feat: begin tui implementation

internal/tui/model.go

@@ -0,0 +1,57 @@
+package tui
+
+import (
+	"hosts-go/internal/core"
+
+	list "github.com/charmbracelet/bubbles/list"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// entryItem wraps a HostEntry for display in a list component.
+type entryItem struct{ entry *core.HostEntry }
+
+func (e entryItem) Title() string       { return e.entry.Hostname }
+func (e entryItem) Description() string { return e.entry.IP }
+func (e entryItem) FilterValue() string { return e.entry.Hostname }
+
+// Model is the main Bubble Tea model for the application.
+type Model struct {
+	list   list.Model
+	hosts  *core.HostsFile
+	width  int
+	height int
+}
+
+// NewModel constructs the TUI model from a parsed HostsFile.
+func NewModel(hf *core.HostsFile) Model {
+	items := make([]list.Item, len(hf.Entries))
+	for i, e := range hf.Entries {
+		items[i] = entryItem{entry: e}
+	}
+
+	l := list.New(items, list.NewDefaultDelegate(), 0, 0)
+	l.SetShowStatusBar(false)
+	l.SetFilteringEnabled(false)
+	l.SetShowHelp(false)
+	l.SetShowPagination(false)
+
+	return Model{
+		list:  l,
+		hosts: hf,
+	}
+}
+
+// Init satisfies tea.Model.
+func (m Model) Init() tea.Cmd { return nil }
+
+// SelectedEntry returns the currently selected host entry.
+func (m Model) SelectedEntry() *core.HostEntry {
+	if len(m.hosts.Entries) == 0 {
+		return nil
+	}
+	idx := m.list.Index()
+	if idx < 0 || idx >= len(m.hosts.Entries) {
+		return nil
+	}
+	return m.hosts.Entries[idx]
+}

internal/tui/update.go

@@ -0,0 +1,24 @@
+package tui
+
+import (
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Update handles all messages for the TUI.
+func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	var cmd tea.Cmd
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "q", "ctrl+c":
+			return m, tea.Quit
+		}
+	case tea.WindowSizeMsg:
+		m.width = msg.Width
+		m.height = msg.Height
+		m.list.SetSize(msg.Width/2, msg.Height)
+	}
+
+	m.list, cmd = m.list.Update(msg)
+	return m, cmd
+}

internal/tui/view.go

@@ -0,0 +1,40 @@
+package tui
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/charmbracelet/lipgloss"
+)
+
+var (
+	listStyle   = lipgloss.NewStyle().Padding(0, 1)
+	detailStyle = lipgloss.NewStyle().Padding(0, 1)
+)
+
+// View renders the two-pane layout.
+func (m Model) View() string {
+	listView := m.list.View()
+
+	var detail strings.Builder
+	if len(m.hosts.Entries) > 0 {
+		entry := m.hosts.Entries[m.list.Index()]
+		status := "active"
+		if !entry.Active {
+			status = "inactive"
+		}
+		fmt.Fprintf(&detail, "IP: %s\n", entry.IP)
+		fmt.Fprintf(&detail, "Host: %s\n", entry.Hostname)
+		if len(entry.Aliases) > 0 {
+			fmt.Fprintf(&detail, "Aliases: %s\n", strings.Join(entry.Aliases, ", "))
+		}
+		if entry.Comment != "" {
+			fmt.Fprintf(&detail, "Comment: %s\n", entry.Comment)
+		}
+		fmt.Fprintf(&detail, "Status: %s", status)
+	}
+
+	left := listStyle.Width(m.width / 2).Height(m.height).Render(listView)
+	right := detailStyle.Width(m.width - m.width/2).Height(m.height).Render(detail.String())
+	return lipgloss.JoinHorizontal(lipgloss.Top, left, right)
+}