles:
+		return tui.PanelStyle.Render(fmt.Sprintf("Files: %d rows", len(snap.Files())))
+	case TabProcesses:
+		return tui.PanelStyle.Render(fmt.Sprintf("Processes: %d rows", len(snap.Processes())))
+	case TabLatency:
+		return tui.PanelStyle.Render("Latency histogram")
+	case TabGaps:
+		return tui.PanelStyle.Render("Gap histogram")
+	default:
+		return tui.PanelStyle.Render("Unknown tab")
+	}
+}