feat(cli): add TextInput with placeholder, masking, validation

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/cli/textinput.go

@@ -0,0 +1,183 @@
+package cli
+
+import (
+	"fmt"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"golang.org/x/term"
+)
+
+// textInputModel is the internal bubbletea model for text input.
+type textInputModel struct {
+	title       string
+	placeholder string
+	value       string
+	masked      bool
+	submitted   bool
+	cancelled   bool
+	cursorPos   int
+	validator   func(string) error
+	err         error
+}
+
+func newTextInputModel(title, placeholder string) *textInputModel {
+	return &textInputModel{
+		title:       title,
+		placeholder: placeholder,
+	}
+}
+
+func (m *textInputModel) insertChar(ch rune) {
+	m.value = m.value[:m.cursorPos] + string(ch) + m.value[m.cursorPos:]
+	m.cursorPos++
+}
+
+func (m *textInputModel) backspace() {
+	if m.cursorPos > 0 {
+		m.value = m.value[:m.cursorPos-1] + m.value[m.cursorPos:]
+		m.cursorPos--
+	}
+}
+
+func (m *textInputModel) Init() tea.Cmd {
+	return nil
+}
+
+func (m *textInputModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.Type {
+		case tea.KeyEnter:
+			if m.validator != nil {
+				if err := m.validator(m.value); err != nil {
+					m.err = err
+					return m, nil
+				}
+			}
+			if m.value == "" && m.placeholder != "" {
+				m.value = m.placeholder
+			}
+			m.submitted = true
+			return m, tea.Quit
+		case tea.KeyEscape, tea.KeyCtrlC:
+			m.cancelled = true
+			return m, tea.Quit
+		case tea.KeyBackspace:
+			m.backspace()
+			m.err = nil
+		case tea.KeyLeft:
+			if m.cursorPos > 0 {
+				m.cursorPos--
+			}
+		case tea.KeyRight:
+			if m.cursorPos < len(m.value) {
+				m.cursorPos++
+			}
+		case tea.KeyRunes:
+			for _, ch := range msg.Runes {
+				m.insertChar(ch)
+			}
+			m.err = nil
+		}
+	}
+	return m, nil
+}
+
+func (m *textInputModel) View() string {
+	var sb strings.Builder
+
+	sb.WriteString(BoldStyle.Render(m.title) + "\n\n")
+
+	display := m.value
+	if m.masked {
+		display = strings.Repeat("*", len(m.value))
+	}
+
+	if display == "" && m.placeholder != "" {
+		sb.WriteString(DimStyle.Render(m.placeholder))
+	} else {
+		sb.WriteString(display)
+	}
+	sb.WriteString(AccentStyle.Render("\u2588")) // Cursor block
+
+	if m.err != nil {
+		sb.WriteString("\n" + ErrorStyle.Render(fmt.Sprintf("  %s", m.err)))
+	}
+
+	sb.WriteString("\n\n" + DimStyle.Render("enter submit \u2022 esc cancel"))
+
+	return sb.String()
+}
+
+// TextInputOption configures TextInput behaviour.
+type TextInputOption func(*textInputConfig)
+
+type textInputConfig struct {
+	placeholder string
+	masked      bool
+	validator   func(string) error
+}
+
+// WithTextPlaceholder sets placeholder text shown when input is empty.
+func WithTextPlaceholder(text string) TextInputOption {
+	return func(c *textInputConfig) {
+		c.placeholder = text
+	}
+}
+
+// WithMask hides input characters (for passwords).
+func WithMask() TextInputOption {
+	return func(c *textInputConfig) {
+		c.masked = true
+	}
+}
+
+// WithInputValidator adds a validation function for the input.
+func WithInputValidator(fn func(string) error) TextInputOption {
+	return func(c *textInputConfig) {
+		c.validator = fn
+	}
+}
+
+// TextInput presents a styled text input prompt and returns the entered value.
+// Returns empty string if cancelled.
+//
+// Falls back to Question() when stdin is not a terminal.
+//
+//	name, err := cli.TextInput("Enter your name:", cli.WithTextPlaceholder("Anonymous"))
+//	pass, err := cli.TextInput("Password:", cli.WithMask())
+func TextInput(title string, opts ...TextInputOption) (string, error) {
+	cfg := &textInputConfig{}
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	// Fall back to simple Question if not a terminal
+	if !term.IsTerminal(0) {
+		var qopts []QuestionOption
+		if cfg.placeholder != "" {
+			qopts = append(qopts, WithDefault(cfg.placeholder))
+		}
+		if cfg.validator != nil {
+			qopts = append(qopts, WithValidator(cfg.validator))
+		}
+		return Question(title, qopts...), nil
+	}
+
+	m := newTextInputModel(title, cfg.placeholder)
+	m.masked = cfg.masked
+	m.validator = cfg.validator
+
+	p := tea.NewProgram(m)
+	finalModel, err := p.Run()
+	if err != nil {
+		return "", err
+	}
+
+	final := finalModel.(*textInputModel)
+	if final.cancelled {
+		return "", nil
+	}
+	return final.value, nil
+}

pkg/cli/textinput_test.go

@@ -0,0 +1,59 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTextInputModel_Good_Create(t *testing.T) {
+	m := newTextInputModel("Enter name:", "")
+	assert.Equal(t, "Enter name:", m.title)
+	assert.Equal(t, "", m.value)
+}
+
+func TestTextInputModel_Good_WithPlaceholder(t *testing.T) {
+	m := newTextInputModel("Name:", "John")
+	assert.Equal(t, "John", m.placeholder)
+}
+
+func TestTextInputModel_Good_TypeCharacters(t *testing.T) {
+	m := newTextInputModel("Name:", "")
+	m.insertChar('H')
+	m.insertChar('i')
+	assert.Equal(t, "Hi", m.value)
+}
+
+func TestTextInputModel_Good_Backspace(t *testing.T) {
+	m := newTextInputModel("Name:", "")
+	m.insertChar('A')
+	m.insertChar('B')
+	m.backspace()
+	assert.Equal(t, "A", m.value)
+}
+
+func TestTextInputModel_Good_BackspaceEmpty(t *testing.T) {
+	m := newTextInputModel("Name:", "")
+	m.backspace() // Should not panic
+	assert.Equal(t, "", m.value)
+}
+
+func TestTextInputModel_Good_Masked(t *testing.T) {
+	m := newTextInputModel("Password:", "")
+	m.masked = true
+	m.insertChar('s')
+	m.insertChar('e')
+	m.insertChar('c')
+	assert.Equal(t, "sec", m.value) // Internal value is real
+	view := m.View()
+	assert.NotContains(t, view, "sec") // Display is masked
+	assert.Contains(t, view, "***")
+}
+
+func TestTextInputModel_Good_View(t *testing.T) {
+	m := newTextInputModel("Enter:", "")
+	m.insertChar('X')
+	view := m.View()
+	assert.Contains(t, view, "Enter:")
+	assert.Contains(t, view, "X")
+}