Task 352: add TUI root scaffold

3 files changed, 274 insertions, 0 deletions

diff --git a/internal/tui/styles.go b/internal/tui/styles.go
new file mode 100644
index 0000000..247411c
--- /dev/null
+++ b/internal/tui/styles.go
@@ -0,0 +1,41 @@
+package tui
+
+import "github.com/charmbracelet/lipgloss"
+
+// Styles groups visual styles for the root TUI scaffold.
+type Styles struct {
+	App       lipgloss.Style
+	Header    lipgloss.Style
+	Tab       lipgloss.Style
+	ActiveTab lipgloss.Style
+	Body      lipgloss.Style
+	Help      lipgloss.Style
+	Hint      lipgloss.Style
+}
+
+// DefaultStyles returns the default style set.
+func DefaultStyles() Styles {
+	return Styles{
+		App: lipgloss.NewStyle().
+			Padding(1, 2),
+		Header: lipgloss.NewStyle().
+			Foreground(lipgloss.Color("#8A8A8A")).
+			Bold(true),
+		Tab: lipgloss.NewStyle().
+			Padding(0, 1).
+			Foreground(lipgloss.Color("#B5B5B5")),
+		ActiveTab: lipgloss.NewStyle().
+			Padding(0, 1).
+			Foreground(lipgloss.Color("#101010")).
+			Background(lipgloss.Color("#8BD3DD")).
+			Bold(true),
+		Body: lipgloss.NewStyle().
+			PaddingTop(1),
+		Help: lipgloss.NewStyle().
+			PaddingTop(1).
+			Foreground(lipgloss.Color("#A0D568")),
+		Hint: lipgloss.NewStyle().
+			PaddingTop(1).
+			Foreground(lipgloss.Color("#777777")),
+	}
+}
diff --git a/internal/tui/tui.go b/internal/tui/tui.go
new file mode 100644
index 0000000..51445f2
--- /dev/null
+++ b/internal/tui/tui.go
@@ -0,0 +1,154 @@
+package tui
+
+import (
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+)
+
+type tab int
+
+const (
+	tabEntries tab = iota
+	tabReport
+	tabTimer
+	tabCount
+)
+
+var tabLabels = []string{"Entries", "Report", "Timer"}
+
+// Model is the root TUI scaffold model.
+type Model struct {
+	activeTab tab
+	width     int
+	height    int
+
+	showHelp bool
+	pendingG bool
+	pendingZ bool
+
+	styles Styles
+}
+
+// NewModel creates a new root TUI model.
+func NewModel() Model {
+	return Model{
+		activeTab: tabEntries,
+		styles:    DefaultStyles(),
+	}
+}
+
+// Init implements tea.Model.
+func (m Model) Init() tea.Cmd {
+	return nil
+}
+
+// Update implements tea.Model.
+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 tea.KeyMsg:
+		key := msg.String()
+
+		if m.pendingZ {
+			m.pendingZ = false
+			if key == "Q" {
+				return m, tea.Quit
+			}
+		}
+
+		if m.pendingG {
+			m.pendingG = false
+			switch key {
+			case "t":
+				m.nextTab()
+				return m, nil
+			case "T":
+				m.prevTab()
+				return m, nil
+			}
+		}
+
+		switch key {
+		case "tab":
+			m.nextTab()
+		case "1":
+			m.activeTab = tabEntries
+		case "2":
+			m.activeTab = tabReport
+		case "3":
+			m.activeTab = tabTimer
+		case "?":
+			m.showHelp = !m.showHelp
+		case "g":
+			m.pendingG = true
+		case "Z":
+			m.pendingZ = true
+		case "q", "ctrl+c":
+			return m, tea.Quit
+		}
+	}
+
+	return m, nil
+}
+
+// View implements tea.Model.
+func (m Model) View() string {
+	header := m.renderTabs()
+	body := m.styles.Body.Render(m.renderBody())
+
+	help := m.styles.Hint.Render("Press ? for help")
+	if m.showHelp {
+		help = m.styles.Help.Render("Tab/gt/gT/1/2/3 switch tabs, ? toggles help, q or ZQ quits")
+	}
+
+	content := lipgloss.JoinVertical(lipgloss.Left, header, body, help)
+	rendered := m.styles.App.Render(content)
+
+	if m.width > 0 && m.height > 0 {
+		return lipgloss.Place(m.width, m.height, lipgloss.Left, lipgloss.Top, rendered)
+	}
+	return rendered
+}
+
+func (m *Model) nextTab() {
+	m.activeTab = (m.activeTab + 1) % tabCount
+}
+
+func (m *Model) prevTab() {
+	if m.activeTab == 0 {
+		m.activeTab = tabCount - 1
+		return
+	}
+	m.activeTab--
+}
+
+func (m Model) renderTabs() string {
+	parts := make([]string, 0, len(tabLabels))
+	for idx, label := range tabLabels {
+		if tab(idx) == m.activeTab {
+			parts = append(parts, m.styles.ActiveTab.Render(label))
+			continue
+		}
+		parts = append(parts, m.styles.Tab.Render(label))
+	}
+	return m.styles.Header.Render(strings.Join(parts, " "))
+}
+
+func (m Model) renderBody() string {
+	switch m.activeTab {
+	case tabEntries:
+		return "Entries screen scaffold.\nList/search/edit wiring lands in next tasks."
+	case tabReport:
+		return "Report screen scaffold.\nWeekly report table wiring lands in next tasks."
+	case tabTimer:
+		return "Timer screen scaffold.\nLive timer integration lands in next tasks."
+	default:
+		return ""
+	}
+}
diff --git a/internal/tui/tui_test.go b/internal/tui/tui_test.go
new file mode 100644
index 0000000..0b42e1f
--- /dev/null
+++ b/internal/tui/tui_test.go
@@ -0,0 +1,79 @@
+package tui
+
+import (
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func TestTabNavigation(t *testing.T) {
+	model := NewModel()
+
+	modelAny, _ := model.Update(tea.KeyMsg{Type: tea.KeyTab})
+	model = modelAny.(Model)
+	if model.activeTab != tabReport {
+		t.Fatalf("active tab after Tab = %v, want %v", model.activeTab, tabReport)
+	}
+
+	modelAny, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'g'}})
+	model = modelAny.(Model)
+	modelAny, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'T'}})
+	model = modelAny.(Model)
+	if model.activeTab != tabEntries {
+		t.Fatalf("active tab after gT = %v, want %v", model.activeTab, tabEntries)
+	}
+
+	modelAny, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'3'}})
+	model = modelAny.(Model)
+	if model.activeTab != tabTimer {
+		t.Fatalf("active tab after key 3 = %v, want %v", model.activeTab, tabTimer)
+	}
+}
+
+func TestHelpToggle(t *testing.T) {
+	model := NewModel()
+
+	modelAny, _ := model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'?'}})
+	model = modelAny.(Model)
+	if !model.showHelp {
+		t.Fatal("showHelp = false, want true after ?")
+	}
+
+	modelAny, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'?'}})
+	model = modelAny.(Model)
+	if model.showHelp {
+		t.Fatal("showHelp = true, want false after second ?")
+	}
+}
+
+func TestQuitKeys(t *testing.T) {
+	model := NewModel()
+
+	modelAny, cmd := model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'q'}})
+	model = modelAny.(Model)
+	if cmd == nil {
+		t.Fatal("quit cmd is nil for q")
+	}
+	if _, ok := cmd().(tea.QuitMsg); !ok {
+		t.Fatal("q key did not return tea.Quit command")
+	}
+
+	modelAny, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'Z'}})
+	model = modelAny.(Model)
+	modelAny, cmd = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'Q'}})
+	model = modelAny.(Model)
+	if cmd == nil {
+		t.Fatal("quit cmd is nil for ZQ")
+	}
+	if _, ok := cmd().(tea.QuitMsg); !ok {
+		t.Fatal("ZQ did not return tea.Quit command")
+	}
+}
+
+func TestViewContainsTabLabels(t *testing.T) {
+	model := NewModel()
+	view := model.View()
+	if view == "" {
+		t.Fatal("View() returned empty output")
+	}
+}