tui: add export modal with csv snapshot export

2 files changed, 245 insertions, 0 deletions

diff --git a/internal/tui/export/model.go b/internal/tui/export/model.go
new file mode 100644
index 0000000..1e875e5
--- /dev/null
+++ b/internal/tui/export/model.go
@@ -0,0 +1,173 @@
+package export
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+)
+
+// Option is a selectable export target.
+type Option int
+
+const (
+	OptionFlamegraph Option = iota
+	OptionCSV
+	OptionCancel
+)
+
+var optionLabels = []string{
+	"CSV snapshot",
+	"Cancel",
+}
+
+var optionValues = []Option{
+	OptionCSV,
+	OptionCancel,
+}
+
+// RequestMsg asks the parent model to perform an export.
+type RequestMsg struct {
+	Option Option
+}
+
+// CompletedMsg reports a finished export with output path.
+type CompletedMsg struct {
+	Path string
+}
+
+// FailedMsg reports an export error.
+type FailedMsg struct {
+	Err error
+}
+
+// Model is the export modal state machine.
+type Model struct {
+	visible   bool
+	selected  int
+	exporting bool
+	status    string
+}
+
+// NewModel creates a closed export modal.
+func NewModel() Model {
+	return Model{}
+}
+
+func (m Model) Visible() bool { return m.visible }
+
+func (m Model) Open() Model {
+	m.visible = true
+	m.selected = 0
+	m.exporting = false
+	m.status = ""
+	return m
+}
+
+func (m Model) Close() Model {
+	m.visible = false
+	m.exporting = false
+	m.status = ""
+	return m
+}
+
+// Update handles modal key navigation and export completion messages.
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		if !m.visible {
+			return m, nil
+		}
+		if m.exporting {
+			if msg.String() == "esc" {
+				return m.Close(), nil
+			}
+			return m, nil
+		}
+
+		switch msg.String() {
+		case "esc":
+			return m.Close(), nil
+		case "up", "k":
+			if m.selected > 0 {
+				m.selected--
+			}
+			return m, nil
+		case "down", "j":
+			if m.selected < len(optionValues)-1 {
+				m.selected++
+			}
+			return m, nil
+		case "enter":
+			option := optionValues[m.selected]
+			if option == OptionCancel {
+				return m.Close(), nil
+			}
+			m.exporting = true
+			m.status = fmt.Sprintf("Exporting %s...", optionLabels[m.selected])
+			return m, func() tea.Msg { return RequestMsg{Option: option} }
+		}
+	case CompletedMsg:
+		m.exporting = false
+		if msg.Path == "" {
+			msg.Path = "done"
+		}
+		m.status = "Exported: " + msg.Path
+		return m, nil
+	case FailedMsg:
+		m.exporting = false
+		if msg.Err == nil {
+			msg.Err = errors.New("unknown export failure")
+		}
+		m.status = "Export failed: " + msg.Err.Error()
+		return m, nil
+	}
+
+	return m, nil
+}
+
+// View renders a centered modal overlay.
+func (m Model) View(width, height int) string {
+	if !m.visible {
+		return ""
+	}
+	if width <= 0 {
+		width = 80
+	}
+	if height <= 0 {
+		height = 24
+	}
+
+	modalWidth := 48
+	if width < modalWidth+4 {
+		modalWidth = width - 4
+		if modalWidth < 30 {
+			modalWidth = 30
+		}
+	}
+
+	lines := []string{"Export"}
+	for i, label := range optionLabels {
+		prefix := "  "
+		if i == m.selected && !m.exporting {
+			prefix = "> "
+		}
+		lines = append(lines, prefix+label)
+	}
+	if m.status != "" {
+		lines = append(lines, "", m.status)
+	}
+	if !m.exporting {
+		lines = append(lines, "", "Enter confirm • Esc cancel")
+	}
+
+	box := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		Padding(1, 2).
+		Width(modalWidth).
+		Render(strings.Join(lines, "\n"))
+
+	return lipgloss.Place(width, height, lipgloss.Center, lipgloss.Center, box)
+}
diff --git a/internal/tui/export/model_test.go b/internal/tui/export/model_test.go
new file mode 100644
index 0000000..a97cd8b
--- /dev/null
+++ b/internal/tui/export/model_test.go
@@ -0,0 +1,72 @@
+package export
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func TestOpenAndClose(t *testing.T) {
+	m := NewModel().Open()
+	if !m.Visible() {
+		t.Fatalf("expected modal to be visible after Open")
+	}
+	m = m.Close()
+	if m.Visible() {
+		t.Fatalf("expected modal to be hidden after Close")
+	}
+}
+
+func TestEnterEmitsRequest(t *testing.T) {
+	m := NewModel().Open()
+	next, cmd := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+	if cmd == nil {
+		t.Fatalf("expected request command on enter")
+	}
+	if !next.exporting {
+		t.Fatalf("expected exporting state after enter")
+	}
+	req, ok := cmd().(RequestMsg)
+	if !ok {
+		t.Fatalf("expected RequestMsg from enter command")
+	}
+	if req.Option != OptionCSV {
+		t.Fatalf("expected CSV as default export option, got %v", req.Option)
+	}
+}
+
+func TestCancelOptionCloses(t *testing.T) {
+	m := NewModel().Open()
+	m.selected = len(optionValues) - 1
+	next, cmd := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+	if cmd != nil {
+		t.Fatalf("expected no command when selecting cancel")
+	}
+	if next.Visible() {
+		t.Fatalf("expected modal to close on cancel option")
+	}
+}
+
+func TestStatusMessages(t *testing.T) {
+	m := NewModel().Open()
+	m.exporting = true
+
+	next, _ := m.Update(CompletedMsg{Path: "out.csv"})
+	if next.exporting {
+		t.Fatalf("expected exporting=false after completion")
+	}
+	if !strings.Contains(next.status, "out.csv") {
+		t.Fatalf("expected completion path in status")
+	}
+
+	next.exporting = true
+	next, _ = next.Update(FailedMsg{Err: errors.New("boom")})
+	if next.exporting {
+		t.Fatalf("expected exporting=false after failure")
+	}
+	if !strings.Contains(next.status, "boom") {
+		t.Fatalf("expected failure reason in status")
+	}
+}